ML20079N360
| ML20079N360 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 02/28/1978 |
| From: | Marcy B, Morgan P NUS CORP. |
| To: | |
| References | |
| RTR-NUREG-1437 AR, NUDOCS 9111110177 | |
| Download: ML20079N360 (38) | |
Text
.
MONTICELLO Ni' CLEAR GEN Pl. ANT ATTACllMLNT 5 9
SECTION 316(b) DDiONSTRATION FOR TJE MONTICELLO NUCLEAR GENERATING PLANT ON 'llE MISSISSIPPI RIVER AT MONTICELLO, MINNESOTA (NPDES PERMIT NO. MN 0000868)
PREPARED FOR NORTIIEPJi STATES POWER COMPANY MINNEAPOLIS, MINNESOTA BY RIC11ARD A. AMISil VINCENT R.
KRANZ BRUCE D. LORENZ
' DANIEL B. WILCOX LUISE K. DAVIS BRADFORD B. OWEN, JR., Ph.D.
ECOLOGICAL SCIENCES DIVISION NUS CORPORATION PITTSBURG11, PENNSYLVANIA FEBRUARY 1978 APPROVED BY:
2-L, BARTON C. MARCY, JR.,,6GER AQUATIC ECOSYSTEMS DEPARTMENT k
, PAUL. V. MORGAN, VICE MMDENT
$W
?
AND GENERAL MANAGER ij
.I h.e i
8' 9111110177 780228 PDR NUREG 1437 C PDR
I i
- I 6e TABLE OF CONTENTS VOLUME I i
Page TITLE PAGE.
i Y
TABLE OF CONTENTS e
11 LIST OF TABLES.
v EIST OF FIGURES.
iX 1.
STATEMENT OF THE PROBLEM.
1 2.
SUMMARY
3 f
3.
DESCRIPTION OF THE PLANT.
a=
9 3.1 LOCATION OF PLANT.
9 3.2 INTAKE DESIGN.
9 3.3 OPERATING MODES.
14 3.4 INTAKE VELOCITIES.
18 3.5 INTAKE VOLUMES 22 3.6 COOLING WATER TEMPERATURES.
26 3.7 BIOCIDE 3.
26 i
4.
DESCRIPTION OF THE AQUATIC ENVIRONMENTS NEAR MNGP.
28 4.1 HYDROLOGY.
28 i
4.2 WATER QUALITY.
35 4.2.1 GENERAL CHARACTERISTICS 35 1
4.2.2 WATER TEMPERATURE.
33 4.2.3 DISSOLVED OXYGEN.
30 4.2.4 OTHER EXISTING OR PLANNED STRESSES 4
IN THE AREA.
41 t
4.3 AQUATIC ECOLOGY.
43 4.3.1 TROPHIC STRUCTURE.
43 l
4.3.2 PRIMARY' PRODUCERS 44 4.2.2.1 PHYTOPLANKTON.
45 4.3.2.2 PERIPHYTON.
47 4.3.2.3 MACROPHYTON.
48 4.3.3 ZOOPLANKION.
49 l
4.3.4 BENTHIC MACROINVERTEBRATES.
50 l
4.3.5 FISH AND FISHERIES.
55 4.3.5.1 SAMPLING METHODS 55 4.3.5.1.1 ELECTROFISHING.
55 4.3.5.1.2 SEINING 57 4.3.5.1.3 DRIFT OF FISH EGGS AND YOUNG 64 4.3.5.2 COMMUNITY STRUCTURE.
68 4.3.5.2.1 SPECIES COMPOSITION l
AND ABUNDANCE 68 l
11
l TABLE OF CONTENTS (Continued)
Page 4.3.5.2.1.1 ELECTROFIS!!ING.
CATCll.
72 4.3.5.2.1.2 SEINE CATCH.
79 4.3.5.2.2 POPULATION DENSITIES.
85 4.3.5.3 SPAWNING AND NURSERY POTENTIAL.
87 4.3.5.3.1 REPRODUCTIVE STRATEGIES.
87 4.3.5.3.2 SPAWNING HABITATS.
89 4.3.5.3.3 DRIFTING EGGS AND LARVAE.
94 4.3.5.3.4 ABUNDANCE OF YOUNG FISH.
103 4.3.5.4 SPORT FISHERY.
105 4.3.5.5 COMMERCIAL FIS!!ERY.
111 5.
INTAKE STUDIES.
112 5.1 ENTRAINMENT.
112 l
5.1.1 ENTRAINMENT MONITORING MET!!ODS.
112 1
5.1.2
'sNTRAINMENT OF FISH EGGS AND YOUNG.
114 i
5.2.1 IMPINGEMENT MONITORING METHODS. pt.
127 '
I 5.2.2 IMPINGEMENT STUDY RESULTS.
130 5.2.2.1 1972-1975 MONITORING.
130 5.2.2.2 1976 MONITORING.
135 6.
IMPACT ASSESSMENT.
168 6.1 PRIMARY PRODUCERS 168 6.2 ZOOPLANFTON.
169 6.3 BENTHIC MACR 0 INVERTEBRATES.
170 172 6.4 FISH.
6.4.1 IMPACT ANALYSES.
172 6.4.2 ENTRAINMENT LOSSES 180 6.4.3 IMPINGEMENT LOSSES.
182 6.4.4 COMBINED IMPACT OF ENTRAINMENT AND IMPINGEMENT.
184
(
7.
REFERENCES CITED.
195
[
l I
111 l
i i
TABLE OF CONTENTS Vol.
TI I
Appendi:2, page 1
ANNUAL WD MONT!!LY FLOW DURATION CURVES, MISSISSIPPI R1VER AT ST. CLOUD, MINNESOTA, 1926-1970.
1-1 2
ANNUAL AND MONT11LY FLOW DURATION CURVES, MISSISSIPPI RIVER AT ANORA, MINNESOTA, 1926-1970.
2-1 3
WATER QUALITY DATA, TURBIDITY MONITORING i
PROGRAM, MISSISdIPPI RIVER AT M1GP.
3-1 4
SCIENTIFIC AND COMMON NAMES OF FIS!!ES REPORTED FROM TIIE MNGP AREA OF T!!E i
4-1 l
5 NUMBER AND WEIGHT OF FISH SEINED, MISSISSIPPI RIVER NEAR MNGP, APRIL 1976-APRIL 1977.
5-1 6
SUMMARY
OF AVAILABLE INFORMATION ON THE REPRODUCTIVE BIOLOGY OF T!!E FISHES IN THE MISSISSIPPI RIVER NEAR MNGP.
6-1 7
NUMBER A!O WEIGHT OF FISH IMPINGED AT
{
MNGP, APRIL 19 C 7-APRIL 19 77.
7-1 8
NUMBER AND WEIGHT OF FIS!! IMPINGED DAILY AT MNGP, APRIL 1976-APRIL 1977.
B-1 i
4 9
0 i
9 e
iv i
i iiiW
~. _ _
~__.__
E j
i 2.
SusAnl r
t l
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section 316(b) of the Federal Water Pollution Control Act Amendments of 1972 requires cooling water users to determine biological uffects of their intake systems and to demonstrate p.
that the design, construction, location and operation of the
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intake systems reflect the best technology available.
Under i
L fh the National Pollutant Discharge Elimination System (NPDES),
t i.((
Section 402 of P.L.92-500, Minnesota has been given the ra l
fj authority to administer the law using the 316 (b) amendments
?
and Minnesota Regulation WPC(u) (3).
The Minnesota guide for the administration of Section 316(b) requires the demonstrator to show the environmental effects of cooling water intakes through documentation of the magnitude of impingement and entrainment impacts (MPCA 1975).
Supplemental information on the aquatic ecesystem in the region of the intake is also requested.
In this section 316(b) Demonstration, Federal and State requirements have been addressed by providing the analysis of entrainment and impingement at the Monticello Nuclear Generating Plant v
(MNGP) and by providing extensive baseline data for the area.
l l
Northern States Power (NSP) has conducted ten years of studies of the Mississippi River ecosystem near MNGP, 3
4 6
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i 9
including three years of preoperational studies.
The waters of the Mississippi River are generally considered to be of good quality and to support a healthy and abundant flora and fauna.
This Demonstration is primarily based upon the study of entrainment, impingement and waterbody populations of young fish at MNGP during April 1976-April 1977.
This period encompassed some of the lowest flows in the Mississippi River in decades.
Consequently, during the study year the plant withdrew relatively high percentagen of river water and, along with the cooling water, entrainable organisms, i
Phytoplankton is the only community of,'rimary producers l
that could be significantly impacted by MNGP intake cperation.
However, phytoplankton is less important to the trophics j
f of the Mississippi River in the MNGP orea than periphyton.
l Periphyton, which has been estimated to contribute'from I
60 to 82% of the primary production in the aquatic environment I.
near MNGP, is not subject to significant entrainment because it is usually at+ ached to the river substrates.
I In the April 1976-April 1977 study year, 19% of the phyto-plankton passing MNGP may have been entrained.
Considerably I
less than 19% would have been impacted since, especially t
I 4
l 3
during open cycle operation, survival of entrained algae would be high.
Considering the low level of impact, the secondary importance of phytoplankton to the t.ophic structure of the river and the rapid regeneration times of algae, operation of the MNGP intake does not represent a threat to primary production in the Mississippi River near MNGP.
Approximately 19% of the zooplankton flowing past MNGP may have been entrained during the study year.
A considerably smaller percentage of the river zooplankton was impacted since, especially during open cycle operation, a high survival of entrained zooplankters is expected.
The trophic importance of zooplankton in the Mississippi River near MNGP is limited due to the low numbers of crustaceans in the community and the limited number of organisms that feed on zooplankton.
Considering the predicted rapid downstream recruitment of zooplankton from benthic habitats and protected shoreline areas, the rapid reproductive rates of the protozoans and rotifers that likely dominate the community and the limited trophic significance of zooplankton in the river, operation i
of the MNGP intake is not considered to have a serious impact I'
on this portion of the aquatic ecosystem.
i 6
4 I
5
Benthic macroinvertebrates may be entrained when they drift or are dislodged by high): flows.
Drift studies near MNGP indicate that numerically the entrainable fauna is composed of 37% mayflies, 28% stoneflies, 30% true flies and 5% other groups.
Based on drift densities in 1973-1974 and the flows during the study year, over one billion organisms could have been entrained at P from April 1976-April 1977.
Consider-ing that drif t constitutes a small proportion of the benthic community and that only 19% of the drift in the area may
[
have been entrained (assuming random distribution of drift in the water), MNGP intake operation is not considered a seriaus impact to the benthic communities of the MNGP area.
The effects of entrainment and impingement on fish communities are a major consideration in assessing the impact of plant operation.
The loss of adult fish due to entrainment of eggs and young at MNGP was estimated by using a simple popu-lation model described.
Losses from impingement were estimated by using a similar model, since most of the fish impinged were young.
The total impact was evaluatud by considering the combined effect-of impingement arai entrain-ment.
Totg1 calculated adult losses were compared with sport fishery statistics and population estimates, when available.
l 6
o sport fish (northern pike, rock bass, smallmouth bass, black crappie and walleye) represented less than 0.1% of the total estimated loss of adult fish (256,003-261,462 fish).
Between 36 and 60 smallmouth bass, or about 21% of the annual sport harvest for the area near MNGP, were estimated to have been lost due to entrainment and impingement.
Estimated losses of 18 to 230 adult bla:k crappie represented about 50% of the sport harvest.
These losses are not con-sidered significant because of the very light fishing pressure I
and resulting low harvests for the stretch of the Mississippi River near MNGP.
Losses of northern pike and walleye were less than 5% of the average ar.nual harvest.
Forage fish, mainly logperch, actsunted for nearly 94% of the estimated loss of all adult fishes.
The estimated loss of 218,000 adult logperch represented about 45% of the estimated spawning population in a 1.8 ha (4.4 ac) area up-stream of the MNGP inteke.
Losses of this magnitude are considered insignificant, based on the minimal impact that comparable percent removal of forage species (mainly minnows) l have had in other rivers.
Rough fish, primarily silver and shorthead redhorse, composed about 6% of the estimated adult loss.
Losses of shorthead l
7
l o'
I o
redhorse were estimated at 35 to 40%, of the 1968 and 1969 adult populcaion and 19 to 25% of the estimated 1976 adult population.
Entrainment and impingement of redhorse in the 1976-1977 study period were considered extremely high when l
compared to previous operational years.
The high redhorse losses in 1976-1977 were attributed to a very successful 1976 year class.
MNGP had not had a serious effect on redhorse populations in previous years and it is postulated that the effect of 1976-1977 losses would not be detectable for several years, if at all.
The operation of the MNGP intake does not appear to have damaged the fish community of the Mississippi River near MNGP since it began operation in 1971.
With the possible exception of the redhorses (see above), losses during the 1976-1977 study are not expected to have a measurable impact on the fish populations in the vicinity of MNGP.
Continued operation of the MNGP intake should not affect the propagation of the balanced indigenous aquatic ccmmunities of the Mississippi River.
8 w-
fn '.
)Ll:
Sib GD 5
MONTICEl.LO NUCLEAR GEN Pl. ANT 6
IMPACT ASSESSMENT ATTACHMENT 5
(
6.1 PRIMARY PRODUCERS Phytoplankton is the only primary producer in the MNGP area
(
that potentially could be significantly irapacted by intake operation.
The MNGP withdrew approximately 19% of the Mi ssissippi River flow during the April 1976 to April 1977
(
study year.
Since phytoplankton is expected to be randomly distributed in the water column of a rapidly moving river like the Mississippi, a maximum reduction of 19% of annual t
phytoplankton production could have occurred during the study year, if 100% mortality is assumed upon passage through the plant.
During periods of open and helper cycle operation high percentages of algae entrained are predicted to survive.
A reduction of this magnitude does not impose a sericus threat to the integrity of the Mississippi River biota, as phytoplankton can reproduce rapidly, thus. minimizing down-stream effects (EPA 1976a).
In addition, phytoplankton is not judged-to be as important to primary production as periphyton in this section of the Mississippi River.
Because periphyton is more or less attached to substrates, it will not be entrained in significant quantities.
(.
(
168 3
t
'e 6.2 ZOOPLANKTON
(-
Zooplankters are susceptible to entrainment because they are virtually free-floating.
However, all zooplankton that is
(
entrained is not killed.
Davies and Jensen (1974) cite I
several studies in which mortality among entrained zoo-plankton was less than 20%.
During once-through operation,
(
it is likely that a large percentage of entrained zooplankters will survive.
During closed cycle operations, most of the zooplankton that enter the system may be killed; however,
(
the number of individuals which are entrained is minimized l
due to the small volumes of water withdrawn from the river.
(
On a volumetric basis, MNGP would have entrained approximately 19% of all zooplankton flowing past the plant during the study year (April 16, 1976 - April 9, 1977). -The short
-(
freproductive cycles characteristic of most zooplankters andLthe low expected entrainment mortalities minimize the effect of entrainment on the zooplankton community.
(
The ecological importance of zooplankton in the upper ~
i Mississippi River is probably. limited.
The_ majority of 0
adult fish consume benthic organisms or other fish.
A_few l filter-feeding benthic invertebrates-(e.g., clams,-some caddisflies and black files) and young fishes feed on zoo-b
_p an ton. ~The' temporary nature of zooplankton in the'lotic l
k g_
169 m.-. -. _.. _. _ - _ _ _ _ _ _.. _ _. _...._ _, - _... _,,.,-,_._., _ _ _ _
~ _
4.
environment and its susceptibility to fluctuations in
(
physicL1 and chemical factors further emphasize the limited role of zooplankton in the trophic dynamics of rivers.
As noted by EPA (1976a), entrainment generally does not significantly
(
1mpact zooplankton because zooplankters have rcpid reproductive rates and short life spans.
(
6.3 BENTl!IC MACROIINERTEBRATES Benthic macroinvertebrates are subject to entrainment when I
they become suspended in the water column through behavioral or catastrophic drift.
Numbers, kinds and periodicity of benthic macroinvertebrates in the drift depend on environ-I mental f actors which influence drif t density and timing and the behavioral. factors of the insects.
I Matter's (1975) study of drift organisms near MNGP indicates that drift is composed of 37% Ephemeroptera, 28% Trichoptera, 30% Diptera and.5% " miscellaneous".
The relative numbers I
and species. composition of macroinvertebrate entrainment samples collected by Gundersen and Lewis (1976) closely resemble those of Matter (1975).
Estimates of worst case entrainment losses at MNGP are presented in Table 6.3-1.
These estimates were made by applying 1976-1977 MNGP intake volumes to the densities which Matt-(1975) found in drift
(
170
(
(
=
TABLE 6.3-1
(
ESTIMATED INVERTEBRATE ENTRAINMENT AT MNGP MAY 1976-MARCH 1977 (1.dapted from Matter 1975)
Number That Would I
Number Drifting Past Be Entrained by 6
MNGP Per Month (x 106)a MNGP Per Month (x 10 ):
May 769 130.7 June
'978 273.8 July 263 81.5 August 1,470 529.2 September 214 53.5 g
November 252 30.2 December 238 52.4 c
g oruary 224 53.8 e
March 336 47.0 TOTAL 4,744 915.5
(
" July 1973-July 1974 drift invertebrate densities at MNGP (Matter 1975) times mean river discharge for the month sampled bBased on invertebrate drift densities per gallon at MNGF
(
(Matter 1975) times percent of river flow withdrawn by MNGP during respective month cExcluding Psychodidae which were imported; suitable habitat does not exist on site for this family
(
(
171
(
\\
i t*
samples taken in the river in 1973-1974.
Matter associated
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high drift densities with high river flows.
Since there were no high flows in the 1976-1977 study period, the a
estimated entrainment ratio shown in Table 6.3-1 may be
(
unrealistically high.
Considt ri.ng that drif t represents a small fraction of the
(
9tanding crop (Bishop and Hynes 1969) and has been considered as production in excess of the carrying capacity of a stream (Waters 1972), and considering the relatively minor proportion
(
of river flow (and drif t) that MNGP entrains, these rates of entrainment should not have a detectable influence on the macroinvertebrate communities near MNGP.
(
6,4 F7.SH
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6.4.1 Impact Analyses Analysis of the impact of entrainment of fish eggs and young at MNGP is based on the population model described by Horst
(
(1975), in wh.ich the numbers of eggs, larvae and juveniles entrained ar6 converted to an estimate of the number of adult fish that would have been produced had entrainment I
mortality not occurred.
(
172
_. _ _ _ _ _ _.. _ _. _ _ ~
(
If the entrained stage is an egg, the estimate of the number of adults lost is calculated as:
N,=SNge"fN e
(
where N, a number of adults S
= survival from egg to adult 9
(
N,= number of eggs entrained 2
= number of adulta needed to be produced by a breeding pair to maintain a stable population
(
F=
total lifetime fecundity of a female based on the generation time (g) of the population and the average fecundity (E)
(
According to Horst (1975), fish lifetime fecundity is the number of eggs produced in the lifetime of a species.
-(
Calculations were made using average lifetime fecundities to permit a comparison of results.
It should be recognized that the average lifetime of a species can be estbmated only
(
roughly and is determined by mortality rates among age classes as well as by life It is also necessary to make the assumption that the limited data available from
(
various locations and times are roughly representative of the indigenous populations near MNGP.
(
(
173
e This procedure used for calculation of lifetime fecundity (F), following Horst (personal communication), is most cleerl/ shown by an example.
Reprasentative calculations for the walleye are shown below.
(
A B
C D
Gurviving Eggs por Weighted eggs Age portion female per female (B x C)
(
l
.50 0
0 2
.25 0
0 3
.125 77,000 9,625 4
.063 119,500 7,529 5
.031 180,500 5,596 6
.017 258,000 4,386
(
7
.008 303,000 2,424 8
.004 333,000 1,332 9
.002 502,000 1,004 10
_.001 484,000
_484 1.001 32,380
(
Population fractions (B), assuming 50% mortality per year, are multiplied by eggs per female (C) to give weighted eggs per female (D).
Total weighted eggs per female is divided by total of fractions, if the latter is not exactly one, to f
give mean fecundity of age classes.
Thit mean fenundity is multiplied by an estimate of mean generation time in years to give mean lifetime fecundity.
How to select the mean generation age has not been clearly defined.
In this report it is assumed to be the age which yields the largest numbers of weighted eggs per female.
This is a conservative approach in that the use of higher mean generation times results in lower Lmpact projections.
174 l
(
(
Survival of white crappie eggs has been determined as 49 to 94% in a study by Siefert (1968); an average value of 75%
has been used in this report.
(
Forney (1976) used fecundity-at-age and larval densities to estimate an egg to larva curvival rate of 0.5% for Oneida Lake walleye.
Egg studies indicated a survival rate of 2.4
(
to 25% in a Minnesota Lak* (Johnson 1961).
The 0.3% survival rate used for white sucker and Catostomidae
(
was based on the observation that as few as 0.3% of eggs may survive to migrant larvae (Geen et c'
.366).
(
A survival of 0.5% has been used for unidentified Cyprinidae.
The normal range of survival for minnows is not known.
The 0.5% value used was based on the observation that unguarded
(
eggs usually exhibit high mortality.
Survival of eggs of the carp (a cyprinid) was estimated as 80 to 94% by Nikolskii (1969).
However, mortality was high when dissolved oxygen concentrations were reduced; this stress is usually not present in the Mississippi River near MNGP.
The habit of depositing adhesive eggs in vegetation may afford protection and may account for observed high survival rates.
Egg survival of 34 to 90% has been reported for another cyprinid, l
175
(
g..
4 the carp-b".eam (Nikolskii 1969).
A range of 0.5 to 94% was
(
used for carp.
If the entrained stage is a larva:
'(
N,=SNyy=
P y
N s,
where I
N, 2 and F are defined as above a
Sy = survival from larva to adult Ny = number of larvae entrained S, a survival from egg to larva The following assumptions are made in this analysis:
', (
There is *.00% mortality of entrained eggs and larvae o
i due to passage through the plant.
o The populations are at equilibrium and have a stable
.ge structure, and the total lifetimo rect lity produces
~
two adults.
o No compensatory mechanism 3 arc operating.
.(
3 o
0.5% of the eggs produced by h species with high fecundity, randomly broadcast eggs and/or nu parental care survive to become larvae [ based on data
(
of Rothschild-(1961) for smelt),
o 75% of the eggs produced by species which exhibit nesting behavicr and a high degree of parental care
(
survive to the larval stage.
276 l
(
(
l o
Larvae are entrained immediat<21y af ter hatching.
Since
(
larvae are entrained at all stages of development, this
^
assumption can lead to an underestimate of the number of potential adults lost.
Survival data among the
(
stages are, for the most part, unavailable.
- However, for many species in this study, the larvae entrained were yolk larvac, making the above assumptions realistic.
(
The.analysin of the impact of fish impingar.ent on the traveling screenu at MNGP was similar to that used for entrainment,
(
since it has been shown that most fishes impinged in 1976 were age 0, i.e., men.bers of the 1976 year class (See Section 5.5.2.2).
The numbers of adults that would have resulted from age O fish impinged was calculated as:
N
=. N a
7 where g
N
= number of adults lost a
s
= survival from juvenile (age O) to mean generation time (g) 4 N
= nnaber of age O fish impinged y
S is calculated as:
(
I9~U S=S S
y g
(
177
(
t-where
(
S
= average overwinter survival, i.e.,
survival from y
age 0+ to age ~i Sg = average annual survival for fish older than age 1 S
was estimated from data supplied by Clady (1975,1976) y and Forney (1976) for yellow perch, smallmouth bass and
(
walleye, respectively.
Survival to yearlings averaged 0.8%
(0.1 to it) for yellow perch and 0.9% (0.3 to 32%) for walleye.
Clady (1975) catimated overwinter survival for young smallmouth bass at 23%.
Survival data for other species during this time period are lacking; however, if 0.1% survival is chosen as the lower limit and 32% is chosen
(
as an upper limit, it seems reasonable to assume that most species will fall within this range.
Annual survivals after the yearling stage are more easily obtained.
Clady (1976) reports average annual survivals for yellow. perch between agcc 3 and 8 of 72%.
Paragamian and Ceble (1975) report average annual survivals of 35 to 45% for age 2 to 8 4
smallmouth bass in the Red Cedar and ? lover rivers in Wisconsin and 34% for age 2 to 7 smallmouth bass in Missouri streams.
Forney (1972) found that annual survival for age g
3 to 7 smallmouth bass in Oneida Lake, New York averaged 60%
over a 13 year period.
An unexploited walleys population in i
178 l
g
.g
-Manitoba showed 20 to 30% survival over a one year period (Kelso and Ward 1972).
In contrast, Nelson and Walburg (1977) found that walleye aged 2 to 9 in three Missouri a
River reservoirs had annual survivals ranging from 44 to
(
62% while survival of sauger ranged from 51 to 58%.
Gerking (1962) found that the annual survival for age 2 to 5 bluegill ranged from 20 to 44% in an Indiana Lake.
Carlander (1977),
(
in a summary of annual survivals for black crappie older than age 2, reported a range of 9 to 36%.
Thus, the annual survivals found in this brief literature review range from
(
9 to 72% for various sport species and levels of exploitation.
Little information is available on annual survival of
(
rough fish.
Jester (1972), in a study of the river carpl sucker of Elephant Butte Lake, New Mexico, reported annual survivals of 41 to 85% for fish age 2 to 10.
Bodola (1966)
(
estimated a 17% annual survival for gizzard shad between age 2 and 6.
Based on these studies, it appears reasonable to assume that rough fish fall within the range of survival values for gamefish.
Assumptions in this method of estimating loss due to impinge-ment are similar to those made for entrainment estimates o
There is 100% mortality for impinged fish.
o No compensatory mechanisms are operating.
(
179
('
Estimates of the number of adults lost due to entrainment of I
eggs and young and the impingement of young will be summed.
This total estimate of potential adults lost to the Mississippi River will then be compared to sport fishing harvests to I
place the losses in perspective.
6.4.2 Entrainment Losses
(
A total of nine taxa sfere chosen for analysis of impact (Table 6.4-1).
Each of the taxa accounted for more than 1%
of the young entrained and all nine taxa represented nearly
(
97% of the identifiable young.
No northern pike, smalLmouth bass or walleye young were collected in entrainment semples in 1976.
The number of young entrained, the number of
(
potential adults lost and the values of fecundity and survival used to calculate losses are summarized in Table 6.4-1.
i Between 248,360 and 250,124 potential' adult fish were estimated
(
to have been lost due to the entrainment of 2,734,000 young over a year.
Rock bass was the only sport species collected in entrainment samples and calculated adult losses of rock
(
bass (106 fish) represented much less than 0.1% of the estimated total adult fish loss.
Logperch, a forage species, accounted for as much as 88% of the predicted adults lost due to entrainment.
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180
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e
.n e.
n n
m e
e s
m
~
TABLE 6.4-1 CALCULATION OF EQUIVALENT ADULT FISil LOST DUE TO TIIE ENTRAINMENT OF EGGS AND YOUNG AT MNGP IN 1976 Nean Mean Generation Survival thsnter mueber of 5
Tuon recundity:Fi rt t9:
r99 to adultes9s r99 to tarvaises tarv to aauitts13 entrain.dt 10 )
adults losteman Carp 28,174 5
1.42x10' O.005-0.94 1.51x10 '-2.84x10~
0.30 3-85 a,b
~
Minnows 901 1
2.22x10~
0.005 4.4 x10~
3.08 13,600 C
d white sucker 13,003 4
3.84x10~
0.003 1.28m10~
1.50 1,920 Silver redhorse 5,970 5
6.7 x10 '
O.003 2.23x10~
0.40 871 d
~
Shorthecd redhorse 11,4 3; d 4
4.37x10~
0.003 1.46x10~
6.33 9,230 d
Redhorses 5,970-11,432 4-5 4,37m10~ ~6.7m10~
0.003 1.46x10 -2.23:10 2.19 3,200-4,R80 Rock. bass 1,094*
2 9.14e10~
0.75 1.22s10 '
O.87 10G
~
Dartsrs 733' 1
2.73x10~
0.75 2.64x10 '
3.88 1,410
~
Logperch 1,615' 1
1.24x10 '
O.005 2.48 10~
8.79 218,000
~
27.34 248,360-250,124 "Carlander 1969 Swee and McCrimson 1966
- Scott and Crosetuan 1973 dIberley 1975
'"cinn 1958a, b
lt' 6.4.3 Impingement Losses I
Thirteen of the 35 taxa impinged on the vertical traveling screens at MNGP were chosen for impact analysis (Table
- 6. 4-2).
Each of the taxa, except northern pike, rock bass, johnny darter and walleyo, represented more than 1% of the total number of fish impinged during the 1976-1977 intake monitoring program (Section 5.2.2).
The 13 taxa represented
(
more than 97% of the total impinged.
The minnows included at least ten species, of which only spotfin shiner and longnose dace individually made up more than 1% of the fish
(
impinged.
Sport species represented less than 10% of the total number of fish impinged.
(
The total number of fish estimated to have been impinged between April 1976 and April 1977 was higher than for any one year period previously examined (Section 5.2.2) and,
(
consequently, adult losses for 1976-1977 probcbly represent a maximum for the operational period of MNGP.
(
Between 7,642 and 10,838 adults were projected to have been lost due to impingement of 38,654 fish during the 1976-1977 study period (Table 6.4-2).
Logperch accounted for the largest portion (31. 2 to 4 4. 2 % ) of the projected loss; minnows were the next most numerous group (21.8 to 31.0%).
Since it appeared that most individuals of these taxa were 182
(
~.
g TABLE 6.4-2
(~
CALCULATION OF ADULT FISH LOST DUE TO IMPINGEMENT AT MNGP DURING 1976 AND 1977
~
Number Survival Number of g
Taxon Impinged o"
to c Adults Lost h
~0
~1 Northern. pike 7
3 8.1 x10 -1.65x10 1
-8
-2 Carp 2,506 5
6.56x10
-8.6 x10 1-215 d
Minnows #
2,366 2,366
(
~
~
White sucker 2,121 4
7.0 x10 -1.19x10 1-252
-8
-2 Silver redhcrse 7,385 5
6.56x10
-8.6 x10 1-635
~
~
Shorthead redhorse 15,295 4
7.0 x10 -1.19x10 1-1,820 1,799
(-
Black bullhea.1 1,799
~
~
Rock bass 175 2
9.0 x10
-2,3 x10 1-40
~
~
Smallmouth bs.ss 1,295 3
2.82x10 -4.66x10 36-60
~3
~1 Black. crappie
- 2,254 3
-8.1 x10 -1.02x10 18-230 35
(
Johnny darter 35 3,381 Logperch 3,381
~4
~
Walleye 35 3
1.2 x10 -1.23x10 1-4 Total 38,654 7,642-10,838
(
"g = Mean Generation Time as defined in Section 6.4.1 See Section 6.4.1.
Species-specific survivals were used when available Includes hornyhead chub, golden shiner, connon shiner, bigmouth shiner,
(
spottail shiner, sand shiner, unidentified shiners, fathead minnow, bluntnose minnow and longnose dace Assumed to be adults when impinged
- Based on size appeared to be 1 year old at impingement
.(
183 t.
l already adults when impinged, the actual number impinged was
(
considered the most conservative estimate of loss.
Most black bullhead impinged appeared to be age 1 or older, so the actual number impinged was again used as a conservative
(
estimate of loss.
6.4.4 Combined Impact of Entrainment and Impingement
(
The total impact of MNGP on the fish populations of the Mississippi River is best evaluated by considering entrain ~
ment and impingement losses together.
The total estimated
(
loss of potential adults due to the operation of MNGP during the one year study period is summarized in Tabic 6.4-3.
The significance of these losses to the populations involved
(
may be examined in several ways.
The number of sport species lost may be compared to estimated sport harvest (Section 4.3.5.4).
Since sport fishing pressure is light in this portion of the Mississippi River, sport harvest is probably not a satisfactory indicator of sport fish abundance or potential yield.
Losses of both sport and rough fish can also be examined in light of the estimated abundance of various populations as measured in 1969 and 1972 to 1977 (Section 4.3.5.2).
(
Little usable catch informrition for forage species is availab?.e, consequently, impact must be evaluated in a
(
184 g
l - - - _
n n
n n
n n
n m
n n
.~
TABLE 6.4-3 TOTAL NUMBER OF POTENTIAL ADULTS ESTIMATED TO HAVE BEEN LOST OUE TO ENTRAINMENT AND IMPINGEMENT OF FISH AT MNGP, APRIL 1976 TO APRIL 1977 Number of Adults Lost Number of Adults Lost Total Number Due to Entrainment Due to Impingement of Adults Lost Northern pike 0
1 1
Carp 1-85 1-215 2-300 Minnows 13,600 2,366 15,966 White sucker 1,920 1-252 1,921-2,172 Silver redhorse 893 1-635 894-1,528 Shorthead redhorse 9,230 1-1,820 9,231-11,050 Unidentified redhorse 3,200-4,880 3,200-4,880 Black bullhead 1-500 1,799 1,800-2,299 y
Rock bass 106 1-40 107-146 m
Smallmouth bass 0
36-60 36-60 Black crappie 0
18-230 18-230 Dartersa 1,410 35 1,445 Logperch 218,000 3,381 221,381 Walleye 0
1-4 1-1 TOTAL 256,003-261,462
" Includes johnny darter a
\\
l('
different manner.
From data on the abundance of young in
(
the drift, an estimate of the number of spawning adults can
^
be calculated in the manner used to arrive at adult losses from entrained larvae.
Where available, estimates of rough
(
standing crop calculated from 1976 seine dath will also be used es a standard of comparison.
(
Sport fish (northern pike, rock bass, smallmouth bass, black crappie and walleye) represented less than 0.1% of the estimated adult loss while forage fish (mainly logperch)
(
represented nearly 94% of the estimeted loss (Table 6.4-3).
Rough fish, such as white sucker, silver redhorse and shorthead redhorse, made up the, largest proportion of the remaining estimated adult loss.
4 Logperch (221,381 fish) and darters (1,445 fish) accounted for 93% of the forage fish lost due to entrainment and impingement.
The estimated loss of over 221,000 logperch is difficult to evaluate because little information on the
(
abundance of this species in the MNGP area is available.
Logperch were not abundant in any of the seine or electrofishing
(;
studies in the vicinity of MNGP (Section 4.3.5.2).
- However, the number of young in the drift in 1976 would seem to indicate that.they are much more abundant than seine studies revealed.
A total of 2,042,000 young were estimated to have
(
186
(
l t l
drifted past the MNGP intake in 1976.
This represents the i
progeny Of 253,000 spawning pairs (based on the fecundity
^
and survival values in Table 6.4-1).
If all individuals were randomly distributed over the area upstream of the
(
intake (approximately 10 ha or 25 ac) in the channel between the south bank of the river and the south shore of Beaver Island (Figure
.3-4), their density would be approximately
(
50,600/ha.
The average catch of logperch in this area in 1976 was one par seine haul (Table 4.3-6) or approximately 285/ha.
This large discrepancy in abundance estimates could
(
be the result of non-random distribution of logperch, an inadequate number of sampling locations, the concentration of logperch in the riffle area upstream of MNGP in the
(
spring of 1976 for spawning when no seining was conducted, and/or the inadequacy of the seine in capturing logperch.
.(
The number of adult logperch lost due to entrainment and impingement represents about 45% of the estimated spawning population upstream of the MNGP intake.
It is not anticipated that losses of even this magnitude will have a serious detrimental effect on the population upstream of MNGP,,
This statement is based on information gathered by several authors on the harvesting of minnows for bait.
The repro-ductive strategy and life history of many minnows and logperch are nLuilar, in that they are short-lived and have 187 I
(
=
low fecundities, apparently high survival rates and, probably,
-(
very high population growth rates.
Larimore (1954) found that annual harvests of up to 50% of the populations of three species of minnow in a 1.4 km (0.87 mi) stretch of
(
Jordan Creek, Illinois for four years produced no discernible effect on the populations.
Brandt and Schreck (1975) found that in Rich Creek, West Virginia there was no detectable
(
effect on forage populations in harvested areas as compared to non-harvested areas.
Brynildson (1959) reported that removals of 23,000 and 28,000 minnows and suckers from a
(
Wisconsin trout str"
'id not appreciably lower population densities.
Summerit (1967) found that, after trying to remove all fish from a 273 m (896 ft) stretch of the Smoky
(
Hill River, Kansas in 1965, cellections in 1966 yielded greater numbers of minnows than 1965.
(
ka estimated 15,966 minnows of at leas t nine species were lost to impingement and entrainment at MNGP during the 1976-1977 study period.
It is not anticipated that a loss of this magnitude will have a detrimental effect on any of the minnow populations in the vicinity of MNGP, as nearly twice as many minnews were captured in 1976-1977 seine collections at MNGP -(Section 4.3.5.2).
l I
188
(
Between 36 and 60 adult smallmouth bass and between 18 and 230 adult black crappie were estimated to have been lost due to impingement of young or yearlings on*the screens at MNGP.
These losses represent about 21% of the average annual spott
(
harvest of smallmouth bass and about 50% of the mean sport harvest of black crappie from the MNGP area (approximately 6-12 km or 3.7-7.5 mi of river near the plant,.Section
(
4.3.5.4) between 1972 and 1976.
Although these percentages appear to be high, it is likely that this reach of the Mississippi River could withstand a greater harvest as, at
(
present, fishing pressure is very light (2,418 to 5,772 m-hr/yr).
For example, a 10' km (6.3 mi) stretch of Curtois Creek in Missouri, which is much smaller than the
(
Mississippi at MNGP, supported an average annual harvest of 732 smallmouth bass at fishing pressures much higher (5,755 to 10,224 m-hr/yr) than those in the vicinity of MNGP
(
(Fleener 1975).
Estimated losses of northern pike and walleye of the magnitude
(
experienced in tha 1976-1977 study period do not pose a threat to either of the populations in the vicinity of MNGP.
These losses represent less than 5% of the apparently low sport harvests for these species near MNGP.
(
189
(
The suckers (white sucker, silver redhorse and shorthead
(
redhorse) accounted for 6 to 8% of the estim ted total adult fish loss.
Between 13,325 and 17,458 adult redhorse (silver and shorthead combined) were estimated to have been lost due
(
to the entrainment and impingement of young.
The combined losses of silver redhorse for 1976-1977 were estimated to
.oe between 1,179 and 1,962.while that for shorthead redhorse
(.
was 12,146 to 15,496 (assuming that the unidentified red-horses were made up of silver and shorthead redhorse in the same proportion as those that could be identified).
In
(
order to place these losses into perspective, they may be compared with populatien estimates made by Hopwood and Scherer (1970).
The storthead redhorse population age 3 and
(
older in the 7 km (4.4 mi) of the river depicted in Figure 4.3-4 was estimated to be 34,500 in 1968 and 33,400 in 1969.
Hopwood and Scherer felt that these estimates were conservative.
Estimated losses of shorthead redhorse in 1976 represent between 35.2 and 46.4% of the estimated 1968 and 1969 populations.
If it is assumed that catch-per-unit-effort (CPUE) for electrofishing is directly proportional to-abundance of a species, the shorthead redhorse population estimate for IS68, along with the 1976 CPUE data,;can be used to roughly estimate the population in 1976 in a manner similar to that used by Hopwood and Scherer (1970):
t-190
4 f
1976 population 1968 population
=
(
CPUE for 1976 DPUE for 1968 For shorthead redhorset
(
1976 population = 34 500 x 77.5 = 62,036 fish qj This type of estimate was not possible for silver redhorse because no population estimate was made in 1968.
When estimatec 1976 locses are compared to the above estimate of
(
shorthead redhorse population, they represent between 19.5 and 25%.
However this extrapolation must be considered e
with caution since two significant changes in sampling
(
technique were made between 1975 and 1976.
In 1975, a pulsed DC electrofishing unit was substituted for the AC unit that had been used since 1968.
No quantitative estimate
(
of the change in catchability of the new gear was made, but Novotny and Priegel (1974) felt that pulsed DC units ware more effective in riverine situctions.
In 1976, the manner of
(
calculating CPUE was also changed so that the amount of time i
I the electrodes were energized was used as a measure of effort instead of the total amount of time necessary to make
(
a run.
This change would tend to increase CPUE relative to earlier years.
These two changes and the concentrating
(
i 191
(
l
'(
effect of low water levels in 1976 en fish probably combined I
to increano CPUE in 1976 relative to other years.
The losses of shorthead redhorse and silver redhorse observed in 1976 are, however, considered abnormal and are believed to be the result of a very successful year class in 1976.
Redhorse young composed less than 1% of the seine catches
(
in 1970 and 1972, but accounted for about 17% of the catch in 1976 (Section 4.3. 5.2).
Abundance estimates available for young redhorse in 1976 were approximately ten times those
(
for 1973 (Section 4. 3. 5. 3, Table 4. 3-11).
Another possible indication of year class strength is the number of young impinged on the traveling screens.
Between 1973 and 1975,
(
no silver redhorse were impinged and shorthead redhorse accounted for less than 3% of the annual number of fish impinged (Heberling and Weinhold 1977a).
In 1976, young
(
shorthead redhorse composed 29.8% and silver redhorse 17.5%
of the total number of fish impinged between January and December (Heberling and Weinhold 1977a).
Between January and
(
early April 1977, silver and shorthead redhorse of the 1976 year-class represented 19.1 and 45.8%, respectively, of the fish impinged.
O It appears that losses due to impingement and entrainment of silver and shorthead redhorse during previous operational 192
(-
years produced no discernable effects on adult populations
(-
as evidenced by CPUE for electrofishing (Figure 4.3-4).
Any effect of impingement losses in 1976 will probably not be detectable for several years, since silver and shorthead
(
redhorse do not appear to become fully susceptible to electro-fishing gear until age 4 or 5 (Hopwood and Scherer 1970, Neudahl 1976).
(
Between 1,800 and 2,299 potential adult black bullhead were estimated to have been lost due to entraiment and impingement
(
in 1976-1977 study period (Table 6.4-3).
This was inter-mediate among the estimates for 1973 (541), 1974 (5,467) and 1975 (747) reported by Heberling and Weinhold (1977a).
(
In summary, the operation of MNGP is not judged to have a serious impact on sport fish populations of the Mississippi I
River near MNGP.
The losses of some forage and rough fish, on the other hdnd, appeared to be rather-high.
Logperch was the primary forage species lost; however, losses were
'I not considered serious in comparison to the estimated spawning population and in light of info,;.ation presented ontheharvestofotherforagespebies (mainly minnows) with similar life history strategies.
Redhorse losses during the 1976-1977 study year were considered extremely high relative to other years because of an apparently very
(
193 i
successful year class in 1976.
It uss estimated that it would be several years, if at all, before the loss could possibly
~
be detected in the population with the gear used currently.
The operation of the MNGP intake does not appear to have damaged the fish community of the Mississippi River near MNGP since it began operation in 1971.
With the possible exception of the redhorses (see above), losses during the 1976-1977 study are not expected to have a measurable impact on the fish populations in the vicinity of MNGP.
Continued operation of the MNGP intake should not affect the propagation of the balanced indigenous aquatic communities of the Mississippi River.
194