ML20079R526

Thermal Effects Monitoring Program 1983 Annual Rept. W/Two Oversize Maps.Aperture Cards Are Available in PDR

ML20079R526
Person / Time
Site:	Diablo Canyon
Issue date:	12/31/1983
From:	PACIFIC GAS & ELECTRIC CO.
To:
Shared Package
ML16340E107	List: ML20079R526
References
B-83-540, NUDOCS 8402020272
Download: ML20079R526 (260)

Text

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TIERMAL EFFECTS MONITORING PROGRAM 1983 ANNUAL REPORT DIABLO CANYON POWER PLANT O

I PACIFIC GAS AND ELECTRIC COMPANY JANUARY 1984 l

O 2 840130 y OWy B-83-540

TifRMAL EFFECTS MONITORING PROGRAM

(-)

'V 1983 AtNUAL REPORT DIABLO CANYON POWER PLANT PACIFIC GAS Ato ELECTRIC COMPANY TABLE OF CONTENTS 1

Section Page E XECUT IVE SUM MA RY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I l.0 I NT R OD U CT I ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 2.0 MONITORING PROGRAM METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 2.1 Intertidal Band Transect (IBT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 2.2 Intertidal Random Point Contact (RPC) Quadrat ........... 2-1 2.3 Intertidal Algal Scrapings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9 2.4 Intertidal Black Abalone Tagging . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9 2.5 Intertidal Black Abalone Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10 ,

2.6 Intertidal S tation Photography . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11 2.7 Subtidal Arc Quadrant (SAO) ............................ 2-12 2.8 Subtidal Fixed Quadrat (SFO) ............................ 2-12 2.9 Subtidal Random Line Point Contact (RLPC) .............. 2-17 2.10 Subtidal Crab Trapping and Tagging . . . . . . . . . . . . . . . . . . . . . . . 2-18 O 2.1 1 Subtidal Fish Observations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18 U 2.12 Subtidal Set tling Plates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.13 Bull Kelp Population Estimates . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-20 2-24 2.14 In Situ Temperature Measurement . . . . . . . . . . . . . . . . . . . . . . . . . 2-25 2.15 In Situ Light Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27 2.16 In Situ Wave / Tide Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-28 3.0 MONITORING PROGR AM RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 3.1 Intertidal Band Transect (IBT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 3.1.1 Algae .......................................... 3-8 3.1.1.1 Endocladio muricata . . . . . . . . . . . . . . . . . . . . . 3-9 3 !.l.2 Gastroclonium ce >lteri . . . . . . . . . . . . . . . . . . . 3-9 3.1.l.3 Gigartina canaliculata . . . . . . . . . . . . . . . . . . . . 3-12 3.1.1.4 Gigartina papillata . . . . . . . . . . . . . . . . . . . . . . . 3-15

! 3.l.l.5 Iridaea flaccida . . . . . . . . . . . . . . . . . . . . . . . . . 3-20 3.1.2 i nver t ebr a t es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-20 3.1.2.1 Anthopleuro elegantissimo . . . . . . . . . . . . . . . . 3-23 3.1.2.2 Holiotis cracherodii . . . . . . . . . . . . . . . . . . . . . . 3-27

B-83-540 il t

1 l

1 1

1 TABLE OF CONTENTS

/~T (CONT'D)

V l Section Page 3.1.2.3 Collisella scabra . . . . . . . . . . . . . . . . . . . . . . . . . 3-31 3.1.2.4 Pa gurus spp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-32 3.1.2.5 Tegula f unebralis . . . . . . . . . . . . . . . . . . . . . . . . 3-36 3.2 Intertidal Random Point Centact CPO Quadrat . . . . . . . . . . . . 3-42 3.2.1 Algae.......................................... 3-48 3.2.1.1 Endocladia muricato . . . . . . . . . . . . . . . . . . . . . 3-48 3.2.l.2 Gastroclonium coulteri . . . . . . . . . . . . . . . . . . . 3-51 3.2.l.3 Gigartino canaliculata . . . . . . . . . . . . . . . . . . . . 3-51 3.2.1.4 Gic artina papillata . . . . . . . . . . . . . . . . . . . . . . . 3-56 3.2.1.5 Iric aea flaccida . . . . . . . . . . . . . . . . . . . . . . . . . 3-59 3.3 Intertidal Algol Scrapings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-59 3.4 Iniertidal Black Abalone Tagging . . . . . . . . . . . . . . . . . . . . . . . . . . 3-59 3.5 Intertidal Black Abalone Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-64 3.6 Intertido! Station Photography . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-64 3.7 Subtidal Arc Quadrant (SAO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-64 3.7.I Algae .......................................... 3-68 J 3.7.1.1 Cystoseira osmundacea . . . . . . . . . . . . . . . . . . . 3-69 3.7.1.2 Laminoria dentigera . . . . . . . . . . . . . . . . . . . . . 3-69 3.7.1.3 Nereocystis luctkeano . . . . . . . . . . . . . . . . . . . . 3-72 3.7.1.4 Pterygophora californica . . . . . . . . . . . . . . . . . . 3-77 3.7.2 Invertebrates.................................... 2-81 3.7.2.1 Anthopleura elegantissima . . . . . . . . . . . . . . . . 3-81 3.7.2.2 Astraea gibberoso . . . . . . . . . . . . . . . . . . . . . . . . 3-83 3.7.2.3 Haliotis rufescens and H. walallensis ....... 3-89 3.7.2.4 Pat iria miniata . . . . . .T. . . . . . . . . . . . . . . . . . .

3-88 3.7.2.5 Pisaster ochraceus, P. giganteus and P. brevispinus . . . . [ . . . . . . . . . . . . . . . . . . . . . 3-93 3.7.2.6 Fugettia producta and P. rich *i . . . . . . . . . . . . . 3-93 3.7.2.7 Pycnopodia helianthoides . . . . . . . . . . . . . . . . . . 3-96 3.7.2.8 5trongylocentrotus francisconus and 5.p apuratus ............................ 3-96 3.7.2.9 Tegula brunneo . . . . . . . . . . . . . . . . . . . . . . . . . 3- 101 B-83-540 lii

V i

TABLE OF CONTENTS I, (CONT'D) i Section Page  !

3.8 Subtidal Fixed Quadrat (SFO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-106 3.8.1 i nver t ebra t es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3- 106 3.8.l.1 Acmoea mitro . . . . . . . . . . . . . . . . . . . . . . . . . . 3-108 3.8.1.2 Anthopleura elegantissima . . . . . . . . . . . . . . . 3-108

. 3.8.1.3 Colonial / Social Tunicates . . . . . . . . . . . . . . . . 3-113 3.8.1.4 Mit rella spp. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3- 1 13 3.8.1.5 Pogurus spp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3- 1 16 3.8.1.6 Puget tio producta and P_. richii . . . . . . . . . . . 3-121 3.8.1.7 Teuulo brunnea . . . . . . . . . . . . . . . . . . . . . . . . . 3-121 3.9 Subtidal Random Line Point Contact (RLPC) . . . . . . . . . . . . . . . 3-126 3.9.1 A l gae . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-126 3.9.1.1 Botryoglossum forlowianum . . . . . . . . . . . . . . 3-126 3.9.l.2 Colliarthron, Bossiella and 5 err aticordia spp. (CBS Complex) . . . . . . . . . 3-127 3.9.2 Subst r at e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3- 130 3.9.2.1 S and . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-130 3.10 Subtidal Crab Trapping and Togging . . . . . . . . . . . . . . . . . . . . . . 3-135

3.1 i Subtidal Fish Observations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-135 3.11.1 Black-and-yellow Rockfish . . . . . . . . . . . . . . . . . . . . . . . 3-142 3.1 1.2 B lack Surfperch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3- 142 1

3.1 1.3 B lue Rockf ish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3- 142 3.11.4 Cabez on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3- 1 5 2 3.11.5 Gross F.ockfi sh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3- 152 3.11.6 Olive R ockfish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3- 152 3.1 1.7 Painted Greenling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3- 160 3.1 1.8 S enori t o . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3- 160 3.11.9 Striped Surfperch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3- 160 3.12 Subtidal Set tling Plates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-160 3.13 Bull Kelp Population Estimates . . . . . . . . . . . . . . . . . . . . . . . . . . 3-180 3.14 In Sito Temperature Measurement ...................... 3-183 3.14.1 Subtidal Temperatures . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-184 3.14.2 Intertidal Temperatures . . . . . . . . . . . . . . . . . . . . . . . . . . 3-191 1

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B-83-540 iv

I 1

, TABLE OF CONTENTS (CONT'D)  ;

1 l

l Section g i 3.15 In Situ Light Measurement ............................. 3-194 i

3.15.1 Sur f ace Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3- 194 4 3.15.2 Underwater Light .............................. 3-194 3.16 in Situ Wave / Tide Measurement ........................ 3-200 4.0 GEER AL OBSERVATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 4.1 1983 S torm E f fect s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 4.1.1 Intertidal ...................................... 4-1 4.1.2 S u b t i dal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3 4.2 El Nino E f fects in 1983 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6 5.0 LITER AT URE CITED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 i

s i

l l

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l N B-83-540 v

LIST OF FIGURES O

V Figure Page 2-1 Locations of Intertidal and Subtidal Biological Sampling Stations ........................................ 2-7 2-2 Diagrammatic Example of Typical Intertidal Station .......... 2-8 2-3 Diagram of Subtidai S tat ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16 24 Locations of Crab Tropping Stations ........................ 2-19 2-S Locctions of Subtidal Fish Sampling Stations ................ 2-21 2-6 Sequence of Settling Plate installation a n d R epl a ce m e n t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23 2-7 Locations of Intertidal and Subtidal Physical Data Sampling Stations ................................... 2-26 3-1 Abundance versus Time for Endocladia muricato at + I f t MLLW (IBI Method) . . . . . . . . . . . . . . . . . . . . . . . 3-10 3-2 Abundance versus Time for Endocladio muricato at +3 f t MLLW (IBT Method) . . . . . . . . . . . . . . . . . . . . . . . 3-1I o

(j* 3-3 Abundance versus Time for Gastroclonium coulteri at + 1 f t MLLW (IBT Method) . . . . . . . . . . . . . . . . . . . . . . . . 3-13 3-4 Abundance versus Time for Gastroclonium coulteri at +3 f t MLLW (IBT Method) ........................ 3-14 3-S Abundance versus Time for Gigartina conoliculata at + 1 f t MLLW UBI Method) . . . . . . . . . . . . . . . . . . . . . 3-16 3-6 Abundance versus Time for Gigartina canaliculata at +3 f t MLLW UBT Method) . . . . . . . . . . . . . . . . . . . . . 3-17 3-7 Abundance versus Time for Gigartino papillato at + 1 f t MLLW (IST Method) . . . . . . . . . . . . . . . . . . . . . . . . 3-18 3-8 Abundance versus Time for Gigartina papillato at +3 f t ML LW (lBT Method) . . . . . . . . . . . . . . . . . . . . . . . . 3-19 3-9 Abundance versus Time for Iridaea flaccida at + 1 f t MLLW (IBT Method) . . . . . . . . . . . . . . . . . . . . . . . . 3-21 3-10 Abundance versus Time for Iridaea floccida at +3 f t MLLW (IBl Method) . . . . . . . . . . . . . . . . . . . . . . . . 3-22 O

V B-83-540 vi

LIST OF FIGURES (CONTINUED)

Figure Page 3-11 Abundance versus Time for Anthopleura elegantissimo at + 1 f t MLLW (IBT Method) . . . . . . . . . . . . . . . . . . . 3-24 3-12 Abundance versus Time for Anthopleuro elegantissimo at +3 f t MLLW (IBT Method) . . . . . . . . . . . . . . . . . . . 3-25 3-13 Abundance versus Time for Holiotis crocherodii at + 1 f t MLLW (IBT Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-28 3-14 Abundance versus Time for Holiotis crocherodii at +3 f t MLLW (IBT Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-29 3-15 Abundance versus Time for Collisello scabra at + 1 f t MLLW (IBT Method) . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33 3-16 Abundance versus Time for Collisella scabra at +3 f t MLLW (IBT Method) . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34 3-17 Abundance versus Time for Pogurus spp.

at + 1 f t MLLW (IBT Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37 3-18 Abundance versus Time for Paguros spp.

at +3 f t MLLW (IBT Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-38 3-19 Abundance versus Time for Tegula funebralis at + 1 f t MLLW (IBT Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-40 3-20 Abundance versus Time for Tegula funebralis at + 3 f t MLLW (IBT Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-41 3-21 Abundance versus Time for Endocladia muricato at + 1 f t MLLW (IPC Method) . . . . . . . . . . . . . . . . . . . . . . . 3-49 3-22 Abundance versus Time for Endocladio muricato at +3 f t MLLW (IPC Method) . . . . . . . . . . . . . . . . . . . . . . . 3-50 3-23 Abundance versus Time for Gastroclonium coulteri at + 1 f t MLLW (IPC Method) . . . . . . . . . . . . . . . . . . . . . . . . 3-52 3-24 Abundance versus Time for Gastroclonium coelteri at +3 f t MLLW (IPC Method) . . . . . . . . . . . . . . . . . . . . . . . . 3-53 3-25 Abundance versus Time for Gigartina canaliculato at + 1 f t MLLW (IPC Method) . . . . . . . . . . . . . . . . . . . . 3-54 O B-83-540 vil i

t, LIST OF FIGURES k (CONTINUED)

Figure Page 3-26 Abundance versus Time for Gigartina canaliculato at +3 f f MLLW (IPC Method) . . . . . . . . . . . . . . . . . . . . 3-55 3-27 Abundance versus Time for Gigartina papillato at + 1 f t MLLW (IPC Method) . . . . . . . . . . . . . . . . . . . . . . . 3-57 3-28 Abundance versus Time for Gigartino papiliato at +3 f t MLLW (IPC Metho'd) . . . . . . . . . . . . . . . . . . . . . . . 3-58 3-29 Abundance versus Time for Iridaea flaccido at + 1 f t MLLW (IPC Method) . . . . . . . . . . . . . . . . . . . . . . . . 3-60 3-30 Abundance versus Time for Iridaea flaccida at +3 f t MLLW (IPC Method) . . . . . . . . . . . . . . . . . . . . . . . . 3-61 3-31 Black Abaione Sampling Locations and Density Estimates in Diablo Cove,1983 . . . . . . . . . . . . . . . . . . . . . . 3-65 3-32 Abundance versus Time for Cystoseira osmundacea in Diablo Cove from March 1976 f'N, to October 1983 (SAO Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-70 V 3-33 Abundance versus Time for Laminaria dentigera in Diablo Cove from Mcrch 1976 to October 1983 (SAO Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-73 3-34 Abundance versus Time for Nereocystis luetkeano in Diablo Cove from March 1976 to October 1983 (S AO Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-75 3-35 Abundance versus Time for Pterygophora californica in Dioblo Cove from March 1976 to October 1983 (SAO Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-78 3-36 Abundance versus Time for Anthooleura elegantissimo in Diablo Cove from March 1976 to October 1983 (S AO Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-84 3-37 Abundance versus Time f'or Astraea gibberoso in Diablo Cove from March 1976 to October 1983 (SAO Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-86 3-38 Abundance versus Time for Haliotis rufescens and H. wollallensis in Diablo Cove f rom March 1976 to October 1983 (S AO Method) . . . . . . . . . . . . . . 3-89 B-83-540 viii

I l

r3 LIST OF FIGURES N~]

(CONTINUED)

Figure Page 3-39 Abundance versus Time for Patiria miniato in Diablo Cove from March 1976 to Oct ober 1983 (SAO Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-91 3-40 Abundance versus Time for Pisoster .

ochraceus, P. giganteus, and P. brevispinus in Diablo Cove from March 1976 to October 1983 (SAO Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-94 3-41 Abundance versus Time for Pugettiq producto in Diablo Cove from March 1976 to October 1983 (SAO Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-97 3-42 Abundance versus Time for Pycnopodio helianthoides in Diablo Cove from March 1976 to October 1983 (S AO Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-99 3-43 Abundance versus Time for Strongylocentrotus purpurotus and

5. f rancisconus (SAG Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-102 3-44 Abundance versus Time for Tegula brunneo in Diablo Cove from March 1976 to October 1983 (SAO Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3- 104 3-45 Abundance versus time for Acmaea mitro in Diablo Cove from March ;976 to October 1983 (SFO Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-109 3-46 Abundance versus Time for Anthopleuro elegantissimo in Diablo Cove from March 1976 to October 1983 (SFO Method) . . . . . . . . . . . . . . . . . . . 3-11I 3-47 Abundance versus Time for Colonial / Social tunicates in Diablo Cove from March 1976 to October 1983 (SFO Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3- 114 3-48 Abundance versus Time for Mitrello spp.

in Diablo Cove from March 1976 to October 1903 (SFO Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3- 117 A

U B-83-540 ix

l LIST OF FIGURES (CONTINUED)

Figure Page 3-49 Abundance versus Time for Pogurus spp.

in Diablo Cove from March 1976 to October 19113 (SFO Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-119 3-50 Abundance versus Time for Puaettia producto and P. richil in Diablo Co7e from -

March 1976 to October 1983 (SFO Method) . . . . . . . . . . . . . . . . . . 3-122 3-51 Abundance versus Time for Tegula brunneo in Diablo Cove from March 1976 to October 1983 (SFO Method) . . . . . . . . . . . . . . . , . . . . . . . . . . . . . 3-124 3 52 Abundance versus Time for Botryoglossum forlowianum in Diablo Cove from March 1976 to October 1983 (SLC Method) . . . . . . . . . . . . . . . . . . 3-128 3-53 Abundance versus Time for C.B.S. Complex in Diablo Cove from March 1976 to October 1983 (SLC Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-31 3 3-54 Abundance versus Time for Sand in Diablo Cove from March 1976 to October 1983 (SLC Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-133 3-55 Bimonthly Cancer antennarius Catch per Unit Effort (CPUE) from August 1976 to December 1983 ...................................... 3-137

, 3-56 Number of Adult Black-and-yellow Rockfish Observed in 50 X 4 m Underwater Band Transect Surveys ....................................... 3-143 3-57 Number of Adult Black Surfperch Observed in 50 X 4 m Underwater Band Transect Surveys . . . . . . . . . . . . . . . . . 3-146 3-58 Number of Adult Blue Rockfish Observed in 50 X 4 m Underwater Band Transect Surveys . . . . . . . . . . . . . . . . . 3-149 i

3-59 Number of Adult Cabezon Observed in 50 X 4 m Underwater Band Transect Surveys . . . . . . . . . . . . . . . . . 3-153 B-83-540 x

l LIST OF FIGURES (CONTINUED)

Figure Page 3-60 Number of Adult Gross Rockfish Observed in 50 X 4 m Underwater Sand Transect Surveys . . . . . . . . . . . . . . . . . 3-156 3-61 Number of Adult Olive Rockfish Observed in 50 X 4 m Underwater Bond Transect Surveys . . . . . . . . . . . . . . . . . 3-158 3-62 Number of Adult Pointed Greenling Observed in SO X 4 m Underwater Bond Transect Surveys . . . . . . . . . . . . . . . . . 3-16i 3-63 Number of Adult Senorito Observed in 50 X 4 m Underwater Band Transect Surveys . . . . . . . . . . . . . . . . . 3-164 3-64 Number of Adult Striped Surfperch Observed in 50 X 4 m Underwater Band Transec t Surveys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3- 16 7 3-65 Numbers of Algol and invertabrote Toyo Colonizing Subtidal Settling Plates A f ter 2-Month Submergence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-175 p 3-66 Numbers of Algol and Invertebrate Taxo Q Colonizing Subtidal Settling Plates of ter increasing Periods of Submergence (2-12 Months) . . . . . . . . . . . . . . . . . . . . . 3-176 3-67 Dry-Weight Biomass on Subtidal Settling Plates Af ter 2-Month Submergence . . . . . . . . . . . . . . . . . . . . . . . . . 3-178 3-68 Dry-Weight Biomess on Subtidal Settling Plates Af ter increasing Periods of Submergence (2-12 Months) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-179 3-69 Number of Nereocystis luetkeano Individuals Observed in Diablo Cove f rom Clif f top Vantage Points, Fall 1970-1983 ............................ 3-181 3-70 Subtidal Weekly Mean Temperatures in North Diablo Cove from July 1976 to November 1983 ....................................... 3-185 3-71 Monthly Meon, Maximum and Minimum Water Temperatures at the Subtidal (-10 f t MLLW)

Diablo Cove Stations 8 and 12 in 1982 and 1983 . . . . . . . . . . . . . . 3-186 d B-83-540 xi

o LIST OF FIGURES (CONTINUED)

Figure Page 3-72 Percentage Frequency of Temperatures at Subtidal Statior 12-10 for the First Quarters of 1982 and 1983 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3- 187 3-73 Percentage Frequency of Temperatures at Subtidal Station 12-10 for the Second Quar ters of 1982 and 1983. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-188 3-74 Percentage Frequency of Temperatures at Subtidal Station 12-10 for the Third Quarters of 1982 and 1983. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-189 3-7S Percentage Frequency of Temperatures at Subtidal Station 12-10 for the Fourth Guarters of 1982 and 1983 . . . . . . . . . . . . . . . . . . . . . . . . . . 3-190 3-76 Monthly Mean, Maximum and Minimum Air / Water Temperatures at the Intertidal

(+ 2 ft MLLW) Diablo Cove Stations 8 and 12 in 1982 and 1983 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3- 192 3-77 Example of Intertidal Diurnal Temperat ure R egime . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-193 3-78 Monthly Mean Surface (A) and Underwater (B)

Light Values Versus Time of Day at Diablo Cove for the First Quarters of 1982 and 1983 ................................................... 3-195 3-79 Monthly Mean Surface (A) and Underwater (B)

Light Values Versus Time cf Day at Diablo Cove for the Second Quarters of 1982 and 1983 . . . . . . . . . . . . . . 3-196 3-80 Monthly Mean Surface (A) and Underwater (B)

Light Values Versus Time of Day at Diablo Cove for the Third Quarters of 1982 and 1983. . . . . . . . . . . . . . . . 3-197 3-81 Monthly Mean Surface (A) and Underwater (B)

Light Values Versus Time of Day at Diablo Cove for the Fourth Quarters of 1982 and 1983. . . . . . . . . . . . . . . 3-198 3-82 Percentage Emergence Versus Elevation in Diablo Cove for December 1982 and January, Fioroary, April and June 1983 ...................................... 3-201 O

B-83-540 xii

_ _ - - - - - - - - - - - - - - I

I

.,q LIST OF FIGURES  !

(d )

(CONTINUED)

Figure Page  !

3-83 Percentoge Emergence Versus Elevation in Diablo Cover for July through November 1983 ..................... 3-202 3-84 Sea Surface Elevation Versus Time (Predicted and Measured) January 26 - 29,1983 . . . . . . . . . . . . . . 3-203 3-85 Sea Surface Elevation Versus Time (Predicted and Measured) July 8 - 1 1, 1983 . . . . . . . . . . . . . . . . . . 3-204 MAPS IN POCKETS Map A - Locations of Intertidal and Subtidal Biological Sampling Stations Map B - Locations of intertidal and Subtidal Physical Data Sampling O

i O' B-83-540 xiii

LIST OF TABLES

-O Table &

2-1 Intertidal Data Collection Station Locations, Status and Types of Data Collected . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 2-2 Subtidal, ENDECO and Miscellaneous Data Collection Statien Locations, Status and Types of Dat a Collected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13 3-1 Summary of Completed TEMP Intertidal Sampling:

+ 1 f t (MLL W) Transe c t s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2 3-2 Summary of Completed TEMP Intertidal Sampling:

+3 f i (ML LW) Transe c t s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4 3-3 Completion Schedule of IBT Sampling by Survey, Dat e, Station and Level . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6 3-4 Mecn Abundance of Anthopleura elegantissimo in the IBT "Tegulo Guadrats" for the Diablo Cove Intertidal Stations from August 1976 - October 1983 .................................................... 3-26 3 3-5 Mean Abundance of Holiotis crocherodii in the IBT Quadrats for the Diablo Cove Intertidal Stations from May 1976 - October 1983 . . . . . . . . . . . . . . . . . . . . . . 3-30 3-6 Mean Abundance of Collisella scabra in the IBT "Te ola Quadrats" for theUioBTo Cove Interti a totions from August 1976 -

O c t obe r 1 983 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-35 3-7 Mean Abundance of Pogurus spp. in the IBT "Tegula Guadrats" for the Diablo Cove Intertidal Stations from August 1976 -

. O c t ober 19 83 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-39 3-8 Mean Abundance of Tegula funebralis in the IBT "Tegula Goodrats" for the Diablo Cove Intertidal Stations from August 1976 - -

O c t ober 1 9 83 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-43 3-9 Completion Schedule of RPC + l f t (MLLW)

Quadrat Sampling by Survey, Date, S ta t ion and Guadra t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-44 O B-83-540 xiv

i LIST OF TABLES O-Q COMINUED 1

Table Page 3-10 Completion Schedule of RPC + 3 f t (MLLW) Quadrat Sampling by Survey, Date, Station and Quadrat . . . . . . . . . . . . . . . . 3-46 3-11 Summary of Completed Intertidal Algal Scraping Program, (+2 f t MLLW) ........................... 3-62 j

3-12 Summary of Completed Intertidal Black Abalone Tagging Sur veys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-63 3-13 Summary of 1983 Intertidal Black Abal one S u rvey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-66 3-14 Summary of Completed Subtidal TEMP Sam p l i ng . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-67 3-1S Mean Number of Individuals per 30 M2+ 2 S.E For Selected Invertebrate Species at Diablo Cove Subtidal Stations (5AO Method), from March 1976 to O c t ober 198 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-82 3-16 Mean Number of Individuals per 0.25 M2+ 2 S.E.

O For Selected Invertebrate Species in Diablo Cove Subtidal Stations (SFO Method), from March 1976 to October 1983..................................... 3-107 3-17 Summary Statistics for Crab Trapping Subtask Surveys 35 - 39 February 1983 - October 1983................ 3-136 3-18 Summary of Abundance and Species Composition of Young and Adult Fishes in Diablo Cove and South Cove i

from May 1983 to October 1983............................ 3-137 3-19 Subtidal Set tling Plate Collection Dates . . . . . . . . . . . . . . . . . . . . . 3-171 3-20 Taxa Encountered on Subtidal Settling Plates, 1983..................................

July 1976 - January 3-173 3-21 Monthly Percentage Emergence at the I and 3 ft (MLLW) Elevations at Station 9-10 and Tidal Ranges for 1983 ................................ 3-205 il B-83-540 xv

LIST OF TABLES CONTINUED Toble Page 4-1 Major Storms - Winter 1983. Extreme Values from omong iI Northern and Southern California L oca t i on s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2 4-2 Sun.mory of Physical and Biological Changes that Occurred as a Result of the Winter Storms of 1983 . . . . . . . . . . . . . . . . . . . . . . . . . 4-4 4-3 Physical and Biological Changes Observed in March 1983 on the -10 f t Subtidal Stations in Diablo Cove and Sou t h Cove . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5 O

O B-83-540 xvi

i s TFERMAL EFFECTS MONITORING PROGRAM

!983 AttRJAL REPORT DIABLO CANYON POWER PLANT EXECUTIVE

SUMMARY

The results of the Thermal Effects Monitoring Program (TEMP) for the Diablo Canyon Power Plant ore summarized and reported for the period January to December 1983. A brief review of activities and data obtained since program inception (1970 is included as background information. The monitoring program currently includes 16 biological and oceanographic study subtasks. The status of all subtasks is briefly described and analysis of data from thirteen subtasks is reported in detail. The detailed reports include the results from:

o intertidal studies including: band transect sampling of algal and invertebrate ppulations, tandom point contact sampling of algal populations, and surveys of black abalone populations p)

(,

o Subtidal studies including: are quadrant sampling of algal and invertebrate populations, fixed quadrat sampling of invertebrate populations, random line point contact sampling of algal populations, rock crab trapping cnd tagging studies, fish observation transects, settling plate sampling of algae and invertebrates, and bull kelp popula-tion estimates o Physical oceanographic studies including: in sito tem-perature, light and wave / tide recordings.

In addition, the effects of severe winter storms in early 1983 and unusually warm water conditions during much of 1983 are described and discussed. The results reported in the 1983 annual report continue to add to the description of the existing marine communities in the vicinity of the power plant's cooling water discharge. Populatbn trends established by these studies will enable on assessment of the effects of the thermal discharge following the startup of the power plant which is anticipated to occur in mid-1984.

p d B-83-540 l

1.0 INTRODUCTION

V The 1983 Thermal Effects Monitoring Program (TEMP) report is submitted in accordance with Provision D.3 (Compliance with Mcnitoring and Reporting Program) and D.7(o) of the NPDES Permit (order number 82-24 as amended in March 1983) issued by the California Regional Water Quality Control Board, Central Coast Region (hereaf ter referred to as the " Board") for the operation of the Diablo Canyon Power Plant. A report summarizing the results of the Thermal Effects Monitoring Program of the cooling water discharge is submitted annually.

Since the power plant did not operate in 1983, there were no thermal effects related to the cooling water discharge to report. This report summarizes the methods and the status of 16 TEMP subtasks (individual sampling and data record:ng activities) and examines in detail the data for selected species sampled in most subtasks. The majority of these subtasks have been performed routinely (with some modifications to their methods and scope) since 1976 when they were designed and implemented under the 316(a) Demonstration Program.

(

The TEMP field studies are designed to yield on extensive data base on the spatial distribution of the major populations of marine flora cnd fauna in Diablo Cove and the surrounding areas that will enable comparative evaluations of the effects of the thermal discharge on these species. Intertidal and subtidal algal, invertebrate, and fish abundances have been quantitatively monitored at regular sampling intervals since 1976. Fixed sampling is conducted at precisely located sampling stations in Diablo Cove and in reference areas to the north and south of the Cove. Certain laboratory tasks (biomass determinations, settling plate analyses and species identifications) are also performed in support of the field studies. Water temperatures, surface and underwater light, ti6s, current, and wave conditions are also being recorded.

This 1983 annual report is the eighth in the series of progress reports to the Board which includes reports dated December 1976, October 1977, May 1978, February 1979, November 1979, August 1980 and January 1983. In addition to O

V B-83-540 1-1

these progress reports, three special reports on the DCPP thermal discharge

(]

'V have been submitted to the Board under the titles of " Assessment of Alternatives to the Existing Cooling Water System" (April 1982), " Thermal Discharge Assess-ment Report" (April 1982), and " Compendium of Thermal Effects Laboratory Studies" (April 1982).

f'i v

O B-83-540 1-2

2.0 MONITORING PROGRAM METHODS Brief descriptions of the methods employed in gathering biological and physical data for TEMP are included in this section. For purpose 2 of clarity, the methods have been broken down into 16 subtasks, each of which is described separately.

2.1 INTERTIDAL BAND TRANSECT (IBT)

. The abundance of cigae and invertebrates is monitored bimonthly at fixed intertidal stations at two levels (approximately +1 and +3 ft MLLW) within fixed 30 m x 1 m bonds (TABLE 2-1, FIGURES 2-1, 2-2, see also Map A in pocket).

Currently,10 fixed horizontal I m2 quadrats per station level are sampled for conspicuous species. Five of these quadrats ("Tegulo quadrats") are more intensively sampled for all macroinvertebrates.

The quadrats are clipped to a transect line strung along the station level.

Abundance estimates of o!gae and encrusting invertebrates are obtained by

dividing each quadrat into 16 blocks, each of which can be subdivided into nine

! ) smaller blocks. Percentage cover estimates are obtained by recording the number of squares (either 1/16 or 1/144) occupiad by a particular taxon. The "Tegulo quadrats" are searched from all angles of view and all macroinvertebrate taxa observed are counted and recorded.

2.2 INTERTIDAL RANDOM POINT CONTACT (RPC) GUADRAT A random point contact method is used to measure percentage frequency of oc-currence as an index of percentage area covered by dominant intertidal algae.

Algal area cover is monitored at bimonthly intervals within fixed horizontal 0.25 m2 quadrats located opproximately in the middle and at either end of the fixed 30 m x 1 m band transects (FIGURES 2-1 and 2-2). The area within the quadrat is sampled by reference to a coordinate grid system defined by markings on the quadrat sides and a cross bar which slides across them, with a total of 400 potential cross points. For each bimonthly survey, an independent set of 60 randomly generated sampling cross points is produced. At each sampling cross O

V B-83-540 2-1

l 1

DIABLO CANYON POWER PLANT

, THERMAL EFFECTS MONITORING PROGRAM $ ACTIVE Q = INACTIVE j SURVEY STATION g em DATA MATRIX &q.

gY C) DATE: 3 JAN 84

[e v 8 8 s 4 @ #

ST ATION 8 D NUMBER h LOCATION q- $ d'4 w 4 641, 286.56N I +3 O O O 1,141, 551.08 E 641, IIl.13 N I +I I,14l,776.62 E O O O 640, 883. N 2 +3 1,141,843.37 E O O O 641,073.07 N 2 +2 O 1,141, 762.57 E O 641, 010.79 N 2 +1 1,141,800.04 E O O O _

640, 561.92 N 3 +3 1,141,986.35 E O O O

)

(V 640, 598.83 N 3 +2 O 1,141, 964.80 E 640,528.23 N 3 +1 i, ici,963.43 e O O O a 3 f hi "fi.i7 e O O O 636,225.90N 4 +2 1,146,097.29E O 636,280.92N N +I I,146,103.88E O O O 636,176.50 N 5 +3 i,146,025.i2 e O O O 636,173.93N 5 +2 1,146,001.34E O TABLE 2-1 Ow INTERTIDAL DATA COLLECTION STATION LOCATIONS,

, STATUS AND TYPES OF DATA COLLECTED 2-2 B-83-540

DIABLO CANYON POV'ER PLANT THERMAL EFFECTS MONITORING PROGP,AM

$r ACTIVE Q = INACTIVE SURVEY STATION g C' e b' DATA MATRIX DATE: 3 JAN 84 e

O y@

w STATION NUMBER $

[

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LOCATION N g

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5 +1 f,36, l 45, 0 6E O O O

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6 636,060.93 N

+3 1,145,920.06 E O O O 6

636,071.08N

+2 1,145,934.6 l E O 636,087.87 N 6 +1 1,145,905.54 E O O O 635,387.13 N 7 +3 1,146,039.83 E O O O 635,383.74 N i 7 +2 1,146,053.23 E O 635,375.21 N l' 7 +I I,146,060.72 E O O O 635,482.24 N g g g 8 +3 I, I46,217.47 E 635,471.44 N 0 +2 1,146,203.19 E O g 635,446.99 N O +I I,146,207.34 E O O O 635,433.89 N g g 9 +3 1,146,313.76 E g

635,431.16 N g 9 +2 1,146,303.16 E 635,414.24 N I l

9 +I 1,146,328.8' E O O O 1

l iO .o f3M,I',o5 "

,.43 E e e e TABLE 2-1 l lNTERTIDAL DATA COLLECTION STATION LOCATIONS, STATUS AND TYPES OF DATA COLLECTED B-83-540

DIABLO CANYON POWER PLANT THERMAL EFFECTS MONITORING PROGRAM ga ACTIVE Q = INACTIVE SURVEY STATION s m DATA MATRIX

[,@

I DATE: 3 JAN 84 g &, 8&e 2 h q$ ~ &g w f fr ha v 8 ST ATION [ A NUMBER $ LOCATION Yg ,

[j Wh 634,536.58 N 10 +2 1,147,175.99 E O O 634,516.10 N 10 +1 1,147,162.28 E O O O 634,184.75 N II +3 1,147,106.09 E O O O 634,164.00 N II +2 1,147,086.22 E O

" +i f,hW19% O O O 634,043.94 N 12 +3 1,146,882.96 E O O O 634.054.14N 12 +2 I,146,864.86E O O 634,066.48 N 12 +1 1,146,981.80 E O O O

,0 13 +3 jg6 371.45 E O O 634,046.82 N 13 +2 1,146, 361.57 E O N

I4 +3 ff!$l,I359.79E

• O O O 634,011.70N 14 +1 1,146,332.60E O O 633,956.52 N 15 +3 1,146,406.01 F. O O O 633,979.20N 15 +2 1,146,397.96E O O TABLE 2-1 O.

INTERTIDAL DATA COLLECTION STAT'ON LOCATIONS, STATUS AND TYPES OF DATA COLLECTED (CONTINUED)

B-83-540 2-4

_ _ _ _ _ _ _ _ i

i DIABLO CANYON POWER PLANT THERMAL EFFECTS MONITORING PROGRAM g ACTIVE Q = INACTIVE SURVEY STATION '

• DATA MATRIX [

O DATE: 3 JAN 84

/ g 'g[v" v D

$[

& gg S $

/ ff ' * ,f f ST ATION [ y NUMBER b LOCATION gd g kg 4v[g 632,708.29 N 16 +3 1,147, 783.23 E O O 632,664.12 N

+2

, 1,147,748.62 E O l ,'

632,644.79 N

+3 i,147,9:2.74 e O O O I8 +3 f,'4f,Dg63.50 E O O O 632,712.01 N i8 +2 i, ic7,652.92 e O 632,922.59 N 19 +3 1,148, 958.64 E O O O 19 632,891.36 N

+2 1,148, 977.59 E O IE +I O O

'4 , 43.3 E O 632, 995.4 l N 20 +3 O O O 1,149.086.69 E 20 +1

'4 l 069.2 E O O O 632,903.7i N 21 +3 1,149,170.01 E O O O 632,871.80 N 21 +2 1,149,158.64 E O 2i +i f32,4 ;21.37 Ne 4g 93 O O O TABLE 2-1 INTERTIDAL DATA COLLECTION STATION LOCATIONS, O STATUS AND TYPES OF DATA COLLECTED (CONTINUED) 2-5 B-83-540

DI ABLO CANYON POWER PLANT THERMAL EFFECTS MONITORING PROGRAM g ACTIVE Q = INACTIVE q SURVEY STATION (g

DATA MATRIX &q.

DATE: 3 JAN 84 g 'e[,4, v[ 8

&  ? e i d~'i ff STATION [ >A y y v4 g 4 NUvBER $ LOCATION /'* tO Yg4 k4 44 634,077.445 N 22 +3 O O 1,146,673.926 E O (opprox.)

22 +2 434.08100N i, 46,607.00E g

635,016.70N 23 +3 O O 1,146,931.91 E 634,954.44 N 23 +2 1,146,931.92 E O 23 +1 f, '4 930.0 E O O

/^NI

(,_

TABLE 2-1 INTERTIDAL DATA COLLECTION STATION LOCATIONS, STATUS AND TYPES OF DATA COLLECTED (CONTINUED)

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B-83-540 2-6

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O OFFSHORE

{ 4---- DOWNCOAST A UPCOAST >

N P 8"

+1 FT MLLW BAND TRANSECT C 9 f5Til R ITl FTil o em ITl _

it -

no Pe A

+2 FT MLLW Temperature Recorder l

N b k +3 FT MLLW BAND TRANSECT -

L g a A 1 r ONSHORE Fixed Standard Quadrat (IB1)

(n = 5 per bond) 9 Reference Stokes T Fixed "Tequia"/ Standard Quadrat (IBT) "" " "*

(n = 5 per band)

O Fixed Rondom Point Contact (RPC) Quadrat (n = 3 per band)

FIGURE 2-2 DIAGRAMMATIC EXAMPLE OF TYPICAL INTER FIDAL STATION

. n

point, a fine metal rod is held perpendicular to the substrate and lowered until a species or the substrate is contacted.

The contact is recorded and if the individual first contacted overlies other species or the substrate, it is gently moved away and the process is repeated for underlying species until an encrusting species or the substrate is contacted. Additional contacts of any one species at one sampling point are not recorded. A number assigned to each species or the substrate corresponds to the order in which it was contacted as the rod was lowered from the surface layer to the substrate at each sampling point.

2.3 INTERTIDAL ALGAL SCRAPINGS Algol scrapings are collected biannually from 25 randomly positioned 0.06 m2 quadrats at permanent stations located near existing intertidal band transects

("AS" stations in FIGURE 2-1, see also Map A in pocket). In each sample, percentage cover estimates are obtained for all attached algae and encrusting invertebrates. Additionally, the numbers of individuals of motile invertebrate species encountered are recorded. All attached algae are then removed using o A metal scraper, placed in a labeled plastic bag and reiurned to the laboratory for

\]

processing, or are frozen to await processing.

Laboratory treatment of each sample consists of sorting all algae into specific taxa. Iridaea flaccida, a very common foliose red alga, is further subdivided into life-history stages (juveniles; immature males, females and tetrasporophytes; mature females; mature tetrosporophytes). Blade counts and bicde lengths are then obtained for each life stage. Each of these sorted life-history categories, along with the remaining sorted taxa in the sample, are placed in separate glass dishes and dried for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of 100 C (?l2 F). Dry weight measurements are then recorded for all sorted specimens.

2.4 INTERTIDAL BLACK ABALONE TAGGING

Block abalone, Ha!iotis crocherodii, are individually tagged, measured and periodically remeasured to estimate and compare averaga growth rates of populations in four areas in the Diablo Canyon study area.

B-83-540 2-9

- . - - - - - . - , - , - - . - - ~ - - - - - - - , -----n..

The location of all tagged individuals is recorded as linear distance and compass direction from o permanent relocatable marker.

Measurement of abalone consists of determining the longest shell dimension with a pair of mochinists' calipers and comparing that distance to a metric ruler, recording length to the nearest millimeter. Precision estimates of the measurement technique are obtained by measuring the some abalone five times using five independent observers.

2.5 INTERTIDAL BLACK ABALONE SURVEY The purpose of this study is to determine os occurately as possible the number and distribution of black obalone, _Haliotis crocherodii, within Diablo Cove. A randomly placed quadrat method is utilized. Beginning near the discharge and running to the south and to the north, Diablo Cove is divided into segments 100 m long. Two stakes positioned neor the discharge structure serve as the origins for the segments in the north and south portions at the cove. A 100-m line marked off in I-meter segments is placed in the intertidal zone at an O elevation of approximately +2 f t MLLW. In practice, the line follows the middle Q of the intertidal portion of the Iridaea flaccida zone. Changes in orientation of the line are marked with a stake or on ofready established intertidal monument.

Distance and bearing (using a hand bearing compass) from the origin stakes and monuments are noted. The end of one 100-m section serves as the origin for the next section. Six sections were established in both the north and south areas of Diablo Cove in such a way that each section con be relocated with reasonable precision.

Using the transect line os a reference point, the area between the estimated 0 and +4 ft MLLW tide levels is delimited. These levels are generally defined as the upper limit of Phyllospadix spp. and the upper limit of Pelvetic fasticiata, respectively. The area thus delimited is considered to be the zone in which most intertidal black abalone occur. Due to the variable nature of the intertidal zone, l

l each 100-m section is irregularly shaped.

l A

'd B-83-540 2-10 i

The total number of square meters encompassed in each section was calculated graphically. It was decided that 10 percent of the area in each section would be a mitable sample. Therefore. each potential 1-m2 site within the section was numbered and random numbers were generated so that 10 percent of the potential sites within a section are selected on a random basis. The site locations were transferred from these maps to a master data sheet listing the section number (NDC l-5 or SDC l-6), the ordinate (1-100 m), and the location of the quadrat to be sampled as onshore (+) or offshore (-).

The field team consists of one recorder and four observers. At each sample locus the following data are collected:

o Substrate type (boulder, cobble, sand, or bench rock) o Amount of relief [ low (less than 30 cm), medium (30-70 cm), high (over 70 cm)]

o Dominant algae

, o Total number of abalone. '

O 2.6 INTERTIDAL STATION PHOTOGRAPHY The intertidal station photorjraphy consists of taking color Kodachrome and infrored photographs of intertidal stations. The general area (" cliff top")

photographs are taken at each fixed station within each of the seven major intertidal areas in the Diablo Canyon study site. All intertidal random point contact (RPC) quadrats are individually photographed.

The photographs from these surveys will be used to document changes in (1)overall area covered by algae within fixed quadrats during comparable seasonal periods, (2) the proportion of green, brown and red algae, and (3) algal health (bleaching, etc.) condition.

B-83-540 2-11

2.7 SUBTIDAL ARC QUADRANT (SAQ)

O Each permanent subtidal station at Diablo Canyon is circular and sampling is conducted on an area of approximately 28 square meters. Each station is subdivided into four equal pie-shaped sections or arc quadrants of 7 m2 sampthg area (TABLE 2-2, FIGURES 2-1 and 2-3). A railrood wheel marks the center of the station. The area occupied by the wheel, plus an additional area surrounding it, (totaling on inner 2 m diameter circle) i: not sampled because of the possible effects of diver cetivity near the wheel. The purpose of fl.is sampling method is to determine the species composition, and the population densities of the more conspicuous, representative, and countable subtidal biota. The number of individuals of each species present in each of the quadrants is recorded. The data from the four are quadrants will be. used to determine spatiot variability within the station.

Taxa to be considered by the arc-quadrant method include (1) the larger motile (nonencrusting and nonhabitat forming) benthic invertebrates for which indi-vidual count data can be made, and (2) several species of the larger (canopy) algae for which point contact estimates of percentage cover (see RLPC method, Section 2.9) are impractical. These algal taxa include Pterygophora californica, Laminario dentigera, Cystoseira osmundacea, Nereocystis luetkeana, and Egregia menziesi!. The invertebrate taxa include all individuals of those taxa printed on the data sheets (Form 7); for those taxa not printed on the data sheets and which satisfy the above requirements, only those individuals greater than I in. (2.5 cm) long are counted. For some species that occur in abundances too high to ef ficiently record total numbers over the 7 m2 crc quadrant (e.g., Acmaea mitra, Tonicella lineata, Colliostoma ligatum, Tegula brunnea and Tegulo montereyi) only the first one-third of each arc (2.33 m2) is sampled.

2.8 SUBTIDAL FIXED QUADRAT (SFG)

Fixed location quadrats are monitored at each subtidal station to determine the species composition and population densities of the smaller, more cryptic subtidal invertebrates, including "hooltat-formers," not quantified by the arc-b v B-83-540 2-12

DIABLO CANYON POWER PLANT THERMAL EFFECTS MONITORING PROGRAM SURVEY STATION $= ACTIVE O=INACT13 DATA MATRIX DATE: 3 JAN 84 a

N, e g o

i aff e*+ *e MBE LOCATIOtJ d' k 4 d' 641,024.83 N I -l o i, ici,398.45 E O O O O O 7 '2 ' "

i -is jlj,3j,290.os E O O O 640,921.06 N 2 -io i, ici,477.33 e O O O O O 2 64

-is f,4j'3y, ?g,6 N O

,92 E O O 640,467.21 N 3 -lo i, ici,73i.43 E O O O O O

3 -is flj'3?68N.o"5 5 EO O O (J 4 -32 635, i04.83 N 1,145,423.72 E O O O 634,643.32 N s -2s i, ing, ii,33 e o o o 634, 781.25 N '

6 -11 1,145, 778.19 E O O O e 635, 246.87 N 7 -lo I,146.125.85 E O O b O e e

-15 f k' , h56.48 E 7 O O O 8 -io f it! is*!.4e E * * * *

• 8 "

-is f it' ?#.i7 E O O O 9 -io

??i>Jif!.91E e e e o e o TABLE 2-2 SUBTIDAL, ENDECO AND MISCELLANEOUS DATA COLLECTION STATION LOCATIONS, STATUS AND TYPES OF DATA COLLECTED 2-13 B-83-540

l DIABLO CANYON POWER PLANT THERMAL EFFECTS MONITORING PROGRAM $= ACTIVE O = INACTIVE SURVEY STATION DATA MATRIX f DATE: 3 JAN 84 8[

i

& 8 o e[ [

aff /e 4 ER D' LOCATIOfJ tv 0 635,182.55 N 9 -i5 1,146,216.87 E O O O i

634,416.17 N 10 -10 j I,146,916.25 E O' O O O O 634,436.02 N 10 -15 1,146,810.42 E O O O 634,314.51 N

-10 l,146,904.89 E O O O O O Il O

634,362.19 N 11 -15 O O O 1,146,819.88 E O O 634,259.73 N 12 -10 O O O l,146,877.20 E O O 634,333.87 N 12 -15 I,146,788.58 E O O O 634,504.38 N 13 -32 1,146,257.59 E O O O O 634,262.07 N 14 -55 1,145,818.10 E O O O 633,417.91 N 15 -50 l,146,277.12 E O O O 17 -10 f, '4h, 83.5 E O O O O 632,447.55 N 17 -20 l,147,549.99 E O O O

~

iS -i o "

f d s.98 E O O O O O 19 -15 ja2,g7.'

4 927.24 E O O O TABLE 2-2 SUBTIDAL, ENDECO AND MISCELLANEOUS DATA COLLECTION STATION LOCATIONS, STATUS AND TYPES OF DATA COLLECTED (CONTINUED)

B-83-540 2-14

~

l DI ABLO CANYON POWER PLANT THERf/AL EFFECTS MONITORING PROGRAM SURVEY STATION $= ACTIVE Q x INACTIVE DATA MATRIX

(') DATE: 3 JAN 84 A

b* b*

ont/g/g i .1 /e BE d' LOCATIOf4  % k <u tv 4 0 632,741.83 N 20 -i 0 i, i49, c49,99 e o o o o o 632,464.93 N

20 -20 l,149,080.70 E O O O 553.18 N 21 -10 632'49,179.27 EO O O O O i, i 632,373.35 N 21 -2 1,149, 26Y.94 E O O O ENDECO IS -15 f, 'g 'l3.17 E ' O ENDECO OS -32 ' '

l 4 362.8 E O ENDECO NE -12 f '4f,28 . 0 E O (cpprox)

ENDECO SE -12 634, 320.00 N g 1,146,870.00 E (approx)

ENDECO SC -15 '

O 4 5' 010. E WAVE sfc 65,536.00 N g RECORDER I,146,761.00 E (approx) 32 INTAKE

-32 633, 515.00 N g g 1, I47, 280.00 E (app,w 99 SIMS

.lo3 633, 100.00 g I,148, 578.00 E (approx) 99 633,421.00 N OFFSHORE 30 l,144,645.00 E g g g

{o} TABLE 2-2 SUBTIDAL, ENDECO AND MISCELLANEOUS DATA COLLECTION STATION LOCATIONS, STATUS AND TYPES OF DATA COLLECTED

' }

B-83-540 2-l

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2-16

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] quadrant count (Section 2.7) or the rondom line point contact methods  ;

(V (Section 2.9). Four circular quadrats with on crea of 0.25 m2 are sampled at each station (see FIGURE 2-3). Quadrat locations were selected on the basis of physical criteria including uniform hard substrate, with two quadrats at a given station lying nearly horizontally and two quadrats lying more nearly vertically, and on the biological criteria that locations be representative of the arc-quadrant's dominant microfounal assemblages. There is no maximum size limit for the invenebrate taxa in these quadrats; minimum size limits are fixed by visual discernat.ility. Hobitat-forming and encrusting forms are quantified by the number of sqvare inches they cover; individuals of oil other taxa are counted.

2.9 SUBTIDAL RANDOM LINE POINT CONTACT (RLPC)

A random line point contact (RLPC) method is used to document the percentage crea covered by habitat-formers; i.e., all macroscopic occuponts of substrcte within the 28 m2 subtidal stations. Although habitat-formers con be either encrusting invertebroi-s or algae, the predominant habitat-formers on the TEMP subtidal stations are algae and this procedure was developed primarily to A quantify algal abundances.

An equal number of points is sampled within each of the four are quadrants so that four statistical replicates are obtained (see FIGURE 2-3). A weighted line with one end attached to a pin (on the railroad wheel marking the center of each subtidal station) is rotated to locate the sampling loci. The line has 10 points marked by small lead weights numbered 0 to 9; their position along the line is graded, with point density increasing toward the station perimeter to counteract the " center bios" introduced by the distribution of points on o radius within a circular crea. Of 100 possible sampling loci created by positioning the weighted line at 10 equidistant locations across the are quadrant, 50 points in each j quadrant are rondomly selected and their location is printed on the RLPC data sheet (Form 10, Rev. C). A total of 200 points is sampled at each station.

Sampling loci are changed for each bimonthly subtidal survey.

(q f i B-83-540 2-17

g The dato collected consist of noting what species lies immediately over the loci h to be sampled and the type of substrate or encrusting invertebrate lying immediately under the loci.

t 2.10 SUBTIDAL CRAB TRAPPING AND TAGGING A series of standard commercial" Igloo" crab trops are fished at subtidal stations (FIGURE 2-4) to obtain data on the rock crab, Concer antennarius. Weather permitting, the trop set program devised for each survey requires approximately seven consecutive days. Eoch of the trop set locations is fished for a 2413 hour0.0279 days <br />0.67 hours <br />0.00399 weeks <br />9.181465e-4 months <br /> period.

Upon retrieval of each trop, the following data are recorded: trop set location, coropoce measurement of individuals, determination of the sex and reproductive O condition of females (berried versus non-berried), and molt or intermoit condi-tion of crabs of both sexes. The specimens are tagged using a "Floy" onchor tog and are released in the immediate vicinity of capture. A " claw index" based on the presence or obsence and/or size of the chelipeds is recorded for each V individual.

Seasonal differences in growth, mortality, migration, and population densities are obtained for this species as a result of these detailed tagging and recapture methods.

2.11 SUBTIDAL FISH OBSERVATIONS Visual observations of fish at fixed subtidal transects provide documentation of the species composition and abundances of subtidal fish assemblages of the Diablo Cove area.

O V B-83-540 2-18

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A single transect is located at each station with the origin of the transect line positioned on the station monument and extending in a straight line for 50 m along a fixed cornpass course (the transect line is oriented from the surface and sunk to the bottom before divers enter the water). The currently active fish 6 observation stations have transect origins ranging in depth from 10 to 32 ft.

Each transect may be either horizontally oriented (extending generally along on isoboth and parallel to the shore) or vertically oriented (extending generally across isoboths and perpendicular to the shore). Observations are made by benthic and midwater observers along transects (FlGURE 2-5) during midday hours (0900-1500). A twc-meter distance was judged to be the maximum for accurate fish observations. To avoid the necessity of normalizing the data taken by a "visu=1 acuity side transect" method, transect observations are limited to fish sighted within 2 m on either side of the transect line and a transect is sampled only when at least 2 m lateral visibility is present, if time and conditions allow, sampling is repeated (replicated) once on each transect within each survey. Water temperature and lateral visibility are measured at each end point of a transect by both benthic and midwater j observers.

2.12 SUBTIDAL SET

• LING PLATES Subtidal settling plates installed nt the shallow subtidal (-10 ft MLLW) stations provide information on the species composition, abundance, distribution and biomass of fauna and flora that initiate biological processes and participate in community development on newly exposed substrates.

At each of the six station wheels, six vertica:ly-oriented asbestos plates (25.3 x 25.3 x 0.7 cm) are attached parallel to each other in a stainless steel rock. All plates are presoaked in freshwater for 30 days to leach out toxic substances.

Each rock is oriented so that its plates are positioned perpendicular to the incoming wave fronts. Two nylon electrical ties attached to one end of the rock identify the left end of the rock facing onshore. Side A of each plate faces left B-83-540 2-20

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m (toward the ties) while side B faces right. The plates are numbered I through 6 from left to right, and plates are sequentially replaced every two months.

In July of each year, all plates are replaced and new pfotes are installed (see FIGURE 2-6). Every two months, certain plates are removed from the rock, insuring the identification of sides A and e, and are piaced in individual buckets, and transported to the laboratory for analysis. A new plate is installed whenever a plate is removed.

In the laboratory, each side of the plate is photographed using Kodochrome color transparency film. A list is made of all taxa found on the plate edge and the outermost 2.6 cm of the plate surface. Any algo over 2.6 cm in length that could possibly offect settlement by sweeping spores and larvae off the plate is categorized as a " sweeper." The length of the longest individual of each sweeper species is measured and recorded. Edges and margins are then scraped clean of remaining material and another photograph taken of each side of every plate.

/,,% Using a seawater-filled chamber with a fixed grid system, an investigator pre-() cisely locates rondom sampling points on the settling plate face. The plate face is designated as that part of the plate located inside of the scraped margin area.

Because of the vertical orientation of the plates in the rock, it seemed likely that differential settlement of algoe and invertebrates would occur on the plates due to the varying light levels striking the plate surface. To minimize sampling error, the plate face is divided into three equal portions (" band levels," see FIGURE 3.4-3 in PGondE 1980). Sampling intensity was identical in each level.

To determine the abundance of taxo found on the plate face, two methods are used: (l) random point contact (RPC) for the macroscopic habitat formers, and (2) rondom 9 cm2 quadrats for the microscopic habitat-formers (individuals less than 2 mm in size). For each band level,100 RPC points and five quadrats are sampled, determined by randomly selected x and y coordinates. For the RPC method, o vertical line is passed through each coordinate and all " contacts" are O

V B-83-540 2-22

O .

MONTH k h j k l R " R* R--* R* R

• R---* R I E 2 R zR R

- 8 g3 R sR OR Z

, as 4 R P. :R

_: 5 R r R%R c.

6 R 2R Each month shown at the top represents a survey during which one, two or

!, six plates are removed from each rock and new plates are installed in their place (R).

t FIGURE 2-6 SEQUENCE OF SETTLING PLATE INSTALLATION AND REPLACEMENT O B-83-540 2-23 1

recorded. The quadrat method provides a visual estimate of the percentage O

Q cover of all individuals less than 2 mm in size. Frequency was recorded as being in one of the following categories: 1 (+ to l%), 2 (l+ to 5%), 3 (5+ to 20%), 4 (20+ to S0%),5 (50+ to 75%), or 6 (75+ to 100%). The above procedures are used for the plate faces on both sides A and B.

upon completion of the above sampling procedures, the plate is removed from the counting chambers, patted dry, and each band level scraped clean with the residue weighed to determine wet weight biomass. Dry weight biomass is then determined after oven drying at 100 C (212 F) for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

2.13 BULL KELP POPULATION ESTIMATES A census of the total number of bull kelp, Nereocystis luetkeana, individuals within Diablo Cove is conducted annually in October. Counts are obtained from permanently marked cliff-top vantage points in the north and south portions of Diablo Cove. Two investigators, stationed in north Diablo Cove, separately count, then average their totals of all bull kelp surface floats (pneumatocysts)

. O)

.( visible in the Diablo Cove sample area (FIGURE 2-l). Two other investigators stationed at the south side of Diablo Cove also count and average their Diablo Cove bull kelp float totals. The two team overages are averaged together for a final estimate of the number of bull kelp plants reaching the sea surface within Diablo Cove. Binoculars with a 7x magnification are used to aid in distinguishing individual plants. Spotting scopes with a greater magnification were also used -

during some surveys previous to 1983.

I In addition to counting, each team develops a map based on general agreement among the observers showir.g the areas in which bull kelp p; ants occur in Diablo Cove.

t Although smaller subsurface plants are not counted by this method, the fall timing of each census is coincident with the peak in surface occurring floats just before they are removed by winter storms. From 1970 to 1982 this study was conducted by the California State Department of Fish and Game. Starting in i (l v B-83-540

2-24

1 l

~

1983 this study has been continued Ly TEMP personnel. The position of the north and south Diablo Cove bull kelp cliff-top counting stations and the boundary lines delineating the Diablo Cove sample area are shown in FIGURE 2-l.

2.14 IN SITU TEMPERATURE MEASUREMENT Temperature recording instruments are placed at the + 2 ft MLLW level on the intertidal stations (FIGURE 2-7 and TABLE 2-1, see also Map B in pocket).

Identical instruments are also placed at the -10 ft (MLLW) subtidal stations (FIGURE 2-7 and TABLE 2-2, see also Map B in pocket.) Tiie data obtained supplement the biological data obtained at intertidal and subtidal stations.

Subtidal and intertidal temperatures are measured in situ at 20-minute intervals and recorded on magnetic tape using Sea Data TR-2 temperature instruments.

Temperature data are also recorded by the light and waveltide measuring instruments (see Sections 2.15 and 2.16, respectively). Temperature resolution is 0.01 C with an occuracy of 0.1 C. Instruments are exchanged at opproximately 45 day intervals with serviced and calibrated units. Tape records are processed and data transferred onto computer media for analysis and storage.

2,15 IN SITU LIGHT MEASUREMENT Light recording instruments are placed at subtidal stations 7-10, Il-10, and Il-15 (FIGURE 2-7 and TABLE 2-2, see also Map B in pocket). A land-based Solar Irrodiance Monitoring System (SIMS) is maintained on the cliff top approximately 1,650 f t southeast of the meteorological tower.

Quantum sensors (L1-COR Model L1-192S, underwater and Model LI-190S, cir) measure PAR (integrated light intensity from 400-700 nm) in units of micro-einsteins/m2/sec, I microeinstein being equivalent to 6.02 x 1017 photor.s. At the subtidal stations, measurements integrated over a 2-minute period are stored on magnetic tape at 20-minute intervals using Sea Data Model TLR-l instro-ments. Temperature data are also recorded at 20-minute intervals. At the terrestrial station, both integrated and instantaneous measurements are recorded

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4 2.16 IN SITU WAVE / TIDE MEASUREMENT Pressure sensing instruments are employed to record surface wave character-istics and sea level changes resulting primarily from tides. Wave data are secorded with a Sea Data Model TWR instrument located offshore Diablo Cove at station 99-30 approximately 760 m (2,500 ft) south-southwest from the power plant discharge point (FIGURE 2-7 and TABLE 2-2, see also Map B in pocket) at approximately 10 m below the surface (water depth = about 30 m). The 1

instrument records the percent of scale value (approximately 0 - 30 lbs/in.2),

i Every'six hours, the instantaneous value is recorded every 2.5 seconds until 127 readings have been made (at the 128th reading, temperature is recorded). Tide data are recorded with a See Data Model TDR-1 instrument located at the bottom at stations 9-10 (in Diablo Cove) and 32-32 (near the power plant intake structure) (FIGURE 2-7 and TABLE 2-2, see also Map B in pocket). The instrument records the percent of scale value (approximately 0 - 30 lbs/in.2),

1 Every 20 minutes, readings are integrated over a 2-minute period. The integrated measurements reduce variation caused by transient surface level changes. Temperature data are also recorded at 20-minute intervals. Both types of instruments are exchanged at approximately 45 day intervals with serviced and calibrated units. Tape records are then processed, the data converted to psi values and transferred onto computer media for analysis and storage.

B-83-540 2-27

3.0 MONITORING PROGRAM RESULTS O

Results of the 1983 field sampling studies are presenied in this section. In addition to reporting the sampling completion status for oli 16 subtasks, this section also includes analyses of the data for selected species from all biological sampling subtasks with the exception of the algal scraping and block abalone tagging subtasks. No abalone tagging activities were conducted in 1983. Data from the two algol scraping surveys are still in prccess. Representative analyses of the physical data (temperature, !ight and wave / tide) are also included in this section. This year's level of analysis extends that presented in the 1982 Annual Report and includes onclyses of additional subtosks. Data from the last (December) survey of 1983 were obtained too late for inclusion in the analysis prepared for this report. These data will be analysed in a future report.

During 1983 two extraordinary events cccurred: unusually severe storms during the first few months of 1983, and obnormally warm water temperatures through the 1983 summer. Very severe surf conditions lasting for relatively long periods of time from January through March 1983, resulted in marked alterations to the OA biological communities and physical substrate in both the intertidal and subtidal zones in many TEMP study areas. Observations and comments on these changes are presented in Section 4.l. Following the storms early in the year, seawater temperatures increased to unusually high levels during the spring and summer months. This temperature change was related to the periodic "El Nino" oceanographic condition. Water temperature data for this period ore presented and discussed in Section 3.14 in this report, and in summary form in Section 4.2.

In the following subsections, discussion of the biological dato includes reference to these unusual marine conditions where their occurrence may have produced changes in species: distributions and abundances.

/ 3.1 INTERTIDAL BAND TRANSECT (IBT)

Six intertidal band transect (IBT) surveys were completed in 1983 (TABLES 3-1, 3-2, 3-3). Five algol species (Endocladio muricata, Gastroclonium coulteri, Gigartino conoliculato, G. papillato and Iridaea floccido) and five invertebrate species (Anthopleuro elegantissima, Holiotis crocherooii, Collisello scabra, B-83-540 3-1 l

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SUMMARY

OF COMPLETED TEMP INTERTIDAL SAMPLING: + I FT (MLLW) TRANSECT 5 Algae Inverfebrates Band Point Algal Std. Inverts.

Survey Date " Precise" Transect Contact Scraping Count Count ,, D I""

No. No. No. No. No. tJo. No. No. No. No. No. . No.

Stations Quadrats Stations Quadrats Stations Quodrats Stations Quadrats Stations Quod ats Statior4 Quadrats 01 April 1976 15 450 16 48 15 45 IS 375 0 0 15 75 02 June 1976 15 450 16 48 15 45 15 375 0 03 August 1976 0 15 75 15 225 16 48 15 45 15 150 04 October 1976 15 75 15 75 15 225 16 48 15 45 15 150 05 December 1976 15 75 15 75 15 225 16 48 15 45 15 150 15 75 15 75 06 February 1977 15 225 16 48 15 45 15 150 15 75 75 07 May 1977 15 225 16 48 15 45 15 15 150 15 75 15 75 08 June 1977 7 105 8 24 7 21 7 70 7 GJ July 1977 35 7 35 7 105 8 24 7 21 7 70 7 35 7 35 10 November 1977 7 105 8 24 7 21 7 70 7 35 7 35 7

N 11 December 1977 12 February 1978 7a 105 7a 21 0 0 7 70 0 0 7 35 7 104 7 21 0 0 13 April 1978 7 70 i 5 7 34 9 135 10 30 0 0 9 90 1 5 9 45 14 June 1978 9 1:15 10 30 0 0 9 90 15 August 1978 1 5 9 45 9 l'!S 10 30 0 0 9 90 1 5 9 45 16 October 1978 9 12? 10 73 0 0 9 86 9 17 December 1978 1 5 43 9 135 10 30 0 0 9 90 18 February 1979 1 5 45 9 135 10 28 0 0 19 April 1979 9 90 l 5 9 45 9 135 10 30 0 0 9 90 20 June 1979 1 5 9 45 9 131 10 30 0 0 9 90 1 5 9 45 21 August 1979 9 135 10 30 b 9 90 l 5 9 45 22 October 1979 8 105 9 27 7 65 23 December 1979 9 1 5 8 40 135 10 30 9 90 24 February 1980 1 5 9 45 5 66 6 16 5 42 25 April 1980 1 5 5 24 9 90 10 30 9 45 1 5 9 45 26 June 1980 9 90 10 10 9 45 27 August 1980 9 I 5 9 45 90 10 30 9 45 5 28 October 1980 1 9 45 9 90 9 27 9 45 29 December I?80 1 5 9 45 9 90 10 30 9 45 1 5 9 45 30 Febroory 1981 9 90 10 30 9 45 l 5 9 45 t

Two stations outside of work plan were sompled.

b New subtask, see TABLE 3-II.

B-83-540

O- O O

, T ARLC 3-1

SUMMARY

OF COMPLETED TFMP INTERTIDAL SAMPLINC: +1 FT (MLLW) TRAtl5ECTS (CONTINtED)

Algae Invertebrates Bond Point Algol Std. Inverts. ' Precise" Survey Date Transect Contact Scroping Count Count T'9"I

No. No. No. Nc. Nn. No. No. No. No. No. th No.

Stations Quadrots Stations Ovoorots Stations Ovodrots Static <is Goodrots - Stations Quadrats Stations Ovoorots 31 April 1981 9 90 9 27 h 9 45 l 5 9 45 i 32 June 1981 9 90 10 30 9 45 1 5 9 45 33 August 1981 9 90 10 30 9 45 1 5 9 45 i 34 October 1981 9 90 10 30 9 45 I 5 9 45 35 December 1981 9 90 10 30 9 45 1 5 9 45 36 February 1982 9 90 10 30 9 45 1 5 9 45 37 April 1982 11 l10 12 36 11 55 I 5 11 55 38 June 1982 Il 110 12 36 11 55 1 5 11 55 g 39 August 1982 il llo 12 36 Il 55 1 5 II 55 g 40 October 1982 6 60 ll 32 6 30 1 5 6 30 41 Decerrber 1982 9 90 9 27 9 45 l 5 9 45 42 February 1983 8 79 9 25 8 40 1 5 8 39 43c April 1983 8 80 12 34 8 40 1 5 8 40 44 June 1983 12 120 12 34 12 60 1 5 12 60 45 August 1983 12 120  !? 33 12 60 1 5 12 60 46 October 1983 7 68 10 27 7 35 1 5 7 33 47 December 1983 10 100 9 26 10 50 I 5 10 50 b New subtosk, see TABLE 3-11.

c One quadrat on the 7+1 f ransect was replaced in survey 43.

l B-83-540

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TABLE 3-2

SUMMARY

OF COMPLETED TEMP ltJTERTIDAL SAMPLINC: +3 FT (MLLW) TRAN5ECTS Algoe Invertebrates Band Point Algal Std. Inverts.

Survey- . Date Taansect Precise" Centact Scraping Count Count "Tegul# -

No. No. No. No. No. tJo, No. No. No.

Stations Quadrats No. No. . No.

Stations Quadrats Stations Goodrats' Stations Quadrats - Stations Quadrots

, Stations Quadrots 01 April 1976 19 570 21 61 18 54 480 19 0 0 18 90 02 Jene 1976 19 570^ 21 61 18 54 19 480 0 03 August 1976 0 18 90 4 19 265 21 61 18 54 19 195 04 18 90 18 90 October 1976 19 285 21 61 18 54 19 195 05 December 1976 18 90 18 90

! 19 285 21 61 18 54 19 195 18 90 18 90 06 February 1977 19 285 21 61 18 54 19 195 i 07 May 1977 18 90 18 90 19 285 21 61 18 54 19 195 18 90 08 June 1977 0 0 4 18 90 12 0 0 0 0 0 0 0 0

. 09 July 1977 9 135 9 27 0 0 9 90 9 10 November 1977 45 9 45

0 0 4 12 0 0 0 0 t 0 0 0 0 F

11 December 1977 7a 105 7a 39 0 0 7 75 0 0 6 30 1 12 February 1978 7 105 8 22 0 0 j 13 April 1978 10 7 75 l 5 6 30 150 10 28 0 0 10 105 5 I i 14 June 1978 1 9 45 10 150 10 28 0 0 10 105 j 15 August 1978 1 5 9 45 10 150 10 28 0 0 10 105 1

I 5 9 45

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! 10 150 10 28 0 0 10 105 t

19 April 1979 1 5 9 45 10 150 10 28 0 0 10 105 I 5 9 45 20 June 1979 10 150 10 28 0 0 10 105 5 1 9 45 I 21 August 1979 10 150 10 28 b 10 105 l 5 9 45 22 October 1979 10 140 10 28 9 95 5 9 3 23 December 1979 1 45 10 150 10 28 10 105 l 5 9 45 d 24 February 1980 7 105 7 19 7 75 l 25 Apri! 1980 5 6 30 10 100. 10 28 10 55 5 9 1 45 l 26 June 1980 10 100 10 28 10 55 l 5 9 i 27 August 1980 45 10 100 10 28 10 55 I 5 9 45 l 28 October 1980 10 100 10 28 10 55 l 5 9 29 December 1980 45 10 100 10 28 10 55 I 30 February 1981 5 9 45

10 100 10 28 10 55 1 5 9 45 i

) o Two stations outside of work plan were sampled.

b New subtask, see TABLE 3-11.

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SUMMARY

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Algoe Invertebrates Bond Point Algol Std. Inverts. ' Precise" Survey Date Transect Contact Scroping Count Count T?b

No. No. No. No. No. No. No. No. No. No. - No.  %

Stations Ovodrots Stations Ouodrots Stations Quadrots Stations Quadrats Stations Quodrots Staticns Quadrats 31 April 1981 10 100 10 28 b 10 55 5 9 1 45 32 June 1981 10 100 10 28 10 55 5 9 1 45 33 August 1981 10 100 10 28 10 55 I 5 9 45 34 October 1981 10 100 10 28 10 55 I 5 9 45 35 Onember 1981 10 100 10 28 10 55 1 5 9 45 36 February 1982 10 100 10 28 10 55 I 5 9 45 3' April 1982 14 140 14 40 14 75 I 5 13 65 38 June 1982 14 140 14 40 14 75 5 1 13 65 w 39 August 1982 14 140 14 40 14 75 l 5 13 65 g 40 October 1982 ll l10 11 31 ll 60 1 5 10 50 Al December 1982 10 100 10 28 10 55 I 5 9 45 42 February 1983 9 90 9 24 9 50 1 5 8 40 l

43c April 1983 14 140 14 39 14 75 1 5 13 65 1 44 June 1983 15 150 14 39 15 80 1 5 14 70 45 August 1983 15 150 14 39 15 80 1 5 14 70 46 October 1983 12 120 12 33 12 65 1 5 II 55 47 December 1983 13 130 12 23 13 70 1 5 13 60 b New sub:ask, see TABLE 3-11.

c Three quadrots on the 7+3 transect were replaced in survey 43.

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B-83-540 3-6

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+

1 O B-83-S40 3-7

Poaurus spp. and Tegula funebralis) that are dominant or otherwise important were selected for analysis. For each species the mean abundance (percentage cover for the algae, number per m2 for the invertebrates) was calculated from

' the ten quadrat samples for the +1 and +3 ft transects for each survey for selected Diablo Cove stations. In the 1982 Annual Report, the results from data collected from 1976 to 1982 were presented. in this report, the results were extended to include data col!ected through October 1983.

I 3.1.1 ALCAE This section includes analysis of the data collected on five algal species within ten m2 uadrats q on each band transect. These species are Endocladia muricato, Gastroclonium coulteri, Gigartina conoliculata, G. papillato, and Iridaea flaccida. Earlier progress reports (LCMR 1978, PGanE 1978) presented preliminary evaluations of the abundance of the major algal species within TEMP band transects for the first year sampling effort (surveys I to 7). Algol percentage cover summaries for this one-year period (April 1976 to May 1977) indicated that 1. flaccida, G. canaliculata, and G. coulteri were among the ten

most abundant species at the majority of low elevation (+l f t MLLW) study sites, whereas l. flaccido, G. papillata, and E. muriccto were commonly ranked among the ten most abundant species at high elevation (+3 f t MLLW) study sites.

! Seasonal variations in abundance for these species from April 1976 to August 1979 were presented by LCMR (1978) and PGanf (1977,1978,1980). In PGanE (1983) seasonct abundance descriptions for these species included data collected up to October 1982. Newly analyzed in this report are dato collected from

( October 1982 to October 1983 for the five algal species. Together with the

! results presented in laat year's report, these results provide a continuous record from April 1976 to October 1983.

Visual observations indicate that Endocladio muricata, Gastroclonium coulteri,

[ Cigartina canaliculata, G.pcpillata, and Iridaea flaccida still remain among the

most abundant algal species within most TEMP study sites. For these species l data from stations 8,9,11,12, and 14 were analysed for seasonal variations for B-83-540 3-8 4

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, the period April 1976 to October 1983 (surveys I to 46). Survey data have been summarized using mean percentage cover values. These values have been calculated from untransformed visually estimated percentage cover data obtained within ten I m2 uadrats q per band transect. The results are organized on a species-by-species basis and are presented below. Percentage cover, measurements obtained using the random point contact method within fixed 0.25 m2 quadrats are presented for these same species in Section 3.2 of this report.

0 3

3.1.1.1 ENDOCLADIA MURICATA Endociadio muricato is the most common alga in upper intertidal habitats in centrol California (Abbott and Hollenberg 1976) including Diablo Cove and vicinity. This low (4-8 cm tall) densely shrubby alga forms clumps or mots on the tops and vertical faces of rocks.

Mean percentage cover data for this species within the +1 and +3 f t Diablo Cove transects are presented in FIGURES 3-1 and 3-2, respectively. Because of its high intertidal distribution, this species was nearly lacking in most +1 f t

transects. This was also true for the wave exposed station 14+3. Seasonal peak

abundances in the +3 ft transects at stations 8,9 and 12 generally occurred in the February to June period each year. Station 12 became completely buried under fragmented rock after the severe 1982-1983 winter storms; consequently, i

the abundance of Endociadio at the +3 ft transect of this station declined and did I

not recover substantially by the following spring and summer. Similar storm effects were evident for this species at station 8+3 where a portion of this transect became buried under sand. A marked drop in percentage cover also occurred at station 11+3. -

3.1.I.2 GASTROCLONIUM COULTERI 4

Literature on Gastroclonium coulteri was reviewed and presented in or earlier report (PGanE 1979). This moderately large, shrubby red alga grows up to 25 cm or more in length. The often densely clumped branches arise from a thick i

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B-83-540 3-1I

mot-like stolon system which can trop and stabilize sand. In the intertidal region of Diablo Cove and vicinity, G. coulteri is most abundant in the mid to lower zones (Burge .and Schultz 1973, LCMR 1978, PGanf 1978).

Within Diablo Cove mean percentage cover values for this species never exceeded 30 percent in the +1 f t transects (FIGURE 3-3) nor 10 percent in the +3 f t transects (FIGURE 3-4). Vnriations in abundance within transects through time do not exhibit consistent seasonal patterns. Winter 1982-1983 storm effects were evident at stations 8+1, and 12+1. Abundances at station 8+1

, declined as a result of sand scour on the low relief bench-rock portion of this station, and did not recover by the following spring and summer probably because of continued sand abrasion or lack of sufficient surviving plant material to create measureable increases in cover by plant regrowth. A sharp decline occurred at station Ii+1 probably as a result of sand abrasion. Abundances declined at station 12+l as a result of cobble burial. Periodic cobble movement at station 12+1 has hindered G. coulteri from becoming re-established. Storm damage to G. coulteri was not evident at station 9+1. This station is higher in substrate relief and has less sand. Plants here are thus less susceptible to continual sand scouring effects compared to piants growing on low relief bench-rock areas such as the upcoast portion of station 8+1.

3.1.l.3 GIGARTINA CANALICULATA A review of the literature on Gigartina canaliculata was presented in a previous report (PGanf 1979). This species consists of narrow branches arranged in a

" Christmas tree-like" pattern. Abbott and Hollenberg (1976) state that the erect branches of G. canaliculata are annual, being produced by perennial basal branches. The life history is quite different from that of G. papillata (see the following section) in that the generations of G. canaliculata are identical in

, morphology. G. canaliculata is generally found only in low intertidal habitats.

G. papillata has a wider vertical range and can be found in both low ond high intertidal zones.

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00000^e0000rcc0000000000000000000000 R . 1 I . I i 1 . . . I . i . . R , R , I .I I I I I I STATION 14 2 -

. W

,s........

o I I I I a a a e a 3 . t , t , t . . . . 1 E E , O I I I I I I I 1976 1977 1978 1979 1980 1981 1982 1983 1964 TIME ITEARS) h; . FIGURE 3-4

---

sa.p!,no Inte-<al > 2 Monthe v

ABUNDANCE VERSUS TIME FOR CASTROCLONIUM COULTERI AT +3 FT MLLW (IBT METHOD)

B-83-540 3-14

Mean percentage cover values for G. canaliculata within the +1 and +3 f t Diablo

" Cove transects are provided in FIGURES 3-5 and 3-6, respectively. Like many other algal species, the abundance of G. canaliculato is usually greater during the spring to fall periods. This is evident primarily in the +1 ft transects where cover is generally greater than 10 percent (FIGURE 3-5). Winter 1982-1983 storm effects were observed for this species primarily at station 12+1 which became buried under cobble (fragmented rock). Recovery has probably been hindered due to periodic cobble movement.

3.1.1.4 GIGARTINA PAPILLATA The life history and general ecology of Gigartina papillata was presented in a previous report (PGandE 1979). The gametophytic plants of this species appear as short (15 cm tall) irregularly shaped blades. The alternate tetrosporeghyte generation has been described as a crustose plant formerly placed in the genus Petrocelis. Seasonal abundances of only the erect blade form (gametophyte generation) plants of G_. papillata are presented and discussed in this section.

n l Mean percerioge cover values within the Diablo Cove +1 and +3 f t transects are plotted in FIGURES 3-7 and 3-8, respectively. At each station this species was generally more abundant in the +3 ft transects. Annual cycles with peaks during the summer months were evident in most transects. Gigartina papillato at station 14+3 occurred in only a few quadrats and in sparse abundance.

Consequently, there were no obvious seasonal changes in cover for this species at this transect. The 1982-1983 winter storm damage (cobble inundation) at station 12 dramatically reduced G_. papillata cover in both the +1 and +3 ft transects.

Similarly, but due to sand scour, the abundances of G. papillata in both transects l

j of station 11 were reduced. During the following spring-summer period, a large portion of the G. papillata population in all study areas were observed to be in a l

bleached condition. This was coincident with the abnormally warm water temperatures.

O B-83-540 3-15

STRTION 06 8 _

O -

,~

sn

%J

~~

Q

. . . . 1 E t e 1 8 . D t a 0 0 2 1 i i I i t t t . . I t a e e i e g STATION 09 8

q1 8 -

t W e...

g O g . . . . . . . . . . . . . , ,u. . . . . . . . . . . . , , . , , l 57flTIOf 11 E 8- .

a.

e E

8 y 8 -

5

=

0 o

i . , , . . . , , . . , , . . , , ,, , , , . , , , , , , , , , . . . .

w M _

STATION 12 E 2 -

E E .

x  :

E i x l an l

l o

. C^^

. I I l . I t . 1 I E 1 B 3 . . 1 I i 1 . 1 R , f A I E 1 I E a E 1976 1977 1978 1979 1980 19e1 49e2 1983 1984 i!NE ITEnf1S ) ---- Scept en0 Interval

• 2 Months FIGURE 3-5 ABUNDANCE VERSUS TIME FOR GIGARTINA CANALICULATA AT +1 FT MLLW(IBT METHOD)

B-83-540 3-16

STAT!DN 08 2 . .

m -

f-

, n' t t . . t . . . f . I f f , t , i f . O f 9 f . f I 8 I E I I I I I I STATION 09 o . l O,

l ,

q m -

• w w

w E

w e ,

E o g . . , , , . . . . . , , . , , . . . . . . . . , , . . . . . . . . . .

STATION 11 e

w o.

e .

e w

c O

m "

e w

Z

.w u

e 1 o OOOOdO 09 d00000d000^O000000000000000000000000 y . . . . . . , , , . . . . . . , , , , . . . . . . . . . . . . . . . .

w M STATION 12 e o o "

Z D

00 C

Z C

w E m -

o y

,p....

1. w - -

h w w m

- w - - -- 4 m

, . , , . . . 1 i . . . 1 i e i . i a e i a a i 1 a e ' ' '

STATION 14 o .

I m -

's' .......

+ ........e c c c y

. . . . 1 1 . . 1 I . f . . I

. . t . . . . I 1 . . i 1 E i 1 I I 1977 1978 1979 19ec 1981 1982 1963 1984 1976 TIME ITEARS1

-~~~

8"'""'*""*"*"'"'

O ABUNDANCE VERSUS TIME l'OR GIGARTINA CANALICULATA FIGURE 3-6 AT +3 FT MLLW (IBT METHOD)

B-83-540 3-17

STATION 08 E -

io

(, -

's 4

o s e t A E f A i I I I 1 1 f R l E I f I 1 I t E I E E E I E I I 2 STATION 09 R -

Tc -

W W

~ '

. .O

..'e e o g , , , , , , , , . . . , , . . . , , , , , . . . . . i . . . > i m

STATION 11 E8

a. -

c o

u

=

8 -

>=

2 b)

\

L*

W M

M STATION 12 8

Z 8

3 m

C Z

C o

m a

o w w -

. I E I E f I I E 1 A I I a 1 E g g g n a E a I f a 1 1 I I I I A E A 1976 1977 1978 1979 1980 1981 1982 1983 1984 TIME (TEARS) _ _ _ . 3..,1,no ine sevat > 2 monens FIGURE 3-7 ABUNDANCE VERSUS TIME FOR GIGARTINA PAPILLATA i AT +1 FT MLLW(IBT METHOD)

B-83-540 3-18 L

ST47 ION 08 8 .

i I

O J

./] -

w/

l ,

G o

n . A E f 1 A . 1 1 . 1 1 . I . . I 1 . . t . I I I I A E 1 . I E i STATION 09 8 -

O q m -

a w

w w

2 O g . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . , , .

<n STATION 11 E O W o -

L -

t W

c u

W O o m -

E E

W Q- &o n

_~A .A__ n fn n, . _ . A.

O g STATION 12 o

z 8 -

"3 to C

z 2

w E O .

p.

l '.~

O - -

. . . . . i i i i , i i i . . . > i i

. . . , , . . . . . . . . . .a STATION 14 m -

1 O ,?C  ? CC CC?CC?CCCC TCCC ?CCCCCCC?CC ?C? . . , ,

i . . , , . . . . . . . . . . . . . , , i . . . . . . .

1 1976 1977 1978 1979 1980 1961 1982 1983 1984 TIME ITEf1RS) - - - - so.,r,,,rei.~ ol , 2 no,in.

v' FIGURE 3-8 ABUNDANCE VERSUS TIME FOR GIGARTINA PAPILLATA AT +3 FT MLLW (IBT METHOD)

B-83-540 3-19

O 3.1.1.5 IRIDAEA FLACCIDA V

A review of. the literature and synopsis of pertinent knowledge on Iridaea flaccido was presented in a previous report (PGoncE 1979). Plants of this red algal species consist of a perennial crustose holdfast from which several blades grow each year to as much as one meter in length. It is one of the most 1

conspicuous and common blade-like red algae in the centrol California mid-intertidal zone (Abbott and Hollenberg 1976}. Cover data for 1. flaccido reflect almost entirely the abundance of the blades because the crustose holdfasts occupy relatively little area.

Mean percentage cover values are plotted for the Diablo Cove +1 and +3 f t transects in FIGURES 3-9 and 3-10, respectively. Excluding station 14, which lacks a +1 f t transect, at any given station this species was more abundant at the

+1 than of the +3 f t transect. In o!! transects, seasonal abundances were greatest during the summer periods. The magnitude of change between seasons in most transects has been quite large. Roughly two-to-three fold differences between maximum summer and minimum winter cover values were recorded. At 4

station Il+3 the abundance of Iridaea flaccida has been sparse since 1976, and thus large seasonal changes in cover were not evident. Like other algal species discussed above, the abundance of l. floccido at station 12 was noticeably reduced when cobbles covered the area during the 1982-1983 winter storms.

i Subsequent spring-summer recovery was hindered by periodic cobble movement.

Seasonal abundance patterns for this species in oli other transects were not appreciably altered.

3.1.2 INVERTEBRATES This section includes analysis of the data collected on five invertebrate species within either five or ten I m2 quadrats (depending on the species) on each band l

transect. These species are Anthopleura elegantissima, Holiotis crocherodii, i Collisella scabra, Pagurus spp. and Tegula funebralis. For each species the mean abundance (mean number per m2) is plotted for each transect from April 1976 to October 1983.

O B-83-540 3-20 i

STATION 08 o

8 -

N, o

R R I 9 I i I I I E i E I E i I I I I E I I I E I I I I E l l f B STATION 09 8 -

T W0 -

!? ~,

- 's ,

O v3 o i i ' i

, , , , , , , , , , , , , , , , , . . . i i i . i i . . = a a e

y STATION 11 ,

c O -

w Q

u W

O s e -

Z w

U c

w i

, 4 w o _. , , , , , , ~, , , . . , i i . . i i i i i e i i i i i i ' ' ' ' ' '

g ,/

E STATION 12 5 8_

g -

2 2

w r

0 -

o ~ ~OC C

, , , , , , , , , , , , , , , . . . i i . . . . - i e i i > '

• i ' '

1977 1978 1979 1980 1983 1982 1983 1984 1976 TIME (TERRSI

- - - - Sampt ing Interval > 2 Months e

Is FIGURE 3-9 ABUNDANCE VERSUS TIME FOR 1RIDAEA FLACCIDA AT +1 FT MLLW (IBT METHOD)

B-83-540 3-21

STATION 08 1 8

l 1

i

~

V D ~~..

t I a R t t t t t a f I I E R R I f i t I f f f 9 I E I I I I I E 8 E STATION 09 T o -

w w

w r

• G'~...;

o o o . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

m e STATION 11 w

a. O, .

c w

a Q

u w

o m -

c w

z w

u N-o 000000 00

$O00000 O' b OOOOOOOd M OdOO W W

M STATION 12 2 o o o .

= -

m cc c

2 e

w O r -

o 00OOO R I I t I t I t a f A I E i t t 3 i I t i a R H E I I E I E I I I I I STATION 14 o '

m -

's ,

\,

,G .,....., -

s r

o R R I g 1 I t A E I E 1 0 1 1 1 I t I i t i g g 3 a 1 9 I . I I b I 1976 1977 1978 1979 1980 19el 1982 1983 1984 TIME ITEARSI

(_) FIGURE 3-10 ---- so.,1,n,ine. ~ .: > 2 nonin.

ABUNDANCE VERSUS TIME FOR 1RIDAEA FLACCIDA AT +3 FT MLLW (IBT METHOD) *'

B-83-540 3-22

l 3.1.2.1 ANTHOPLEURA ELEGANTISSIMA Anthopleuro.elegantissima, the aggregating sea onemone, is distributed in the middle intertidal zones from Alaska to Baja California, Mexico (Morris et al.

f 1980). A. elegantissima exhhits two distinct forms in the intertidal zone:

aggregating and solitary individuals. Aggregating individuals are usually small and occur in Anse groups of up to several thousand individuals per m2 The large solitary Anthopleura can attain a maximum width across the tentacular crown of 25 cm. An extensive review of the biology of Anthopleuro was presented in PGondi (1979).

FIGURES 3-1l and 3-12 summarize the mean abundance of A_. elegantissimo in the five "Tegula quadrats" of the Diablo Cove stations from surveys 3 (1976) to 46 (1983). There are generally more A_. elegantissimo at the +3 than at the +1 ft level for all surveys combined (TABLE 3-4). The onemones at stations 8+3, i1+1, 11+3, and 12+3 are the aggregating form, whereas those at stations 8+1, 9+1, 12+1 and 14+3 are solitary individuals.

O The wide differences seen between the number of Anthopleura of the Diablo Cove stations are probably partially due to the variations in the station tidal height and degree of wave exposure. Ricketts et al. (1968) and Morris et al.

l (1980) state that A. elegantissimo is mainly found in semiprotected, rocky, l middle intertidal creas. Sebens (1982), working in Washington state, found higher densities of A. elegantissimo in the upper intertidal than in the lower zones; the larger anemones (solitary individuals) were usually in the lower intertidal. A similar situation is seen at the Diablo Cove intertidal stations.

1hree of the cove stations, (8+3, Il+3, and 12+3) generally exhibited lower abundances of onemones during summer months. Large fluctuations between surveys were seen in the number of individuals at station i1+3 which is covered by sand on many surveys and uncovered on others.

The severe winter storms of 1982-1983 had little effect on Anthopieuro of the

+1 f t level in Diablo Cove, as shown in FIGURE 3-il. A reduction in their O

B-83-540 3-23

STSITION 08 3 -

m -

f !i l W o

STATION 09 S -

m -

t'w '

O 3 I OOdC Z O 000000000000 0000000000d0000 d- -% O I E I E E I I I I i 1 I E I I a t k I 1 I i 1 I f i 1 E A I 1 1 R w

e E

D o ,

n C

w A

E w

am E

D 5

w l z V E z

S STATION II 8 -

C w

E o \

g

\

1 i

l O

E E A I 1 e i 2 e i I e I E E I I I E k i B 1 1 E I i 1 E A I 2 I I I STATTON 12 S -

m -

O ,

I a b a a 1 I t I t t t t i I a I t d I t i e a t i 1 E A A R 1 R A i 1976 1977 1978 1979 1960 1981 1982 1983 1984 t

l TIME (TERRS)

( FIGURE 3-11 ---- so.,:,,,rne. ~ o: > 2 a.,en.

ABUNDANCE VERSUS TIME FOR ANTHOPLEURA ELEGANTISSIMA AT +1 FT MLLW(IBT METHOD)

B-83-540 3-24

STATION 08 r

O

• ' ~

g.  %

O

, , , , , , , , , , , , , . . . . . i e a i = ' ' ' ' ' ' ' ' ' ' ' '

STATION 09 2 -

m -

c' w

+-

gm m__

$ 0

, , b, , ,

,' _ . . . .h e - _A m^ ^^^ ? ^^^^^

, , , , , , , ,i . . . . >

a M 00d00000

= ' ' ' ' ' ' ' ' ' ' ' '

E STATION !!

$ o g -

e w

L E s Q b'O ...

[

u O

, , , , . , , . . . . . , , , , , , , , , , , , , , , i i a a n ' '

$ STATION 12

$ o O .

. ..e

[ g,' .,

i ., /

0 -

-l  :

g' i(\

O STATION 14 2 -

,D.

t-s,

\- '

1976 1977 1978 1979 1960 1981 19e2 1983 1984 TIME (TEMS) ----

u. Ne > 2 we

, q,,) FIGURE 3-12 ABUNDANCE VERSUS TIME FOR ANTHOPLEURA ELEGANTISSIMA AT +3 FT MLLW (IBT METHOD)

B-83-540 3-25

)

O l TABLE 3-4  :

MEAN ABUNDANCE OF l ANTHOPLEURA ELEGANTISSIMA IN THE IBT "TEGULA QUADRATS" FOR THE DIABLO COVE INTERTIDAL STATIONS FROM AUGUST 1976 (SUP.VEY 3) TO OCTOBER 1983 (SURVEY 46)

Mean 2 Number of Station Abundance Std Surveys Level +1 (number /m2 ) Error (N) 08 2.5 0.5 43 09 0.0 0.0 39 11 40.2 4.1 44 12 2.2 0.4 44 Mean 2 Number of Station Abundanc Std Surveys Level +3 (number /m ) Error (N) 08 27.7 3.3 42 09 0.1 0.1 42 ll 176.8 23.1 42 12 71.2 7.7 42 14 1.5 0.3 35 O B-83-540 3-26

(] abundance at station i1+1, with the highest mean abundance of onemones for V this tidal level of the Diablo Cove stations (TABLE 3-4), occurred during the summer surveys of 1983.

At the +3 ft level, stations 8, II and 12 showed a reduction in abundance of Anthopleura following the 1982-1983 winter storms. This reduction was a result of sand cover in a few "Tegula quadrats" of stations 8 and i1 and the more extensive perturbations sustained at station 12, as described in detci! in Section 3.1.1, above.

3.1.2.2 HAllOTIS CRACHERODil Black abalone, Haliotis cracherodii, typically inhabit the rocky intertidal and subtidal regions to o depth of 3 m (20 ft) from Oregon to Baja California, Mexico in the intertidal they are usually found along ledges and in crevices; in favorable habitats they are commonly found clustered together. In and around Diablo Cove, black abalone was observed to be one of the most numerous and conspicuous of the intertidal invertebrates (Burge and Schultz 1973, Gotshall et al.1974, North et al.1975). Burge and Schultz (1973) reported that block abalone are more abundant than red abalone (H_. rufescens) in the low intertidal at 0 to -2 ff MLLW. They recorded a mean black obalone density in north Diablo Cove of 2.7 individuals /m2based on observations along two intertidal transects.

More detailed information on the biology of black abalone in the Diablo Canyon study area was presented in PGondE (1979).

FIGURES 3-13 and 3-14 summarize the mean abundance of Haliotis at the five Diablo Cove study stations. It should be noted again that abalone were counted in all 10 quadrats of the band transects, not only in the five "Tegulo quadrats" as were the other four invertebrate species.

As shown in TABLE 3-5, the range of mean abundances of black abalone is from a minimum of no obalone ever observed at station i1+3 to a maximum of 5.8

.J B-83-540 3-27 i

.m. ._. _ .,-,-.,.-c_y_ .

- ,-%_ _. ,,-, . ,.,. ,, __,,-_..y y-_. . - r... ..r.,_,..-y-- ,_ __ ._ - . _ . ,_

STATION 08 2 -

m -

)

J

's s O

, , , . . . . , , . . . . . . . . . . . . . i i e i i = * ' ' ' ' ' a_

STATION 09 2 -

m -

N '

w o -

'.'n.* m r - - i i . r i * - e a i i ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' '

y e

C 3

o m

m W

L m

w as r

n 5

R y (J =

Z 3 STATION I!

m C O -

=

C w

E e -

p_=m m 4. . _ e m a- - ~

W. - ^

,, ",- ,',", , . , . . . . . . . . . . . e a i = ' ' ' ' ' ' ' ' ' ' '

S T AT T LIN 12 2 -

1 I

l m -

o 000 0d 0 7 ,

^^9^^^^^O' 000d00000d00000d00000 1976 19i7 1978 1979 1920 49fa 1962 1963 1984 TINE (TERRSI N ---- Sampl ena Inteeval

• 2 Months d FIGURE 3-13 ABUNDANCE VERSUS TIME FOR HAllOTIS CRACHEROD!l AT +1 FT MLLW(IBT METHOD)

B 83-540 3-28

STATION 08 O.

(T

\-mj! a -

, n--x.-m . . d ~ ~ - - ~s . w _ _ _ Mh . . # -w _ . h - _ _ _ _mmm-STATION 09 O _

m -

43' f

w O o E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

W e

e STATION ff m O o -

n e

W L

e w m -

m r

n Z

w a Z g

O 0000d000 dOOOOOdOOOOO^OOOOOdOOOOOdOOOOOdOOOOO s ,y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5 STR7f0N 12 m

e O Z

e w

r m -

, m-n --n n- - --n an - a _- u n - n - d _- nK n n n n n

. . . . . . . . . 1 . . . . . . . . . . . . . . . a . . . . . . . . .

STATION f4 o.

. **b" -.. 5..

. . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . .

1976 1977 1978 1979 19ec 19el 1922 1983 1984 TIME (TERRS)

---

h Ne > 2 we

\_/ FIGURE 3-14 ABUNDANCE VERSUS TIME FOR HAllOTIS CRACHERODil AT +3 FT MLLW(IBT METHOD)

B-83-540 3-29

, TABLE 3-5 l MEAN ABUNDANCE OF HAllOTIS CRACHERODil IN THE lBT OUADRATS FOR THE DIABLO COVE INTERTIDAL STATIONS FROM MAY 1976 (SURVEY l} TO OCTOBER 1983 (SURVEY 46)

Mean 2 Number of Station Abundance Std Surveys Level +1 (number /m2) Error (N) i 08 2.1 0.4 45 09 2.3 0.5 41 ll 0.2 0.1 46 i2 0.1 0.l 46 Mean 2 Number of Station Abundancq Std Surveys Level +3 (number /m') Error (N) ,

08 0.2 0.1 44 09 3.1 0.3 43 11 0.0 0.0 44 7

12 0.1 0.1 44

, I4 0.7 0.I 37 i,

I B-83-S40 3-30 l

. . -. ,, .- - , . . - . . - - . , - , - - - . . , , - - - - - - - ---~~---v - - - - - - - - - - - - - - ~ - * ' ' ~ - " ' ' ~ ~ ' ~ * '

_- - .. -. = - .- .

obolone/m2 during December,1979 at station 9+3. This table also shows that l stations in south Diablo Cove have o very low mean abundance of abalone compared to,the stations in north Diablo Cove. Mean abundance for Haliotis at station 14+3 lies between these two extremes.

Good abalone habitat is exposed to moderate to extreme wave shock, usually has moderate to high substrate relief with many cracks, crevices or under-boulder areas, and is in an area of adequate food supply. However, predation by man and/or sea otter may reduce the numbers of abalone from areas which are l otherwise suitable habitat. The degree to which the present distribution of block abalone in Diablo Cove reflects predation pressure is at present unknown. The decreases in mean abundance of the abalone at stations 8+1,9+1, and 9+3 after 1979 are very likely the result of sea otter predation. The sharp decrease noted

! at station 8+1 between August and December 1979 probably resulted from predation on a high density of abalone in a relatively small crea (about 2 m2),

One otter feeding for a few days or a week in this area could reduce the number of abalone significantly (Benech and Colson 1976).

!O The abundances of black abalone on the Diablo Cove intertidal stations have not changed significantly from those presented in lost year's report. However, many abalone were observed either dead or with badly damaged shells in the intertidal '

areas of Diablo Cove immediately following the worst of the winter storms of 1982-1983.

l 3.1.2.3 COLLISELLA SCABRA Collisello scabra, commonly known as the ribbed or rough limpet, occurs from i

Oregon to Bajo California, Mexico. They are found in the upper rocky intertidal l and splash zones, and prefer horizontal surfaces and gentle slopes. Maximum length is 35 mm (McLean 1978), and the largest individuals at Bodego Head, r California, have been estimated to be 11 years old (Morris et al. 1980). This l

l t

i O B-83-540 3-31

limpet feeds by grazing on thin films of algae and diatoms during high tide, and V

then returns to a specific "home site" where it remains during low tide.

FIGURES 3-15 and 3-16 :uminarize the mean abundance of C. scabra in the five "Tegulo quadrats" of the five the Diablo Cove stations from 1976 to 1983. There was a greater abundance of C. scabra at +3 ft than at +1 f t, except at station 14+3 which had only a few individuals per m2 TABLE 3-6 presents the mean number of C. scabra per m2 in the "Tegulo quadrats" for all surveys combined.

The differences in abundance of C_. scobra between the two levels reflect the preference of these limpets for rocks in the upper intertidal zone. All of the

+1 f t transects and station 14+3 are submerged more often than the cther +3 ft transects, and C_. scabra is not adopted to survive in these wetter areas.

The 1982-1983 winter storms generally reduced the abundances of C. scabra at stations 8+3, i1+3,12+3, and 12+1, probably as a result of burial of one or more "Tegulo quadrats" by sand or rock rubble At station 8+1 C. scabra increased O

\'J sharply in abundance probably as a re ult of a large number of newly settied limpets coloairing the sand-scoured substrate.

3.1.2.4 PAGURUS SPP.

Three species of Paqurus comprise the common intertidal hermit crab populo-tions in the Diablo Cove study areas. Pogurus samuelis, probably the most common and abundant species, ranges from Vancouver Island, Canada, to Baja California, Mexico. Within this range P_. samuelis is usually found in the middle intertidal zones. Pagurus hirsutiesculus, with a range from northern Japan through Alaska into southern California, generally lives in lower intertidal zones than P_. samuelis, but the populations overlap. The third common hermit crab species is P. granosimanus. These hermit crabs are found in tide pools and the more protected creas of the lower middle to low intertidal and subtidal areas from Alaska to Baja California, Mexico.

O B-83-540 3-32

STATION 08

, i O -

an O i l

. .m a dM ,,,,,,,,,

- - ... i . ... . ,, ,,,,,,

STATION 09 2 -

m -

m e .

o O'OOO" W OOO

...=...........................,,,

O^OO '080000000 N# 00

= . .

w w

C n

O n

c w

L e

w m

x n

5 w

l

~

u 6 z G

i V o z

3 S'RTION 11 D O c- o _

Z C

w r

3 -

- 1 I E E E i R R I A 1 a I

. 1 E i a 1 . . A i 2 i E 1 I E a i i R 1 t i STATION r2 8 -

E -

% ;. A h A K d . A E I A B A 1 I 1 2 I I d R R R I 1 9 A A I 1 A E 1 A a E I E R R R I 1977 1978 1979 1980 1981 1982 1983 1984

1976 TIME (YEARS) ---- S amp! ng Int erval > 2 Months p

td FIGURE 3-! 5 ,

ABUNDANCE VERSUS TIME FOR COLLISELLA SCABRA AT +1 FT MLLW(IBT METHOD)

B-83-540 3-33

. - - - - - = _ - . _ - - - . -.

STATf0N 08 o

• o.n . ,

a

,0**** '

o stall 0N 09 S -

2 0 9 ~~~~'

y . . .. i,,,...,,,,,,,,,,,,,,,,,,,,,,,

cr g ,

STATION !!

" g .

e W

sk e

W 2

a

~

q ..

m u

g g o ,.... y

) E 3

co C STATION 12 z 8 -

e -

tu E

o

= - ,P ... .,

h o -

i l STA7!ON 14 2 -

I , -

,e, , N, .

t .

? ~, ,

. .. t l

l o

_jf ,,,,,.'.......,', i ~,_

.,,...,,.'*........ ~~ 2 r , ,

1976 1977 1978' 1979 19ec 1921 1982 1983 1984 TIME ITEARS) ----

so.eline Interval > 2 Menens FIGURE 3-16 ABUNDANCE VERSUS TIME FOR COLLISELLA SCABRA AT +3 FT MLLW(IBT METHOD) l B-83-540 3-34 l

l L

O TABLE 3-6 MEAN ABUNDANCE OF l

COLLISELL A SCABRA IN THE IBT "TEGULA GUADRAT5" FOR THE DIABLO COVE INTERTIDAL STATIONS FROM AUGUST 1976 (SURVEY 3) TO OCTOBER 1983 (SURVEY 46)

Mean 2 Number of Station Abundance Std Surveys Level +1 (number /mt) Error (N) 08 II.7 4.8 43 09 0.1 0.1 39 ll 11.7 3.2 44 12 6.2 3.3 44 Mean 2 Number of Station Abundanc Std Surveys Level +3 (number /M ) Error (N) 08 26.2 7.3 42 09 17.1 3.3 41 11 60.1 10.1 42 12 35.1 S.S 42 14 1.3 0.S 35 i

i B-83-540 3-35

i p Although the adults of these three species are not too difficult to identify to the V species level in the field, the juveniles are very difficult to separate taxonomi-cally. Becayse juvenile hermit crabs are ubiquitous in the intertidal zone, no attempt has been made to separate the species and all three species are recorded as "Pogurus spp."

FIGURES 3-17 and 3-18 summarize the mean abundance of hermit crcbs in the five "Tegulo quadrats" at the Diablo Cove stations from 1977 to 1983. TABLE 3-7 presents the mean number of Pogurus/m2 for all surveys combined.

On the average, the abundance of Paqurus at +1 f t is greater than at +3 ft, except at station 12 where abundance was greater at +3 f t. Pogurus are found at all stations, usually throughout the entire year.

The abundances of Pagurus spp. during the 1983 surveys have changed little from previously sampled abundances in Diablo Cove (PGancE 1983). At +3 f t, overall abundances appear to have dropped slightly in 1983 as compared to previous years.

3.1.2c5 TEGULA FUNEBRAllS The black turban snail, Tegulo funebralis, occurs from Vancouver Island, Canada l to central Baja California, Mexico (Morris et al.1980). Within this range, T.

I funebralis occurs in the intertidal zone with its greatest population densities generally between the +1 and +5 f t tidal levels. These snails are primarily herbivorous and feed on microscopic algol films, attached fleshy algae and drif t algae.

l l Within the Diablo Canyon study areas, the black turban snail is the most ubiquitous and abundant animal encountered in the intertidol. The abundance of T. funebralis as mean number of individuals per square meter in the "Tegula quadrots" for the four +1 f t and five +3 f t stations in Diablo Cove and Diablo Point are shown in FIGURES 3-19 and 3-20. There are generally more _T_.

funebralis at +3 than at +1 f t, with the exception of station 14+3 (Diablo Point)

O B-83-540 3-36

STAT 10N 08 O

O ,

6 i

O -  !

a O

STATION 09 2 -

3 -

m

~

f% ..

-e'

> w u

E n

e w

e E

E 5

d

( E E

S Ss4710N 11 C E -

Er

(

l 8 -

O o

STATION 12 S-

\

S -

O . , , , , , . . . . , , , .

1978 1979 1980 1981 1982 1983 1984 197F 1977 TIME ITEARS) - - - - somet ine Intervat > 2 Months O FIGURE 3-17 ABUNDANCE VERSUS TIME FOR PAGURUS SPP.

AT +1 FT MLLW(IBT METHOD)

B-83-540 3-37

STCTION 08 8 -

S -

4 U

%8 ..[6

• OO-STATION 09 8 -

x 8 -

e h..j E O E

D STAT!DN I!

O O O m -

e W

IL e

E O a _

r m

5

[s h e O E -.. ,

t a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

z S STATION 12

• 8 -

z -

e w

E S -

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i STATION 14 O

(

l 3 -

1 i

I

, _Me A h e a...nen J 1976 1977 1978 1979 1980 19e! 1962 1983 1984 TIME (TEARS) _ _ _ ,

3,,,, e ns Int erwar > 2 Monene hi v FIGURE 3-18 ABUNDANCE VERSUS TIME FOR PAGURUS SPP.

AT +3 FT MLLW (IBT METHOD)

B-83-540 3-38 1 __. _ _ . . - _ _ _ . __ __ _ _.

, TABLE 3-7 MEAN ABUNDANCE OF PAGURUS SPP.

IN THE IBT "TEGULA QUADRATS" FOR THE DIABLO COVE INTERTIDAL STATIONS FROM AUGUST 1976 (SURVEY 3) TO OCTOBER 1983 (SURVEY 46) i l

4 Mean 2 Number of StoGon Abundance Std Surveys Level +1 (number /m2) Error (N) 08 14.2 2.1 43 09 10.5 1.9 39 il 14.0 2.7 44 12 23.1 3.6 44 Mean 2 Number of Station Abundance Std Surveys Level +3 (number /2) Error (N) 08 9.3 1.6 42 09 8.7 1.5 41 ll 12.6 3.6 42 12 26.7 5.I 42 14 3.6  !.4 35 I

l O B-83-540 3-39

STAT!DN 08 8 .

S -

s a %cm -

STATION 09 8 -

3 -

2 5

= c d

,e-N-_:-,_,,a-( h _J'i w

E STATION II 8

us 8

a .

e

• U e

W m 8., -

r

_a O

g Q o . .

Z E STnTTON 12 8 -

z C

W r

8 u -

l

\

C9a_

g 1984 1977 1978 1979 1r30 1991 1982 1983 197C IIME ITERRS) _ _ _ . sonor ens Inter <a! > 2 Montne FIGURE 3-19 ABUNDANCE VERSUS TIME FOR TEGULA FUNEBRALIS AT +1 FT MLLW(IBT METHOD)

B-83-540 3-40

STATION 08 8 -

8

~ ~ *

(T O  ?.)

~

o STATION 09 8

~ -

'g... -i l

w o r , , , . , ,,,,,,,,,i,,,,,,,,,,,,,,,,,,,,

W e STATION !!

C O D

o O. -

v>

C W

L C O W O \'

a3 a -

r ',

5 D '

b----

u O 2 g

z D

O STATION 12 CD .a e

O. -

z W

E 8~ -

\

G.,~.

O STATION 14 8 -

, , , , g 1980 g , , ,

1981

,,,,,',,s ft . b 1982 1983

, I , ,

1984 g

1976 1977 1978 1979 TIME (TERRS) ___. 3 ,,,,,,,go,,,,,, , 2 Monen.

FIGURE 3-20 ABUNDANCE VERSUS TIME OF TEGULA FUNEBRAllS AT +3 FT MLLW(IBT METHOD)

B-83-S40 3-41

N which, despite its elevation, exhibits the lohest mean number of abalone of all transects ceidered in this analysis. TABLE 3-8 presents the mean number of

_T_. funebralis per m2 for all surveys at each station.

One nc+iceable feature of FIGURES 3-19 and 3-20 is the large fluctuations in the mean abundances of Tegula over the study period. The mean abundances of turban snails at +1 ft at all Diablo Cove stations show seasonal trends with highest abundances in the winter surveys and lowest abundances, very nearly zero in most cases, in the summer surveys. At +3 ft transects in Diablo Cove there is no definite seasonal cycle.

The high degree of wave exposure is probably a significant factor in explaining the almost complete absence of T. funebralis at Diablo Point and the relatively lower numbers of snolis at the stations in north Diablo Cove (more wave action) than those in south Diablo Cove (semi-protected). Microhobitat is probably important in explaining some of the variability in the mean abundance of Tegula; certain quadrats (i.e., locations) may provide better shelter to Tegula than other quadrats.

There appear to be no significant changes in the abundance of T. funebralis during the 1983 intertidal surveys as compared to previous years at the +1 ft transects although abundance may be slightly lower than in previous years at station 12+I and slightly higher than in previous years at station 8+!.

At the +3 f t transects, the abundances of Tegula in 1983 show little change from .

previous years at stations 8+3,9+3 and 14+3. Both station Il+3 and 12+3 show a sharp, although not on altogether uncharacteristic, drop in Tegula abundance following the winter storms and a large increase in abundance in the later summer and fall surveys.

3.2 INTERTIDAL RANDOM POINT CONTACT (RPC) QUADRAT Six intertidal random point contact quadrat surveys were completed in 1983 (see TABLES 3-9 and 3-10). In the following sections, the Diablo Cove station quadrat . data (percentage contact) for five algal species are presented, B-83-540 3-42

O TABLE 3-8 MEAN ABUNDANCE OF TEGULA FUNEGRALIS IN THE IBT "TEGUL A GUADRATS" FOR THE DIABLO COVE INTERTIDAL STATIONS FROM AUGUST 1976 (SURVEY 3) TO OCTOBER 1983 (SURVEY 46)

Mean 2 Number of Station Abundance Std Surveys Level +1 (number /m2) Error (N) 08 II.6 4.3 43 09 3.2 1.1 39 ll 39.9 15.7 44 12 70.5 21.8 44 Mean 2 Number of Station Abundancq Std Surveys Level +1 (number /mz) Error (N) 08 l18.8 16.9 42 f 09 47.9 6.9 4l ll 96.7 15.7 42 12 173.4 23.9 42

, 14 0.1 0.1 35 O B-83-540 3-43

l l

l l

Year 1976 1977 1978 1979 1980 Desigmted g .- x g

> ga g 4g.u d $ L.gk i.

g .- u o w p .- o I("9

, dk4d o$m d 4 $0$4 4 d$$k <d$

swvey i2 3 4 5 6 7 8 9 10 ll 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 i+1 B

^\

C A __

2+l B C

A 6+1 B C

A -

71B -

g C -

g A -

< 8+1 8 C

8 Q ^

9+1 8

$ A 10+1 B A '

II+l B C

A 12+l B C

A 14+1 B - -

l C - -

A 19+1 B -

C A

20+l B C ,

l TABLE 3-9 COMPLETION SCHEDU'_E OF RPC +1 FT (MLLW) QUADRAT SAMPLING BY SUR\'dY, DATE, STATION AND GUADRAT O

B-83-540 3-44

O Ye<r 1981 1982 _ 1983 s N k b h survey 30 31 32 33 34 35 36 37 38 39 40 f.I 42 43 44 45 46 O A

l+1 B C

A 2+1 B C -

A 6+1 B C

A -

p 7+1 B

< C b A 4 B+1 B b C

@ A 4 9+1 B 5 c P A m

10+1 B C

O A 11+1 B ,

C A

12+1 B C -

A- ~

14+ 1 B - --

C- -

A 19+1 B i C A

20+1 B C

TABLE 3-9 COMPLETION SCHEDULE OF RPC +1 FT (MLLW) GUADRAT l SAMPLING BY SURVEY, DATE, STATION AND QUADRAT (CONTINUED) i l

O l

l B-83-540 3-45

Yew 1976 1977 1978 1979 1980 8 ag ao & ,5 Desigeted o x c gy k k <p A 6at E" 8" e" %" 5 <F t " E' k <Fd b e" k" 3 <F8a

~t sm 1 2. 3 4 5 6 7 8 9 10 ll 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 A - - ._

i+3 B - -

C - -

A 2+3 B -

C A '

6+3 B l I

A '

7+3 8 -

C -

e- A i

< 8+3 B I

C A -

b 9+3 8 -

Q C -

Q A z 10+3 8

_O C -

Q A -

$ 11+3 B C

A '

O 12+3 B '

C ,

A -

14+3 B -

C -

A 15+3 B C

A ,

19+3 B 3 C -

20+3 C A

22+3 B C

TABLE 3-10 COMPLETION SCHEDULE OF RPC +3 FT (MLLW) GUADRAT SAMPLING BY SURVEY, DATE, STATION AND QUADRAT O

B-83-S40 3-46

Year 1981 1982 1983 4 <gd- u o - e44p-g0 Desigrmted o u -e plia9,h

<go$o wy 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 e A

i+3 B C

A --

2+3 8 -

C j A

6+3 B l C

A 7+3 B

< A g -

O 8+3 B 4

C A

Q 9+3 B  !

% C

^

-b 10+3 B

< C

$ A ,

11+3 B C

A 12+3 B C

O 14+3 B A

C

~

A -

15 3 B -

l C ~

i A  ;

l 1943 8 ,

C 20 3 C A -

22+3 B - --

C -

TABLE 3-10 l COMPLETION SCHEDULE OF RPC +3 FT (MLLW) QUADRAT

! SAMPLING BY SURVEY, DATE, STATION AND QUADRAT (CONTINUED) i O

B-83-S40 3-47

documenting changes in species abundance from 1976 to 1983. The IPC method is presented in Section 2.2 of this report.

3.2.1 ALGAE This section includes percentage cover values obtained by using the random point contact method within fixed 0.25 m2 quadrats for five algal species (Endocladio muricata, Gastroclonium coulteri, Gigartino canaliculata, G. papillata, and Iridaea flaccida). These data are complimentary to visually estimated percent-age cover data obtained within band transects (Section 3.1 in this report).

Random point contact data for these species have been presented in an earlier report (PGanE 1980) which included data collected from April 1976 to August 1979.

In this section individual quadrat data from stations 8, 9, i1,12, and 14 ore presented for the five species for the period April 1976 to October 1983. The results are organized on a species-by-species basis below.

i l

O 3.2.1.1 ENDOCLADIA MURICATA l

Percentcge cover values obtained using the random point contact method for Endocladio muricata are presented in FIGURES 3-21 (+1 ft) and 3-22 (+3 ft).

This species is found primarily in high intertidal habitats, and consequently its abundance within Diablo Cove (stations 8,9,11,12,) has been greater at the higher l elevation (+3 ft). At the wave exposed station 14 area, which is located on the l south headland of Diablo Cove, the distribution of Endocladio is displaced higher l in elevation (about +4 f t MLLW) and is generally not found at +3 ft. Trends in nearly all +3 ft quadrats in Diablo Cove indicate that this species is most

, abundant during the summer (April to June) months. The severe 1982-1983 l winter storms reduced Endocladio in some quadrats (8+3A, i1+3C,12+3A and B) to lower abundances than did previous winter storms. Quadrat 8+3A became completely buried under sand as a result of these storms.

B-83-540 3-48 l

1

. _ _ . _ . - - . . _ _ _ _ . , - ___ --...,_x _ . _ _ _ _ . . _ . _ , _ _ _ _ . . _ _ . _ _ , _ _ . - , _ _ . _ . . . _ _ _ _ - - - . ,

STATION 08 O

~ -

s o -

O _= de = eb+ M + m e=ceb =d::=.==,=,=

++io  :::=

.a . . . . .

STATFON 09 O

~ -

O -

\

O e + + e-ass  ::++ m m +e- +===,=====,=,========

STATION 11 O

e ~ ~

t

+

0 L

e C O ,

e -

, z u

(m E

, O

==_:e=.=..es**+

.1 . . . .

+

t .

• • ======'5'e=== m ++======,=====

I 1 . t . . 1 , . . . . 1 . t I . t , , ,

STATION 12 O

~ -

[

O -

O - ,-. . m m e m

. m 4 m e. ._ ::c c:

STATION 14 l

l O l

~ ~

i t

I O -

s

^ ^ ^ ^ '^ ^ ^^^^^^^^^ ^^^^^ ^ ^^** ^^^ ^^^

O

,"".".^ , , , . . . . . . . . . . , , . . . . , , . . . . . . .

1976 1977 1978 1979 1960 19PI 1982 1983 1984 d ---. a .,:,n, ret.-<o: > 2 no,in. TIME ITERRS) o g,,,,,, p 0 Quad-at B FIGURE 3-21

• Cuad-=* C e , . -, - , , e , , o , ano,.

.WSDo!S 00D.0- to DS ABUNDANCE VERSUS TIME FOR ENDOCLADIA MURICATA d,".-.,e es.oo:.

AT + 1 FT MLLW (IPC METHOD)

B-83-540

. 49

STATION 08 8 .

I k .

/ q..CCCC a

- . . . . . . . . . . . I - I I I E E ' '

STATION 09 8 -

3..q e - *---- 4 _mja=_d:::-der:

. . . . . . . e : 2. . . . . . . - - . . . . . .

STATION 11 8 -

g .

W 0

W W

O o cr m -

z W

u o o m S7ATIUN 12 8 -

8 -

I

. Js ,

, , . , , . . , , , , . . . . . i i . . i .. ..........'

STATION 14 8 -

3 -

o h::d  ::  : :::::::::::

1978 1979 1980 1983 1982 1983 1984

-} 1976 1977 IM i EARS)

'~'/ ---- Sosp: en Int.rva! > 2 Monthe o cyao-at n O Caed-st B 5 0 =8-at C FIGURE 3-22 e,. ,-,nt.n or ae .

swoeots opp.a to oe ABUNDANCE VERSUS TIME FOR ENDOCLADIA MURICATA a cr. .ne .w.oor.

AT +3 FT MLLW(IPC METHOD)

B-83-540 3-50

e 3.2.1.2 GASTROCLONIUM COULTERI b

Percentage cover values obtained using the random point contact method are presented for Gastroclonium coulteri in FIGURES 3-23 (+l ft) and 3-24 (+3 f t).

This species is found more commonly in lower elevation habitats and consequent-ly abundances are greatest at +1 f t. Peaks in percentage cover have generally occurred during the spring to fall periods but have not necessarily been consistent from year to year in any of the quadrats. Af ter the 1982-1983 winter and through fall of 1983 roughly half the quadrats, which during previous years had substantial amounts of Gastroclonium, had cover values of less than one percent. The decrease can be attributed to storm damage. Gastroclonium commonly traps sand among its rhizomatous holdfast. High water motion probably caused the trapped sand to abrode these plants. The lack of recovery during the following spring to fall period is probably due to a lack of sufficient amounts of overwintering plant material to produce a measureable increase in percentage cover by regrowth. However, other factors may have contributed to this lack of recovery: (1) an insufficient amount of spores and growth of new

( plants; and (2) competition for space and light (in some cases Ulva spp. and Porphyra spp. quickly colonized and grew in quadrats disturbed by storms).

Grazing con prevent or limit algol establishment, but grazers have not been present in these quadrats in appreciable number since the studies began. The unusually high water temperatures persistent through the summer of 1983 may have inhibited growth and/or colonization of Gastroclonium but this species exhibited normal seasonal increases in abundance in other locations exposed to similar water temperature.

3.2.1.3 GIGARTINA CANALICULATA Percentage cover values obtained using the random point contact method are presented for Gigartina canaliculata in FIGURES 3-25 (+l f t) and 3-26 (+3 f t).

Giacrtina canaliculata is found mainly at lower elevations, and consequently it has been more abundant at the +1 than the +3 f t level. An exception to this is at the wave exposed station 14 where intertidal algal vertical ranges are elevated due to wave run up. Gigartino canaliculata abundances at +3 ft at this location O B-83-540 3-51

STATION 08 8 -

c l

s 0 -

!/

}

^ ^^^

o . ,0,, 0..- ,

^

^

-*^ 00 ^!00 , - ^

e a a a i a i i e i i e i i . . , i i i i i . . i i i i e i . i i STATION 09 o

O -

o m -

.. . f

. . . . . ' . . . . . ... ..A - .. .

-  ? Oc n

STATION !!

o O -

W c

U kJ o o g us -

W Z

! W l U W

fm U

l O ,. ;:. _ _'; . $ 1 ,

^

0 ,. 0-- Of dt If 0.- I w U- 1 I 1 9 I E a a 1 a 1 1 I d I a t I E i g s I t t 8 1 a e A i t STAlI0N 12 0

2 -

o m -

I I

o Sw O=. 2 MM w :== T: = O=====

I I

==== ===

I I I i I ' b R 1 1 E i I A E E 8 I I I I I I I I I I I 1 e i R R STATION 14 o -

N l

0 -

o = ===d: = =

9 I i 1 I t a t

==60=== = === == ======

a g a g a 3 g g g g g g a g g g g g g

=

, y g , g , g 1976 1977 1978 1979 1980 1981 1982 1983 1984 fq

-*-* Soap! rne Interval > 2 Month. TIME ITERRS) g g,,,,,, g

(

• 8"*8'"' 8 FIGURE 3-23 . K Quaaeat C C<eepeimting o' ocovo

.secol. =ce.a- to e.

ABUNDANCE VERSUS TIME FOR CASTROCLONIUM COULTERI "*"*"'d'**

AT +1 FT MLLW(IPC METHOD)

B-83-540 3-52

STATION 08 --

O

• N O -

g n w + m -e =

o

= = = = e+ . e-. eems-m

. ..t . . t , , . t . . t . t . . . . , , , , . E i e t i . t .

STATION 09 o ~

N Q -

o ====

. . . =.=t

==

-=

---b, t i , t m m +ee m

, , . . . . t , , ,

4==,===

t t . . E i t STATION !!

O -

~

e W

o O

W O O _

e -

s z

W U

b s

0

" a = ===d===

I I 1 I i 1 ,

e=================d:====d===========

t 1 1 1 1 I I e 1 i t t t I I E I E 2 t t i e t I A 1 i STATION 12 1

O -

n D_

l l

! o = = = = se---ee m**mem = = = = d = = = = = d = = = = _ = _ = = = = . t t t i 1 e i E i i t I E I t E I E E E E , t t i I I I B E t i t t STATION 14 O

O -

O -

s -a t

- s, o c==== - = = = = c d c = = c =. == = -do==,=== === = == i & I a 1 . E E f I 2 a I t t I t I A E I I A t i E I I t i E I I 1978 1979 1980 1981 1982 1983 1984 i

m 1976 1977 o Quao-at A d ---- s..,r .no r ae.r..t > 2 nonen. TIME (YEARS)

O Quedaat B w Quaceat C FIGURE 3-24 e,....,n,,,, ,, ...,.

94sD010 appea* to De ABUNDANCE VERSUS TIME FOR GASTROCLONIUM COULTERI AT +3 FT MLLW (IPC METHOD)

B-83-540 3-53

STATION 08 8 .

o v

O

," , " , , , , , , . . , , , . i . . i e i i a * ' ' ' ' ' ' '

STATION 09 8

, 4. . .

N ,

\ ,

o -

• i i a a = ' ' '

, , , , , , , , , , , . . . . . . . . . i i a STATION !!

a-8

- l W

c u

Lu O

tr o, y -

Z W

O tr 0

- W

~ ~

O ~ - " , ~ ~, ~ ~ ,~, , d=":  ::: ~,fI: .U**0' g STATION 12 8 -

O 1%[ a c . is . - - -

..' - 't

, , , , , , , , , , , , , , i i i i i - i i - a i i - ' ' ' ' ' ' ' '

STATION 14 R -

2 -

o b================z: :

f I & 3 I E a 1 1 I $ I 1 A B R

=====:=======

, I t t I a E R R I

===z g g i g g , , ,

1980 1981 1982 1983 1984 1976 1977 1978 1979

(,h TIME ITERRS) o cuaa-at n

~~~- Sampi neg interval > 2 Nantne O cuadrat B

\~ ')

• cu=orat c FIGURE 3-25 c<eap=enting o' above EdeDo!* appe0* to be o ' "e rent ed.oor.

ABUNDANCE VERSUS TIME FOR GIGARTINA CANALICULATA AT +1 FT MLLW (IPC METHOD)

B-83-540 3 54

STATION 08 O

n -

O -

% ==

d O - . .. . . .. . ....

. . . . Ah ,,,,,

STATION 09 o

O- -

l i

O e -

M .- 4-'

T , " ,' ', ' i ' 7, ,

, , , +, ,', . . . , ,~ .waAa "'

, , . , , , , . . u STATION 11 O -

W e .

w c

U W

o O G

z W

U e

f~% w 4

' O 0 = ese , e-e- ,-e-e****e******* **********e* = = = = d : : : :

( , , , , , , , . . , , , , , , , , , . . . . . . . . . . . . . .

STATION 12 O

n -

O.

O k-nn Y b --- A b***---- ----

1 E I a E 1 1 , I d I i i I I I 1 1 i f i , 1 E 1 i t i I b t t I I i STAlfate 14 O

O -

, liil

~n%

O A B B R R I , b 1 I a t I t i t E I 1 I f 1 I I I I I I I , t E I I I 1976 1977 1978 1973 1980 1981 1982 1983 1984 Somet ans Intervat > 2 Nontne TIME (TEARS) o cuoa-ot A O) FIGURE 3-26 O cuad-at e m cuooroe e e<.rp-,ne.no .* ooo<.

ABUNDANCE VERSUS TIME FOR GIGARTINA CANALICULTATA 'g,7,'.', l,'f'oo'r .

• AT +3 FT(IPC METHOD)

B-83-540 3-55

?

have been similar to those found at the +1 f t level of other, but more protected, C stations. Spring-summer increases in percentage cover have been consistent i from year to, year at most +1 f t quadrots at stations 9 and l 1. This pattern is not as evident in the other quadrats. The winter 1982-1983 storms which, relative to other years, appreciably lowered the abundance of other species such as Gastroclonium coulteri and G. papillata, in several quadrats did not affect G.

canaliculato to the same degree except in quadrat 12+1 A, The lack of noticeable ,

effects on G. canaliculata may result from the fact that its thallus form (Iow lying branches) is structurally better able to withstand wave forces.

3.2.1.4 GIGARTINA PAPILLATA '

'l Percentage cover values obtained using the random point contact method are presented for Gigartino papillata in FIGURES 3-27 (+l it) and 3-28 (+3 ft). In north Diablo Cove (stations 8 and 9) the cover values of G. papillato have been generally greater at +3 f t. In the south Diablo Cove (stations iI and 12) the abundance of this species has been more similar among the high and low elevations. This is due to the wave protected nature of south Diablo Cove.

O Algae commonly found in mid-to-high tidal ranges along wave exposed shores are able to colonize and grow in lower elevation habitats in protected areas.

Gigartina papillata at the heavily wave exposed station 14 area occurs mostly above 3 ft and consequently its values within the station 14 sample sites were never greater than one percent. In other station quadrats where G. papillato was sufficiently abundant, seasonal trends indicate that this species is most common i

during the spring to fall period. The winter storms of 1982-1983 appreciobly lowered G. papillato abundances which in turn offected the typical spring-fall increase for this species in some quadrats (8+1 A, 8+3A, ll+1C,12+1 A and C, j 12+3A) in 1983. Goodrat 12+1B was located on a boulder which was displaced l and has not been sampled since. Goodrots 12+1C and 8+3A were temporarily buried under cobble and sand. Considerable bleaching of this species' population was observed throughout the spring and summer of 1983 in all study areas.

Presumably this was due to unusually persistent warm water temperatures I

throughout this period.

l O B-83-540 3-56

STATION 08 O

O ~

v Q O 09b O I

-O^. 9 0N O I E

_ O A t i I I E E

-O I I 1 R I E 1 I & I a 1 1 E B E I f I I 3 A I

$T_A_T ION 09 O -

N 3 -

9

_ , .,8. A _?_ . a.a__ ___ _ m W_ _ _ )_

i i E & R R R 1 E E i A E I I a E 1 2 R R R E 1 1 1 1 1 A 9 I 1 1 R 1 STATION ]!

O g O -

w O

tJ L

L3 n I

C m-Z \

w LJ E

W .

.A sh .Jm an-s-- --- m-m h - . - - - v -mi,

( ) O _A _B A-m - m - r _,.m n

-m i i n

e m ,

e i i i i

-m mmm ,

e e a ie a a a a m

i e I e I L

I

'(/ _i a a i a R i i a i

. SJ ATJ ON 12 O

u.

O

. . , M'--

, __ .m -

o _ _

1 i E E 8 E E 8 3 3 1 8 I E a i i 1 2 2 1 I 1 1 1 i i I I i 1 R E E STATION 14 l

. O -

\

u l

e O

O =- - - - - - - ---54 : 0:OO:: O = : : O 044=000 OOO E I I I E I f I 2 R I I i I & 1 E R R I E 3 k 1 a ) 3 J J f a E 2 R 1978 1979 1980 1981 1982 1983 1984 19/6 1977 TIME ITEARS) O Cuadrat A

's o e,ooro, e j FIGURE 3-27 W Cuad-at C c< -a-'at'as or anoe.

ABUNDANCE VERSUS TIME FOR GIGARTINA P APILLATA AT +1 FT MLLW (IPC METHOD) '0 N',['.*Joo': . **

a B-83-540 3-57

STGTTON 08 8 -

i 8 -

g A.Y o m TO00O 514170N 09 O

2 -

P,

/,

O -

in 'N' w.~~..,

. ..a.*__iA.A. m. M2 STATION !!

O E

w 3 -

c U

w Y a

c o - ',

n Z  : ',

w .'

u E k (,m . .

(y) ,...............

i . , .

I o

\

l . .

O S14110% i2.

2 -

3 -

a

\ .

\ -

,et _ _ _

\ ..

, .,\ .,

I . . . ..,,,,,.....,,,,..,,,,.....,,..

I STATTOA 14 l Rh 2 -

l l

l o , = = , = =A_

, , ,. _ : . ,- = = =. = = *. 4e+ ,-e+e--ee

= = = == .: .: =,=, , . , , ,

l 1976 1977 1978 1979 1980 1961 1982 1983 _ 1984 1

,- m ---- so.p:eno Int.-<a: > 2 Monen, TIME ITEARS) o cuaa-at n (y;

I 1 FIGURE 3-28 o coaarat e M cuaarat C ABUNDANCE VERSUS TIME FOR ClGARTINA PAPILLATA e<.-o-,nt na o< ano<.

AT +3 FT MLLW(IPC METHOD) 'C7U' a n"e".',*.~..': . "*

l B-83-540 3-58 1

3.2.1.5 IRIDAEA FLACCIDA (v]

Percentage gover values obtained ur.ing the random point contact method are presented for Iridaea flaccida in FIGURES 3-29 (+1 ft) and 3-30 (+3 f t), respec-tively. I_. floccida abundance in many of the intertidal random point contact quadrats has been greater in the spring to fall months in most years from 1976 to 1983. This is especially so in quadrat 12+1B and C and all three quadrats at 14+3. This seasonal pattern is not as evident in some quadrats (8+3C,12+3C).

The severe winter storms of 1982-1983 did not noticeably alter the seasonal pattern or cover of I. flaccida in most quadrats. Two exceptions were at the

+1 f t level at station 12. The large boulder which was the quadrat B sample site was displaced, and has not been sampled since. Guadrat C temporarily became completely buried under fragmer+ed rock.

3.3 INTERTIDAL ALGAL SCRAPINGS The objective of the algal scraping subtask is to provide algal biomass informa-tion for comparison between pre-operational and operational power plant phases.

l Two algal scraping surveys were completed in 1983 (TABLE 3-11). Data from l these surveys are still in process of being summarized, and thus algol scraping biomass results are deferred.

3.4 INTERTIDAL BLACK ABALONL TAGGING l

l Nineteen intertidal black abalone (Haliotis crocherodii) tagging surveys were l completed through 1982 (see TABLE 3-12). Analysis of the data collected thus for have sufficiently defined the field growth rates and mortality rates of black abalone to meet the original objectives of this subtask. Therefore, no surveys ware conducted in 1983.

l l

l O 3-59 l B-83-540 l

l

O STATIGN 08 e -

O w

• O f

_m#n:

.......f A f . .1 .u- I 1 f

.....t

_ 8- W i . . 1 . . . . .

STATf0N 09 O

O_

O "

m

, A_ -

STATION !!

O O "

W O

LJ W

(b O e .n -

=

W

\ #

O t

y . . , , . . . , , , , . . . . . . . . . . . . . . .

STATTON 12 O

O_

\

O W

\ -a O ,- ,. , a

.. . w. . . . . . , , . . . . . .

STAT!Oh 14 .-_

O "

l N 1

, O_ -

! , ______ _ _ ___ _- _ _ ' _ ______ A ______ _ __,

. . 3 . . t . I 1 . . t . .t .. 1 R I I . f . 1 . . E . t . l .

1976 1977 1978 1979 1980 1981 1982 19P3 1984 TIME (TEARS)

O "" '"' ~'*' ' ' " "'"'

e'cuse 3-29 l N Quodaat C l ABUNDANCE VERSUS TIME FOR 1RIDAEA FLACCIDA c,. ,.,ne.,, , ...<.

t AT +1 FT MLLW (IPC METHOD) '".,",..,*e**.*o*".*:*.**

d -

B-83-540 3-60

STATich 08 S -

O d

m L L w_ _ _ a - _ A _ _ _ _ _-

h > _D ,,...

STATION 09

\

3 -

8:::,..

i

-s

+ v

'\

O .

1 I I I I 1 I I E E I E A I I I I t 1 3 1 1 1 I i f 1 1 1 1 3 i e

W C

U W

O C

s z

W u

/~N $

(-) '

STATION 12 8 -

8 -

o IvN A _A _ w_ A ~

I I t i I t b I I i l . 1 I E 9 R k I E , i E E I I I E I t R R R STATICA 14 8

k

's ,

o. -

. . s,. ,

6 i e

O 1977 1978 1979 1980 1961 1982 1983 1984 1976 p ---- so.pr ene Intervo! > 2 Menen. TIME (TEARS) o g ,,,,,, a o cuaa at e

\

• owaa at c FIGURE 3-30 e,. o-.,t.,o .. ...,.

ABUNDANCE VERSUS TIME FOR 1RIDAEA FLACCIDA *a O %,i' .["*f~ * **

.oo:.

AT +3 FT MLLW (IPC METHOD)

B-83-540 3-61

t O

TABLE 3-11

SUMMARY

OF COMPLETED INTERTIDAL ALGAL SCRAPING PROGRAM

(+ 2 FT MLLW)

Station

• Survey and Date i 2 3 4 l August 1979 X X X X 2 November 1979 X -- -- --

2 December 1979 -- X X X 3 January 1980 X -- -- --

3 March X X X p) 1980 --

X

( 4 May 1980 -- -- --

4 June 1980 -- X X X 5 August 1980 X X X X 6 January 1981 X X -- X 6 February 1981 -- -- X --

X X **

7 June 1981 X 8 December 1981 -- X X 8 February 1982 X -- --

9 June 1982 X X X X X X **

10 January 1983 X X **

II July 1983 X l

• 25 scrapes were taken at each station marked "X"; for loco-tions, see FIGURE 2-1.

station 4 deleted from program.

f i

O B-83-540 3-62 1

l l

l

L i

O TABLE 3-12

SUMMARY

OF COMPLETED INTERTIDAL BLACK ABALONE

.. TAGGING SURVEYS Number in parentheses ( ) is the number of abalone stations sampled Number Number i

Survey of of Date Abalone Abalone Tagged Receptured iI/78 I 442 (4) --

1/79 2 --

140 (4) 4/79 3 --

l15 (4) 5/79 4 142 (4) 62 (1) 6/79 5 209 (4) 170 (4) 7/79 5 14 (1) 169 (3)

I O 9/79 I/80 6

7 113 (4) 168 (4) 136 (4) 212 (4) 3/80 8 73 (2) 157 (2) 5/80 9 --

276 (4) 7/80 10 134 (4) lI8 (4) 1I/80 Ii 66 (3) 137 (3) 2/81 12 139 (4) 180 (4) 5/81 13 III (4) 222 (4) 7/81 14 29 (3) 151 (3) i 8/81 15 29 (1) 112 (i)

I I /81 16 --

86 (1) l/82 17 --

l74 (4) l 4/82 18 68 (3) 129 (3) .

! 5/82 19 --

18 (1)

!

• No surveys were conducted in 1983.

O

B-83-540 3 63 l

l

1 l

1 i

3.5 INTERTIDAL BLACK ABALONE SURVEY Detailed discussion on habitat preferences, life history, and ecology of black abalone (Haliotis crocherodii) was presented in a previous report (PGandi 1979). 1 Eight transects within the Diablo Cove intertidal zone were sampled for black abalone in 1983 (FIGURE 3-31),with two transects (NDC I and SDC 5) deleted due to unworkable tide conditions. A total of 1,218 sampled quadrats yielded 490 cbolone for an average density of 0.38 individuals per m2 (TABLE 3-13). The southernmost headland, SDC 5, is also a favorable abalone habitat but was not sampled in 1983.

Black abalone are most abundant in intertidal habitats with numerous rock crevices and large boulders for protection, and most animals were observed in north Diablo Cove where this type of substrate predominates. Specifically, maximum densities of black abalone were found in the headland area of north Diablo Cove (1.55 abalone per m2). The most abalone counted in a single square meter was 31 individuals in the NDC 3 area. The least productive cove area (0.0i abalone per m2) was the relatively flat benchrock terrace and cobble beach southeast of the discharge structure.

3.6 INTERTIDAL STATION PHOTOGRAPHY intertidal station photography was completed in the six surveys conducted in 1983 (see TABLES 3-1 and 3-2).

3.7 SUBTIDAL ARC-QUADRANT (SAQ) l ,

Five subtidal surveys were completed from February through October 1983 (TABLE 3-14). Each subtidal survey includes sampling by the SAO method (Section 2.7), as well as the SFO and SLC methods (Sections 2.8 and 2.9,

respectively). In the following sections data are presented showing the distribu-tion and abundance of four algal and nine invertebrate taxo from survey I (May 1976) through survey 39 (September 1983).

B-83-540 3-64

O O O b DISCHARGE ST RUCTURE'-

g o

I

, SDCI m j.

( ~S N l f if.

of NDCI

.)

[ . NDC2

'(Not Sampled)

SDC 2 t f

\

6.-: s~

/ ',/... $ ~j '

SDC 3 i f -.W NDC3 y

.(

,'r' / .l' BLACl< 3A _Otir DENSITY (Not ampled) .

g ,,.-  :.

~]

'S / 1983 SURVEY  :. l ) <F /

/ 0 -  :: .s5 _ /

< 0.50/m2 , g ,

t IDC 4 . ,

\ - .

h~

b 4.

0.50 - 1.00/m2 SDC 4./

"/

[s NDC 5

_g-1

- 5 .+

/ jv

?. t u > . l.00/m2 A' j

i s

t .: A

n{.{.h..

/

i J

^/

i

/

} i

(:

' y}

/

• a: ,

t l.,)~

.(

J (eg 9.J y

,,/

) fC ' Note: Sampling areas are diagrammatically indicated.

(" S FIGURE 3-31 i!

BLACK ABALONE SAMPLING LOCATIONS AND DENSil Y ES11 MATES IN DIABLO COVE,1983.

a mw n TABLE 3-13

SUMMARY

OF 1983 INTERTIDAL BLACK ABALONE SURVEY Number Number Mean of of Number of Guadrats Abalone Abo!one Station Sampled Found per M2 4

NDCI NOT SAMPLED NDC2 226 50 0.22 NDC3 732 194 0.84 NDC4 IC4 46 0.28 NDC5 51 79 I.55 Total North Diablo Cove 673 369 0.55 O SDCi 190 2 0.01

~

SDC 2 125 28 0.22 SDC 3 199 16 0.08 SDC 4 91 75 0.82 i SDC 5 NOT SAMPLED i

Total South Diablo Cove 605 121 0.20 l TOTAL I,278 490 0.38

(

B-83-540 3-66

O O O TABLE 3-14

SUMMARY

OF COMPLETED SUBTIDAL TEMP SAMPLING No. of No. of No. of No. of No. of S ti RLPC 30 m2 are  % m2 Algal  % m2 Fish Observations SurveI and Date Quadrats Quadrats Quadrats Scrapings Quadrat No. Stations (2 repl.)

Sampled Sampled Sarnpled Sampled Token Photos 01 May-Aug 1976 32 -

128 128 93 -- 14 02 Sept-Dec 1976 28 112 112 IIS 84 116 13, I (I rept.)- (I station w/l replicate) 03 Jen-April 1977 28 112 112 115 84 12 14 04 May. Aug 1977 17 68 68 69 51 2 14 05 Sept-Dec 1977 3 12 12 12 9 0 13 06 Feb-Mar 1979 5 20 20 21 0 -- 2 07 April-May 1978 9 36 36 37 0 0 6 08 June-July 1978 9 36 36 37 0 0 4 (2 repl),2 (I repl.)

09 Aug-Sept 1978 9 36 36 37 0 0 6 10 Oct-Nov 1978 6 24 24 25 0 10 6 11 Dec-Jan 1978-79 4 16 16 17 0 0 0 12 Feb-Mar 1979 8 32 32 32 0 0 6 13 April-May 1979 9 36 36 36 0 0 6 7 14 June-July 1979 5 20 20 20 0 0 6 g 15 Aug-Sept 1979 9 36 36 36 0 0 6

. 16 Oct-Nov 1979 9 36 36 36 0 0 6 17 Dec-Jan 1979-80 7 28 28 28 0 0 6 18 Feb-Mar 1980 5 20 20 20 0 0 0 19 April-May 1980 9 36 36 36 0 0 6 20 June-July 1990 4 16 16 16 0 0 0

21 Aug-Sept 1980 8 32 32 32 0 0 0 22 Oct-Nov 1980 5 20 20 20 0 0 6 23 Dec-Jan 1980-81 2 8 8 8 0 0 6 24 Feb-Mar 1981 1 4 4 4 0 0 0 25 April-Moy 1981 9 36 36 36 0 0 6 26 June-July 1981 9 36 36 36 0 0 0 27 Aug-Sept 1981 0 0 0 0 0 0 6(I repl.)

28 Oct-Nov 1981 7 28 28 28 0 0 0

'; 29 Dec-Jan 1981-82 4 16 16 16 0 0 6 30 Feb-Mar 1982 7 28 28 28 0 0 6 31 April-May 1982 10 40 40 40 0 0 6 32 June-July 1982 10 40 40 40 0 0 0 33 Aug-Sept 1982 7 28 28 28 0 0 0 34 Oct-Nov 1982 2 8 8 8 0 0 2 (2 rept.),4 (I rept.)

35 Dec-Jan 1982-83 2 8 8 8 0 0 0 36 Feb-Mar 1983 0 0 0 0 0 0 0 37 Apr-May 1983 10 40 40 40 0 0 9 (I rept.)

38 Jun-Jul 1983 10 40 40 40 0 0 ll (I rept.)

39 Aug-Sep 1983 10 40 40 40 0 0 11 B-83-540

The TEMP subtidal stations to be considered in this report are only those located O within Diablo Cove:

North Central South 4

Diablo Cove Diablo Cove Diablo Cove 8-10 13-32 10-10 9-10 12-10 i 9-15 10-15 12-15 The digits to the left of the hyphen in the station designation refer to the location of the station and the digits to the right of the hyphen indicate the approximate depth of the station in feet below MLLW.

3.7.1 ALGAE i

! This section includes seasonal abundance descriptions for four brown algol

species counted in the TEMP Diablo Cove subtidal stations. The species are Cystoseira osmundacea, Laminaria dentigera, Nereocystis luetkeano, and Ptery-gophora californica. These brown algae are commonly referred to as kelp and are of considerable importance as a habitat and food source for various fish and invertebrates. When they occur in high numbers their blades form canopies which shade the bottom and regulate the composition and abundance of under-

story algae. Abundance data for these species during the first year sampling period (1976-1977) were presented earlier in LCMR (1978) and PGanE (1979).

The field data for these four algal species are counts of plants greater than 20 cm long. All plants in each of the four arc quadrants (each arc quadrant encompasses 7 m2) are counted. The four arc quadrant counts have been averaged in this report to give the mean number of plants (N=4) per 7 m2. The following sections discuss the analysis conducted on data collected from 1976 to 1983.

'O B-83-540 3-68

_ - - , , ~ . - - - - . . , , . _ _ . . - - - - _ . - - ._ -- - _ - - . _ _ _ _ - . - - - - , - - - ~ , . . . . - - . , _ . . . - - - - . . . - _ _ - - , _ . _ , _ , - - _ _ , .

3.7.1.1 CYSTOSElR.A OSMUNDACEA Cystoseira osmundacea is a summer surface canopy-forming kelp plant. During the winter individuals of this species appear as a rosette of brcnches about 0.5 m long. As spring approaches these branches produce fronds which elongate and float on the surface to form a canopy. This canopy persists through the summer and is later removed by foll-winter storms leaving the basal portion to i overwinter and begin frond production again the next spring. Surface canopy-forming C. osmundacea plants are normally attached in water less than 10 m depth. Plants growing in deeper water usually do not produce floating fronds presumably due to reduced light. Data obtained at the Diablo Cove stations are presented in FIGURE 3-32.

i In general, Cystoseira osmundacea has been less abundant than Pterygophora californica and Laminaria dentigera (see Sections 3.7.1.4 and 3.7.1.2, respective-

ly), but more abundant than Nereocystis luetkeana (see Section 3.7.1.3). Exclud-ing station 13-32, its distribution has been such that abundances have been similar among the TEMP Diablo Cove stations. At station 13-32 only one C.

osmundacea plant was found on one sampling occasion. Recruitment occurrence for this species, as with most other algae, is most common during the spring and summer months. Accordingly, abundances have been greatest during these periods. However, the numbers of recruiting C. osmundacea individuals have generally been low and thus seasonal abundance variations for this species have not been as large in magnitude as those seen for P_. californica and L_. dentigera.

C_. osmundoea abundances in all the Diablo Cove TEMP stations have been quite stable from 1976 to 1983.

3.7.l.2 LAMINARIA DENTIGERA Laminoria dentigera, like Pterygophora californico (see Section 3.7.l.4), is a perennial tree-like kelp plant extending roughly one meter off the bottom. Its life history and general ecology have been presented in an earlier report (PGandi O

B-83-540 3-69

STATION 08 E - I SAM LE DEPTH -10 FT MLLM o *

(g 9

\ r G'

,,,,,,g2- %. -Og -O---O

S' o

STATION 09 E ~

SAM *LE DEPTH -10 FT MLLN E -

o e3 e e 3 _

u. _ _ e h -G g.....-oe.g_. o h ___ 8

, , . . . . . , . . , , . i . . , ,

t A i , t 1 ,,,,.1 , t t t n

• STATION 10 6 '

E - SAM *LE CEPTH -l'O FT MLLN g

tu Q.

oc tu m

3- O m

• ta Q'n - ~ 3 .....

(v) o o z

2 m

l cc STATION 12

$E w

- SAM *LE DEPTH -10 FT MLLN r

E -

a  % h. c n _

'l'% . g. . .

1976 1977 1978 1979 1980 1981 1982 1983 1984 TIME (TERRS) ----

sa.ot ene Inter <a! > 2 Months i

t l

(Os_j FIGURE 3-32 i

ABUNDANCE VERSUS TIME FOR CYSTOSEIRA OSMUNDACE A IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SAQ METHOD)

B-83-540 3-70 l - , -- -.

O STAT]DN 09 2 - SAMPLE DEPTH -15 FT MLLM

..........-r- b ... ... --- G ..g , -- O' ,, ....

= ,,,...,,,,.g .

STATION 10 0 -

SAM *LE dip 7N -15 Fi MLLM A

s in N o N . ,o ,.. ,o

n. r ,'

)

g .

\_J E ,

7 " , ~, , , , , , , , , , , , 7, , , , , , , , , , , , , , , ,

5 STATION 12 tu .

SAM *LE GEpih -15 FT MLLM y3 -

c o

Z

=a as c

Z c

E -

na

,,,,.......L. ,

,i' O I

, , , , , , , E i I E I A E I f I I f a g 3 , e a , t e , t 8 9 1 f STATION 13 I N -

SAMPLE DEPIM -32 FT NLLN l

3 -

- _ 'm _ _ _ x _ _

• " 7 , , ", , , , , , ," ?, 7 . " ," , ,, ,

1980 1983 1982 1983 1984 p 1976 1977 1978 1979 TIME (YERflS) > 2 Montne

() _ _ _ . 3 ,,, 3 , n , , e ..-,a

> FIGURE 3-32 (CONT.)

ABUNDANCE VERSUS TIME FOR CYSTOSEIRA OSMUNDACEA B-83-540 IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SAQ METHOD) 3-71 l- - -

1979). Individuals of this species are counted in the stations and density dato p'# are presented in FIGURE 3-33.

Laminaria dentigera has generally been less abundant than Pterygophora cali-fornica (see Section 3.7.1.4). However, unlike P. californica, abundances for L_.

dentigera have been more similar among the Diablo Cove stations. Con-sequently, L_. dentigera has been only slightly less abundant than P,. colifornico in the north Diablo Cove stations (8-10, 9-10,9-15). But in the south Diablo Cove stations (10-10,10-15,12-10,12-15,13-32) P,. californica has been roughly twice as numerous as L. dentigera. Recruitment for L. dentigera, as for most other kelps, occurs more of ten during the spring-summer months. Thus, within the TEN.P stations there has been considerable seasonal variation in L_. dentigera plant densities. Aside from short-term seasonal fluctuations, overall annual abundances indicate that this species has not declined to the extent seen for P_.

californica. Stipes of l_. dentigera are more pliable than P_. californica stipes, and thus L. dentigera is less susceptible to breakage and loss during storms.

l This may be why L. dentigera abundances at some stations have remained j relatively stable while P. californica abundances declined.

l (v9 I

3.7.1.3 NEREOCYSTIS LUET KEANA Nereocystis luetkeano (bull kelp) density estimates are provided by two methods:

(1) counts made underwater within TEMP fixed stations, and (2) counts of surface canopy-forming plants from cliff-top vantage points. Density data obtained by j the former method (counts within Diablo Cove subtidal TEMP stations) are l discussed in this section. Cliff-top counts are presented and discussed later in this report (see Section 3.13).

The life history and other pertinent information for Nereocystis luetkeana was presented in PGond5ii (1979 and 1982). The large macroscopic sporophyte generation alternates with a microscopic gametophyte phase on on annual cycle.

Seasonal abundance trends in the Diablo Cove stations show this cycle (FIGURE 3-34). Plants are most common during the spring to fall periods and are almost t

O B-83-540 3-72 l

L

STRTION 08 ~

o -

, ' SR TLE DEPTM -10 FT MLLW

=

I S

O t") ......

V H *** -- * -e. ..p ... ..e-+-K v j

o

- . . . . . . . . . . . . ..,,,,,,,,,,,,,,,,,,,,i STATION 09 o '

SAMPLE DEPTN -10 FT MLLN 3 -

=

,,. [ ' N .. o...e. 4 -

• s -e.... b .....; .,

b c STATION 10 -

w O $44*LE DEPIN -10 FT MLLN

a. * -

c w

cn r

c. -

W u

z

~~~-

,,, . 9

~'

0 --

%,j co o _

C 2 STATION 12 Z SAM *LE DE*T51 -10 FT MLLN I o* .

S -

.- % . e-e ' \ ..& .

3g79 1990 1981 1982 1983 1984 1976 1977 1978 TIME (TEARS) v l ---- S amo! s ne interval

• 2 Montme FIGURE 3-33 ABUNDANCE VERSUS TIME FOP, LAMINARIA DENTICERA IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SAG METHOD)

B 83-540 3-73

STATION 09 g .

SAMLE DEPTN -l'5 FT MLLN

.. g. . . ... Q ~ ,L*'

'O'

--O ', ..i.. -&

o .

a g e a a g i 1 e a R k I I I a f 1 E 9 I f i t E I I E I I I 8 E I E STATION 10 g -

SAM *LE CE*IN -15 ri stLM A

a o

e tu l' .... g

, s_/ @ , , , , . . . , , . , , , . . . . . . . . . . . > > - . i - - - -

a Z

l STATION 12 tu @ -

SAM *LE DE*TH -15 FI MLLW u

z C

C Z

m i $o .

2

~~

,., ---[....

t e a r a e e 1 1 1 1 1 E 1 8 i E E E I I E I I I I I I I I I I I I I STATit'N 13 o . SAM *LE DEPTN -32 FT MLLN

..... 4- - -

( .....,;,,--- -.....,- ,

l - ......., ,- ,

o.

~ g. ..

d .

1 a -

t , t a a E E B b 2 R R a 3 t e a a # t i E E R 1 1 A a t E I E I I I l 1976 1977 1978 1979 1980 1981 1982 1983 1984 TIME (TEARS) ---- so.pr ine Intervan

• 2 Monene FIGURE 3-33 (CONT.)

ABUNDANCE VERSUS TIME FOR LAMINARIA DENTICERA B-83-540 IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SAO METHOD) 3-74

STATION 08 SM/LE DEPTH -l'c FT KLL!1 0 -

(

V) p---e, .

E, ,'

i. ,

n - . m ,,f ~ n '2 ~.n. m .& . nm

- - - 1 a - - w - w w w e

w - w a e a a 3 3 e w - -

a e e r a a g T I E I A I t e a e a e e a a e a e a STATION 09 SAeLE DE*TN -10 FT MLLW 0 -

r'w 0 a -

o e

W (L

$, Am: m m _,c ,a,/

n.__ ... [ m .b. [

co ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' '

E s

Z STATION 10 SAeLE DEPTM -10 FT MLLW W O -

u 2

C C

Z 3

(D C 3 -

2 C

kJ E

h k. mmm m mm m a J- _ m mm m mm -mm o

v ,

STATION 12 SA ELE DEPTH -10 FT MLLW

E -

O w ~

l l '

o e c & A E 1 B ch -

A E I I $ $ E

=c-~

A I

& c= =~ = = = = = c = ==

I I E I f f E t E E E I E I E E 8 E I a I 1980 1981 1962 1983 1964 1976 1977 1978 1979 TIME (TEARS)

---

Saepr ens Interva:

• 2 Montne

(

i l

l l

FIGURE 3-34 ABUNDANCE VERSUS TIME FOR NEREOCYSTIS LUETKEANA IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SAO METHOD)

B-83-540 3-75 l

I (D.

6 s

\

STATION 09 8 -

SAMPLE CEPih -15 FT MLLN

^

'~ n_ - - n a . . O .n _

yn e A a . . . . . . , , , . . . .

STATION 10 0 - SAM *LE DEPTH -15 FT MLLN S

a

.o -

C w

(L.

{N

\j o %C ^

C CCC C O CCCCC C CC C C CCC C CC CCC D

z STATION 12 w8 u

- SAM *LE DE*ih -15 FT MLLN z

C O

z m

en C O -

=

C W

r o

E .A 1 0

. . t .

00000 3

O O OCOh 000900 .00

. . . . . . . . E I E

^

h 00 0 0 B 0 ?C STATION 13 8 -

SAMPLE DEPTH -32 FT MLLN l O .

I o %i c c

. , , . . . . . . . . . . . . . . . i i . . . . . . . . . . . . . -

c0 0 CCc l 1976 1977 1978 1979 1960 1981 1982 1983 1984 l ~-

') TIME (TEAf!S) ___. 3 ,,,;,n,:n,,,,a1 > 2 Montne FIGURE 3-34 (CONT.)

B-83-540 ABUNDANCE VERSUS TIME FOR NEREOCYSTIS LUETKEANA l IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SAO METHOD) l . - . . - .- _3-_76

always absent during the winter seasons. In addition, due to its annual turnover cycle, there can be large differences in abundance between years and between stations. The abundances of Nereocystis at stations 10-15,12-15, and 13-32 were very low from 1976 to the present. The low densities of this species at these stations are probably attributable to lack of suitable substrate (i.e., large amounts of sand cover), a low frequency of substrate turnover, and/or lack of sufficient light caused by shadowing Pterycophora californica canopies (see Section 3.7.l.4).

In view of the large seasonal and between-station variations recorded for Nereocystis in the past, the Nereocystis abundances recorded in 1983 are not considered to be unusual despite the severe storms that occurred early in the year (see Section 4.1),

3.7.l.4 PTERYCOPHORA CALIFORNICA Pterycophora californica is a perennial tree-like kelp plant extending roughly one meter off the bottom. Its life history and general ecology were presented earlier g)

C. by PGandE (1979). Abundance values from 1976 to 1983 are presented in FIGURE 3-35.

The abundance of this species has generally been greater in south (10-10,10-15, 12-10, 12-15, 13-32) than in north (8-10, 9-10, 9-15) Diablo Cove stations.

Recruitment of Pterycophora normally occurs durina the spring and summer months and con create large differences in seasonal abundance. At station 9-10 there was a substantial increase (recruitment) during the summer of 1983. This increase was facilitated by the previous winter storms which opened up fresh substrate for colonization. The increase in Pterycophora plants at this time was the largest observed for this station since the beginning of this study in 1976.

Despite large variations in Pterycophora recruitment and mortality, this species has always been a conspicuous alga at all TEMP subtidal stations. Long-term (year-to-year) obundance trends for this species at stations 9-15 and 12-iS appear to have been quite stable. Gradu-' long-term decreases were apparent at O

B-83-540 3-77

STATION 08 g . SRMPLE CEPTH -10 FT MLLN (O

\,,.)

• ~

....~~

f't%... . . O, . .. ... Y'~ g,

'OO 4--...}... g o = ' ' .

, , , . . . , , , . , . . . i , . . , , . . i . ....=.a STRTION 09 E . SAM *LE DEPTH -10 FT MLLN

• E s -

N e

.. ~~~ 0-O ' ' ' - o -..e....... g . 9___ y _____ ...

w

,3 o , . , , , , , , , , . , , , , , , . . . . . . - . . . . ' ' .

E

$ STATION 10

• O o . SAM *LE DE*Th -10 FT MLLN w

• t.J z

C Q

z 3 O 2

O v W ' ""

v a STATION 12 g . SAMPLE DEPT * -10 Fi MLLN S -

.. oe. .

g

..e.e.s,,g' .f ~

O

, , , , . , , , , , . , , , , . . . . . i i . . . . . . = ' ' ' ' '

1977 1978 1979 1980 1981 1982 1983 1984 1976 TIME (TEARS)

- - - - Samp; eng Inteava! > 2 Months FIGURE 3-35 j ABUNDANCE VERSUS TIME FOR PTERYGOPHORA CALIFORNICA IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SAO METHOD)

B-83-540 3-78

O f \

V<

STATION 09 SRMPLE DEPIN -15 FT MLLN

...Q , 0-. ---

• --D 3--O' ~9..,

o B 1 e t i E I t i t I e i t I f R E I E I E I R f t B if E A E E i I STATION 10 o

2 -

SRMPLE CEPTH -15 Fi MLLN Os 4 o n' E -

c- i,e W e c.

, x i $

c3 o

\j r . . . , , . . . . . , , . . . i . . . . > > . . . . . . . > > . i i 3

5 STATION 12 y2 -

SRM*LE DEPTN -15 FT MLLN 2

C Q

z

.3 rn C o

' y. ..J

~

w E ,

o

. , , , , . , , . . > > , . . . . i i . . . . . . . i . . > > > e . -

STATION 13 o

O .

SRM*LE DE*TH -32 FT MLLN 8 -

.....4............4............4....__ .. . .... ... 1...g. .. . . g. g o

. , , , , i i i . . . ..iiie i e e e i i i i e e i i i a e n a i 1976 1977 '978 1979 1980 1981 1982 1983 1984 TIME ITEARS) n\s. ---- Soap! eng Interva! > 2 Monthe FIGURE 3-3S (CONT.)

ABUNDANCE VERSUS TIME FOR PTERYGOPHORA CALIFORNICA B-83-S40 IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (iAQ METHOD) i 3-79 l ._ . _

stations 8-10,10-10,12-10, and 13-32. At station 10-15 there was a dramatic

(']

U and steady decline in Pteryaophora densities over the course of this study.

Station 10-15,was originally occupied by adult Pteryqophora plants dominating stable substrata creas. Densities (once greater than 100 plants / 7 m2) were so great that the blades of these plants once formed nearly a continuous canopy over the station. The abundance of understory algae was sparse because of the shading effect of the thick canopy. Pterycophora recruitment occurred each spring-summer, but the young plants were confined to unstable substrate areas which were not under the direct shading influence of the adult canopy.

Consequently, these juvenile plants were short-lived due to their attachment on unstable substrate (rocks small enough to be moved by water movement). As the adult plants gradually senesced or were broken by storrns, the shading effects of the canopy were reduced, which increased opportunities for new plants to colonize these stable substrata. However, instead of Pterygophora, other species (primarily Botryoglossum farlowianum, see Section 3.9.l.l. in this report) be-came more abundant.

() Storms are a principal factor structuring nearshore subtidal communities in centrol California (Foster 1982). At station 10-15 the gradual reduction of Pterycophora was likely the result of ineffective recruitment concurrent with repeated winter storms removing more and more adult plants. Although storms can override grazing effects (Cowen et al.,1982), increased grazing pressures by abundant species such as Tequia brunneo (Section 3.7.2.9 in this report) could have influenced the decrease in the number of Pterygophora plants at station 10-

15. However, juvenile Pterycophora plorts have commonly been observed during the spring months; furthermore, the abundances of other algal species such as Laminario dentigera (a closely related kelp species susceptible to grazing) have remained relatively stable at this station (FlGURE 3-33). Therefore, storm breakage and natural senescence were probably the chief factors which lowered the abundance of Pterygophora at station 10-15. The fact that L. dentigera does not appear to be similarly affected by storms may be attributed to its more elastic stipe being less prone to breakage compared to the more rigid stipe of Pterycophora.

O U

B-83-540 3-80

O 3.7.2 IINERTEBRATES C/

This section contains descriptions of the abundance of nine taxa of macroinver-tebrates sampled by the SAG method (for sampling methods see Section 2.7).

Data collected consist of counts of individual organisms. For this report, data for nine species were selected for analysis. These are the enemone Anthopleura elegantissima; the sea stars Patiria miniata, Pisaster ochraceus and Pycnopodio helianthoides; the sea urchins Strongylocentrotus francisconus and S_. purpuratus; the gastropods Astraea gibberosa, Haliotis rufescens and Tequia brunnea; and the crab Pugettia producta. Descriptions of the general biology and thermal ecology of most of these species were presented in PGandE (1979).

Data for three invertebrate taxa in this section have been combined with those of their congeners to increase the data base for the genera. Data for Haliotis rufescens, the red abalone, were combined with those for the flat abalone, Holiotis walallensis. Pisaster ochraceus data were conibined with data for P_.

brevispinus and P_. giganteus because these latter taxa are generally subtidal species. Strongylocentrotus francisconus and S. purpuratus were combined as a single taxon.

For each species, the total counts for each arc quadrant (one arc quadrant encorapasses 7 m2) were averaged to yield a mean (N=4) abundance for each station sampled. An exception to this is the data for Tegula brunnea, where counts were made within one-third (2.33 m2) of each arc quadrant. An overview of these species' abundances through time (averaged over all surveys) is presented in TABLE 3-15.

3.7.2.1 ANTHOPLEURA ELEGANTISSIMA Anthopleuro elegantissima is commonly called the aggregating sea anemone because in the intertidal it frequently forms aggregations of up to several thousand individuals. Subtidally, Anthopleura is found as large, solitary (D

U B-83-540 3-81

t i

T ABLE 3-15 l

MEAN NUMBER OF INDIVIDUALS PER 28 M2 12 S.E. FOR SELECTED INVERTEBRATE SPECIES AT DIABLO COVE SUBTIDAL STATIONS (SAO METHOD), FROM j MARCH 1976 TO OCTOBER 1983 .

Number of Stronaylo-Station / Surveys Anthopleuro Astroco Holiotis Tequio centrotus Pycnopodio Pisoster Potirio Poettio Level (N) cleaantissimo ainberos.. spp. brunneo* spp. helianthoides spp. miniato producto 1

8-10 25 2.0 1 1.I l.8 1 1.2 2.6 1 0.5 94.1 1 27.0 0 f.8 1 0.5 0.5 1 0.3 9.6 1 4.6 1.1 1 1.0 1

9 10 25 2.911.3 1.0 1 0.5 1.2 1 0.9 57.5 1 12.6 0.1 1 0.2 1.4 1 0.5 0.6 1 0.3 15.9 1 6.8 0.4 1 0.4

., 10-10 33 9.4 1 2.4 4.7 1 1.7 0.2 1 0.2 88.9 1 22.0 0.1 1 0.1 1.6 1 0.4 0.5 1 0.3 27.9 1 4.4 1.1 1 0.7 I ta I cb 12-10 34 4.2 1 1.1 4.4 1 1.6 0.1 1 0.1 75.4 1 18.4 0 1.6 1 0.6 0.4 1 0.3 13.8 1 2.6 1.0 1 0.6 4 ro 9-15 25 8.2 1 2.4 3.0 1 1.3 0.4 1 0.4 97.4 1 22.2 0.1 1 0.1 1.9 1 0.8 1.0 1 0.7 35.8 1 5.2 0.7 1 0.4

{

10-15 34 26.214.8 l1.1 1 3.6 0 96.8 1 16.6 0.1 1 0.1 2.811.0 1.0 1 0.5 60.0 1 6.2 0.4 1 0.4 12-15 31 10.0 1 2.0 6.9 1 1.7 0 59.0 1 14.4 0.I 1 0.1 1.110.4 0.610.4 49.01 6.2 0.5 1 0.3 13-32 10 14.3 1 4.6 7.3 1 1.6 0 38.7 1 30.6 0.1 1 0.1 1.9 1 1.7 4.9 1 2.1 70.0 1 12.6 0 i

i

• Number per 2.33 m2 ,

)

]

4 B-83-540

individuals in cracks, crevices and under ledges in rocky areas or in the sand at the base of a rock shelf or boulder. The variation in abundance of Anthopleura seen at a given station through time may be largely due to the difficulty of

, sampling these animals when they contract after being disturbed into inconspic-vous sand-covered bumps on a rock.

FIGURE 3-36 shows the abundance of Anthopleura over time for the subtidal stations in Diablo Cove. These anemones occur at all stations in numbers that range from on average of 2 to over 25 individuals per station per survey sampled (TABLE 3-15). This table shows Anthopleura to be more abundant on the stations in south Diablo Cove than on those in the northern part of the Cove.

Anthopleura are also shown to be more abundant on the deeper stations than on the shallower ones.

i 3.7.2.2 ASTRAEA GISBEROSA Astraea gibberosa, the red turban (or top) snail is fairly common in the Diablo O Cove subtidal stations. This species seems to prefer creas with thick mots of articulated coralline algae. Turban snails are probably exclusively herbivorous and have been observed to eat both drif t and attached algae. Although no studies on the size distribution of Astraea in the Diablo Canyon area have been

{ done, they appear to have a distinct bi-modal size distribution: the smaller size class is centered at approximately 25-35 mm shell diameter (1-1.5 in.) and the larger class is centered at 60 mm and larger (2.5-3 in.).

The abundance of Astraea through time is shown in FIGURE 3-37 for the Diablo Cove subtidal stations. They occur in numbers ranging from an average of I to iI individuals per station per sample (TABLE 3-15). Astraea appears to be more abundaat in south Diablo Cove (stations 10 and 12) than on those in north Diablo Cove (stations 8 and 9). It may also be slightly more abundant at -15 f t than at

-10 f t.

l l

l B-83-540 3-83

O .

STATION 09 o SAM *LE DEPTN -10 FT MLLN m -

, , : _ } ------ # a . & "* O.._ ~ __.. - G e -O' -- -- --

~

~

.~ ~ . ~ . ~ . . . . .~. . . . . . . . . . . . . . . . . . . . . . .

e o STATION 10 <-

yo . SAMPLE DEPTH -10 FT MLLN a

E -

l m

• E i s- -

s' ,' ,

sa

,e  ;- . ,o M '

/ #

80 8 V so . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

I C

2 STATION 12

$o x

SAMPLE CEPTN -10 FT MLLN m ~

a & .

c.._

1976 1977 1978 1979 1920 1921 1982 1983 1984 TIME ITEARS)

---

Samp! no Interval

• 2 Months l

l FIGURE 3-36 ABUNDANCE VERSUS TIME FOR ANTHOPLEURA ELEGANTISSIMA IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SAQ METHOD)

B-83-540 l 3-84 1

l l

f N.Y STATION 09 O -

SAMPLE DEPTH -15 Fi MLLW m -

, i p... . . O, g, g-'

- . . . . . . . . . . ... s ,

O j I k 9 A a e i 1 R 9 E I I A i E t A A I 2 2 I E 3 R & E R E R A I STATION 10 E,a SAM *LE GEPTH -15 FT HLLW X

r b o m -

e W

(L B-e-.... Q ... Q

'd o , , , . . , , , , , , , , , , . . . . . . . . i . . . . . . . . . . .

1 STATION 12 W SAM *LE DEPTH -15 FT MLLN y o .

e Q

z 3

cn C .,

2 m -

c W

r A*

,' N.,

O .

b I E E I B A I E I E i 1 I 1 i I i t B i t 2 i g a a a e a 3 3 1 I I STATION 13 o SAMPLE DEPTH -32 FT MLLW

v. -

O , i . . . . . . . . . . . i - = = = =

1978 1979 1920 1963 1982 1983 1984 n 1976 1977 TIME ITEARS) ---- so.,tene ine. .: > 2 Monen.

i (y)\

FIGURE 3 36 (CONT.)

ABUNDANCE VERSUS TI' TOR ANTHOPLEURA ELEGANTISSIMA B-83-540 IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SAO METHOD) 3-85

STATION 08 SIM7LE DEPTH -10 FT MLLn o_ ,

' m -

'L,/ ,E' , :

, 4 -- m .! d # ,/ A _ _ , . . o_ _ m STATI0h 09 o .

SAMPLE DEPTH -10 FT MLLN E

a t- m -

C IAJ n n 3 .., 3 .- .. n -- --* O .n---- Q g -

3 r . , . , , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

z-STATION 10 yo _

SAM *LE DEPTH -10 FT MLLW z

C O

z 3

cn C

z C

ttJ r

' & O----- ,,.

. . . . . . . . . ." .~. . . . . . .

STATION 12 o .

SAM *LE CE*TN -10 FT MLLN m

1 I

O,, l

- % __. h.. m o I I I I E

. . . . . . . . . . . . . . . . . . I E E I E E I E I I I I 1976 1977 1978 1979 19e0 19P1 4962 1983 198#

TIME (TERRS) ---- Sompting Interval

• 2 Montne O

i Q FIGURE 3-37 l ABUNDANCE VERSUS TIME FOR ASTRAEA GIBBEROSA l IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SAO METHOD) 1 B-83-540 l 3-86

I d

. STATION 09

$ AMPLE DEPTH -15 FT MLtd oh m

- , ,4. , ,,

,,,. ,,,,.. g STATION 10 SAM *LE DEPTH -15 FT MLLW E

r'w a

> 0 -

c 4.

A n ^--On A 3 3 _~ n_~ W"-% -W 3 M--- q3

,. n ....,,,.. . . . ,

g , , , , . . . . . . . . . . . . , , . . .

z t

~

STATION 12 SAMPLE DE*TH -15 FT MLlW Uo z

E O

z 3

cn C

2 m W

CI T ,k ~,

b' '

y .... ..... M , , . . . . . . . . . . . . . . . . . . . .

. 7 7, , , , , . . . T.

STATION 13 SAMPLE DEPTH -32 FT MLLN o .

m -

--~~~~

j ,,,,,5,.....

~~~~~'~~~ '"O s,

. . . . . . . n . .

, , . . , , , , , , . . , , , , . , . . . . n n n 1979 19ec 1921 sE*2 1983 1984 1976 1977 1978

/] j TIME (TEMS) ---- Samp! sng Interva! > 2 Months FIGURE 3-37 (CONT.)

ABUNDANCE VERSUS TIME FOR ASTRAEA GIBBEROSA

! B-83-540 IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SAG METHOD) 3-87

O 3.7.2.3 HAllOTIS RUFESCENS AND H. WALALLENSIS V

Red abalone,,Haliotis rufescens, and the flat abalone H_. walallensis are both present in Diablo Cove although only two flat abalone have been recorded from the TEMP subtidal stations in Diablo Cove since May 1976. Burge and Schultz (1973) described the shallow (0 to 6 m) depths along most of the inside perimeter of Dicbio Cove as excellent abalone habitat with a large population of H.

rufescens and densities in some areas of 1.29 abalone /m2. The entire subtidal community structure, including abalone abundance, changed dramatically a few years af ter the Burge and Schultz (1973) study with the arrival in 1974 of the southern sea otter.

l As seen in FIGURE 3-38 and TABLE 3-15 Haliotis are neither common nor abundant in the TEu,P subtidal stations in Diablo Cove. North Diablo Cove stations 8 and 9 show the greatest abundance of abalone through time. At station 8-10, Haliotis abundance declined steadily with time. No Haliotis have been observed on stations 10-15 or 12-15 in south Diablo Cove or on station 13-32 in the center of the Cove.

3.7.2.4 PATIRIA MINIATA The common bat star, Patiria miniata, is a conspicuous macroinvertebrate in the SAO samples. Bat stars are omnivorous scavengers, not predators as are most asteroids, and are seldom seen actively moving about. They are commonly found on unconsolidated sediments or cobbles and are easily disloaged from the substrate.

The abundance of Patiria through time is shown in FIGURE 3-39 for the subtidal stations in Diablo Cove. Patiria is more abundant in the southern half of Diablo Cove than the northern half and its abundance increases with increasing depth (see also TABLE 3-15). This distribution is probably related to the lower j turbulence in these areas. Patiria are present in numbers ranging from on average of about 10 to 70 individuals per station per survey (TABLE 3-15).

lO B-83-540 3-88

STAT!ON 08 3 - STiGPLE DEpiN -1C Fi MLLW

?

I.

("% , .

Q ,.: *8e %,  ;

...Y o- -e-. ...g_ _ _ ,,_

- STATION 09 o*

$498LC DE*TN -10 FI MLLW v'e a

3 m -

t W .

}k D, m :_ m m

/, G -- O -

' % . ..' - O .,0%. , _ _ __

z . . . . , , . . , , . . . . . . . . . 2 , , , . . . .

m 5 STATTON 10 to 3 - $44*LE DE*iN -10 Fi MLLW u

2 C

o 2

m to C . .

2 C

w I

(h o m - m - - mmm m m mm -mAm mm m m

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. . . . . . . . . . . . t i , , . , 1 . . I 1 . . . . t B t 1 I I t STAT!0h 12

$4M*LE CEpiH -10 Fi MLLW m -

O C C C C C CCCCCCCCCCCb D CCC CC C C ^ 'C C CCC i , , . . , , . . . . . . . . . . . . . . . > i . . . . . . . . . i 1976 1977 1978 1979 1980 1981 1982 1983 1984 TIME ITEARS)

Sosol ens Interval

• 2 Months O

Q FIGURE 3-38 ABUNDANCE VERSUS TIME FOR HAllOTIS RUFESCENS AND H. WALLALLENSIS --

IN DIABLO COVE FROM MARCH 1976 B-83-540 TO OCTOBER 1983 (SAO METHOD) 3-89

l J

E a

< r- STATION 09 EE a.

~ '

SAM *LE DEPTH -15 FT Mttd b .

E

$* ~

I'!

z

@ o  ; ; ;

333 e 'g__.n_; m ; g 3,*'G'% 3 3 ;

g. . _ _ g/

3 > - i e i i . , . . . , , , , , , , , , , , , , , , , , , , , , , , ,

1979 1980 1981 1982 1983 1984

$ - 1976 1977 1978 g TIME ITERRS) uJ ---* Samp! rne Inteeva! > 2 Months E

i l

l l

l FIGURE 3-38 (CONT.)

ABUNDANCE VERSUS TIME FOR HAllOTIS RUFESCENS AND H. WALLALLENSIS IN DIABLO COVE FROM' MARCH 1976 TO OCTOBER 1983 (SAO METHOD)

B-83-540 3-90

STATION 05 SAMPLE DEPTH -10 FT KLL83

, G

% e - / /'N l ' ' - --.....

l ,

t

..'.... -M , ...O ..e

{'

. . A A . . t a t i I a R , t , , . . . .,~t . . t , t , , a R , , ,

STATION 09 . ~ = -

o SR"*.! DEPTN -10 FT MLLW O .

A a g .

t*

c W

Q.

, g g ' ~ g._.. e _g Ly ... m - G -a. ***** 'g..O**** u ... ***** %

= = * * ' ' ' ' ' ' ' ' ' ' ' = ' i a = 'a a i i i = a a = a i a a r a 3

5 STAl10N 10 SAMPLE DEPTH -10 FT MLLW w 3 .

u z

E Q

z 3

m E o .

2 E

ha g ..... M ****  % -..-.

I i t i I f a f .1 1 i e a i e 1 3 d I a A I a i I t t t t t t t A E a STATION 12 0 -

SAM *LE DEPTM -10 FT MLLW Q

l R .

l . \

6. .

o e B i t I I t a a e a a t a i 1 1 1 I E I $ i f f I t A I 1 a A i E I 1976 1979 1920 19F1 19F2 19e3 1984 1976 1977 TIME ITEMS) ---- Soop!sna Interval

• 2 Nontne W FIGURE 3-39 ABUNDANCE VERSUS TIME FOR PATIRIA MINIATA IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SAG METHOD)

B-83-540 3-91

/'T STATION 09 o SAMPLE DE*TN -15 FT MLLW o .

3 -

. . . . . . . . . .. . e4 ,..o... - . O- . .e *~ G -- 0--- ----- %

. ...,,...............,,,..,, . . a, . . .

STATION 10 e SAM *LE DEPTH - b F~ MLLW o .

E a

o 3 -

e w

O

~~~

e..... [ }" . 4 I

m STATION 12 y$ .

SAM *LE CEPIN -15 FT MLLW z

C O

z m

to E osn -

C W

E -

o N

s., g .ee- % ..%"

STATION 13 SAMPLE DE*TH -32 FT MLLM l

3 -

....................;............-.----~~----~~"*"*%---e~%

o 1972 1977 1978 1979 1960 1961 1982 1983 1984 O

g TIME (YEARS) ---. ......,. T,,..~., , , ..,...

FIGURE 3-39 (CONT.)

ABUNDANCE VERSUS TIME FOR PATlRIA MINIATA B-83-540 IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SAQ METHOD) 3-92

3.7.2.5 P10 ASTER OCHRACEUS, P. GIGANTEUS, AND (v] F. BMhVISPINUS These three species of Pisoster occur intermittently on the Diablo Cove subtidal stations. Of the three, P_. ochraceus and P_. brevispinus are the most common in the shallow subtidal areas whereas P_. giganteus are more abundant in the deep subtidal area:. As an active predator on mussels and barnacles, P_. ochraceus, the ochre sea stor, is a common and important member of the rocky shore intertidal communities. It is generally replaced in the shallow subtidal areas of Diablo Cove by P_. brevispinus, also on active predator on molluscs.

FIGURE 3-40 shows that the abundance of Pisaster on the subtidal stations is low, generally averaging one or two sea stars per station when present. On station 13-32, Pisaster was present in significantly higher numbers with an average of about 5 sea stars per station for each of the 10 surveys (TABLE 3-15).

Pisoster was present in slightly more than 50 per cent of the surveys sampled at stations 8 and 9 and in less than 50 percent of the surveys sampled at stations 10 p and 12, with the exception of station 10-15 where Pisaster was present in most b of the 34 surveys.

3.7.2.6 PUGETTlA PRODUCTA AND P_. RICHil Pugettia producta is a member of the spider crab family but is commonly called the kelp crab. Large adults are generally found in the canopy of the brown algae Cystoseira and Pterygophora. Juvenile P. producta are distributed throughout the intertidal and shallow subtidal areas, usually in the subconopy algae.

Pugettia richii, the decorator or spider crab, is common subtidally in the subconopy or understory algae, particularly the articulated corallines. Both species are herbivorous and are important forage items for various fishes found in the study area (Guast 1968, PGancE 1979).

(O)

B-83-540 3-93

STATION 08 _

Q

~

$4MTLE DEPTH -10 FT MLLW

') m -

V

. . AxA A __.. a . : a. 2 A . .Q..~A s STATION 09 3 -

SAM *LE DEPTN -10 FT MLLW E

a o m -

c w

Q.

c I ya LA

....G . .-- --- a _.n._. .

, _ ..... _I E , . . . . , , . . . . . . . . . . , . . . . . . . . . . . . . . . . . f

~'

5 STATION 10 W SAM *LE DE*!N -10 FT MLLW u 3 2

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Z 3

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2 C

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STATION 12 3 -

SAM'LE DE*TN -10 FT MLLW m -

O O - 0 0% O h #O W m#m 0 0hOOO h O 00 1976 1977 1978 1979 1980 1981 1982 1983 1984 TIME IYEARS) --_. S..,:,n,rne..,.: > 2 Montne C

d FIGURE 3-40 ABUNDANCE VERSUS TIME FOR PISASTER OCHRACEUS, P. GIGANTEUS, AND P. BREVISPINUS IN DIABLO COVE FROM MARCH IT/6 B-83-540 TO OCTOBER 1983 (SAO METHOD) 3-94

.O

. STATTON 09

$44*LE DE*IN -15 FT MLLa en

• • - -et , ~ B .. n , m ., J . n ..m.__ 2"9 _ n M- -

t I 1 A I 1 8 I i b 1 I E t I i i R I E E i i I E I I I I I I 1 1 1 I I

STATION 10

- SAM *LE CEpih -15 ri M*. LW A

s -

s on cr tu EL.

y 5 mo W, .

. N.A- - - m  %. . _ n .n n.

n,

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• a i - ' ' ' '

m

• STATION 12 kJ O -

. SAM *LE DE*iS -15 ri MLLW u

z C

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m e

C m "

z C

tu l

o n. .n s.. .. .<M l'u n n D ~A -cL-

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I I I n t 3 a 3 t i s I t E E I 1 R E E I I I 3 I I I E I I I I I STATION 13

- SAM *LE DE*T5 -32 r; gttw l

l

....................... ............. .............................p....o-'y o .

& R 1 h t t E A I E i a t I e a I t t I t b b f E E I R 1 A I E 1 i 1976 1977 1978 1979 1980 19e1 1982 1983 1984 TIME ITEARS)

---

so.ptins Inte-vot > 2 Mcsene FIGURE 3-40 (CONT.)

ABUNDANCE VERSUS TIME FOR PISASTER OCHRACEUS, P. GIGANTEUS, AND P. BREVISPINUS IN DIABLO C0VE FROM MARCH IT/6 B-83-540 TO OCTOBER 1983 (SAQ METHOD) l 3 -93

(~N The graphs in FIGURE 3-41 show the abundances of Pugettia for each Diablo Cove subtidal station through time. In general, the abundances of Pugettia are low and its ogcurrence on the subtidal stations is sporadic. It appears to prefer the shallow areas (no Pugettia have been found on station 13-32).

Pugettia producto was found in densities up to 27 individuals /m2 and P. richil in densities up to 245/m2 within kelp holdfasts in Montere> Bay, California (Morris et al.1980). The TEMP methods do not involve kelp holdfast sampling (which is a destructive technique); therefore, the TEMP data may well underestimate the abundance of these species.

3.7.2.7 PYCNOPODIA HELIANTHOIDES Pycnopodic helianthoiries, commonly cc!!ed the sunflower star, is a large, fast moving, active predator on sea urchins, bivalves, chitons, gastropods, other sea stars, sea cucumbers and crabs (Morris et al.1980). Proximity to or contact with Pycnopodia initiates an escape response in many of its prey species, including

[ ) obalone (Montgomery 1967). They are very conspicuous when present on a station and are not easily overlooked by divers.

As seen in FIGURE 3-42, Pycnopodia was present at all stations in virtually all surveys sampled. The average number of Pycnopodia present on a station is between I and 2; station 10-15 in south Diablo Cove had a slightly higher abundance than the other stations (TABLE 3-14). These sea stars do not appear to show a preference for a particular area or depth within Diablo Cove.

3,7.2.8 STRONGYLOCENTROTUS FRANCISCANUS AND S_. PURPUR ATUS Both the red sea urchin, Strongylocentrotus francisconus, and the purple urchin, S_. purpuratus, occur in the Diablo Cove subtidal stations. Strongylocentrotus displays two basic types of feeding behavior depending upon the prevailing environmental conditions: (1) feeding predominantly on drif t algae, especially brown algae, and (2) grazing on attached microscopic and macroscopic algae. In TN areas where Strongylocentrotus is abundant, it may play a significant role in h

B-83-540 3-96

m STATION 08 1 3 -

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l 1

a m - ., m - M mm .,s. - . ci_, . - '- ,- m .M 197E 1977 197e 1979 1980 19e1 1962 1983 1984 TIME ITEMS) ---- Soop! ens Inteavo! > 2 Montne I

] FIGURE 3-41 ABUNDANCE VERSUS TIME FOR PUGETTI A PRODUCTA IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SAO METHOD)

B-83-540 3-97

U~

STATION 09 o ~

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, a g3 C STATION 12 2

e o- SAM *LE DE*IN -15 Fi MLLW w -

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O C, C, ,-C, . . . .CCC C C C C',O CC -,-

NCC -- AM 19C0 19El 1982 1983 1984 1976 1977 1978 1979 TINE ETERRS) ---- Samol,ne inteeval > 2 nonene 1

FIGURE 3-4I (CONT.)

O V ABUNDANCE VERSUS TIME FOR PUGETTIA PRODUCT A IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SAO METHO B-83-540 3-98

STATION 08 1 2 SAM?LE DEPTH -10 FT MLLif l

n m -

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=

n n .

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1 . 1 . . , , a . . . . E , 1 . . . . . . . . . I I . . . . I . . I I 1976 1977 1978 1979 1980 1981 1982 1983 1984 l

TIME (YERRS) ___. so pr ene Intervat > 2 Montne i

i

(~ FIGURE 3-42

(

ABUNDANCE VERSUS TIME FOR PYCNOPODIA HELIANTHOIDES IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SAQ METHOD)

B-83-540 3-99

e

\  ;

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STATION 09 o . SAM *LE DEPIN -15 ri nttw w -

w,  % . c.. a & ~C .. , n

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km e . . . --- O % .. _ ~ .m **%

x , , , , , , ,,n , , , n m

• STATION 12 WO - SAM *LE DEpi5 -15 FT MLLd u

2 C

Q z

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ABUNDANCE VERSUS TIME FOR PYCNOPODIA HELIANTHOIDES B-83-540 IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SAO METHOD) 3-100

(j determining the species composition and relative abundance of the associated cigae.

Prior to 1974, Strongylocentrotus densities in Diablo Cove reached 105/m2 in areas described by North (1971) as " barren areas," because of the almost complete lack of algae (Denech and Colson 1976). The densities of both species of urchins were reduced drastically due to foraging activities by the southern sea otter which arrived in Diablo Cove in 1974. As indicated in TABLE 3-15 and FIGURE 3-43, a total of less than 15 Strongylocentrotus were counted on all subtidal stations in Diablo Cove over all surveys since May 1976.

3.7.2.9 TEGULA BRUNNEA Brown turban snails, Tequia brunnea, are ubiquitous and the most abundant invertebrate species sampled by the SAO method in the Diablo Canyon TEMP subtidal study areas. The majority of adult Tegula are found of f the bottom, in fm the fronds and stipes of the large brown algae Pterygophora ar.d Cystoseira.

\

(V Juveniles are generally associated with the understory algae particurlorly the {

fleshy red algae. These snails are probably exclusively herbivorous with a I marked food preference for the brown algae (Morris et al.1980, PGandE 1979).

Because of their high abundance on the subtidal stations, which makes accurate counting difficult and time consuming, Tegula brunnea is sampled only in the first one-third of each are quadrant (sample area = 2.33 m2). As shown in FIGURE 3-44, T. brunnea is abundant at all subtidal stations in Diablo Cove.

From TABLE 3-15, the mean number of Tegulo per station per survey ranged from nearly 40 to nearly 100 individuals. It appears to be about equally abundant in both the north and south Diablo Cove stations as well as at both the 10 and 15 f t depths. The abundance of Tegula brunnea generally drops sharply at depths over 20-25 f t as is indicated by their low numbers at station 13-32.

An unexplained feature of FIGURE 3-44 is the general increase in the abundance of Tegula at all stations from the early surveys until survey 17 when a sudden O

U B-83-540 3-101

s STATich 09

• . - SRNPLE DEPTH -10 FT NLLN E

a 3m

+ c 4'

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t Io m: O O.O . .O. O. . . . . OO O O ' . ".

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. . 2 . A . a . 1 . A 1 . 1 A i 1 . . t & . I . . E . . . 1 . 1 E 1 g

1976 1977 1976 1979 1980 1981 1982 1983 1984 TIME (TEARS) _ _ .

sa el ene Interval > 2 Montne t

i f

i l

1 FIGURE 3-43 i

l ABUNDANCE VERSUS TIME FOR STONGYLOCENTRCTUS PURPURATUS AND S. FRANCISCANUS (SAO METHC ~"-

B-83-540 3-102

,-e, . _ , . _ ,,, , , , , , _ ,_n ,_g ,, .,, _ - - _ _ _ _ _ _ _ . , , , , ,,7

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(J 1 ST41Ich 09 o . SAM *LE DE*Th -15 FT MLtd e -

o O O O 0000 O 00000 . . . . , .

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SAM *LE CEST*t -15 FT MLLW E

s , .

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1 o - SAM *LE DEPTH -32 FT MLLN m -

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-9 1 1 h O 00 1 E . . I E I t 4 1 m t E 1976 1977 1978 1979 1980 1981 1982 1983 1984

(

8 TIME ITERRSJ ___. 3 ,3,no Intervan = 2 Monen.

FIGURE 3-43 (CONT.)

ABUNDANCE VERSUS TIME FOR STONGYLOCENTROTUS PURPURATUS AND S_. FRANCISCANUS (SAO METHOD)

B-83-540 3-103

STRTTON 08

~

~ -

5 AMPLE DEPTM -!0 FT KLLW

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1977 1978 1979 1960 1921 1962 1983 1984 {.

1976 I NNOI ---- Seept ens Interval > 2 Montne .

FIGURE 3-44 l ABUNDANCE VERSUS TIME FOR TEGULA BRUNNEA IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SAO METHOD)

B-83-540 3-104

\

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staff 0N 09 8

SAM *LE DE*TN -15 FT MLLW

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m STATION 10 C O N3 su SAM *LE DE*TH -15 ri MLLN

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t.a Z i c

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3 . SAM *LE DEPTH -32 FT MLLW g..-...........................__.,,__,_ f ..... -

N &976 1977 1978 1979 1950 1961 1982 1983 1984 i

) ,

TIME (YEARS) ---. samaring Interval > 2 Montne

! FIGURE 3-44 (CONT.)

B-83-540 ABUNDANCE VERSUS TIME FOR TEGULA BRUNNEA IN DIABLO COVE FROM MARCH 1976 TO OCTOBEFI 1983 (SAO METHOD) 3-105

decrease in the numbers of Tegula occurred at most of the subtidal stations.

This is best seen at stations 8-10,10-10, and 12-10.

3.8 SUBTIDAL FIXED QUADRAT (SFO)

Thirty-nine subtidal surveys were completed fron$ May 1976 to October 1983 (see TABLE 3-16). Each subtidal survey includes sampling by the SAQ, SFO, and SLC methods (see Sections 2.7, 2.8, and 2.9, respectively).

In the following sections, data are presented showing the abundance over 39 surveys of seven invertebrate taxa sampled by the SFO method. Only dato collected from TEMP subtidal stations located within Diablo Cove are includeo in this report. See FIGURE 2-1 for the locations and depths of these stations.

3.8.1 INVERTEBRATES This section contains a description of the abundance in the TEMP subtidal stations of seven invertebrate taxa sampled by the SFO method: Anthopleura i

elegantissima, Tegula brunneo and Pugettia producta (abundances of these species as sampled by the SAG method were discussed above in Sections 3.7.2.1, 3.7.2.9, and 3.7.2.6.) and the hermit crabs, Pogurus spp., the gastropods Acmaea mitra and Mitrella spp., and the habitat forming colonial / social tunicates.

For six of the seven species, counts of all individuals within each of the four fixed quadrats (0.2S m2 each) were made. For colonial / social tunicates, estimates of cover in square inches (1 in.2 = 6.45 cm2) were made in the quadrats. These data were then converted to square centimeters and averaged to obtain a mean (N=4) number of square centimeters cover per 0.25 m2 for each station.

n B-83-540 3-106

O O O l TABLE 3-16 l MEAN NUMBER OF INDIVIDUALS PER 0.25 m2 + 2 S.E. FOR SELECTED INVERTEBRATE

, SPECIES AT DIABLO COVE SUBTIDAL STATIONS (SFO METHOD), FROM MARCH 1976 TO OCTOBER 1983.

Nember of

, Station / Surveys Anthopleuro Pogurus Pugettio Acmaeo Mitrello Tegolo C/S*

l Level (N) Elegantissimo spp. spp. mitro spp. brunneo tunicates l

] 8-10 25 0 43.4 1 10.2 6.5 12.4 1.7 1 0.8 32.118.6 11.2 1 2.0 4.4 1 1.0 J i j 9-10 25 0 28.719.2 5.9 1 2.8 2.9 1 1.0 26.718.6 I5.1 1 4.1 2.9 1 0.8 l ,

10-10 33 0.4 1 0.2 37.118.2 1.9 1 0.8 1.2 1 0.6 15.114.2 12.5 1 3.0 5.8 1 I.4 i E I2-10 34 0.3 1 0.2 41.1 1 11.1 6.4 1 2.2 0.9 1 0.6 11.8 1 3.0 17.7 1 4.6 8.3 1 1.4 l

j 9-15 25 0.8 1 0.2 42.3115.8 5.6 1 I.8 3.4 1 1.0 6.0 1 2.2 15.7 1 3.6 6.3 1 1.6 i

10-15 34 1.9 1 0.2 23.515.8 2.7 1 1.0 5.0 1 1.6 2.2 1 0.8 15.2 1 2.6 9.1 1 1.2

, 12-15 31 1.0 1 0.2 42.611.07 4.2 1 1.4 1.1 1 0.6 14.2 1 3.6 5.5 1 1.8 4.0 1 1.0 j i3-32 10 2.3 1 0.8 3.6 1 2.8 0.9 1 1.2 1.9 1 1.4 0 2.2 1 1.4 4.6 1 2.4 I i

• Values are in.2 per 0.25 m2 1

J B-83-540 j

i.

, ,,_34, ng.-

3.8.l.1 ACMAEA MITRA Acmaea mitra, commonly referred to as the white-cap or dunce-cap limpet, is found from the low intertidal to the shallow subtidal. Acmaea mitro breeds in the winter and spawns when the sea temperature is at or near minimum (Morris et al.1980). Ricketts et al. (1968) state that individuals of this species are usually solitary. In Diablo Cove, Acmaea mitra are not uncommon. Adults seem to prefer the relatively unstable boulder and cobble habitat while juveniles are found on coralline crust covered rocks.

FIGURE 3-45 presents the mean abundance of Acmaea mitra from the SFO method. It can be seen that this species has been present at all stations in Diablo Cove, and during most surveys the maximum abundance occurs at station 10-15. The number of individuals varies both within and between years at all staticns. The data indicate a slight increase in the number of individuals at station 10-15 during fall surveys.

3.8.1.2 ANTHOPLEURA ELEGANTISSIMA A brief description of Anthopleura eleoantissima was given in Section 3.7.2.1 above. FIGURE 3-46 shows the mean abundance through time for the TEMP subtidal stations in Diablo Cove. As explained earlier, these data are not appropriate for defining the distribution of Anthopleura. They are, however, similar to a marking or tagging study for Anthopleuro if the data are examined on a quadrat by quadrat basis for each station. At station 12-15, for example, a single Anthopleuro eleaantissimo has been recorded in fixed quadrat 2 for all but seven of the 31 surveys. This station has been sampled since May 1976.

Therefore, it appears that Anthopleuro con live at least eight years and will remain in essentially the some location for that length of time, b

v B-83-540 3-108

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1977 197e 1979 1960 1981 1976 TIME (TEMS)

• l - - - - Soopt eng Interval

• 2 Montne l

\

j FIGURE 3-45 ABUNDANCE VER5US TIME FOR ACMAEA MITRA IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SFQ METHOD)

B-83-540 3-109

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$44*LE CEPTN -32 FT MLLw

• • • • • i***-***................. ,,,,,,,,,,__ _ ,

g e i e u I I E A d 1 e i I 1 I 1 I E i k 2 A f I I E a f E 2 I I I 1976 1977 1978 1979 1980 1983 1982 1983 1984 TIME (TEARS) ----

s o.o r ine Interval > 2 Montne FIGURE 3-45 (CONT.)

ABUNDANCE VERSUS Tly,E FOR ACMAEA MITRA B-83-540 IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SFO METHOD) 3-110

d I

i STATION 10 o 544*LE DEPTM -10 FT MLLW l R

a in N

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d" c

w a

l c - - : - - - ___ m a- -^^

$4----- n__ _ _ n__ u - _ _ _

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.5 STATION 12 _

o SAMPLE CEPTM -10 FT MLLW w .

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1977 1978 1979 1980 1981 1982 1983 1984 1376 TIME ITERRS) ___. 3 ,,,,,,,go,,,,,,3 , 2 Montne i

l 1

l FIGURE 3-46 ABUNDANCE VERSUS TIME FOR ANTHOPLEURA ELEGANTISSIMA IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SFO METHOD)

B-83-540 3-1Ii l

t

, . , , - - - - - _ - . _ . - ,. . .. . -,,...n - - - ---.,..-- - - - -. . - - .

STATION 10 0 .

SAMPLE DEPTM -15 FT MLLd m

0

,, 5, e J= = A= = mm --%e... _ p . ...m fN g STATION 12 C,

SA%*LE CESTN -15 Ff MLLW e .

w Q

e w

m r

j m -

w u

z

$a z . . . '.-- A*

^%

. . ... A . M '.- . . .- .* - ". .

3 m

" STATTON 13 SAMPLE DEPTM -32 FT MLLW I

$o w

r m -

, gc c...................----------------"----"--""-""*"""%.....,...w 1978 1979 14PO 19el 1982 1963 1984 q 1976 1977 TIME (TERRS) s a.pl e ns Inc -<a:

• 2 Ponen.

gj - - - -

FIGURE 3-46 (CONT.)

ABUNDANCE VERSUS TIME FOR ANTHOPLEURA ELEGANTISSIMA B-83-540 IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SFO METHOD) 3-112

3.8.1.3 COLONIAL / SOCIAL TUNICATES The colonial / social tunicate sampling category includes individuals in at least five genero (Aplidium, Archidistomo, Distoptio, Ritterella and Didemnum) en-compassing at least fifteen species of colonial tunicates and four species of social tunicates in the Diablo Canyon study area. Tunicates are encrusting, filter-feeding animals that are generally more abundant on vertical surfaces and underhangs than on horizontal ones. The colonial tunicates have their individual zoolds embedded in a common tunic material, while the zooids of the social tunicates are generally separcted from each other, being only connected at their base. It is sometimes difficult to distinguish these two categories of tunicates in the field, so they have been recorded as one entity. The individual zooids undergo a sexual reproduction (budding) and are not very long lived, but the colony as a whole con live up to one or two years and even longer for some species.

The mean number of square centimeters per 0.25 m2 through time of colonial /

h social tunicates is present in FIGURE 3-47. This " taxon" was found during almost every survey at all the stations. No one station consistently had the maximum area covered throughout the study period. Since survey 17, the mean area covered by colonial / social tunicates at station 9-15 has decreased. There was generally more area covered at stations 10-I0 and 12-10 (south Diablo Cove) than at 8-10 and 9-10 (north Diablo Cove) throughout all of the surveys.

3.8.1.4 MITRELLA SPP.

Diablo Cove is within the geographical distribution ranges of three species of _

Mitrella: M. aurantioco, M. tuberoso and M. carinato. The majority of the '

individuais found in the study area are M. carinata, commonly referred to os the carinate dove shell. Mitrella is abundant on subtidal kelp holdfasts and appears to be a microcarnivore and detritus feeder. When feeding on algol blades, it is probably eating the attached (epiphytic) material and not the algae itself. Dove shell is probably an important forage item for certain fish and the shells of dead individuals are used by small Paqurus spp.

B-83-540 3-113

STATION 08 549PLE DEffM -10 FT KLLit

-w

• E

',,, M, ,

. N, ,, O "-- -- g ,

g . , . . . . . . . . . . . . . , , , . , , , ,,,,.........

t

@3 STATION 09 O ,

SAM *LE DEPTN -10 FT MLLN

. c *

• W W

r eR n

m N

>i.,","*,

w ,___ ,+ .u-e-..&-. 4. 4 - " ' e ~*

• c, g . n . n . . i i a i . . . . . n i . . . > , , , , , ,

o m STATION 10 t

kJ SAMPLE DE*TN -10 FT MLLN

~

hE

~

W z '

W t,,2

, R a

m

• • • ,,e-g . . . . . . . . . . . . . . . . . . . . , . ..... ,,,,..,,

z STATION f2 e

yo SAM *LE CE*TN -10 FT ML6N e

E ~

~ f**'. .

..ed 1976 ' "1977 1978 1979 1980 1981 1982 1983 1984 ,

TIME (TEARS) i

~~~ Seep!tng inteeval > 2 Nontne ,

l l '

D i FIGURE 3-47 t

G ABUNDANCE VERSUS TIME FOR COLONIAL / SOCIAL TUNICATES IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (5FO METHOD)

B-83-540 3-114

STATION 09 o $RMPLE DEPTN -15 FT MLLO e -

(' ,

i o .

V *

-.........3.g V ,,' .

\, ..e--=... p. .g__ f...m

,o .

. . . . . . . . . .... ..... ............ .i s

e e STATION 10 Q

E,

• SAMPLE DEPTN -15 FT MLLW D w c .

W e=

w r

o g n '

..,, T..,

O o .>>>.. . . . . . . .

, , . . . , , . . .......iiii g

E S14Tf0N 12 Eo wa "

SAM *LE DEPTH -15 FT MLLW

>=

w

.E De z

WO ,

L.s M

_ ... **** * 'h' W . . .~. . . . .. .... i .......i. .

8 STATTON 13 3E SAMPLE DEPTH -32 FT MLLM C o ya "

i

• ....y.

~ ....... ,

• • • .....: ...- \

..... 4. o- -- . . o.,

o iiii i . i i . . . .

. . i , , i i . . .,,,ii .....

1976 1977 1978 1979 1980 1981 1982 1983 1984 i

• TIME (TEARS) ___. 3 ,,,;,n,gne,r,,3 , 2 Montne

[

FIGURE 3-47 (CONT.)

i l

fh Q ABUNDANCE VERSUS TIME FOR COLONIAL / SOCIAL TUNICATES l IN DIABLO COVE FROM MARCH 1976 TO I OCTOBER 1983 (SFO METHOD)

B-83-S40 3-115

in t

v) FIGURE 3-48 presents a graphical representation of the subtidal fixed quadrat data for Mitrella spp. at all of the Diablo Cove stations. At each of the stations, there is variation both within and between years. Stations 8-10 and 9-10 generally had the greatest number of individuals, although not for every survey.

No Mitrella were ever found in the fixed quadrats at station 13-32. The variation in the abundance of this taxon in any one quadrat through time appears to be directly influenced by the algal species present. As the algol species decrease, the abundance of Mitrella decreases.

3.8.1.5 PAGURUS SPP.

Three species of Pacurus spp. are found in the Diablo Cove study areas: Pocurus samuelis, P. hirsutiusculus, and P_. cronosimanus. Adults cnd juveniles of cll three species occur from the intertidal to at least the shallow subtidal zone.

Two species of subtidal hermit crabs may also be included in the Paqurus spp.

categories: Isocheles pilosus and Pacurus bakeri.

r Paaurg spp. are scavengers on plant and dead animal matter. They have been ,

observed to pick tentacles off tube worms and the tube feet off of sea urchins and may kill a snail for its shell (Ricketts et al.1968). Hermit crabs are on important item in the diet of the pile surfperch, Damalichthys vacca (Morris et al.1980), a common fish in the Diablo Cove study areas, and other fish species as well.

The mean abundances through time of Pocurus spp. are presented in FIGURE 3-

49. The SFO method samples many more small Paqurus individuals than is practical to sample by the SAG method. At each station there is both within and between-year variation. No one station consistently had more individuals throughout all of the surveys. The lowest abundance of Paqurus occurred at station 13-32 (see TABLE 3-6).

O B-83-540 3-116

STATTUN 08 i

@ . SAMPLE DEPTH -10 FT MLL:3 3 -

\ /

-a...@ -ll'~.f~-o-0-+...}~. __. _.._....

STATTON 09

! . SAMPLE DEPTN -10 FT MLLM E

a m

N c3 8 -

c La.4 A

r

,,... - 3-f-

, , , , , ,' O .

~

9... - % ..O....

......... A z

STATION 10 O

d0 z

- SAMPLE CEPTH -10 FT MLLM C

Q z

s cn C Om -

C LaJ r

m' .m7

( ,

O

. . . . . . . . . . . h__.........h_.

4, , a STATION 12 h . SAMPLE DEPTH -10 F1 %.LN 3 -

g

- O ^ h. e ~n - m'- a ..a O - e m n.. A 1 i . A a R A k I E R I E 1 I . A I A i i 1 . . R . E E E E 8 I E E I 1976 1977 1978 1979 10PC 1961 1982 1983 1984  :

TIME ITERRS) ---- Samp!rne Interra! > 2 Months l

• i l

l l

(

FIGURE 3-48

~

ABUNDANCE VERSUS TIME FOR MITRELLA SPP.

IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SFO METHOD)

B-83-540 3-117 t

jh g

STATION 09 0 - ,

SAMPLE DESTM -15 FT MLtd 9

m -

f '.,

l s-..~..., . .'

l 7.

~~'o~.

l

, ._,o' m

m f STATION 10 e 3 - SAMPLE DEPTN -15 FT MLLN w

L e

w m

E

@m w

U

' ^ ^^^ ~ ~~

Q ".",",",'T","

. ~ . ' . ."

.~7, ,", , , , , , , , , ,

o

" STATION 12 z SAMPLE DE'TH -15 FT MLLW e

w 3 -

r S -

i a ! -.... ~*h* h d , g __ m ,, _ m 1976 1977 1978 1979 1990 1981 1992 1983 1984 .

TIME (YEABS) ---- Soap 3 rne Inteeval

• 2 Montne 1 l

1 FIGURE 3-48 (CONT.)

843-540 ABUNDANCE VERSUS TIME FOR MITRELLA SPP.

IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SFO METHOD) 3-118

STRTION 08 o SAMPLE DEPTH -10 FT MLLt3 2 -

8 -

\,j

,.: g :....p s. e*s--- o. -e- -- ** ' 'V*-- --- es*

STRTTON 09 o $44'LE DEPTN -10 FT MLLN 2 -

R s

in N o .

ci

• c W

' s.. e ... ~

O** g .... - G .4 5, .

, m. .....f e- a ' . . .

m ' ' ' ' ' ' ' ' ' ' ' ' ' > = = ' i * . = . .

x m

• STRTION 10

~o SAMPLE DE'TH -10 FT MLLN w2 L)

C O

z 3

to cS -

z C

w i---OO' ...&

g g g g g g g 3 3

' . .E . 1 1 1 1 . E 1 . I t t l 3

' I E E E 1 R STRTION 12 u SAM *LE DEPTH -10 FT MLLW 2 -

8 -

a -3 \A e 33 9 g - -- '-,

geec aget gge2 gge3 gge4 1976 Ig77 1978 gg79 j

TIME ITERRS)

- - - - Saep! ens Interva! > 2 Months U FIGURE 3 49 I

ABUNDANCE VERSUS TIME FOR P ACURUS SPP.

IN Dl'ABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SFO METHOD)

B-83-540 3-l 19 i

L .

/7 b

\j)

STATION 09 8

~

SRM*LE DE*TH -15 FT MLLM S -

. , __ ,..V ..e. A --'---- 02^^*- Q '-+ - q

' I I E I E I . , i , A , I , , ,g , g g ,,,,s K x g g STATION 10 8

SAM *LE DESTN -15 Fi MLLW G

e in o -

fn C

W (1.

-m g A . 8 *-- M ----. M

[v ' g

, g z

~ STATl0N t2 O

SAM *LE DE'Th -15 FT MLLM d

z C

o z

s a2

, CS -

z i C l W

, A ........

-a-...y STATION 13 ,

O SAMPLE DEPTH -32 FT MLLN i i

l i ...........- - % , .

~

__,........... .,w l 1976 1977 1978 1974 1980 19P1 10P2 1983 1994 TIME (TEARS) ---- Sampl ene Intervo!

• 2 Months l 3 FIGURE 3-49 (CONT.)

l B-83-540 ABUNDANCE VERSUS TIME FOR PAGURUS SPP.

IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SFO METHOD) 3-I20

d 3.8.l.6 PUGETTIA PRODUCTA AND PUGETTIA RICHil The spider crabs Pugettia producta and P_. richii were briefly described in Section 3.7.2.6 above. Pugettia appear to be more abundant based on the SFQ data when compared with the SAQ data (Section 3.7.2.6). The SFO method records juvenile spider crabs which are generally more abundant than the large adults. Though adult P_. richii are common in Diablo Cove, they are often cryptic and covered j with a layer of sand.

The SFQ data for the mean number of Pugettia at all the Diablo Cove stations through time is presented in FIGURE 3-50. The number of Pugettia varied both within and between years at all stations. Abundance was low, usually overoging less than two Pugettia per 0.25 m2 quadrat. The greatest mean number of Pugettia, seven individuals per quadrat, was found during survey 17 at station 9-

10. No one station consistently had more individuals than any of the other stations. The fewest number of Pugettic were found at station 13-32.

, 3.8.1.7 TEGULA BRUNEA Brown turban snails, Tegula brunnea, were described in Section 3.7.2.9. Varia- <

tion in the abundance of Tegulo in the fixed quadrats at a given station is partially a result of the different habitats included in each fixed quadrat, particularly if the quadrat contains a large Pterygophora or Cystoseira plant.

Densities calculated from SFO data for Tegula are greater than the densities calculated from the SAQ sampling method due to the fact that juveniles in the ,

understory algae were sampled by the SFQ method and not by the SAQ method. ,

4 FIGURE 3-51 presents the SFO data of the mean abundance of Tegula brunnea at all the Diablo Cove stations through time. Individuals of this species were found at all stations during most all of the surveys. No one station consistently had more individuals than the other stations during all of the surveys. At each station the number of Tegula brunnea varied both within and between years. At stations 10-10 and 12-10 between surveys 10 and 18 and station 12-15 between surveys 10 and 15 there were more Tequia brunneo than during the other surveys.

B-83-540 3-121

STATICN 08 o .

$1MPLE DEPTM -10 FT MLLet

f. m -

f. ,

< \, .

(~

. .,, s, i

--- iN , ' ' , ,

, t' 'm o

STATION 09 o, .

S4M*LE DEPTS -10 Fi MLtd 5

E Ln N '.

's, ' ,, '

f vt

's ,!

C ', .'

y P......Q --- .

3..a ...

,- O m ,

yo O O O O O -

m O

r 3

5 sinilas so w o .

SAMPLE DE*ih -10 Fa MLtd La z

C Q

z J 3 m

e ,,, .

z E

w p ..... p '

-3 A A ---- %

%gj/

ij o 1

.- .- _ h.#. mAA R E R R a i b d a 1 1 E 1 1 1 1 A i A E a I 1 1 1 d i I t i E A STATION 12 o, ,.

S4M*LE DE*75 -1 C F MLLA o

m -

o O O O O O 003C' F SN^O2

• 10 ~~ O" ; O -;

A i d I 1 & a f 1 A E 1 k 2 1 1 1 E 1 R A 1 E A E 1 h i 1 b I & I E 1976 1977 1978 1979 19PO 19e! 1982 1983 1984 TIME (TEARS)  ;

---

Sampf ens Intervat > 2 Montne a FIGURE 3-50 ABUNDANCE VERSUS TIME FOR PUGETTIA PRODUCTA AND P. RICHil -

IN DIABLO COVE FROM MARCH 1976 B-83-540 TO OCTOBER 1983 (SFO METHOD) 3-122

p

(

+

STRT10N 09 O -

SAM *LE CE'Th -15 ri MLLW e

.O o

,a ,, ,..

,,...+

% .. ... /

, . , ,.a . , , , , , , g g

' I . I . . . . . . 1 . . , 1 S T RT ( Ot. IO O -

SAM'LE DE*TH -15 r; gttw U

e Lo N

gm -

c Lu

- - - . > . ___ , N, , , Mm o 7, , , , , , , , , , , , ,

V E . . . . . . .

m 5 STRT10N 12 SAM *LE DE*75 -15 Fi MLLW W

o 3 -

Z C

O Z

3 CD C g .

Z C

W E

e

*-b O ^ ^ ^ ^'

i STRil0N 13

(

SAMPLE DEPTH -32 FT MLLN 3 -

i m

• • • • • • • +---.-..... ,

,0 4..... ,,,,,, _

3q70 goeg gget 1962 1983 1984 1976 1977 1978 O TIME ITERRS) ---- s ... . o r 4. .~.: , 2 n ,. .

V FIGURE 3-50 (CONT.)

ABUNDANCE VERSUS TIME FOR PUGETTIA PRODUCTA AND P. RICHil B-83~S40 IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SFO METHOD) 3-l23

- _ . - .. . ._ ~ .. ---

STATION 08 o - SAMPLE DEPTH -10 FT MLLN

-; q .. '. ,W ~

~

...- G ,..

o a a A e a a I , t i a g e a 5 1 A i e A t E E 1 i , I I A 1 1 R I E E STATION 09

! . SAM *LE D'EPTH -10 FT MLLN E

s tn N

ci 0 -

c w

Q.

N (D O ,. J_ 2 - _ . 0 9 6.e -%.... . - - G - -n . . . - - % - G -

&- -- -- ' - - -b g . , , . . . . . . . , , . . . . . . . . . . . . . . . . . . . . . . i 5 STATT0h 10 w I .

SAM *LE DEPTH -10 FT MLLW u -

z C

o Z

3 cn C O -

m z

C W

r

/O * , ,2 ^

m em . n 2_ . - - - O ~ ^ ._ . m

\, } . . , , , , , , , . , , , . . . , , . , , , , , , , . n . . . . . . n STATich 12 SAM *LE DEPTN -10 FT MLLW S -

. , : - e .% o - --m._O...-,

1976 1977 1978 1979 1980 1981 1982 1983 1984 l*

TIME (TEARS)

---

Sampl ang Interval > 2 Monthe b

, FIGURE 3-51 s

i (

ABUNDANCE VERSUS TIME FOR TEGULA BRUNNEA IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SFO METHOD)

B-83-540 3-124

a f

STATION 09 O

O - SAM *LE DE*TH -15 FT MLLW 3 -

, g _ . .;. oO& 4--- G---@--- O . - n . .---- Ge - e---- M------ N S 1 1 I E I E 1 2 1 1 1 A B t 1 1 I I I 1 I E R R I e a i b I A B t STATION 10

! - $498LE DEPih -15 Fi MLLW E

e in U O gm -

c W

Q-E n - - ~ c C 000 O b, 0-a n O ^W -M---- W--- m (UO) E , . ' i , i i . . , , , , . i , , , , , , , , , , i .

a

$ STATION 12 y 0 -

S AM*LE DE*ih -15 Fi MLLW o

z C

O z

o co C g -

z C

y .*

r .'

o

}*W STATION 13 O - SAM *LE DEPTN -32 FT MLLN i m -

/

~ .. O, O e .............----- ;--------- --- - -- ----~~~'~~~**'~~~~~~~"~~ W A B $ I I E R A i 1 I E R 1 9 I R a i 2 1 A R A 1 R R R 2 1 I I 1 I E 1976 1977 1978 1979 1980 1981 1982 1983 1984

/m y) TIME ITEARS) ---- S ... l . 1, . .~ . :

• 2 n o .,,.

FIGURE 3-51 (CONT.)

ABUNDANCE VERSUS TIME FOR TEGULA BRUNNEA B43 N IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SFO METHOD) 3-125

'(o) 3.9 SUBTIDAL RANDOM LINE POINT CONTACT (RLPC)

The SLC method has been described earlier in this report in Section 2.9. A total of 39 SLC surveys have been completed over the period 1976 to 1983 (TABLE 3- 14).

3.9.1 ALGAE The following sections are devoted to presentations of percentage cover data for the foliose red alga Botryoglossum farlowianum and the articulated coralline algae complex consisting of Colliarthron spp., Bossiella spp., and Serraticardia spp. ("CBS complex"). B,_. forlowianum and the CBS complex have been described as being among the most abundant algal taxa in most TEMP subtidal study sites (LCMR 1978, PGondE 1979). Abundance descriptions in these reports were based on data collected within the first two and one-half years of this program.

Seasonal abundances presented in this report for these taxa are based on more recent data collections. The sampling period considered for this report is September 1976 to September 1983.

Data collected are the number of points at which a species occurs within ecch of the four are quadrants (total points sampled = 50). When divided by 50, the values for each species are considered to represent percentage cover values.

The four values on each station were averaged to obtain the mean values presented. ,

3.9.l.1 BOTRYOGLOSSUM FARLOWIANUM Botryoclossum farlowianum is a perennial foliose red alga that occurs primarily epiphytically on articulated coralline algae (Calliarthron spp. and Bossiella spp.,

see Section 3.9.l.2.). It is one of the most abundant seaweeds in shallow subtidal Diablo Cove habitats (PGandE 1979). Hymenena spp., a closely related and similar appearing species, is occasionally found mixed in clumps of f)

V l

B-83-540 3-126

p

@. forlowianum and the data for this species is combined with Q. farlowianum in this report.

Percentage cover measurements for @. farlowianum (plus Hymeneno spp.) in the Diablo Cove stations from 1976 to 1983 are presented in FIGURE 3-52. On a year-to-year basis, this species' obundance has been relatively stable at all stations. Variations within the year show a tendency for higher abundances during the svenmer months. An overall long-term gradual increase in cover is noticeable at stations 10-10 and 10-15. This may be attributed to a simultaneous decrease in Pterycophora californico (FIGURE 3-35) whose subsurface canopies con limit, by shading, the abundance of understory algae.

Since articulated coralline algae provide o substrate for attachment of Q.

farlowianum, the abundance of @. farlowianum in shallow water has been generally greater in areas where there is more articulated coralline algae.

Hence, in the post, @. farlowianum has been slightly more abundant in north (8-10, 9-10, 9-15) versus south (10-10,10-15,12-10,12-15,13-32) Diablo Cove C stations. However, over recent years the abundance of E. farlowianum at j

stations 10-10 and 10-15 has increased (probably as a result of diminishing Pterycophora canopies) and now approaches the abundance at the north Diablo Cove stations.

3.9.l.2 CALLIARTHRON, BOSSIELLA AND SERRATiCARDIA SPP.

(CBS-COMPLEX)

Calliarthron spp., Bossiello spp. and Serraticardia spp. (commonly described as articulated coralline algae) are recorded as one sampled category ("CBS complex") due to their similarities in morphology and growth habits. Based on percentage cover, these three genero combined were found to be one of the most common taxa in most TEMP subtidal fixed stations (PGandE 1979). For this report, the CBS complex does not include Bossiella californica ssp. schmittii.

This plant is more readily distinguishable from other members of the genus Bossiello. Also, for the TEMP subtidal stations it has been found only at station 13-32 and in small quantity. From 1976 to 1983 seasonal abundances of the CBS

(

rs B-83-540 3-127 l

STATION 08 o

2 -

57MPLE DEPTN -10 FT CLLCO f~h 8 -

"*"- ~'

,D* *

...... .. +.,_

o staff 0N 09 o

2 -

SAM'LE CEPTH -10 FT MLLW C

E P-o .

, ' -- 's ,

g

~... .

o . , ~

U N

N W o STATION 10 e 2 w

SAMPLE DEPTN -10 FT MLLW b .

w U

z m

co

~

.../ ,

C (7

's J E

V . . . . . . . . . . . . . . . . . . . . ...............

STAT 10N 12 o

2 -

SAM *LE DESTN -10 *T MLtd' S -

o

. . <(*'- Q.. \,g. y l 1976 1977 1978 1979 1980 1981 1982 1983 1984

TIME (TEARS) '

1 s.,;.pl e ne Inter val > 2 Nonens I

1 l

FIGURE 3-52 ABUNDANCE VERSUS TIME FOR BOTRYOGLOSSUM FARLOWIANUM l lN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SLC METHOD) i B-83-540 3-128

?

%/

STATION 09 o

2 .

SAMPLE CEPTN -15 FT MLLM o .

. O'+ ../ ,

', ,e N. '4 o

1 . . . . . . . . . . . I 1 . I f . . . . . . . . . . . . . . . . . .

STATION 10 o SAM *LE CE'Th -15 FT MLLd n

E t%

e w

A o .

C U .... .,

o w M JOOa n./ o o . . . . . . . . . . . . . . . . . . . . . . . i > > . . . . . . . . .

e e-6 STATION 12 u o SAM *LE CESTN -15 FT MLtd e o W

A, w

U z

c o o m -

O Z

3 E,

$ .00' '  ;'

4 2 ,

C

, g r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ,

STATION 13 I C .

SAMPLE CEPTN -32 F7 MLLM S -

I e l _  ! J ..... 4..........................

1979 1980 1981 1982 1983 1984 f) 1976 1977 1978 TIME ITEARS) Samp! r ns Int erval > 2 Monthe i

l 1

Nel ----

FIGURE 3-52 (CONT.)

B-83-540 ABUNDANCE VERSUS TIME FOR BOTRYOGLOSSUM FARLOWIANUM IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SLC METHOD).

3 129

. ~.

complex have been relatively constant at all Diablo Cove TEMP stations (FIGURE 3-53). With the exception of station 10-10 in south Diablo Cove, overall abundances have been slightly greater in north (810,9-10,9-15) versus south (10-15,12-10,12,-15,13-32) Diablo Cove stations. This may be related to variations in the amount of suitable stable rock substrates among the Diablo Cove stations.

3.9.2 SUBSTRATES The abundance of various types of substrates (rock, cobble, sand) within TEMP Dinblo Cove subtidal stations was presented in PGanE (1979). The data described in this earlier report were from the first years sampling period (1976-1977). In this report seasonal changes in sand cover are presented for the period 1976 to 1983. Sand cover is of biological interest since it relctes to storm disturbance effects as well as providing information on substrate suitability /non-suitability and availability within the TEMP stations.

3.9.2.1 SAND l t

One of the principal community structuring forces in central California subtidal habitats is high water and sand motion. Seasonal data on sand cover in the Diablo Cove TEMP subtidal stations are presented in FIGURE 3-54. Although these data do not provide direct indications of disturbance or sand movement (i.e., a station with constant values of sand cover does not imply absence of transport), it does provide information on the amount of non-suitable substrate l for algol and invertebrate attachment. Sand transport is revealed b" over measurements only when sand cover changes appreciably through time.

Stations 12-10 and 12-15 provide examples where large amounts of sand have been deposited and removed: sand cover has generally been higher during winter and lower during summer periods. Excluding station 10-15, sand cover has been higher in south Dichio Cove (10-10,12-10,12-15,13-32) versus north Diablo Cove (8-10, 9-10, 9-15) stations.

O B-83-540 3-130

1 I

STATION 08 l o . .

2 -

34?#LE CEPTH -10 FT MLLu I l

(

,... h ,- ...o---e - -%-e -/~~,

o STATION 09 O

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e 5

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. .:. . . . %. . [ " ,. O -g. ... . - Ge' ' \ ,;N e , -

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uo STATION 10 e3 w

SAM *LE CEPTH -10 FT MLLN h

W u

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c STATION 12 o

SAM *LE CEPTH -10 FT MLLsd i

E -

..a*'-Q.. \ j o

i . , , . . . ... . ,, ...... .ii....,,i..

1976 1977 1978 1979 1980 1981 1982 1983 1984 TIME ITEA85) i

---

Samp! sng Interval > 2 Months l

l l

l t

FIGURE 3-53 ABUNDANCE VERSUS TIME FOR CBS COMPLEX IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SLC METHOD) l B-83-540 3-131 i

i - - - - - - . - _ - - _ _ - - _ _ . , , - _ _ - - _ _ - _ _

/

a STAT 10N 09 0 .

2 - SAMPLE CE*TH -15 FT MLLN 3 -

O. .. ...c-

~~"

'O-. s, O

. E & 1 . . . . . . . 1 . I i 1 E , 1 A . 1 I . B . . . . . A 1 .

STATION 10 8

. - SAMPLE CEPIN -15 FT MLLN m

a t~

c w

~ ~~~~

f v w t

'% o e . . . . . . . . . . > > > . . . . . . . . . . . . . . . . . . . . . .

i c

N U O STATION 12 C 3 w

SAM *LE CE*Th -15 FT MLLN 9:

w U

z e O o m -

z (y"8'

' ' 7- .,,

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z 6O r , . . . . . . . . . . . . . . . . . . . . . . . . . . . . , , , . . . .

STATION 13 S - SAM *LE CESTN -32 FT MLLN O, .

...~~'" ....,_

.... g ----O, 1 . . . . . . . 1 . 1 E , . . . . . . . t . . A a f . . . . 1 . A .

t Q 1976 1977 1978 ~1979 1980 TIME (TEARS) 1981 1982 1983 1984 t, f ___. 3,,,, , no r ne.~al

• 2 Mene ns FIGURE 3-53 (CONT.)

ABUNDANCE VERSUS TIME FOR CBS COMPLEX B-83-540 IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SLC METHOD) 3-132

STATION 08 -

E -

SAnPLE DEPTN -10 FT MLLt3

,0. . ' '

%<' -.g '

'O., .. ,

a . . . _ .a . . .

STATION 09 _

,E -

. SA4*LE CESTH -10 FT MLLW m

iE r-C ko .

, 's ,:

c l. o' .

W / ...f 9..

@ i . . . . 2 i . . . . .~.. ... ... .. ..~.....

w 6

uo STATION 10 C - SAMPLE DEPTN -10 Fi MLLW W

W U

z C o am -

Z g

( z -

\

$o r . > > . . . . . . . . ..... >>. . . ........

STAil0N 42 ,

o

- SAMPLE CEPTM -10 FT MLLW 9.

l , *

. g . -O-G, / '

m - '

1 o _

1976 1977 1978 1979 1980 1981 1982 1983 1984 {

TIME (TERRS) i

---

Soapling Interval

• 2 Monthe q, FIGURE 3-54 ABUNDANCE VERSUS TIME FOR SAND

IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SLC METHOD)

B-83.540 3-133

d STATION 09 R - SAMPLE CEPTN -15 FT MLLW 2 -

p.

,' D- - . ,# ', 'N, g..e ..

..g ,

O .,

g. . . . . . . . . . . . . . . .. . . . . . . . .

STATION 10 SAM *LE GE*TH -15 FT MLLN 2 -

C e

P=

c W

L S -

e Y ,Q Qd 8 w

@a . . . . . . . . . . . . . . . . . . . . . . . . . . . .......

$ STATION 12 SAM *LE CE*TN -15 FT MLLd e O., -

W h

w -

u ..... .

so a m -

z .-

,a 3

na e

2 bO r . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....... t STATION 13 l a

o 3 - SAMPLE DEPTN -32 FT MLLN O -

" ~ ~ ~ ~ ~ ~l -..g

...................------" \p ~

O . .......

. . . . . . . . . . . . . . . . . . . . . 1 1 1963 1984 O 1976 1977 1978 1979 1980 1981 1982

,1

\ TIME (TERf1S 1 ---- Samp!,ng Interva: > 2 Monens f FIGURE 3-54 (CONT.)

I ABUNDANCE VERSUS TIME FOR SAND IN DIABLO COVE FROM MARCH 1976 TO OCTOBER 1983 (SLC METHOD) 3-134 l B-83-540___.-...- _. .. _ _

3.10 SUBTIDAL CRAB TRAPPING AND TAGGING During 1983, five subtidal crab trapping surveys were conducted, with the February 1983 survey cancelled due to rough sea conditions (TABLE 3-17). Each of the completed surveys consisted of 70 or 72 trop sets deployed over a 6-day period. Total numbers of Concer ar.tennarius trapped, and catch per unit effort (i.e., number of crabs trapped per '24-br trap set) for completed surveys are presented in TABLE 3-17. FIGURE 3-55 presents long-term changes in CPUE from August 1976 to October 1983. A detailed discussion of catch trends, aspects of the ecology, and life history of Cancer antennarius can be found in the TEMP 1982 Annual Report.

3.1i SUBTIDAL FISH OBSERVATIONS Underwater fish observation surveys have been conducted since August 1976.

The information obtained will provide a basis for comparing changes in abun-dance and composition of fish prior to and during the operation of the power plant. Fixed sampling sites were located in areas likely to increase in water I l temperature from the thermal discharge of the power plant, and in areas with no predicted increase.

l Prior to 1983, six fish transect stations were actively sampled (stations 6,7,8, 10,13 and 14, see FIGURE 2-5). The general physical features of these transects were described by PGandi (1983, p. 3-69). Beginning with survey 35 in l

l January 1983, five additional stations (4, 5, 9,11 and 12) were reactivated for l sampling resulting in a total of eleven active fish transect stations. (Note, however, that limiting conditions may not allow all transects to be sampled in every survey.) Of the eleven stations, five (4, 5, 6, 8 and 12) are oriented

parallel to the shoreline or follow depth contours and six (7,9,10, i1,13 and 14) l are oriented perpendicularly to the shoreline or across depth contours.

I The physical features of the five reactivated stations are briefly described below. Station 4 follows the -25 ft isoboth from subtidal station 5-25 on a compass bearing of 270 deg ees. A small stand of kelp, Macrocystis pyrifera, is B-83-540 3-135

O i l

, TABLE 3-17

SUMMARY

STATISTICS FOR CRAB TRAPPING SUBTASK SURVEYS 35-40 (1983)

CPUE*

Total No.  % Upper Lower Survey Date Crabs Males N Mean 95% Cl 95% Cl 35 2-83 Survey cancelled due to rough sea conditions 36 4-83 215 67.7 72 3.03 3.42 2.64 37 6-83 280 63.6 72 3.88 4.60 3.16 38 8-83 360 51.1 72 5.02 6.18 3.86 39 10-83 447 46.8 72 6.21 7.40 5.02 40 12-83 294 55.1 70 4.20 5.10 3.30

• Number of crabs trapped per 24-br trap set i

d

!O B-83-540 3-136 5

, ~ . . . _ . . . - . _ -

- - - . . - - - . - - - ' - - , - - - ~ - ' ---~'-*-=' +' """~ "' -~'-~-** -'" ~ ~ ~ ~ ' - ~ ~ ~ ^ ~ " ~ ~ ~ '

• O O O Q

$3 Y

O i

is- I 8

Li.

i Vertical bare represent 95% confidenne intervals dout Itw means.

b Humber of tr@ sets = 77 far oil surveys except August . November 1976, g and Jeuary 1977 (n=75), February 1980 (n=&R), January 1981 (n=65),

l ed December 198? In=70). Sample size n=94:4.

l 3 io- I cr

yr -

. . I i

l

G5 u r - l I

< i i i .

" i i 7----Iy,&*

i i  ! , ._.

i

' l/.N

's qj'I i c{ '

i /NAx, *

, 1/' VNisk*i '

l -

/1 4yist I

\1-7 I i -

i MP MhV JAtl NAH MAY Jt P f N IX C f f t's APH Jt i At'O OC'Y ((C fii) A H Jtti AhG OCT I CF H APH $ ts A(O OCT li C fitt A[*H [tJ AlsG OCT [1 C F[B APH Jth4 A G OC'T I C I

- 1976- - 1977 1918 1979 I?RO - 1981 -

1987 1963 TIME (MONTHS)

FIGURE 3-55 BIMONTHLY CANCER ANTENNARIUS CATCH PER UNIT tttORT (wUE) FMOM AUGUST 1976 TO DECEMBER 1983 CPUE was defined as the mean number tropped per 24 hr trop set.

, located 30 m inshore end 40 m upcoast of this transect. The bottom is rock outcropping and large boulders with Laminaria and foliose red algae. Shallow caves and ledges are present throughout this area. Station 5 in north Diablo Cove extends from subtidal station 8-10 along the -10 ft isoboth to subtidal station 7-10. The transect crosses rock ledges and Phyllospadix beds. The relief is moderate (less than 2 m). Station 9 originates at subtidal station 11-15 in south Diablo Cove and traverses 50 m of rock outcropping and a major sand channel. B, Iders are common along this transect. Station 11 is located near the center of Diablo Cove, downcoast from the main channel. Depths range from -32 ft at the origin (subtidal station 13-32), to -47 f t at the terminus. The transect runs parallel to rock ledges which support dense Pterygophora stands.

Station 12, located in South Cove, follows tae -10 f t contour from subtidal station 20-10 (a benthic station not sampled for algae and invertebrates at this time). High relief boulders with coralline crusts and articulated coralline algae are common in the area.

Eight species of fish were selected for detailed analysis on the basis of their V overall abundance. A brief summary of the composition, total abundance, and overall rank of each species in 1983 is presented.

During the 1983 surveys from May through October (mid-winter surveys were cancelled due to unfavorable weather), 5,297 fish comprising 47 taxa (14 of which were observed fewer than 6 times) were observed in Diablo Cove and South Cove (TABLE 3-10). Ten species comprised about 90 percent of the total young and adult fish observed in the 42 transect samples obtained in 1983: -

senorita (43 percent), kelp bass (12 percent), black-and-yellow rockfish j (8 percent), painted greenling (6 percent), rockfish juveniles (4 percent), topsmelt (4 percent), blue rockfish (4 percent), striped surfperch (3 percent), black surf-

perch (2 percent), and tubesnout (2 percent).

Juveniles of eleven taxa made up 51 percent of the total fish observed with juvenile senorita comprising 54 percent of all juvenile fish, fo!! owed in abund-ance by juvenile kelp bass (24 percent), and juvenile black-and-yellow / gopher rockfish (8 percent).

B-83-540 3-138

_ ~ . _ . . _ _

, TABLE 3-18

SUMMARY

OF ABUNDANCE AND SPECIES COMPOSillON OF YOUNC AND ADULT FISHES IN DlABLO COVE AND SOUTH COVE FROM MAY 1983 TO OCTOBER 1983.

Total Total Percentage Total Percentage Number Percentage Number Adult Number Juvenile Species Observed Composition Adults Composition Juveniles Composition Oxylulis californica 2,294 43 842 33 1,452 54 (senorita)

Paratabrax clothratus **

641 12 2 639 24 (kelp bass)

Sebastes chrysomelas (black-md-yellow rockfish) 429 8 208 8 221' 8' Oxylebius pictus 319 6 319 12 0 0 (painted greenling)

Sebastes spp.

(unid. rockfish) 233 4 0 0 233 9 Atherinidoe unid.

212 4 212 8 0 0 (topsmelt)

Sebastes mystinus

• g94 g g93 7 g* ..

(blue rockfish)

Embiotoca lateralis

%/ (striped surfperch) 164 3 128 5 36 I  !

7 Embiotoca jacicsoni "

(black surfperch) 126 2 121 S S ,

Autorhynchus flavidus 82 2 82 3 0 0 Ttubesnout)

Gibbonsta spp.

62 I 62 2 0 0 (kelpfish)

Scorpaenichthys marmoratus (cabezon) 61 1 61 2 0 0 Damatichthys vacca **

(pile surfperch) 54 I 48 2 6 e

Heterostichus rostratus 44 0 0 (giet kelpfish) 1 44 2 [

Hexogrammos decogrammus Twelp greenling) 39 I 39 2 0 0 Cottidae unid.

(sculpin) 37 1 0 0 37 I Sebastes rostrelliger (grass rockfish) 36 1 23 1 13' l'

• Juveniles of this species may have been recorded as "Sebastes spp."

• Value less than 0.5 percent.

O B-83-540 3-139

n TABLE 3-18 Ih'

SUMMARY

OF ABUNDANCE AND SPECIES COMPOSITION OF YOUNG AND ADULT FISHES IN DIABLO COVE AND SOUTH COVE FROM MAY 1983 TO OCTOBER 1983.

(CONTINUED)

Total Total Percentage Total Percentoge Number Percentage Number Adult Number Juvenile Species Observed Composition Adults Composition Juveniles Composition Sebastes cornatus *

• 35 1 35 I (gopher rockfish)

Cymotogaster aggregata 28 1 28 1 0 0 (shiner surfperch)

Sebastes otrovirens *

• 24 1 24 I (kelp rockfish)

Orthonopios triacis "

23 23 1 0 0 (snubnose sculpin)

Sebostes courinus n g7 . .

37 g (copper rockfish)

Rhacochilus toxotes "

16 16 1 0 0 (rubberlip surf perch)

Artedius spp. **

(sculpin) 16 16 1 0 0 m Sebestes curiculatus 15 " 0 0 15' l'  ;

I i (V ) (brown rockfish)

Opbiodon elongatus f 12 " 12 1 0 0 (lingcod) -

Brochyistius frenatus " "

(kelp surfp rch) 11 11 0 0 Cebidichthys violoceus gi n gi n TE;cnkeyIoce eet) o o Sebastes_ serranoides 11 ** 10 " l' **

(olive ruckfish) l l Cephotoscyllium ventriosum ** **

10 10 0 0 (swell shark) l Hypsurus coryi ** "

(rainbow surfperch) 8 8 0 0

{

Coryphopterus nichoisii " **

8 8 O O (blockeye goby)

Trochurus symmetricus ** **

6 6 0 0 tjock mockerel) other taxa (total of 14 species)

(less than 5 individuals counted 19 " 19 " 0 0 during sampling period)

Totals 5,297 2,594 2,703 O^*

• Juveniles of this species may have been recorded as "Sebastes spp."

k " Value less than 0.5 percent.

1 B_83 540 3-140 l

l - _ . . , _ _ _ - _ . , _ _ _ _ -- -

l l

Adult fish numbered 2,594 and represented 43 taxa The five most abundant adult taxo were senorito (33 percent), painted greenling (12 percent), topsmelt (8 percent), black-and-yellow rockfish (8 percent), and blue rockfish (7 percent).

Of o!! individuals counted,76 percent were observed within I m of the bottom.

Similar mid-water and benthic distribution ratios were common to all stations.

The most abundant taxa seen on the benthic portion of transects, for all surveys combined in 1983, were senoritos (3 percent), juvenile kelp bass (10 percent),

pointed greenling (6 percent), and black-and-yellow rockfish (4 percent). The most abundant fishes in the mid-water were senoritos (12 percent), topsmelt (4 percent), and kelp bass juveniles (3 percent)

The following species were selected for detailed abundance summaries:

o black-and-yellow rockfish (Sebastes chrysomelas) o black surfperch (Embiotoco jacksoni)

, o blue rockfish (Sebastes mystinus) j o cabezon (Scorpaenichthys marmoratus) o gross rockfish (Sebastes rostrelliger) o olive rockfish (Sebastes serranoides) o pointed greenling (Oxylebius pictus) l o senorita (Oxyjulis californica) l o striped surfperch (Embiotoca lateralis) l l

Aside from these species which are commonly recurring taxa, certain other species have been observed in high abundance only at certain periods. For l example, during 1979 and 1981, bocaccio appeared in large numbers but have not been observed on the transects since that time. Summaries of the available life history information on all of the above species was presented in the 1982 annual i report (PGancE 1983).

i O B-93-540 3-141

3.11.1 BLACK-AND-YELLOW ROCKFISH Black-and-yellow rockfish, Sebastes chrysomelos, ranked third overall, with 429 adults and juveniles present during 1983. The numbers of adult fish counted on the transects from 1976-1983 are presented graphically in FIGURE 3-56. This species comprised 8 percent of all juvenile fish and 8 percent of all adult fish encountered. All adult blue rockfish were benthic dwellers. The juveniles were evenly divided between the midwater (45 percent) and benthic habitat (55 percent). In 1983, adults were found on all stations except station 11 which is deeper than the preferred depth range of these fish. Seasonally, more adults were seen in spring and fall than in summer. Black-and-yellow rockfish were the most abundant juveniles of the rockfish family in 1983.

3.11.2 BLACK SURFPERCH Black surfperch, Embiotoca lacksoni, ranked ninth overall and comprised i

2 percent of the total 1983 fish count. The numbers of adult fish counted on the transects from 1976-1983 are presented graphically in FIGURE 3-57. All but one j

of the 126 adults were found within I m of the bottom. This species was observed on all stations but was most abundant at station 4.

3.11.3 BLUE ROCKFISH l

l Glue rockfish, Sebastes mystinus, ranked fifth in abundance of adult fish for 1983 and accounted for 7 percent of all adult fish observed on the transects. The numbers of adult fish counted on the transects from 1976-1983 are presented graphically in FIGURE 3-58. Nearly two thirds of these fish (64 percent) were found within I m of the bottom. Only one juvenile was counted during 1983.' No blue rockfish were seen in south Diablo Cove (stations 8,9,10) during 1983.

Seasonully,27 percent of the blue rockfish were observed in spring,19 percent in l summer and 54 percent in fall. In spring, South Cove stations 13 and 14 had by for the greatest abundance of blue rockfish. In the summer, north Diablo Cove .

stations 4 and 6 had the highest abundance. In the fall, station 4 in centrol north B-83-540 3-142 l

l l

STATION 04 d -

n 6

i /

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e _ - a . o STATION 05 8- 'l d

n -

O 00

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STATTON 06 w d u

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n z

e c

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ha _. e Qm 5  ! o elii c@ 9 e Q_  ! O! oe !eo o 9 co '

(s)

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g-d -

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t O O I e l O

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O O 00 O O O O O d  :  : :  : ::. . Od=t= ::  :  :: 5 : : :  ::

. I . . F . . g . . . . . a . . . . . . . .

1 1 1 . . 1 I 1 1984 A .

1979 1980 1981 1982 1983 1976 1977 1978 TIME (TEARS) m w.a.ot.- e... ,at..,

0 e.ata.c ca..-<==+=,

.C' t

FIGURE 3-56 NUMBER OF ADULT BLACK-AND-YELLOW ROCKFISH OBSERVED IN 50 X 4 m UNDERWATER BAND TRANSECT SURVEYS B-83-540 3-143 1

STATION 09 9 -

O q n -

f ) O

\_ / O O O O O O! _. O e - - _

, , . . . , , . , , . , , . . , , . , , , , . , . . . , ,','T , , , ,

STATION 10 d -

0 0 0 0 C. O m -

00 O . O. .

O O O OO O. O O .

O O OO 00 O O O O O , O. O O. . Ol 0 o

STATION !!

6- d u -

W m

Z C

e e

y m -

(L e

$ 0 0 m E

[v; z d  :  : : :

STATION 12 S -

O i m -

. . O Oj O l OO O' O l O 0; O O l d STATION 13 5 1 8.

- f.

a d -

m O

o . G!QG c' 2m _4 % Q Q 99 9 od 9998o o! 9 09 197E 1977 1978 1979 1990 1981 1982 1983 1984 n TlHE LTERRS) a g,a. t.- e...-<at o, f s

(

v

) O Senth c Cose-<st o, l

FIGURE 3-56 (CONT.)

D-83 @ 0 NUMBER OF ADULT BLACK-AND-YELLOW ROCKFISH OBSERVED IN 50 X 4 m UNDERWATER BAND TRANSECT SURVEYS I

3-144

4 4

i i

STATION 14

~

8. g

~

E i l 5 +

I 55 a.

5 '

O E O 0:

o .

om 9 2 _ Q am 0 . o a9a_- _ go

=o ee'e 9e I

1976 1977 3973 1979 ggen 3961 19e2 1983 39e4 TIME deaf!S) m n . a... .- c o.. . . .. . .,

O eenenne cos.-vateen l.

t l  !

4 l

I i

FIGURE 3-56 (CONT.)

NUMBER OF ADULT BLACK-AND-YELLOW ROCKFISH OBSERVED i B-83-540 IN 50 X 4 m UNDERWATER BAND TRANSECT SURVEYS 3-145

STATION 04 8 -

I

/m o

/

'- m -

O o 99  ? 9 9 90 STAT 10N 0S U -

m l

0 O

} ,

O O:.O a a a a a a a . n i a a a , e e e e i e e a a a a a e e a e n . a e a f

STATION 06

• d u -

w sn z

C e

W

$m n-O! O O.

O O

O O

e O O O 0:

E O' 00 00 O O O E O M O . CD O O O ON OE

,f'% .

l--

za --

I.'. 7 ' , .' --, ' ' ' . -T l- '-.'- ', .'

s - - - - -- -.

(j i i , . .. . ' ' . .' '.'.'i i n i . . - i STATION 07 .,

U - O O

O m -

O O O 00 O Oi O O OO' O OO O Oi O . O O .

W .

O d

e i I t I a E t I 1 . . A 9 R t i R I e i I I A E A f R R 1 0 . 4 A E STATION 08 d -

g 8

m -

O O O O O' O O O 0; O O Ob o 00 W .

O O 00 O o

E E A 1 i R I R R 1 R R a a , a 1 t 3 1 a f . E E A 1 1 1 1 A E E E I 1976 1977 1978 1979 19ec 1981 1982 1983 1984 rs TIME (TEARS)

M Medeoter Gese*votrom

) FIGURE 3-57 a ,,,,,,,e....,,,,,,

('a\

NUMBER OF ADULT BLACK SURFPERCH OBSERVED IN 50 X 4 m UNDERWATER BAND TRANSECT SURVEYS B-83-540 3-146

staff 0N 09 e

l

( * -

i )

LJ O 00 E. O O o ..........

STATION 10 8 -

o -

n O

a _ m' __a- _a o .. _ m e @9 o em . . m Q_ Q __

STATION 11 W d -

u --

w n

2 O e

e s

e W W O a.

e

{N i $ 0 Oi r o O

'd So . . . ................................

STATION 12 O

m -

0:

00 o

I l

STATION 13 ,

s 0 - O t

l O Og i

m - 0 0 1 O OO O O! O O NO O O C aq O O O l

i O Ol .

MOO. 00 .

00 .

i d .

1978 1979 1980 1981 1922 1983 1964 gg 1976 1977 i n TIME (TEARS)

V W Meaeater Cose-<oteen O Sentnic ceservat on I

FIGURE 3-57 (CONT.)

l B-83-f40 i NUMBER OF ADULT BLACK SURFPERCH OBSERVED IN 50 X 4 m UNDERWATER BAND TRANSECT SURVEYS 3-147

I a

j i

STATION I4 f

UN -

O M o ,

E O.

i e O O Ee -

O O .

O Ol j a. O 00 O O O O OO .

e .

g Di O O. O O O g W O O . CD e O O O O

,a - - - - -

1977 1976 1979 1960 1981 1922 1983 1964 1976 TIME (TEARSI e n.... . e...r,. ..,

O Bentnre Someeration f

4 T

J i

FIGURE 3-57 (CONT.)

B-83-540 NUMBER OF ADULT BLACK SURFPERCH OBSERVED IN 50 X 4 m UNDERWATER BAND TRANSECT SURVEYS

- - - _ .3. 1_4 8 - -

r STATION 04 8 -

N -

v ,

m 0 gi.

o , , 5 ..!. 5. ." . . , , , . . . . . . . , , , , , , , . . . . =.'5 .= . , . ,

staff 0N 05 m -

e u o = = = c:

. . . . =. . .=. . . . 3.

STATION 06 u 8 -

w a

z C

c e am -

c-.

w t  ;

O e

• w m

r O o , E m O m:

O= 54 aa Q. g_ O @o 81 o .E o ;9 o m

( ,)

s_

E o -

STATION 07 __

8 - ,

o m -

• O gi "a Q E b o m g e - Q Q = _ Q 92 _E h e act a O =0 o . . . . . . . . . . . . , , . . . . , , . , , , , , . . . . , , , . ,

STRTION 08 .

o -

o O , .

o _ _. _ :

1979 19e0 1981 1982 1983 1984 1976 1977 1978 TIME (TEARS) a n,... .- e...-,.e..,

o FIGURE 3-58 o e.,,n,. e....,,,,,,

(v)

NUMBER OF ADULT BLUE ROCKFISH OBSERVED IN 50 X 4 m UNDERWATER B AND TRANSECT SURVEYS B-83-540 3-149

STATION 09 i I

l l

i l

m -

(~

k,s/ o o - - _ _ _

= '

o STATICN 10 1 S -

)

d .

m

=

. . ,:, := , = , = ,::, = , e = ,e:

a STATION 11 b

y O.

w m

z cr w

v.

c (t

W "h a

ec

• w cn a r

3 0 _

= 0 _

(

e x

j

, ,.,T ,,,,,,,,,>..,,,.,,,,,et, ,,,,,

'd n STATION 12 2 -

a m -

o a _ _ - a . _g g STATicu 13 o

O a -

• w w

O

• o W o

W O E@

0 - Q% 2 . _, 9. .

.$e s8 1970 1077 1978 3979 39gg ,gg; )9g; )9e3 )gp TIME ITEAaS) w n , a,at e- ce.e <ar . a,

(~'$

s /

FIGURE 3-58 (CONT.) o entn e cou <ar ,a ,

~.-

NUMBER OF ADULT BLUE ROCKFISH OBSERVED B-83-540 IN 50 X 4 m UNDERWATER BAND TRANSECT SURVEYS 3-150

_ _ . . _ _ . _ . _ . _ . _ _ . . ~ . _ . . . . . _ . _ _ m _- . . _ . . . _ _ _ _ , _ . . _ _ _ . . -

.m._ _ _ _ . . _ _ _ _ , _ - . = . - _ - _. _ . . _ . -

1t 1 i i

I e

I i I

' i 1 i

}

t

[

t I

t STATION 14 l 8 .

u 1, W i n

1 2 cr f i i

C - t Y N OO e . o n w 0  !

e n g E E O h, E _a m' O Emi mQ _ ! _9 9 E- m O g,,e: 0 ,, j 1, .J97C

. . . .1977

. . . .1976 . . . . . . . . . . . . . . . . . . . . . . . . . .

i 1979 19ec 19e! 1962 1983 1984 ,

4 TIME (TEARS) '

i

N Meceotea Sose-set L i o e.nen,c e... ,.e..'on , t i

}

i ,

t t

. i i t i l j

I I

l i

l

\

i.

t L

i

=

+

1 i FIGURE 3-58 (CONT.)

J l

' NUMBER OF ADULT BLUE ROCKFISH OBSERVED i IN 50 X 4 m UNDERWATER BAND TRANSECT SURVEYS t t

B-83-540 1

3-151 l

t

Diablo and the South Cove stations had relatively high numbers of blue rockfish (FIGURE 3-58).

3.11.4 CABEZON

] Cabezon, Scorpaenichthys marmoratus, ranked twelfth in 1983, accounting for 2 ~

percent (61 fish) of all adult fish observed. The numbers of adult fish counted on the transects from 1976-1983 are presented graphically in FIGURE 3-59. No juveniles or egg masses were observed along the transects. Cabezon were ebserved at all stations and were most abundant at station 4.

3.11.5 GRASS ROCKFISH t

j Grass rockfish, Sebastes rostrelliger, ranked seventeenth in 1983. The numbers of adult fish counted on the transects from 1976-1983 are presented graphically in FIGURE 3-60. Most juveniles were probably grouped in the Sebastes spp.

category because of uncertainties in field identification. The thirteen juveniles that were positively identified underestimate their actual abundance in the l population.

The 23 adults seen were distributed among all stations except stations 11 and 13 in South Cove. All adults were located within I m of the bottom.

l

{ 3.11.6 OLIVE ROCKFISH Olive rockfish, Sebastes serranoides, ranked twenty-ninth in total abundance during 1983. Only one juvenile was seen. The numbers of adult fish counted on t

the transects from 1976-1983 are presented graphically in FIGURE 3-61. Olive i rockfish occurred in only 21 percent of the transect samples. Of the 10 fish seen, six were within one meter of the bottom and four were in the water column (FIGURE 3-61).

l i

l B-83-540 3-152 n v .---w.e ae . ,,,,-----------m w-- ,, r , _ , , . . , , , - ,-,-,,-r--,w n--,vr , . -,----.m---g -,~-n- ~ ,

-y y----v -

en

57A710N 04 es -

O s * ~

l 0 N.,)l O O: O O' OO O O _ , _ _

, , . , , , 1 STATION 05 O -

m -

0:

O O d = = . =. .=. r. . . . . . . , , , . , , , , . , , , , , , --

STATION 06

% O -

y W

u, z O cr w

s E

O w m -

O

o. O O e OO O 00 O O g ,

O O O O O O O O O 2- 0 0 0 0 00 O O O OO

("N

t. }

Eo _. . .

. =. .

=,r  : :

, , , , . . .=====,::, . e. . . . e. . .=. =. . =. .=. =. . e. . , ===

v STATTON 07 4 -

O m -

O O O O O O O O O O O O O O O O O O O 00 00 00 O O O d

. . , , , . . . . . . . , , e ,e . . . . . . . . . . . . . . . . . . . .

STATION 08 de -

m -

0 0 0 0 0 O O O O O O O O OO O O O O O O

1970 1977 1976 1979 1920 19f2 19f; 9f* 10f4 TIME trEA95)

/T FIGURE 3-59 m n.a.=t.- e... <=t o,

\vl O 6 ente.c Cose <at e en NUMBER OF ADULT CABEZON OBSERVED IN 50 X 4 m UNDERWATER BAND TRANSECT SURVEYS B-83-540 3-153

>DlW1n%'Flohl \

o -

I i

i m -

^

/ '; OO l

\ '-'

l I 0: O O .

0 00 d O =- = - = - __

i . . . . . . . . . . . , . . . . . . . , , , , . . . . . , , , , , ,

STATION 10 o -

m -

0 0 0 0 00 0 0 0 0 0 0 0 0 0 O 00 O O O o

O t 4 1 5 5 1 1 1 b 4-e-e e-se i E I a 9 3 t I 3 g . 3 E A 1 1 I I E I a a i A 1 1 STATION 11 w 4* .

u w

u, z

e s

e n w

n e O w

a3 r

0 O~ O OO So , . , =, , . . . . .

r

_, , , , , , , , , , . . . , , . . . , ],] ,,

i I,  ;

't j STATfcN 12 m -

O' O

O o  : :  : : -

1 E A E a I & I B 1 R 1 1 R E .

I A E E d I I I I I I E I A I I I I I STATICN 13 o -

i O

m -

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 CD 0 0 0 00 O O O O d

. . . . . . . . , , . . > > . . . . , , , . , . . . . . . . . . , i ,

97C ;977 297P 1979 1990  ; 9f; 1992 19f3 1994 T ! *f f ITEGRSJ e g . a.or.- Co.. <at e, O Be,tn c Cose <a

.e, cs FIGURE 3-59 (CONT.)

/ j

\~/

NUM,BER OF ADULT CABEZON OBSERVED

! B-83-540 I IN 50 X 4 m UNDERWATER BAND TRANSECT SUPVEYS 3-154

.. . __ ._ _ ._. _. . _ _ . _ _ . _ . . . . . . . _ _ = - = . _ - . . _ ._. _ _ . _ _ _- _m _

d I 1 I 1,

l l

i STRT10k 14 ,

w d~ .

u t au en a

e

' c O

cm -

O a .

O e O CD C O O g O O O 0 00 O O O

, r O 00 00 O O O O O! 0 00 Sd

! 1970 1977 1976 1979 19ec 1921 1922 1983 1984 TIME (7 EARS) >

1

, a * , a,a t .- co.. <a: . .,

, O e.,i n . . co.. ,a t . .,

t 1

1 1

4 i

5 1

1 4

i FIGURE 3-59 (CONT.)

l NUMBER OF ADULT CABEZON OBSERVED i B-83-540 IN 50 X 4 m UNDERWATER BAND TRANSECT SUPVEYS 3-155 l

STCTION 04 n ~

m -

\

/

\<

l

\ i

%/

O cs  :  : - - -

. . . . , , . . . . t

, i . , , , , , , . . . . . i , , . .-. . . . ,

STATf0N 05 2 -

I m -

O; O o

1 E i A 1 , 1 e 3 a 2 i 1 e a a a 1 i A 1 1 A E E t A , 1 e a e t i STATICN 06

.o .

u" W

n Z

cr

• tc N

cm -

E O. O e O O w 0 cn 0 00 OO r OO O 00 m O O (3

a i 3o a i i i i i . . . , . . . , , ,

5--4r t . . . . . , , , , , , , , . . , , . .

STATION 07 Q ~

m -

0 0 0 0 0 0 0 0 0 0 0 0 o

a i E i A B A A I a I E D 9 R R I t t i I i 1 E i E I I . E a 1 A B B STATION 08 S -

m -

0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 O 00 O O o

i E A R A B E I t A 1 I i i I I t I t 9 I I I 1 i e f 9 I B I 1 I i 197C 1977 1978 1979 199C 19e1 1922 363 1954 TIME (TEARSJ

<^ FIGURE 3-60 *

• a,a t .- c o.. <=t a,

!]T O e.,t..c ce.. <=i o, NUMiBER OF ADULT GRASS ROCKFISH OBSERVED IN 50 X 4 m UNDERWATER BAND TRANSECT SURVEYS B-83-540 3-156

. - - _ _ _ _ 1

STATION 09 O. ,

l

/ >

(y} O' O O

OO o O STATION 10 0 -

m -

0 0 0 0 0 0 O.

O E .

O OO O O 00 OO O N O O O O

o" STATION 12 WD m -

z c-e e

w a

m -

e e

co r

D O

,m o O

)

\ /

%J STATION 13 o

~

~

m -

O O O O O O O O O o

. . . , 1 , . .

t 1 1 . , , . . L , , . . . I 1 . , i 1 . . . 1 .

STATION 14 0 -

m -

0 0 0 0 0 0 0 0 0 .

O e o 00 O O o

, , , . . , , , , . , , . . , , , . . . . , , . , . . . . . i , , , ,

197f 1977 1976 1979 1900 1961 19f2 1953 1954 TIME HEA951 (S

f

) e g u se.- Co.. <at.on 3 Pentn c Cese <.st o, B-83-540 FIGURE 3-60 (CONT.)

NUMBER OF ADULT GRASS ROCKFISH OBSERVED IN 50 X 4 m UNDERWATER BAND TRANSECT SURVEYS 3-157 l

l I

anutonggrwr a -

i l

m 7s 5

s i

%s <

c  : :  : : 9 -_

STRTION 06 0 -

m -

a R - E O

, - = = . . . . - . ,

== :: = = ::

., STATION 07 o N w

vi z

T sc e-e8 w

N o,

a-e cn r W o O e- O

.:  : :  : =0 Of : =0  : : = 2 88 ==,

. - - - . = > > , . . , , , , , . . , , , , , , , , , , , ,

'q s / STAT 10h 08 v

O.

~

m O

• . N n O  : :  : : : :: : :: C: ,=,  :  : : : : : :

. = i a a a . i i . . . . . .=d. , , , , , , , , , , , = c =,

STATION 09 O -

i l

l

, m -

W O  : :

. r i . > . e a i . e i i i . . . , , , , , , , , , , , , '--~

,~- , , , ,

1970 1977 1976 1979 19ec 199; iggy 39g3 ;a,4 TIME iTEAaS)

W M e a.at - co.. <at e, es FIGURE 3-61 O es,tn.c cose <at en t

y

\<

V NUMBER OF ADULT OLIVE ROCKFISH OBSERVED IN 50 X 4 m UNDERWATER BAND TRANSECT SURVEYS B-83-540 3-158

STATION 10 a -

m -

w

,/ m._ ,

I, ,b

%d O

m w o

,= . = =. = .= = = :: = : == =  ::  : : :

. G S 2 1 . .

= 0  : ::

4 5 1 S f . . . t . . . , 1 . . 3 E , . . A .

STATION !!

o - .

m -

a a

o  :  : O uo u

w u, STATION 12 z o e -

T 9-w W

Q tr w

co r

n 4

N d O

, ) . . . . . . , , , , . . . . . . . . . . . . . . . . . . . . . . . . .

%/

ol STATION 13 O, "

8 rw o  : :  : :  :  : : :: = : ::  :  :  :. .: : : : :  : ::

. . . . t . . 5 I t i n 1 . , .

1 1 I E t A 2 . . t . . .

I t 1 I STATION 14 o -

4 O O

m -

m O O O

O O- O N O O E OO o OE

. . . . , , . . . . . . i i i i , . . . . . . . . . . . i . . . > > .

197C 1977 1978 - 1979 1990 19P1 1962 1963 1994 TIME (TEARS)

/ex .

. w. m i.- ce.. ,o:..,

e U,) O eentn.c ces. vot o, FIGURE 3-61 (CONT.)

B-83-540 NUMBER OF ADULT OLIVE ROCKFISH OBSERVED IN 50 X 4 m UNDERV'ATER BAND TRANSECT SURVEYS 3-159

3.11.7 DAINTED GREEl{ LING Painted greenling, _Oxylebius pictus, ranked fourth in abundance in 1983. The numbers of adult fish counted on the transects from 1976-1983 are presented graphically in FIGURE 3-62. Pointed greenlings were least abundant at station 8 and most abundant at the reinstated station 4 (FIGURE 3-62).

3.11.8 SENORITA Senorito, Oxy]ulis californica, is a ubiquitous species in the Diablo Ceve area. It occurs throughout the year and has ranked first in abundance since 1976. In 1983 senorita ranked first for both adults and juveniles (43 percent of all individuals, 33 percent of all adults, and S4 percent of all juveniles). The numbers of adult fish counted on the transects from 1976-1983 are presented graphically in FIGURE 3-63. The majority of senoritos, both adults and juveniles, were found within I m of the substrate (58 percent of the adults and 79 percent of the juveniles). Seasonally, adult senoritas were most abundant during spring and least abundant in summer. The juveniles were abundant only during the fall.

3.11.9 STRIPED SURFPERCH

' Striped surfperch, Embiotoca lateralis, continued to be the most numerous Embiotocid observed thus far. This surfperch ranked eighth (164 adults and juveniles) and comprised 3 percent of all fish in the 1983 census. The species ranked sixth among adult taxa, and sixth among juveniles. The numbers of adult fish counted on the transects from 1976-1983 are presented graphically in l

FIGURE 3-64. All but four of the 128 adults were found within im of the

, bottom. Adults were seen on all stations with greatest numbers found at j

station 6 and fewest at station ll.

3.12 SUBTIDAL SETTLING PLATES i

Settling plate data from surveys I (July 1976) to 40 (January 1983) are presented in this section. Data on spatial and temporal variation are analyzed for both B-83-540 3-160

O STA110N 04 2 -

m t ,

'.'%J O

. Q' _ m O 00 STATTON 05 o

0 0

,n O

O O O O O O~ O O --

STATION 06

- 8 -

a w

n z

cr e

e o -

w Q

e w

F Oe O

,fm, 3a _ a _ o O a . Q: cm _ c 9..

9 Om9 e o @ eQ 9- Q cc

(%s) ,,,, ,

514Tf0N 07 2 -

.O n --

o 00 0 0

_ 9 9 a = e9 cc es 9. 0 00 O . . Q 9 9e9 9 cc 51'4T10N 08 S -

,n 0 0 0 0 0 0 0 00 O O O O O O OO OO 00 O O O o

a

• . i . . . , , , . ,

1970 1977 1978 1979 1980 19f; 1992 19e3 3964 TIME ITEARS)

,-'s *"

• n- co n-<oe..,

FIGURE 3-62 (v; O e.',"m.

e e... ,ot..,

NUMBER OF ADULT FAINTED GREENLING OBSERVED IN 50 X 4 m UNDERWATER BAND TRANSECT SURVEYS B-83-540 3-16l

2 -

i4 0

, t e -

a O 00 O ,

O O i o - - - - - O

, , , , , i , ,

,,,,,,,,,,,,,,,,,,,,,,-l

STATION 10 2 -

O O O O

O O O' c

0 0 0 0 0 0 0 0 0 0 O O O O 00 O O O O O! OO O 00 O O . O , O O

, , i i, 4

o SIAffch 11 u 3 .

w ,

m z

cr e

s-e 3 w

a.

a-W co O

5 4 o a a; a E D' 9_g _

, , , , , i , , , , , , , , , , , , , , , , , , , , , , , ,- ,

O STATICA 12 2 -

0 0

m -

0 0 0 0

0' O O

i ,

Si A1 late 13 S -

S -

0 o o a 2 OQ@ S a ab a cb 2 a_ S0 03_

, , , , , , , , , , , , , , , , , , , , , , , , , . . , i i i i i , ,

197C 1977 3978 3979 Jgec 39ej Jge; 19e3 1984 TIME ITEARS)

W 4eoeatea Cose votion FIGURE 3-62 (CONT.) O e.,en,c e...-<ae,.,

NUMBER OF ADULT PAINTED GREENLING OBSERVED B-83-540 IN 50 X 4 m UNDERWATER BAND TRANSECT SURVEYS 3-162

. _ . ._ _ __ _ . _ - . _ . - . _ _ _ . . . _ _ _ _ . - _ _ _ _ _ _ _ . _ . . _ _ . . _ _ _ . _ . _ . _ _ ~ _ _ _ - _ _ _ _ . _ . _ .

i  !

1.1

'~.  !

l

}

t t

l 1 r STATich 14 8

g -

w m ,

a a

T l E i e S -

w a i

e

.y i-l-

! E x

r.

a_ 9e 9 _ GO cm u 9? G 20 00 0T.','.'.

8O? 00 T , ' , ' , . ' .- ' , ~, 7 7 ' , ' ', . ' . . ' ' , , ', '.

197C 1977 197e 1979 1980 1921 1962 1923 1994 TIME ITEARS) l W Measatee Caseavat e,  !

o e.,en:. ca.. <ae,a, '

1 f

1 j

'l i

4 4

4 FIGURE 3-62 (CONT.)

i NUMBER OF ADULT PAINTED GREENLING OBSERVED B-83-540 t

3-163 i

t

, STATION 04 S -

E -

f n l 0, ) m O

j %J i

o O _ Em o STATION 05 2 -

o n -

o o e =

m@

. . .=. . . . . . . . . . . . . . , , . . , , . . . . . . ., , , , , _

STATION 06 g

o . -

na m

z cr a-

>=

5E o.

=

O 04 8

/m> ,

Io _ f - M .a a . 9m ( 0$ 0 0 g m2 9 m ag s

, STATION 07 0

o o

g 6

O O 5 o o

=a J 9O e5 a

=m O o o - - - = m W. __ ,,, , _ g a _9 _

' * . in . . . . . . . , ,~, , , , . . . . . . . . . , , . . . . . . . l

. STATION 08 S -

O

" n ev O

D nW y no 8 0 $ 0 o

_ E

. . . , .O _ =

, ,- . .o . . . . .

E s 1 I a

_a 21 0

.3 89_

_ _s 1 , , t . . . . .

1976 1977 1978 1979 19ec 1981 19e2 19e3 19f4 TIME 4TEAnS)

A FIGURE 3-63 * " "'*~ # "~"*' '

(

s O eenen.c cesea<at en NUM.BEP, OF ADULT SENORITA OBSERVED IN 50 X 4 m UNDERWATER BAND TRANSECT SURVEYS B-83-540 3-164

w g STATION 09 o - 8 m

(,

N./

~)

O w

. _ n - - _

> > . , , , i > > , , . , , , , , , , , , , , , , , , , , ,--- , , , ,

STATION 10

~ -

w w

k .

O g a *

• 8

- a 50 ou j O

o

_ a _a- _m aC m o - ,., _ c - a- - _ _ .

s o __

STATION 11 O

w O_ -

O ,

m z

c e

e yS -

w e

W m

2-m u

, ~s, a o - _ _ n 9 g , , a , , , , , , g g g g g g , , g a , i l E E t l t r t t E 9 a STATION 12 8 -

c, m -

O O

5 o - O - _ - O, o,

STATION 13 I

w O

m -

m O

• O O

O o o _ _

197f 1977 E_ _ _ 9. 2 5 9 --

o af a_ = $_ _[

197e 1979 19e: 1991 1962 1993 19ev

-~ TIME arEAas; a 5.o..e.- ... <oe..,

('-)s o e.,e,.. e... , e.e, FIGURE 3-63 (CONT.)

B-83-540 NUMBER OF ADULT SENORITA OBSERVED IN 50 X 4 m UNDERWATER B AND TRANSECT SURVEYS 3-165

- . - _ . . . - . - . - . ~ . _ . - . . . - . ....

i i

i 1

1 i

l i.

i i

e i

STRT10N 14

.- 8

• u N I Lu I

• l' z

f T E'

c.

8 -

a i-

.] O I

c R '

t! ,

a3 0- g i r .

3 o '- .

9 . m - QWwo a S0 00 l ] , _ _ _ -

_ _ - _0_: _m..

3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ,

1970 1977 197e 1979 19?O IsP1 1962 1963 1994 TIME (TEARS) i l

j W 4tasst.- Co..=voteo9 o e.,t n , e c o.. ,a t ..,

j I

i [

I i

e I

i i

r I

FIGURE 3-63 (CONT.) '

NUM.BER OF ADULT SENORITA OBSERVED IN 50 X 4 m UNDERWATER BAND TRANSECT SURVEYS B-83-540 t 3-166 7

STATION 04 8 .

O O

O e -

Oj O O

O;

(,h * *

'%.,i w

• e d  : 0 _ _ _

g STATION 05 o

a '

o 9 @ @

o s.

STATION 06 8

o w

v>

z Cr e

d -

e n w

a.

e

' O o o EI S CQ Q c 9 0 c ",

09QQ. .

_ 03 f/~'s., ... . . . . , , , , , , , , , . , ,..

(  !

i kJ STATich 07 1 8 r

l l

. c _

d 5 g g.osq_gy8 e g3 ,9 o_,,g o ,3 STATION 08 6 "

i O l

l d

. , = 5, . $ 9 . . ,

^

, 95

, .9, ?, , , ,9,$". . b, , ,?@. =.f . 99 @ h . " ," 9, . . . .

l 1970 1977 197P 1979 1960 19?i 19fi 19f3 iGf4 I

TIME nEAR51 I

, . w Mea. ate- Cose <at o, 1

/,)

t.'

FIGURE 3-64 0 Pn.c e. o <at. ,

NUMBER OF ADULT STRIPED SURFPERCH OBSERVED IN 50 X 4 m UNDERWATER BAND TRANSECT SURVEYS B-83-540 3-167

STATION 09 rx

! )

'N J O O OO E O s d

STATfch 10 d .

OO e n

. OO 0 O O O O O OO O E O CD N O OO 0; e o a O O O O 00 0

STATION 11 u

W 5 -

n z

G cr cr .

WM (L

sc W

ca 5 5 0 0 0

,cs e o

, g ......,e , , , , , , , . . , , . . . . .,,.. ..;...

,V STATTON 12 h-o m -

O o e o! 2 0 @ OS STRTTON I3 0

0 oo o

..,,E6S e- 2ej0ce23gj_g. . c6 g_ 6e29 ._O 1970 3977 297* !379 1960 19f; 1962 19P3 19f4 TIME 11EA953 a n . a.s, .- c e.. <az c,

(')

\s' FIGURE 3-64 (CONT.) 0 8'"" c on ~at n NUMBER OF ADULT STRIPED SUPEPERCH OBSERVED B-83-540 IN 50 X 4 m UNDERWATER BAND TRANSECT SURVEYS 3-168

1 4

b i .

i

! sinirou u E

E

58 -

5 o E o :. o' o 2 EG = 8J c 2 Of a,og 8 mm 2 es . o 8m2.- o ca 4

1976 1977 397e 3979 19ec 39e3 39e; 3ges 3ge4 TP" 11EA953 m n,...t.- e... ,. ..,

0 8enen.c Cose voteen iO t

i

~

i 4

FIGURE 3 44 (CONT.)

NUMBER OF ADULT STRIPED SURFPERCH OBSERVED B-83-540 IN 50 X 4 m UNDERWATER B AND TRANSECT SURVEYS 3-!69

species richness (all methods combined) and dry-weight biomass. Data collected since January 1983 and analyses of settlement patterns of Individual taxa over time, on both short and long-term plates are not presented at this time but will be considered in a future report.

TABLE 3-19 lists the dates on which plates were installed and collected, and the number of stations sampled within each survey. A list of 93 algal taxa and 67 invertebrate taxa (including Ascidiocea, which are chordates) identified on the settling plates is presented in TABLE 3-20. Of the algol taxa, 73 percent were red algae,16 percent brown algae, and 9 percent green algae. The predominant invertebrate groups were bryozoons (28 percent), enidarians (16 percent),

annelids (15 percent), and protozoons (13 percent). Of the tc'al number of taxa observed,40 algol taxa and 37 invertebrate taxa were recorded from the short-term plates (2 month exposure). On the long-term plates (4 to 12 month exposure) the number of taxa nearly doubled: 78 algal and 65 invertebrate taxa were recorded.

FIGURE 3-65 presents the total number of algal and invertebrate taxa encoun-tered on the 2-month plates from 1976 to 1983 at the six stations in Diablo Cove.

The number of attached taxa varied both within years and between years. No one station consistently had more taxa than the other stations. There was a trend toward increasing numbers of attached cigae on the spring-summer plates.

During many years, the number of attached invertebrates on the summer-fall plates increased. This may have resulted from increased larval settlement, a finding similar to those of studies at Woods Hole, Massachusetts (Osman 1977) and San Francisco Bay, California (Ehrler and Lyke 1980).

With an increase in the submergence time of the plates, there was on increase in the number of colonizing algal and invertebrate species (FICURE 3-66). This finding is consistent with the findings of other marine colonization studies (Saito et al.1976, Grigg and Morogos 1974, Fager 1971). In some cases the number of taxa, especially the algal species, reached a peak on the 8 and 10 month plates and then dropped slightly on the 12 month plates. This decrease may indicate that the maximum number of taxa was reached in this period of exposure in p

B-83-540 3 170

l l

TABLE 3-19 SUBTIDAL SETTLING PLATE COLLECTION DATES Number Plates of Removed /

Survey Study Stations Installed Date Number Year Sampled Per Station July 1976 I i 14 6*

September 1976 2 1 14 1 November 1976 3 1 14 2 January 1977 4 l 14 2

March 1977 5 l 14 2 1 May 1977 6 l 14 2 July 1977 7 i/2 14 6 September 1977 8 2 10 1 November 1977 9 2 10 2 January 1978 10 2 6 2 March 1978 li 2 6 2 May 1978 12 2 6 2 July 1978 13 2/3 6 6 s September 1978 14 3 6 i November 1978 15 3 6 2 January 1979 16 3 6 2 March 1979 17 3 6 2 May 1979 18 3 6 2 July 1979 19 3/4 6 6 September 1979 20 4 6 I November 1979 21 4 6 2 January 1980 22 4 6 2 March 1980 23 4 6 2 May 1980 24 4 6 2 l

July 1980 25 4/5 6 6 September 1980 26 5 6 i November 1980 27 5 6 2 January 1981 28 5 6 2 March 1981 29 5 6 2 May 1981 30 5 6 2

• Installation only.

1 B-83-540 1 3-171 l

/

TABLE 3-19 k

SUBTIDAL SETTLING PLATE COLLECTION DATES (CONTINUED)

Number Plates of Removed /

Survey Study Stations Installed Date Number Year Sampled Per Station July 1981 31 5/6 6 6

September 1981 32 6 6 1 Novembar 1981 33 6 6 2 January 1982 34 6 6 2 March 1982 35 6 6 2 May 1982 36 6 6 2 July 1982 37 6/7 6 6 September 1982 38 7 6 i November 1982 39 7 6 2 January 1983 40 7 6 2 March 1983 41 7 6 2 May 1983 42 7 6 2 July 1983 43 7/8 6 6 September 1983 44 8 6 i November 1983 45 8 6 2 i

i 1

3-172

TABLE 3-20 TAXA ENCOUNTERED ON SUBTlDAL SETTLING PLATES, I ' (/"%I mj JULY 1976 - JANUARY 1983 (Rondom point contoct, quadrat and edge /mcrgin methods combined)

ALCAE Chlorophyta Rhodophyta (Cant.)

Bryopsis corticutons Costroclonium coulteri Clodophorales Gelidium coulteri Enteromorpho linio Gelidium spp.

Enteromorpho spp. G aortino exasperato/_C. corymbifero green filoments, unid. G'aortino harvevano Halicystis ovalis Gioartino leptorhynchos 5poncomorpho spp. Giocrtino spp.

Ulvo spp. Holymenio spp./Schirymenio spp.

Herposiphonio verticillota Hymeneno flabellicero Phaeophyta Hymeneno spp.

Iridaea cordato Brown filaments, unid. Iridoeo heterocorpo Coformenio spp./Soronthero spp. Joncrewskio cordneri Cystoseiro osmundocco Lourencio spectablis Desmorestio ficolata Mernbranoptero multirometo lietvoneurum colifornicum Membranoptero weeksice 5ctocorpoles Membranoptero spp.

Ecrecio menriesii Microcladio borealis Gif fordio cronuloso Mictoelodio coulteri fg Holorhipis winstonii Haploaloin ondersonii Neoocordhiello acodichaudii V}

[

Laminario denticero Laminoriales (juve le)

Neoptiloto denso Non-coralline crust Phycodrvs setchellii Nereocystis ivetkeano Phveodrys spp.

Phocophyto (juvenile) Platythnmnion pectinatum Pfervoophora californico Plotythamnion spp.

Pleonospr.rium scoorrulosum Polyneuro totissimo Rhodophyta Polysiphonio spp.

Porphyro occidentolis Antithomnion defectum Porphyra spp.

Antithomnion spp. Prionitis spp.

Antithomnionello poeifico Prostrate red filaments Asterocog coroneri Pseudoctoiophloco confuso Botryoqiossum famowinnom Pterochondrio woodii Bronchioolossum undulatum Pteroeladio coloatossoidas Colliorthron spp./Bossiello spp./Serroticordio spp. (CBS) Pterosiphonio dendroideo Collithomnion spp./Pleonosporium spp. Red algol turf 01 (straight or bronched filaments)

Coltophyllis firma Red algol turf 02 (feather-like)

Collonbyllis flabellulata Rhodoolossum roseum Collophyllis pinnoto Rhodophyto (juvenile)

Colloobvilis spp. Rhodvmenio collophyllidoides Collophvilis vioinceo Rhodymenio spp.

Corollino of ficinalis Rhndoptilum plumosom Corollino spp. Tif faniello snvderice Corollino spp./CBS (juvenile)

Corollino vancouveriensis Corolline crust Bacillariophyta Cryptopleuro spp.

Cryptopleuro violocco Diotom chains, unid.

Delesseriocece (juvenile) Liemophora spp.

Ervthrophyllum defesserioides Os V

B-83-540 3-173

l l

TABLE 3.20 (CONTINUED) f ( TAXA ENCOUNTERED ON SUBTIDAL SETTLING PLATES, JULY 1976 - JANUARY 1983 (Rondom point contact, quadrat and edge /morgin rnethods combined)

INVERTEBRATA Protoroo Crustacea Folliculina spp. Bolonus crenotus Forominifero, unid. Batonus spp.

Gromio oviformis Bolonus spp./Tetroelito scuomoso Guinooelocotino spp. Bolonos tintinnobolum Protozoon, unid. Bornocle scar Radiolarion, unid. Gammarideon tube, unid.

Rosofino spp. Tetroclito scuomoso Spirillino spp.

Zoothomnium spp.

Mollusco Porifero Dendrocomo tituelto Mocomo spp.

Encrusting sponge, unid. Pelecypodo, unid.

Leveendra beathi Podndesmos cenio Leucosolenio spp.

Ectaprocta/Entgracta Cnidaria Aeteo onovince

] Abietinnrio spp /4rtutoreth app./Sertogrio spp. (ASS)

Aaroonhenio struthionides Alcyonidium polvoum Barentsin spp.

Anthozoon, unid. Coulibucolo ciliato Bolononbyllin elecons Coutorompht s spiniferum Epioctis profifero Costorio robertsonice E_udendrium colifornicum Crisia spp.

Hatietystus curiculo Encrusiing bryozoon, unid.

Hydroid, unid. Erect bryozoon, unid.

ObelH spp. Filicrisia spp.

Sertularello spp. Flustrellidro spp.

Synenryne spp. Hi,,podiplosia spp.

Hippothoo bvolino Lichenopora spp./Tubofiporo spp.

Annelido Microporello cofifornico Microporello tribroso Hydroides nocificus Jonon spp. Microporello spp.

Gexlospiro vitreo Rhynchoronn spp.

Tricellorio spp.

Phroomotonomo californico Pileotoria spp.

Protoloeospiro spp.

Salmacino tribronchiot1 Serpulidae, unid.

Spirobranchus spinoy*

5pirorbidoe, unid.

CHORDATA (Tunicata) MISCELLAPEOUS CATEGORIES Colonial / Social tunicate Egg case, unid.

Metandrocorpo toylori Bore plate 50titory tunicate, unid. "Diotom filrn" (Tr0Didemnum spp.

B-83-540 3-174 l

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\ PERIODS OF SUBMERGENCE (2-12 MONTHS) l 3-176 t

Diablo Cove and that the total number of attached taxa for plates (of the some O

U/ size) exposed for longer periods of time would fluctuate about a mean value.

These are similar to Osman's (1977) findings in his Atlantic Coast settling plate study.

Maximum dry-weight biomass on the short-term (2-month) plates was obtained from late spring to early fall (FIGURE 3-67). The amount of biomass varied throughout the year as well as between years. No one station consistently had the greatest amount of biomass. The seasonality in attached biomass was directly related to seasonal algal and invertebrate attachment. The greatest biomass was found on the September 1977 plate from station 6 which yielded almost 19 grams of material over a 2-month period. Maximum weights at most of the other stations also occurred during this survey. This peak of biomass was primarily attributable to the presence of large numbers of attached barnacles.

Typically, dry-weight biomass increased with increasing exposure of the long-term plates at each station (FIGURE 3-68). It can also be seen that the amount of accumulated biomass varies between the different years. As on the short-(V9 term plates, maximum amounts of biomass were generally observed at station 6 where nearly continuous wave surge and currents provided favorable conditions for growth of barnacles and bryozoons. In this case, the weights recorded were directly related to the dominant barnacles and bryozoons present on the plates.

These two species are much heavier per unit area than are any of the algae. In some instances, the weights on the 12-month plates were less than those on the

!0-month plates. Boyd (1972), working at Bodega Harbor, California, found that there was not always a continual increcse in biomass as the community develops because total biomass depends on the plate's history of biological interactions. It is possible that such interactions (intra- or interspecific competition for space, and/or predation) have caused biomass to decrease on some of the 12-month plates.

O y B-83-540 3-177

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3.13 BULL KELP POPULATION ESTIMATES (D

V The bull kelp, Nereocystis luetkeano, is a fast growing annual kelp plant. Its life-history and other pertinent information were presented aarlier by PGandE (1979,1982a). The large conspicuous sporophyte first appears in spring and reaches the surface to form a canopy in summer-fall. By winter most plants have reached annual senescence and have been removed by storm wave activity.

Bull kelp ranges from Alaska to San Luis Obispo County, California (Abbott and Hollenberg 1976). This species as well as other species with southern ranges ending near Point Conception is believed to be limited at this southern extent by the warmer water temperatures south of Point Conception.

Bull kelp density data from the TEMP Diablo Cove fixed subtidal stations (arc quadrant sampling) has been presented earlier in this report (Section 3.7.1.3).

Population estimates for the entire Diablo Cove area are presented and discussed here. Diablo Cove population estimates are obtained by averaging the total number plants counted by four observers from permanent cliff-top vantage points. Counts are obtained annually each fall. For details of the method see p) y Section 2.13 of this report. Although counting plants from shore based stations does not consider smaller subsurface plants, the fall timing of each census coincides with the time most plants are sufficiently large to be on the surface and before they have been removed by winter storms. One problem with this sampling technique is that occurate counts are difficult to make when densities are high. Counting individual plants becomes difficult due to plants visually obscuring one another. This method does, however, provide easily obtained abundance estimates useful for evaluating year to year relative changes as well as providing maps showing the distribution of bull kelp patches in Diablo Cove.

The year to year changes in the number of bull kelp plants within Diablo Cove from 1970 to 1983 are presented in FIGURE 3-69. These counts coincide with the fall season each year. Cursory observations indicate that during the winter periods nearly all of Diablo Cove is devoid of surface bull kelp. Thus, the abundance pattern of bull kelp appears to vary in on annual cycle with winter minimums alternating with fall peaks. In 1970 and again in 1971 there were O

V B-83-540 3-180

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1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 TIME (YEARS)

FIGURE 3-69 NUMBER OF NEREOCYSTIS LUETKEANA INDIVIDUALS OBSERVED IN DIABLO COVE FROM CLIFF-TOP VANTAGE POINTS, FALL 1970 - 1983.

I i

about 5,000 surface plants in Diablo Cove. During these and previous years the Q

V abundance of bull kelp in Diablo Cove was believed to be limited by sea-urchin (Stronaylocentrotus spp.) grazing (North 1969, Burge and Schultz 1973). From 1973 to 1977 there was a marked increase in bull kelp densities. This was concurrent with the southern range extension of the sea otter (Enhydra lutris) into the Diablo Canyon coastline region (Burge and Schultz 1973). Presumably the increase in bull kelp densities was a direct result of sea otters consuming sea-urchins.

From 1979 to 1982 the density of bull kelp was much lower (about 1,000 plants in Diablo Cove) than in previous years. This decrease may be attributed to the fact that other slower growing perennial algae gradually out compete bull kelp for space and light. In 1983 bull kelp abundances rose markedly to nearly 10,000 plants. This marked increase may have resulted from the detrimental effects of s

the 1982-1983 winter storms on bull kelp competitors and substrate disturbance in nearshore areas. The loss of canopy and resultant increase in light levels may have allowed existing bull kelp gametophytes to become reproductive and young bull kelp sporophytes to survive and grow. This may also have provided

) opportunities for bull kelp to recolonize areas in greater densities than noted during previous recent years. Although this increase in juvenile numbers was substantial, the condition of the mature plants later in the year was poor. El Nino (worm water) oceanographic conditions occurred early in the spring and persisted through the summer of 1983, elevating water temperatures to over 18 C along the Diablo Canyon coast (Section 3.14.1 in this report). Canopy-forming plants at this time showed premature signs of senescence. Plants appeared yellow rather than brown and blades were disintegrating. Fertile sori, which normally appear during the late summer /early fall, never fully developed on most plants. These field observations are consistent with thermal tolerance laboratory findings which indicate that water temperatures near 18 C are detrimental to bull kelp juvenile sporophytes (PGand 1982b).

Trends depicted by cliff-top counts and subtidal arc quadra counts (Section 3.7.1.3 in this report) are similar only in showing that the abundou of bull kelp varies on on annual cycle. Actual year to year abundance trends a. not similar B-83-540 3-182

/7 because of methodological differences and differences in the bull kelp popula-(v) tions sampled. A point in case occurred during the spring to fall period of this year (1983). Cliff-top counts indicated that bull kelp densities in Diablo Cove at this time were higher than those of the past several years. This trend was not evident in the arc quadrant data for the same period. The reason for this is the patchy nature of bull kelp occurrences. Casual underwater observations revealed that in 1983 bull kelp recruited primarily outside of the areas on which arc quadrants are located.

3.14 IN SITU TEMPERATURE MEASUREMENT Subtidal and intertidai temperature data have been collected at Diablo Canyon continuously since July 1976. The purpose of these measurements was twofold:

to develop a baseline assessment of temperature regimes in the vicinity of Diablo Cove prior to power plant operation, and to provide an interpretive data base to supplement marine biological investigations at subtidal and intertidal sampling locations. -

O)

%~.

During 1983, temperature data were collected from eight intertidal stations (TABLE 2-1) and ten subtidal stations (TABLE 2-2). The historical temperature data base spans a seven-year period at six subtidal and four intertidal locations in Diablo Cove. Temperature measurements were also recorded at eight additional subtidal and ten intertidal stations during the first year of the study.

This report presents a summary of subtidal water temperature data collected at stations 8-10 in north Diablo Cove and 12-10 in south Diablo Cove, and intertidal air / water temperature data from stations 12+2 in south Diablo Cove and 8+2 in north Diablo Cove from January 1982 to November 1983 (see location map, FIGURE 2-1 and Map A, in pocket). Earlier temperature data from subtidal locations in north Diablo Cove are also presented in order to illustrate long-term seasonal trends in water temperature. Missing subtidal data in FIGURE 3-71 reflect primarily periods of severe storm activity which prevented divers from installing the instruments.

O i

V B-83-540 3-183

3.14.1 SUBTIDAL TEMPERATURES

(

Water temperatures within Diablo Cove are influenced by both large scale coastal oceanographic phenomena and local coastal topography. As a generaliza-tion, three current " seasons" occur during the year, upwelling, oceanic, and Davidson. During the spring and early summer, upwelling results from the combined effects of prevailing north-northwesterly winds and Coriolis forces.

Nearshore surface waters are moved offshore and replaced by colder, nutrient laden bottom waters. However, localized upwelling may occur at any time of the year in the lee of headlands such as Point Buchon, north of Diablo Cove. When prevailing winds subside during summer months, upwelling ceases and the oceanic season ensues. During this period water temperatures are influenced by the cool southerly flow of the California current. In late summer or early fa'l, the northward flowing Davidson current develops inshore of the California current creating a warming trend along the coast. All of these oceanographic processes influence the ocean's thermal environment at Diablo Canyon and produce the variations revealed in the temperature data collected (FIGURE 3-70).

O U Subtidal temperatures recorded in both north (station 8) and south (station 12)

Diablo Cove generally reflected these seasonal changes. Monthly means, minima and maxima for each station are presented in FIGURE 3-71. Relative frequency distributions for temperatures at subtidal station 12-10 for the same period are presented in FIGURES 3-72 to 3-75. South Diablo Cove was consistently warmer than north Diablo Cove . The protected nature of south Diablo Cove apparently results in a longer residence time for water, thus allowing increased solar warming. Coldest annual temperatures in both areas occurred during the period March through June with monthly means as low as 9.6 C. In contrast to previous years, average monthly spring temperatures for both 1982 and 1983 did not drop to their normal low of 10 C. The warming trend which normally occurs in the late summer months, in 1983 began in June. This warming trend continued through the summer of 1983, resulting in the highest seawater temperatures recorded in Diablo Cove during the course of our studies. Maximum values of monthly means occurred in October at all stations and reached a high of 19.5 C.

of Station 12-10. Mean monthly temperatures greater than 16 C were recorded A

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from August through October at both subtidal stations. Relative frequency distributions for the summer months of 1982 and 1983 show that although maximum monthly mean temperatures for 1982 were above 18 C, the sustained high monthly mean temperatures observed in 1983 were not evident in 1982.

These unusual conditions are generally attributed to the influence of the "El Nino" phenomenon along the California coast. This phenomenon is normally associated with unusually warm water off the coast of South America and large scale atmospheric fluctuations in the southeastern Pacific Ocean. There are a number of theories as to the mechanism producing the "El Nino" effects along the California coast. Originally it was thought that warmer sea water tempero-tures off California were caused as a result of diversion northward of a portion of the warm equatorial current which offect the South American coast. It is now thought that the California effects largely derive from atmospheric conditions offshore. These atmospheric conditions may also explain the anomalous southwesterly winds of last winter, which battered the California coast with large seas (see Section 4.1).

-O yf 3.14.2 INTERTIDAL TEMPERATURES Montlity means, minima and maxima for air / water temperatures from January 1982 through November 1983 at stations 12+2 (south Diablo Cove) and 8+2 (north Diablo Cove) are presented in FIGURE 3-76. The some general pattern in annual temperature fluctuations described for subtidal stations occurred at the inter-tidal localities. However, due to periodic exposure to air, intertidal areas are subject to wider variations in temperature. FIGURE 3-77 illustrates an example of intertidal temperature changes in Diablo Cove resulting from the mixed semi-diurnal tides which occur along the California coast. As the +2 f t MLLW level became exposed to air during late morning and early af ternoon hours, tempera-tures rose above ambient water temperature to a maximum of 24 C. Immersion subsequently returned temperatures to ambient i1 C. When exposure to air occurred during nighttime hours temperatures fell below ambient, in this case to a minimum of 4 C.

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3.15 IN SITU LIGHT MEASUREMENT Radiant solar energy in the visible light spectrum (400-700 nm) is necessary for j

algal photosynthesis and primary production. This photosynthetically active

+

radiation (PAR) impinging on Diablo Cove was measured in units of microein-steins /m2/sec (hereaf ter referred to as "microeinsteins") continuously from 1981 to 1983 at two permanent subtidal locations (-10 f t MLLW) in north and south Diablo Cove and one permanent terrestrial location (approximately 103 ft MLLW) (see FIGURE 2-7 and Map B in pocket). In addition, solar energy was '

measured at the terrestrial station. The purpose of these measurements was to develop a baseline assessment of PAR within Diablo Cove and to provide on interpretive data base to supplement both laboratory algal growth experiments and field biological investigations. Light measurement instruments and sampling methods were described previously in Section 2.15.

4 3.15.1 SURFACE LIGHT Measurements of PAR at the terrestrial monitoring site were used to approxi-i mate solar irradiance values at the surface of Diablo Cove. Mean daily i: irradionce curves for each month in 1982 and 1983 are presented in FIGURES

3-78 to 3-81. Maximum values of full sun plus sky PAR occurred in June of both 1982 and 1983, reaching nearly 2000 microeinsteins with an approximate day length of 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />. The month with lowest PAR was December with maximum values below 1000 microeinsteins and an approximate day length of 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br />.

Mean PAR for the winter months of 1983 (January and February) were lower

than those recorded in 1982. This may be attributed to increased cloud cover j - during the extended storm period of 1983.

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FIGURE 3-78 MONTHLY MEAN SURFACE (A) AND UNDERWATER (B) LIGHT VALUES VERSUS TIME OF DAY AT DIABLO COVE FOR THE

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l FIGURE 3-81 MONTHLY MEAN SURFACE (A) AND UNDERWATER (B) LIGHT VALUES i VERSUS TIME OF DAY AT DIABLO COVE FOR THE j [G m)

FOURTH OUARTERS OF 1982 AND 1983 B-83-540 3-198 i

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o Light extinction resulting from dissolved and suspended particulates, and the seawater medium itself o Shading from algal canopy cover.

I Underwater PAR values at -10 ft MLLW in south Diablo Cove are presented as mean daily irradiance (microeinsteins/m2/sec) curves for each month of 1902 and 1983 (FIGURES 3-78 to 3-81). Data for the winter months of 1983 are lacking due to subtidal stations being inaccessible durir.g severe storm periods. Highest daily underwater PAR values always occur between i100 and 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br /> (24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> time), when the angle of solar incidence on surface waters is greatest, thus

minimizing reflection. These hours of maximum illumination had greatest underwater PAR values during spring months for the following reasons

(1) increasing day length and angle of solar incidence; (2) subsidence of nearshore turbulence from winter storms resulting in less light attenuation by suspended particulates; (3) minimal algal canopy cover.

1 Greatest mean underwater PAR values exceeded 400 microeinsteins in spring i

months of 1982, with high values also occurring in July 1982. With decreasing day length in fall and algal canopy cover reaching maximum densities, submarine illumination in south Diablo Cove fell to its lowest monthly mean values in October 1982 and August 1983. However, water clarity in areas offshore from Diablo Cove usually improves during fall months when calm sea conditions prevail. Although fewer suspended particulates are present in fall, algol canopy cover apparently causes a significant reduction in submarine illumination.

Throughout 1983 submarine PAR values were significantly lower than those recorded in previous years. During the spring months of 1983, underwater light levels in Diablo Cove were depressed probably by increased concentrations of l particulates suspended by scouring of the substrate during storm activity in that period. The cleared substrate allowed for establishment of a luxuriant algal subconopy and an extensive Nereocystis surface canopy (Section 3-13). These l

factors probably contributed to the low underwater PAR values during the summer months of 1983.

l l

B-83-540 3-199 l

3.16 IN SITU WAVE / TIDE MEASUREMENT O

Ocean surface tidal data have been cellected at Diablo Canyon continuously from 1981 through the present at subtidal station 9-10 in Diablo Cove (-10 ft MLLW ). In addition, tidal data were collected beginning this year at subtidal station 32-32 in the plant's intoke cove (-32 f t MLLW). The purpose of these measurements was to develop a data base of tidal conditions within Diablo Cove and to provide data to supplement intertidal temperature measurements (Section 3.14.2) and field biological investigations.

Cumulative frequency plots of tidal data at station 9-10 for the year 1983 are 4

presented in FIGURES 3-82 and 3-83. These plots illustrate percentage emer-gence for each 0.5 ft elevational increment. A comparison of values from the above figures for the I and 3 ft elevations are presented in TABLE 3-21, along with the tido! range for each month. Missing vclues for the months of March and May occur because periods of severe storm activity prevented access to subtidal stations. FIGURES 3-84 and 3-85 present measured and predicted tidal curves for two time periods in 1983. Predicted tidal values are from NOAA tables (Avila i

(Gj Beach substation). FIGURE 3-84 illustrates levels during a period of severe j storm activity, whereas FIGURE 3-85 illustrates levels during a period of calm.

These two periods were chosen for comparison because of their similar p edicted i tidal curves and ranges.

Cumulative frequency plots of monthly tidal data do not show pronounced differences between months. Asymptotes for all curves occur at approximately 6.5 ft at the high end and 0.5 ft at the low end of the curve. Points of 50 percent emergence consistently occur at approximately 3.5 ft. Data from these graphs at I and 3 ft are presented in TABLE 3-21. Little difference in percentage emergence occurred between months at these mid-tidal levels. An exception to i

this occurred in April 1983. Consistently lower high and low tides caused increased emergence at the mid to low elevations. This was accompanied by a decrease in the overall range of the tides for that month as is also shown in the table. Tidal range was found to vary significantly between months. Maximum tidal range occurs during the spring tides of winter (December and January) and the spring tides of summer (July and August). The largest tidal range B-83-540 3-200

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TABLE 3-21 MONTHLY PERCENTAGE EMERGENCE AT THE I AND 3 FT (MLLW) ELEVATIONS AT STATION 9-10 AND TIDAL RANGES FOR 1983.

Percentage Extreme Elevations Emergence (ft MLLW)

+1ft +3 f t (MLLW) (MLLW) Max. Min.

December 1982 11.47 35.98 8.4 -1.3 January 1983 9.63 31.14 8.3 -1.9 February 1983 6.13 36.00 7.4 0.0 March 1983 no data April 1983 16.13 48.15 6.0 -0.2 May 1983 no dato June 1983 11.77 37.12 7.0 -1.0 July 1983 10.75 39.43 7.2 -1,1 August 1983 8.02 36.69 7.3 -0.9 September 1983 7.92 38.84 6.7 -0.8 October 1983 9.43 36.93 6.3 0.0 November 1983 7.09 36.53 6.8 -0.1 B-83-540 3-205

occurred in January with a range of 10.2 ft. Although tidal ranges do vary

[] between months, the levels of emergence within that range appeared to remain fairly constant.

For the most part, tidal data obtained in Diablo Cove closely follow predicted tidal values (NOAA 1981) ca is shown in FIGURES 3-84 and 3-85; however, there is a 0.5 to 1.0 f t difference between measured and predicted levels during certain portions of the tidal cycies. The difference is most evident at the higher low water time when a difference of up to I ft was observed. Differences between predicted and measured elevations during high tide periods as presented in FIGURE 3-84 ore a result of wave activity, which at the coastline may be more severe during high tides. The differences between predicted tides at the Port San Luis substation and measured tides at Diablo Cove are not unexpected based on similar comparisons in other coastal areas and con be attributed to differences in exposure between the two locations. The protected harbor at Port San Luis is not subjected to the prevailing offshore winds as are open coastal locations such as Diablo Cove. Strong offshore winds con produce changes in sea-level, producing water levels higher than predicted (NOAA 1981).

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4.0 GEERAL OBSERVATIONS U-s 4.1 1983 STORM EFFECTS in the months January, February and March, abnormally severe winter storms occurred along the California coastline. The January storms coincided with the highest tides of the year. During these three months, Seymour (1983) identified eight discrete storms (TABLE 4-1). Many beaches were denuded of sand, leaving only cobble or bedrock. Piers and breakwaters on the central California coast suffered major damage. Shoreline cliffs were also eroded. While established sand beaches elsewhere in the state were being eroded by wave transport, Diablo Cove was on area of sand and cobble deposits.

4.1.1 INTERTIDAL The storms dramatically altered the physical and biological character of many of the TEMP intertidal stations. During the second week in February, the initial trips following one of the major storm periods were made to the intertidal to investigate the status and general condition of the sampling stations. The biological effects were mostly evidenced by reduced algal cover as a result of wave action and sco'uring. In areas where boulders had been overturned, attached invertebrates normally present on the undersides of rocks (e.g.,

barnacles and tube worms) were observed to be exposed.

i On the north Diablo Cove and South Cove beaches, which consist mostly of large cobble and boulder fields, a number of black abalone were observed out in the open and were not well attached to the rocks. Several chalone were found that had been crushed by overturned boulders. During a follow-up trip two weeks

later, no abalone were seen out in the open. The abalone observed out in the cpen two weeks earlier may have either died or returned to protected habitat.

No quantitative estimates of the storm induced mortalities were obtained.

B-83-S40 4-1

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TABLE 4-1 MAJOR STORMS - WINTER 1983.*

EXTREME VALUES FROM AMONG II NORTHERN AND SOUTHERN CALIFORNIA LOCATIONS Storm inclusive Max. Sig. Max. Peak Number Dates Wave Ht. (f t.) Period (sec)

I 18-20 Jan. 16 17 2 23-25 Jan. 18 20 3 26-29 Jan. 24 20 4 12-14 Feb. 18 22 5 18-21 Feb. 15 18 6 28 Feb.,2 Mar. 23 21 7 8 Mar. 16 18 8 17-18 Mar. 14 20

• Af ter Seymour, R. J.1983. Extreme waves in California during winter,1983.

State of California, The Resources Agency, Department of Boating and Waterways. April 21,1983. 18 pp.

B-83-5/0 1

4-2

1he most immediate and dramatic change was evident in south Diablo Cove at station 12 where a portion of a large seaward rock pinnacle was eroded by the storm waves. The resulting rock debris and fragments completely buried all algae and invertebrates in the vicinity of station 12. Boulders on the upcoast portion of station 7 in north Diablo Cove were moved to new locations. Station 23, located immediately north of the discharge, like station 12, became completely buried under newly transported cobble and sand. However, the area had been only sparsely populated by algae and invertebrates prior to the storms.

By April, station 10 (located immediately south of the discharge), which had once supported a diverse assemblage of algae and invertebrates, become buried under sand. These physical disturbances and changes were the largest that have been observed in the intertidal zone since the beginning of the studies in 1976.

A summary of observations relating to the storm-induced physical and biological changes is provided for each TEMP intertidal station and surrounding areas in TABLE 4-2. These comments are based on qualitative observations made in February and April 1983 and are not based on any analyses of specific quadrat data collected during the sampling analysis.

4.1.2 SUBTIDAL All subtidal station monuments remained in place during the storm period.

However, one settling plate rock and numerous individual settling plates were lost. During March, a reconnaissance of the -10 ft stations was conducted and the observations on physical and biological changes observed are summarized in TABLE 4-3.

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B-83-540 4-3

TABLE 4-2

SUMMARY

OF PHYSICAL AND BIOLOGICAL CHAN 5 (G)

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THAT OCCURRED AS A RESULT OF TFE WINTER STORMS OF 1983 Station / Location Physical Changes Biological Changes 1,2 North Reference largely bench rock stations. No change. No obvious changes.

6 Fields Cove Bench rock station. No change. No obvious changes.

'l North Diablo Cove Severe boulder rolling. Boulders size of Algoe scoured. More Tetroclito and desk with +1 ft MLLW oigoe cast up to Spirorbidae seen because of overturned

+5 ft MLLW (distance of 10-15 m). Up- boviders. More Potiria miniata out in coast end of transects demolished. Iden- open.

tify of origin end lost. Some +1 it quad-rots now of -l f t level due to bociders being moved. Temperature canister dis-placed several meters but rests at same tidal height at new location. Boulder with 7+3 RPC "A" rolled over.

8 North Diablo Cove Sed on bench area of the +1 f1 transect Algae on bench area scoured leaving remwed. Bench area contains the most coralline and non-coralline crusts as the quadrots. Sand and cobble deposited on most conspicuous organisms.

upcoast portion of +3.0 transect.

9 North Diablo Cove At 9+1 o large boulder rolled resulting in Most species appeared lower in abund-a " looser" transect line. Transect was ance. Outside of station abolone out in shortened 35 cm at origin to avoid the open, cheging the positions of all quadrots.

(

\' y) 10 South Diablo Cove Bench rock and boulder station became Algae ond invertebrates buried.

buried under cobble and sand.

Il South Diablo Cove Bench rock station so no major substrate Whole station sand scoured. Foliose shif ting other than large amounts of sand algae rare. Coralline and non-corolline deposited on downcoast end.

crusts only major algae along entire

+1 f t transect.

12 South Diablo Cove Completely buried under fragmented Almost no signs of life. Some algae rock from clif f. Elevation raised roughly recorded in arcos which became portially I f t 12+1 RPC T" gone and 12+1 RPC uncovered indicating some algae con "C" buried, withstand burio! for several weeks.

14,1S DiabloPoint Bench rock stations. No change. No obvious changes.

19 South Reference Boulder rolling. Most species appeared to be reduced in abundance. Abolone seen out in the open prior to survey 42.

20 South Reference More cobble deposited on beach. Elevo- Algoe scoured, tion is raised by as much as I f t. 20+I RPC T" buried.

22 Bose of Globlo Point Station on bench rock. No substrate No obvious changes.

shif1ing.

23 Immediately of discharge north Buried under cobble. All RPC quadrat This station was newly established in sites gone.

Jmuory 1983 and was to be sompted.

Enteromorpha, Ulva, Porphyra, and leculo, which were the primary inhabi-tants, are no longer pretent.

O B-83-540

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TABLE 4-3 THE PHYSICAL AND BIOLOGICAL CHANGES OBSERVED IN MARCH 1983 ON THE -10 FT SUBTIDAL STATIONS IN DIABLO COVE AND SOUTH COVE Station Physical Change Biological Change 6 Boulder disturbance, Heavy recruitment of phaeophytes on 6 settling plates lost clean substrate (mainly Nereocystis) 8 Boulder disturbance Little noticeable change 9 Some scoured areas Littie noticeable change 10 Sand deposition Phaeophyte damage, burial of part of O' attached algol and invertebrate com-munity 12 Sand deposition Phaeophyte damage, burial of part of attached algol and invertebrate com-munity 19 Boulder disturbance, Apprecioble amount of Ulva spp. and 6 settling plates lost Enfermorpha settlement on cleared boul-der / rock areas B-83-540 4-5

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4.2 EL NINO EFFECTS IN 1983 1 Past occurrences of the El Nino oceanographic conditions have resulted in major marine biological changes in the past. The extent of effects from the 1983 El 4

Nino is currently under investigation by the scientific community. In the Diablo '

Cove vicinity both oceanographic and meteorological characteristics were abnor-mal during 1983. Temperature data for each month of 1982 an31983 were discussed in section 3.14. The storm dates which may be related to El Nino are presented in TABLE 4-1. Qualitative obser.ations during biological surveys in ,

1983 suggest several uncommon events which may be attributed to El Nino:

o Early senescence of bull kelp.

The bull kelp survey was conducted in October in each of the previous years since 1976. Because of prolonged warm water temperatures in 1983 the plants began to degrade and decompose earlier than normal and therefore the survey was conducted one month early to obtain a maximum surface count of this annual plant.

o Discoloration and bleaching of Gioartino exasperato/com-i pressa.

On most shallow-water stations, (8-10, 9-10,12-10 and 19-10) Gigartina exasperata was observed to be bleached and discolored forming color patterns of extreme contrast over the bottom.

o Fish normally found only south of Point Conception were present in the study area during 1983.

During the September-October survey, kelp bass, Parolabrox clotharatus, was abundant throughout the sampling area. In addition several other species of fish j that are normally found in southern California were also present although they

) did not occur on the transects. Large schools of blacksmith, Chromis puncti-l pinnus, were seen over pinnacles near the offshore sector of south Diablo Cove.

l A single sighting of the rock wrasse, Halichoeres semicinctus, was made in South Cove and Girella nigrocons, the opaleye, was recorded in the water column at station 4. Several dozen juvenile opaleye were found in local tidepools.

B-83-540 4-6 l

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L_- _-

p 5.0 LITERATURE CITED U

Abbott 1. A. and G. Hollenberg.1976. Marine algae of California. Stanford dniversity Press. xii + 827 pp.

Benech, S. V. and E. W. Colson. 1976. Size and distribution of the California sea otter population in the vicinity of Diablo Canycn Nuclear Power Plant, October 1973 - December 1975. PGon(E, Dept. Engng. Res. Rpt. No.

7846.11-76.

Boyd, M. J.1972. Fouling community structure and development in Bodego Harbor, California. Ph.D dissertation, U.C. Davis,191 pp.

Burge, R. T. and S. A. Schultz. 1973. The marine environment in the vicinity of Diablo Cove with special reference to abalones and bony fishes. Calif.

Dept. Fish and Game, Mar. Res. Tech. Rpt.19. 433 pp.

Cowen, R. K., C. R. Agegion and M. S. Foster. 1982. The maintenance of community structure in a centrol Californiu giant kelp forest. J. Exp. Mar.

Biol. Ecol. 64:189-201.

Ehrler, C. P. and E. B. Lyke. 1980. Settlement and growth of the fouling organisms at Alamedo Marina, Son Francisco Bay, California, pp. 175-188.

Proceedings of the 5th international Congress on Marine Corrosion and Fouling, Biologia Marina, Barcelona, Spain.

Foger, E. W.1971. Pattern in the development of a marine community. Limnol.

Oceanogr. 16:241-253.

Foster, M. S.1982. The regulation of macroolgol associations in kelp forests.

pp.185-205, i_n: L. Srivastava, ed. Synthetic and degradative processes in marine macrophytes. W. De Gruyter Co., Berlin.

Gotshall, D. W., L. L. Laurent E. E. Ebert, F. E. Wendell and G. D. Forrens.

1974. Diablo Canyon Nuclear Power Plant Site Ecological Study Annual Report, July 1973 - June 30,1974. State of Calif., Resources Agency, Dept. Fish and Game, Mar. Res. Adm. Rpt. 74-10.

l Gotshall, D. W., L. L. Laurent, and F. E. Wendell.1977. Diablo Canyon Nuclear Power Plant Site Ecological Study Annual Report, July 1,1975 - June 30, l

1976. State of Calif., Resources Agency, Dept. Fish and Game, Mar. Res.

Admin. Rpt. 77-18 and Quarterly Rpt. No.12. April 1,1976-June 30,1976.

! Grigg, R. W. and J. E. Maragos. 1974. Recolonization of hematypic coral on submerged lava flows in Hawaii. Ecology 55:387-395.

Hoefner, P. A., Jr., and W. A. Von Engel.1975. Aspects of molting, growth and survival of male rock crabs, Concer irroratus, in Chesapeake Boy. Cheso-peake Sc. 16: 253-265.

,O B-83-540 5-1 l

LCMR.1978. Pacific Gas and Electric 316(o) demonstration program preopero-

[ ,] tional data base summary. Vol.1.

G/

McLean, J. H. 1978. Marine shells of Southern California. Natural History Museum of Los Angeles County, Science Series 24.104 pp.

LI-COR 1981. Instrumentation for biological and environmental sciences.

[ brochure] . 47 [ +2] pp. Li-COR, Inc., Lincoln, Nebraska.

Montgomery, D. H.1967. Responses of two holiotid gastropods (Mollusco),

Holiotis assimilis and Holiotis rufescens, to the forcipulate asteroids (Echinodermato), Pycnopodio helianthoides and Pisoster ochraceus. Veliger 9: 359-368.

Morris, R. H., D. P. Abbott and E. C. Haderlie. 1980. Intertidal Invertebrates of California. Stanford University Press. 690 pp.

NOAA,1981. Tide Tables 1981- West Coast of North and South America. U.S.

Dept. of Commerce. National Oceanograph and Atmospheric Administro-tion. 231 pp.

North, W. J.,1971. Biological impact. In: Environmental Report, Units I and 2, Diablo Canyon Site. PGondE. July 1971.

North, W. J.,1969. Biological effects of a heated water discharge at Morro Bay, California. Pages 275-286 in: R. Morgolef, ed. Proc. 6th Intern. Seaweed.

[]

sv North, W. J., E. K. Anderson and F. A. Chapman. 1975. Marine ecological transect studies. In: Environmental Investigations at Diablo Canyon,1974.

PGondE, Dept. Engng. Res.

Osman, R. W.1977. The establishment and development of a marine epifounal community. Ecological Monographs 47:37-63.

Passano, L. M.1960. Molting and its control. In: T. H. Waterman (ed), The Physiology of Crustaceo I: 473-536. Academic Press, New York.

PGondE. 1977. Diablo Canyon Nuclear Power Plant 316(o) Demonstration. Mine Month Progress Report. October 1977.

PGondE. 1978. Diablo Canyon Nuclear Power Plant 316(o) Demonstration. Nine Month Progress Report. May 1978.

PGondE. 1979. Diablo Canyon Nuclear Power Plant 316(o) Demonstration. Nine Month Progress Report. November 1979.

PGondE. 1980. Diablo Canyon Nuclear Power Plant 316(o) Demonstration. Nine Month Progress Report. August 1980.

PGondE. 1982. Thermal Discharge Assessment Report. Diablo Canyon Power Plant. March 1982.

('V B-83-540 5-2 l

l w PGondE. 1983. Thermal Effects Monitoring Program. 1982 Annual Report.

) Diablo Conyon Power Plant. January 1983.

Quast, J. C.1968. Observations of the food of the kelp-bed fishes. Calif. Dept.

Fish Game, Fish Bull. 139:109-142.

Ricketts, E. F., J. Calvin and J. W. Hedgpeth.1968. Between Pacific Tides,4th edition. Stanford University Press. 614 pp.

Saito, Y. H. Saski and K. Watonobe.1976. Succession of algol communities on the vertical substratum faces of breakwaters in Japan. Phycologia 15:93-100.

Sebens, K. P. 1982. Recruitment and habitat selection in the intertidal sea onemones, Anthopleuro elegantissimo (Brandt) and A. xanthogrammico -

(Brandt). J. Exp. Mar. Biol. Ecol. 59: 103-124.

Seymour, R. J.1983. Extreme waves in California during winter,1983. State of California - The Resources Agency. Dept. of Booting and Waterways.

Special Rpt. 18:pp.

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