ML20072L309

Draft Vol 1 to Environ Studies of Braidwood Cooling Pond, 1982

ML20072L309
Person / Time
Site:	Dresden, Braidwood, 05000000
Issue date:	12/31/1982
From:	Larimore R, Skelly T ILLINOIS, STATE OF
To:
Shared Package
ML20072L288	List: ML20072L309
References
NUDOCS 8303310230
Download: ML20072L309 (27)

Text

Tv . .n < :

,a ,.

.. - e . , _ . .

?

- .u- -

=:.; .

w.bJ [_

ENVIRONMENTAL STUDIES OF BRAIDWOOD COOLING POND,1982 VOLUME I - TEXT SUBMITTED TO COMMONWEALTH EDISON COMPANY DECEMER 1982 BY ILLINOIS NATURAL HISTORY SURVEY CHAMPAIGN, ILLIN01S R. W. LARIMORE PRINCIPAL INVESTIGATOR THOMAS M. SKELLY PROJECT COORDINATOR 8303310230 830328 PDR ADOCK 05000237 . 'I -

O PDR J

DRAFT ,

s T s SECTION 4 -

\c .

YEAR TWO OF THE BENTHIC INVESTIGAT'ON 0F THE BRAIDWOOD CDOLING POND s

i ll by Gary L. Warren, Michael J. Wiley -

i and Stephen T. Sobaski

< ' s, .

l x-4

',4

-g i

m,

?. , .

as

• . g 4

5  %.

3 5

4

+ --.x

• g 4.

k

.. 1

. , - c. ~ _,

, , . . , , ...m . ~

J a t

, --:- ., _. .s oa /

h a

4 h

TABLE OF CONTENTS -

EA99 c

s, ABSTRACT. . . . . . . . . . . . . . . . . . . . . . . . 4-Iv I NTRODUCT I ON. . . . . . . . . . . . . . . . . . . . . . 4- 1 METHODS AND MATER I ALS . . . . . . . . . . . . . . . . . 4- 1 RESULTS AND DISCUSS ION. . . . . . . . . . . . . . . . . 4- 3 -

Overall Pond Community. . . . . . . . . . . . . . . . 4- 3 Communities of Ol d versus New Basins. . . . . . . . . 4- 5 Transect Effects. . . . . . . . . . . . . . . . . . .

4- 8 S UMMARY . . . . . . . . . . . . . . . . . . . . . . . . 4 -1 1 LITERATURE CITED. . . . . . . . . . . . . . . . . . . . 4-13 i

A e l

's, 4

i 1

s l

g

't i

i w

4-11 k

- 1r - - .--. _ _ . _ _ . _ . _ _ _ _ _ . _ _ _

ie S

, LIST OF FIGURES AND TABLES Eage Figures 4-1. Benthic sampling locations on Braidwood cooling pond. . . . . . . . . . . . . . . . . . . 4-14 Tables i

4-1. Mean density (no./m2) and percent composition of major taxonomic groups collected from Braidwood cooling pond during 1981 and 1982 . . . 4-15 4-2. Benthic macroinvertebrates collected from Braidwood cooling pond during 1982, with mean density (no./m2), percent composition, areas of occurrence, and density means significantly different (T-test; a<0.05) from 1981 denoted. . . . . . . . . . . . . . . . . . . 4-16 4-3. Mean density (no./m2) and percent composition of the . ten most abundant genera and species collected from Braidwood cooling pond during 1981 and 1982 . . . . . . . . . . . . . . . . . . 4-19 .."

4-4. Yearly overall, basin, and station means of selected elements of community structure . . . 4-20 4-5. Taxa and Indices which, during 1982, had-significant differences (T-test; a<0.05) between means of former stripmine basins and newly flooded areas and/or significant Pearson correlations with depth . . . . . . . . . 4-21 4-6. Mean density (no./m2) and percent canposition of major taxonomic groups and ten most abundant genera and species collected from each of the four sampling transects at Braidwood cooiing pond during 1982. . ... . . . . 4-22 4-iii

s, ,

6 ABSTRACT Results of ' the initial 2 years of the Braidwood cooling pond benthic investigation Indicate the development .of two distinct community types within the pond--a profundal community associated with the original stripmlne basins and dominated by Paranais frict, Chaoborus nunctinennis, Procladius, and Chironomum, and a-J littoral community associated with the more recently Inundated areas and dominated by Cladotanvtarsus, & frict, Polvoedilum, -and t

EAIA1ARAIRAs.

T SIgnIfIcant Increases In mean tota 1 macroinvertebrates and mean number of taxa per- sample site occurred In both basin types from 1981 to 1982. Taxonomic compos!t' lon of the stripmine basin communities remained relatively

. unchanged - from 1981, but four of the fIve most abundant taxa of

( the newly flooded areas cf 1981 were ' absent from the list of the ten most. abundant. littoral taxa of 1982. One-way' analyses of variance among transect means of taxa densities and community indices detected only one significant difference in the 1982 data.

T-tests between transect means of yearly taxa densities revealed i

signifIcant increases in the abundance of several species.

Benthic community composition and density'within the original

~

l stripmine basins will probably remain fairly constant in the future; however, composition and abundance of the community of the more recently flooded areas may fluctuate for some time as the basin matures and a depositional layer develops upon the bottom.

l 4-iv f-

\_ , _ , , s., , ~ . . -- +--~v - *~ " ~ ' ~ ~ " ~ ' "

S.

YEAR TWO OF THE BENTHIC INVESTIGATION OF THE BRAIDWOOD COOLING POND INTRODUCTION The primary emphasis of the second year of the Braidwood cooling pond benthic investigation was identification of maturational and/or successional changes which may have occurred within the macroinvertebrate communities since the initial year of the study. Specifically, the year two objectives were: (1) to continue to quantify the elements of community structure i

(distribution, taxonomic composition, and standing crop) for the i

d whole lake community and to identify dif ferences between the two

- study years among these elements, and (2)N continue to monitor differences existing between the old (stripmine basins) and new (more recently flooded basin) communities and to document the manner in which these communities have changed since year one of the study.

MATERI ALS AND MEBODS The sampiIng strategies and methods employed during year two of the study were identical to those used during year one (Wiley and Warren 198i). During the two collections of 1982 (15 April 4-1

and 14 July) samples were taken from sites along transect stations 1, 2, 3, and 4 (Figure 4-1). Transects 1-3 extended from old stripmine basins onto newly flooded (December 1980) areas. At these locations two replicate samples were obtained at each of sites A, B, and C (old stripmine basin) while one sample was taken at each of sites D, E, F, and G (newly flooded basin). Transect 4 was located completely along a newly flooded area; two replicates were taken at each of sites A-E during each collection. .

Samples were obtained with a petite ponar dredge (area sampled

= 0.024 m-2), elutriated (mesh size = 600 pm), and preserved with 80% ethanol in quart jars. In the laboratory, each sample was examined under a stereo-dissecting microscope with magnification to 40X. Organisms were hand-picked from detritus and inorganic material, identified to the lowest positive taxonomic level utilizing the literature in Appendix 4A-1, and counted. Raw data +

were converted to number of organisms per square meter.

Organisms that required slide-mounting for identification, such as Oligochaeta and Chironomidae, were cleared in 10% KOH solution or Amman's lactophenol and mounted in polyvinyl f actophenol or Hydramount, identifications were then made using a compound microscope with magnificat.f on to 1000X.

Ancillary measurements taken concurrently with each collection are recorded in Appendix 48-1 and include depth, water temperature, e

and dissolved oxygen at each sampling site.

e.-

4-2 N

}

RESULTS AND DISCUSSION OVERALL POND C0letJNITY The two benthic collections obtained from _Braidwood cooling pond during 1982 were - dominated numerically, as in 1981, by

-Oligochaeta (Naldidae and Tubificidae), Chironomidae, and Chaoboridae (Table 4-1). Fif ty-two macroinvertebrate taxa were collected during both years (Table 4-2), but the pattern of species dominance dif fered slIghtly in 1982 and mean densities of many taxa increased substantially. The naldid Paranals fricI was the most abundant taxon collected in year two of the study, occurring with a mean density of 4451151 m-2 (henceforth, all densities reported herein will be in numbers of Individuals per m-2). In 1981 L frici was not among the ten most abundant taxa and its year one. mean of 1016 I s s i gni f i cantly less than its 1982 population mean. For the second year the epifaunal midge Cladotanvtarsus was the second most abundant taxon collected, its population tripling in size from 105126 in 1981 to 332 66 in 1982.

The phantom midge, Chaoborus nunctioennis, which ranked first in

, abundance in 1981, was third most abundant in,1982, but. Increased its population by an average cf 60 m-2 The chironomids Pseudochironomus and Dierotendloes, the fourth and fifth, respectively, most abundant taxa in 1981, declined very

, substantially (although not statistically significantly) In 1982.

4-3

i They were replaced by two other midges Polvoedilum (143130) and Procladius (135126) (Tables 4-2 and 4-3). -

Several species were collected for the f f rst time from Braidwood cooling pond during 1982. The most abundant of these were the naldid Hals communis (80135), the tubtficid Aulodritus oloueti (59 32), and the chironomid Paraklefferiella (35112).

Other taxa appearing for the fIrst time included the of Igochaetes Limnodrilus cervix and Chaetocaster dischanus, the Trichoptera Oecetis and Polvcentreous cinereus, the alderfly SIalls, and the chironomid Corvnoneura (Table 4-2). Taxa present in 1981 but absent in 1982 included the snail Physa and the chironomids Nanocladius and Pseudosmittia; of these only Pseudosmittia occurred in relatively large numbers in 1981 (615), and only in newly flooded areas. Competition for space. among rapidly growing populations in the shallow areas of the pond flooded in 1980 may eccount for the deelIne of the Pseudosmittia population.

The mean number of macroinvertebrates per sample site in 1982 ranged from 82 at Station 4B in July to 12,222 at Station 20 In April, with an overall mean of 2,467i267. This mean is nearly double that of the older lakes Cof feen, Sanachris. and Shelbyville (Warren and Buckler 1981) and is significantly greater (T-test; a

<0.05) than the overall density (943 98) of Braidwood cooling pond in 1981 (Table 4-4).

Coupled with the large increase in overall mean density in 1982 was a significant increase (nearly double) of the mean number 4-4

l _

of taxa present per sampling site (Table 4-4). Mean species diversity remained nearly equal to the values calculated for 1981, while mean evenness (a measure of the distribution of individuals among species) decreased significantly from the previous year (Table 4-4). These measures of community structure are indicative of a trend toward increasing numbers of organisms and taxa per sampling. site, but of an overall dominance by one taxon or a very few taxa with large numbers of Individuals. .

COMMUNITIES OF OLD VERSUS NEW BASINS Ouring 1982, Naldidae and Chironomidae dominated the relative abundance of both the original stripmine basins and the areas of the pond most recently flooded; in addition, Chaoboridae were dominant in stripmine basins only (Table 4-1). Despite this i

domination by similar major taxonomic groups, the striking I

dissimilarities in the species composition of the two basins l demonstrated in 1981 were again very apparent in 1982. The l

l stripmine basin communities were dominated by Paranais frici (6091305), Chaoborus ounctioennis (516il79), Procladius (192151),

and Chironomus (150148) (Table 4-3). In the pond areas fIrst inundated in 1980, Cladotanvtarsus predominated the community (5241109) and & frici densities dropped to 3111115, ranking it second in abundance. Other taxa comprising more than 5% of the l.

total shallow basin community were Polvoedilum (191150) and l

Paratendices'(136144) (Table 4-3).

4-5 l

L As in 1981, the vast difference in the taxonomic compositions of the two communities present in the pond is attributable to physical characteristics of the two basin types. The depth of the stripmine pits provides a habitat characterized by a homogeneous silt-clay substrate and low levels of dissolved oxygen during periods of thermal stratification. Taxa such as Chaoborus nunctioennis, Chironomus, and Procladius are well adapted to such hypolImnetic stresses and are typical dominants of profundal communities (Brinkhurst 1974, Wetzel 1975). These three taxa were significantly more abundant in the originally flooded basins and significantly positively correlated with depth (Table 4-5).

However, the predominance of the old stripmine basins by Paranais friel is somewhat puzz l ing. In general, naldid populations are confined to the littoral areas of lakes and thrive best on hard substrates (Learner et al. 1978). In Braldwood cooling pond during 1982, P_,.

frici occurred in large nt;mbers in silt and clay at depths of up to 17 meters. Little is known of the biology of individual naldid species, and P_ frici may have exceptional habitat preferences.

, The recently Inundated basins of Braidwood cooling pond lack a substantial silt and detritus depositional layer on the bottom and offer a littoral habitat ideal for domination by an epifaunal taxon such as Cladotanvtarsus. The other dominant chironomids of

, the newer basins, Polvoedilum and. Paratendines, are also common constituents of littoral assanblages (Coffman 1978). Of all the 4-6

L taxa present in the more recently flooded areas, only Cladotanvtarsus occurred in significantly greater numbers than in the stripmine basins; however, densities of several other chironomids were negatively correlated with depth (Table 4-5).

Although the dif ference in taxonomic compositions of the two basins was great, no significant differences were found between the 1982 basin means of diversity, evenness, number of taxa per site, or total macroinvertebrates (Table 4-5).

• Mean total macroinvertebrates and the mean number of taxa collected per site from both the original stripmine basins and the most recentiy flooded basins increased signifIcantly from 1981 to 1982 (Table 4-4); year-to-year differences in the taxonomic compositions of both basin types were also quite apparent. The greatest change evident in the stripmine basin communities was the previously noted increase (although not statistically significant) of the E.ca s.Ls frici population. Other stripmine basin t

ants whose populations increased significantly from 1981 i nc i .i de d Erna.Lu1M, Ch i ronans, a n d Ca e n i s (Table 4-3).

Noteworthy taxa which decreased in density between the two study years in the originally flooded basins included ceratopogonids of the Paloomvia complex. These predaceous biting-midge larvae may have been unable to compete for-food with the rising populations of two other predators, Chaoborus nunctioennis and Prociadlus.

e*

4-7 w 1

[

't

/ .

Four of the five most abundant taxa present in the newly i

flooded basins in 1981 ( Ps e u d o c h i r oammjLs , D.l c r oi.e n d i c e s ,

i Chaoborus nuncticennis, and Paloomvia complex) were absent from

~

i the lIst of the ten most abundant taxa in 1982 (Table 4-3). Larvae of Pseudochironomus, Dierotendices, and the Paloomvla complex are often associated with aquatic macrophytes or periphyton growing upon macrophytes (Saether 1977, Coffrnan 1978, Simpson and Bode 1980). Populations of these taxa may have declined due to the disappearance (decomposition) of the substrate provided by terrestrial plants and stubble present on the old field portion of the basin prior to lake fill. The rapidly expanding i

Cladotanvtarsus population may also have displaced the former

! dominants by more ef ficiently competing for available space. The i

L ounctioennis population may have declined due to the decrease of preferred food organisms (zooplankters) associated with the I

aforementioned decaying vegetation. Dominant taxa whose populations increased significantly from 1981 to 1982 in the recently flooded basins of the pond included Cladotanvtarsus, Paranais frici, Polvoedilum, and Paratendloes (Table 4-3).

t TRANSECT EFFECTS l

One-way analysis of variance revealed a significantly larger .

population of Chironomus at Transect I than at any.other transect In 1982. No other signifIcant di f f erences among 1982 transect I

4-8 g.

l

. ~

means of taxa densities - or Indices of. community structure were detected.

The taxonomic make-up of transects 1, 2, and 3 during 1982 was

. quite similar.

Paranals frici, Chaoborus nunctinennis, and Cladotanvtarsus dominated all three locations; no other taxon accounted for more than 9.6% of the total community density at any of the three transects (Table 4-6). Transect 4 differed slightly from the other transects in that L ounctioennis was not among the three most abundant taxa and accounted for only 5% of the totcl assemblage. The lack of a profundal zone at this location explains the depressed Chaoberus density.

T-tests between yearly density means of each transect detected significant increases in total macroin' vertebrates at transects 1, 2, and 3 from 1981 to 1982. The mean number of taxa per sample site also increased significantly at all transects during the same period. Species diversity and evenness remained statistically unchanged at ali four sampIIng _ locations from 1981 to 1982, with the exception of a significant decrease in diversity at Transect 2 (Table 4-4).

.- Dominant , taxa increasing significantly in abundance from 1981 to 1982 included total Oligochaeta at transects 1, 2, and 4; total l

Chironomidae at transects 1 and 2; Cladotanvtarsus at transects 1 and 3; and Procladius at transects 2, 3, and 4 (Table 4-6).

l .

I 4-9 '

~

L .

Results of the initial 2 years of the Braldwood pond benthic investigation Indicate the development of two distinct community types within the pond--a prof undal community associated with the original str1pmine basins present prior to construction of the cooling pond and a ilttoral conmunity associated with the shallow, more recently Inundated areas. Benthic community composition and density within the stripmine basins will probably remain reasonably stable, but the community of the new basins may fluctuate greatly in constitution and abundance for several years as a depositional layer develops on the pond bottom. Diversity Index values are typical for those of a relatively new reservoir; evenness indices indicate a fairly strong dominance by a single or very small number of species (Parenah frici in The stripmine basins and Cladotanvtersus in 1he shallow basins). Mean total densities in Braidwood cooling pond during 1982 were much higher than those of several other central lilinois reservoirs, but the rapid population growth which occurred frm 1981 to 1982 in the pond will level off or even begin to decline in the future as the carrying capacity of the more recently flooded areas is reached and a'more mature community develops.

G 9

e 4-10 *

~.

of . ,

SUMMARY

1. Fif ty-two macroinvertebrate taxa were collected in both 1981 and 1982 from the Braidwood cooling pond. The overall benthic community was dominated by OfIgochaeta, Chironomidae, and Chaoboridae each year.

2. Benthic population densities per sample site ranged from 84 to 12,222 during 1982. The mean total density of 2,467 was a statistically significant increase over the 1981 mean total of 943, and is substantially greater than the mean densities recorded for lakes Coffeen, Sangchris, and Shelbyville.

3. As in 1981, two distinct benthic community types were present in the pond--a profundal community in the stripmine basins dominated by Paranais frici, Chaoborus euncticennis, Chironomus, and Procladius, and, in the most recently flooded areas, a lIttoral community dominated by Cladotanvtarsus, & frici, Polvoedilum, and Paratendices.

4. Calculated values for Indices of diversity and evenness were indicative of the strong domination by a single taxon in both of the community types present in the pond. Both Paranals frici and Cladotanvtarsus overwhelmingly predominated their respective communities.* -

4-11

v 5.. Significant increases in mean total macroinvertebrates and mean number of taxa per sample site occurred in both basin types from s

1981 to 1982. Taxonomic composition of the stripmine basin communities remained relatively stable except for the explosion of

.the Paranals frici . population. Four of the five most abundant taxa in the newly flooded areas of 1981 were absent from the list of the ten most abundant littoral taxa of 1982. -

6. One-way analyses of variance among transect means of taxa densities and community indices detected only one significant difference (in Chironomus densities) in 1982. T-tests between transect means of yearly taxa densities revealed significant increases in numbers for several species.

7. Benthic community composition and density within the original stripmine basin will probably remain f airly constant in the future; however, composition and abundance of the community of the more recently flooded areas may fluctuate for sc=e time as a depositional layer develops upon the pond bottom.

i 1

4-12

LITERATURE CITED

(

Brinkhurst, R. O. 1974. The benthos of lakes. MacMillan Press Ltd., London. 190 p.

Coffman, W. P. 1978. Ch i r, nomi dae. Chapter 22 ln R. W. Merritt and K. W. Cummins, eds. Aquatic Insects of North Amerca.

Kendall/ Hunt Publishing Co., Dubuque, Iowa. 441 p.

Learner, M. A. , G. Lochhead, and B. D. Hughes. 1978. A review of the biology of British Naldidae (01Igochaeta) with emphasis on the lotic environment. Freshwater Biology 8:357-375.

Saether, O. A. 1977. Taxonomic studies on Chironomidae:

Raansl.a dl.ujli, Pseudochircram n , and the Harnischla complex. Bull. Fish. Res. Bd. Canada 196:1-143. ,

Simpson, K. W., and R. W. Bode. 1980. Common larvae of Chironomidae (Diptera) from New York State streams and rivers with particular reference to the fauna of artificial substrates. New York St. Mus. Bull. 439. 105 p.

Warren, G. L., and J. H. Buckler. 1981. Benthic investigations at Coffeen Lake. Section 7 in J. A. Tranquilli and R. W.

Larimore, eds. Environmental Studies of Coffeen Lake, vol. I:

7.1-7.30. lilinois Natural History Survey final report to Central lilinois Public Service Co., Spr ingf i el d, Illinois

( unpubl Ish ed) .

Wetzel, R. G. 1975. Limnology. W. B...Saunders Co., Philadelphia.

743 p.

Wiley, M. J., and G. L. Warren. 1982. Benthic Investigation of the Braidwood cooling pond Section 4 .[a R. W. Larimore and T. M. Skelly, eds. Environmental Studies of Braidwood Cooling Pond, 1981, vol. 1:4-1--4-21. Illinois Natural History Survey fIrst annual report to Commonwealth Edison Company, Chicago, IL (unpublished).

l

\

9 4-13 i _ _________

PLANT -- /

.~

+ INTAKE DISC H ARGE 4 '

CANAL _ @- .. __ ...

1 E

. . .a l

G p y.  ;

\, D A #I l ' -

o f ****

D p} ~, ,

,* .{

'% 'a @ 7' l l 0

9. l G APA l

',~ h.

N p '.,,,..--d..,

l g4 /h { BRAIDWOOD g J COOLING

.5 , f ,

j so 590 g .-

' METERS

,,,- ----- pag g RIPRAP C-- - ---w.----...__......n.,,,,_,,,,,'

' D SPOIL BANKS Figure 4-1. Benthic sampling locations on Braidwood cooling pond.

4-14

e

.].

}

Table 4-1.

1981 and 1982.

Mean density (no./m2) and percent composition of major taxonomic groups collected f rom Braidwood cooling pond during

, Entire lake Stripmine basin 14ewly flooded basin i 1981 1982 1981 1982 I 1981 1982 Mean Mean Mean Mean Mean Mean no./m2 5 no./m2, 5 no./m2 $ no./m2 g no,f,2 g no./m2 g EttjaC SED.vD.s Tubtffcidae 20 2.1 78 3.2 Tubtfictdae 42 4.5 34 1.3 Tubtflcidae Haldidae 52 5.6 1 0.1 112 4.9 633 25.7 Naldidae 38 4.1 1,001 37.4 Naldidae 64 6.8 Enchytraeldae 14 1.5 0.2 645 28.2 5 Enchytreeldae 0 0 6 0.2 Enchytraeldae 2.8 g Pelecypoda Gastropoda 1 0.1 0 0 Pelecyppda 2 0.2 0 0 Pelecypoda 26 0 0 5

0 0.2 0

18 1.9 2 0.1 Gastropoda 5 0.5 0 0 Castropoda 0 Caenidae 13 1.4 59 2.4 0 3 -0.1 Caenidao 9' 1.0 70 2.6 Caenidae 12 f.3 51 2.2 Ephemer idae 1.2 17 0.7 Ephemeridae l il 21 2.3 27 1.0 Ephemeridao 3 0.3 10 0.4 Cheoboridae 197 21.1 257 10.4 Chaoboridae 358 38.5 i

Cera topogonidae 516 19.2 Chaoboridae '59 6.3 46 2.0 72 7.7 44 1.8 Ceratopogonidae 94 10.1 53 2.0 Ceratopogonidae Chironceldae 524 54 5.8 35 1.5 56.1 1,180 47.8 Chironomidae . 312 33.5 95 8 35.7 Chironomidae 704 Others 12 1.3 7.8 75.1 1,362 59.5 192 Others 50 5.3 17 0.6 Others 15 1.5 22 1.0 Total Invertebrates 934 100 2,467 100 Total Invertobrates 931 100 2,682 100 Total Invertebrates 938 100 2,291 100

8- ,

, '.~

, s.

i Table 4-2. Benthic macrotnvertebrates' collected f rori Braldwood cooling pond during 1982, with mean density l

(no./m2), percent cceposition, areas ot ' occurrence, and density incans significantly dif f erent (T-testg u <0.05) from 1981 denoted.

Station Means significantly Taxa Mean density $_cceposition Old basins. New basin i 2 3 4 different

~

Annellda Oligochaeta (total) 902 36.6 x x x _x x x +

TubtfIcldae AufodrIlus clauett 59 2.4' -x x x. x x x Limnodellus cervix 1 .' x x L. glararedelarus 10 - 0.4 x x x x x L. hoffrelsterl 6 0.2 . x x- x x x Tubtfez tubtfex 2 0.1 x x Italdicae- 57 - 2.3 x x x x x x +

Chretogaster AJy banus 1 -* .. x x i'

• hra sp. . 1

• x x *

• L dIrritafa 7 0.3 x x x x x x

!! sis sp. 5 0.2 x x x x L so29_unu 80 3.2 x x x x x x +

& ParJalls 33 1.3 x x x x x~

L variabills 1 e x x x

+

EDr.cEAls f rict 445 18.0 .x x x x x x Stvlaria lacustris -3 0.1 x x Enchytraeldae - 5 0.2 x x .x' x -x-Mol l usca -

Gastropoda Planorbidae 2 0.1 x x Arthropoda insecta Ephemeroptera Caenideo Cacnis sp. 59 2.4 x x x x x x +

S ie

e

. 4,

' Table 4-2 Icontinued).

Station Taxa Mean density 5 composition .Old basins Means significantly

. fJew basin 1 2 3 4 different EphernerIdes Nexaoenia sp. 17 0.7 x Odonata x x x x x Zygoptera Coenagrionidae Argia sp. 1 *

.x Trichoptera -

Hydreptil idae 1

• x ityAID0111A x-1 -* x 'x 3 Orthotrichia 1 *

.x e

Leptoceridae x O accells t

• x x x Polycentropodidae Enlycentropus cinereus 3 0.1 x f4galopfera x x. x S tal idae Stalls

• Diptera 1 x x ChnoborIdae Chachorus nunctinennis 257 10.4 x Ceratopogonidae x x x x x CutIcalden 1

• Dasvhella x x 2 0.1 x x Ea.jp.QayJJI complex x x x 41 1.7 x x x x x x Chironomidae (total) 1.180 47.8 x x Tanypodinae x x x x +

Ablabes1rla sp. 4 0.2 x scalatalysus sp. x x x x 7 0.3 x x x Ecncindhis sp. 135 5.5 x x x x x x +

3

+ _

{

. .t

• Table 4-2 (continued).

Station Tara Mean density 5 composition . Old basins Means significantly New basin 1 2 3 4 different Orthecladlinao 3 0.1 x x x

1. fprynoneuca sp. 1 '

x x EcJsg1gs m svivestr1s group 1

• x x EpDICnclAdlus sp. 1 .* x x Paraklefferfella sp. 35 1.4 x x x x x x +

Chironominae. 1 8 x x Chironomini p ChIronemus sp. 96 3.9 x x x x x x w fIadocefma sp. .+

M 20 0.8 x x. x x x . +

Etyetochfronomus sp. 32 1.3 x x x x x x

+

Etyototendipf,s sp. 6 0.2 x x x x x

.DJrrotendipss sp. ,

25 1.0 x x x x x x Ingpehironomus sp. 1

• x x L ntaricans 1

• x x x D1yototendipsa sp. 5 0.2 x x x x .x' ifatr u shia sp. .t 8 0.3 x x x .x x x +

Microchironomus sp. 69 2.8 x x x x x x +

Parachfronomus sp. 3 0.1 x x x x -

Paratendines sp. 133 5.4 x x x x x x +

Polvoedilum sp. 143 5.8 x x x x x x + '-

1 Pseudochironomus sp. 3 0.1 x x x x 'x x stretochtronemus sp. 3 .0.1 .x x x x x Tanytarsini 2 0.1 x x x x x Cladotanvtarsus sp. 332 13.5 x x Paratanvtarsus sp. x .. x x x +

7 0.3 x x x x x Tanvtarsus sp. 30 1.2 x x x x x x +.

• denotes less than 0.1% composition x denotes taxon present

+ denotes 1982 mean density significantly greater than 1981 mean

- denotes 1982 mean density significantly less than 1981 mean

f t

Table 4-3. Mean density (no./m2) and percent composition of the ten most abundant genera and species collected fran Braldwood cooling pond during 1981 and 1982.

Entire lake 'Stripmine basin Newly flooded basin

. Mean Hean Mean no./m2 $ no./m2  % no./m2 y J.op ha laz.a L*D1

1. Ibaoborus nunctinennis 197 21.1 1. Chaptatus sansfjpina.ls n 358 38.5 1. Cladotanvtarsus 155 16.5

2. Cladotarvtarsus 105 11.2 2. Enippmyh complex 94 10.1 2. Essy.dochfronomus 125 13.3

_ 3. Enlasetyla complex 72 7.7 -3. Polypedflyjn 50 5.4 3. DJcrotendiscs 85 9.1 3 4. Pseudochironomus ,71 7.6 4. Cladotanvtarsus 46 4.9 4. Chap 3rtus punctioennis 59 6.3 e

5. DierotendIAts 50 5.4 5. Paratendipss 29 3.1 5. Ealprmyla complex 53 5.7

@ 6. Enl.ypedIlum

7. Paratendloes 42 4.5 2.1

6. Ahlfts lublirg 28 3.0 .6. Enlyrrdilus . 35 3.7

• 20 7.11cxpgcaja 21 2.3 7. Pero j!1gitata , 33 3.5

8. pfro dlalta.ta 20 2.1 8. Procladius 16 1.7 8. Chlrrremus 25 2.7

9. Chironemus 19 2.0 9. Earfnals AJr1 14 1.5 9. Entafanytarsus 22 2.3

10. Paratanvtarsus 14 1.5 10. Ebfronorius 12 1.3 10. Tanvtarsus 10 I.1

10. Etyr,toch f ronomus 12 1.3 19B2 1.*Paranats frict 445 18.0 1. Paranals frict 609 22.7 1.*Cladotanvtarsus 524 22.9 2.*Cladotanvtarsus 332 13.5 2. Chachorus punctinennis 516 19.2 ' 2.'Paranals friel 311 13.6

3. Chaoberus nunctroennis 257 10.4 3.'Proefadius 192 7.2 3.*Polveedilum 191 8.3 4.'Polvoeditum 143 5.8 4.'Chironomus 150 5.6 '4.'Enratendtoes 136 5.9 5.'Procladius 135 5.5 5. Paratendfoes 130 4.8 5. flals racemal.3 106 4.6

6.

• Par a t end l oes 133 5.4 6. Cladotanvtarsus 97 3.6 6. Autodritus ofouett 101- 4.4 7.'Chironomus

~

% 3.9 7. Potvoedflum 84 3.1 7.*Procladius 88 3.8 8.'f*terochtronomus 69 2.8 8.'Caents 70 2.6 8.'Mferochtronomus 73 3.2 9.'Paloomyh complex 41 1.7 9.*Microchfronomus 64 2.4 9. BAls oardalIn 60 2.6

10. fia.ls cardelta 33 1.3 10. Paloomvla complex 51 1.9 10. Chironomus 52 2.3 t

'Donotes significant increase over 1981 mean (T-test; oc0 05) 9

s Table 4-4. Yearly overall, basin, and station means of selected elements of community structure.

'. Total flumber of macroinvertebrates taxa / site Diversity Evenness 19B1 Overall *943(i 98) 54.58 1.83 *2.51 Old basin *936(1141) *4.56 1.68 *2.26 j> New basin *950(i136) *4.60 1.96 *2.73 no Station 1 *1,270(1205) *5.00 1.45 2.44 Station 2 5674(1117) *4.44 *2.18 2.80 Station 3 5815(1166) *4.35 1.80 2.70 Station 4 .- 987(1244) *4.50 1.92 2.14 1932 Overall *2,467(1267) *8.21 1.73 *1.24 Old basin *2,682(1.451) 58.42 1.64 *1.14 New basin *2,291(i317) 58.04 1.80 *1.33 Station 1 *2,976(1625) "8.45 1.78 1.07 Station 2 *2,780(1653) *8.55 *1.56 1.25 Station 3 *2,371(i428) *7.70 1.62 1.28 Station 4 1,741( 370) *8.15 1.95 1.38

• Denotes yearly means significantly dif ferent (T-test;a <0.05).

e

.g*

Table 4-5. Taxa and indices which, during 1982, had significant -

dif ferences (T-test;a <0.05) between means of former stripmine basins and newly flooded areas and/or significant Pearson correlations with depth.

T-tests Pearson correlai 2ns Did basin New basin Correlation Taxon /index mean mean coefficient a Derg dialtata 10.50 3.82 ns 0.2068 0.033 Nais spp. 7.00 2.86 ns 0.1876 0.048 IL. variabil ls 2.33 0.00 ns 0.2372 0.017

e. Hexaaenia 26.83 9.55 0.037 -0.0764 ns

' r'u Chaoborus ggnettoennis 515.67 45.82

"' 0.014 0.3582 0.001 -

Procladius 192.50 87.82 0.049 0.2207 0.025

~ Chironomus 150.50 51.55 0.040 0.4185 0.001 Cladopelma 37.33 6.68 ns 0.2203 0.025 Cryotochironomus 23.33 38.18 ns -0.2869 0.005 Dicrotendipes 18.67 30.55 ns -0.2349 0.018 Polyoedilum 84.00 190.91 ns -0.2836 0.005 Cladotanvtarsus 96.83 524.05 0.001 -0.3697 0.001 Tanvtarsus 22.17 37.23 ns -0.2536 0.012 Diversity 1.64 1.80 ns -0.2152 0.028 Evenness 1.14 1.33 ns 0.0060 ns Number of taxa 8.42 8.05 ns -0.1368 ns Total invertebrates 2,682 2,291 ns 0.0560 ns ns = not significant

~*

{_ 6 t . m

.g ' e **

s f

i Table 4-6. Mean density (no./m28 and percent compostiton of major taxonmic groups and ten most abundant genere and species collected f rom each of the four sampling transects at Braldwood cooling pond during 1982.

Transect 2 Transect 3 Transect 4 Transect 1 Mean Mean Mean Mean

• no./m2 $ no./m2 $ no./m2 $

no./m2 $ ,

EajQC Stral&A 2.7 Tubtftcidae- 123 5.2 Tubtiteldae 48 2.7 Tubificidae 149 5.C Tubtffctdae 76 390 21.6 665 22.3 Naldidae 937 33.7 Naldfdae 537 22.6 Naldidae Naloidae Enchytreefdee 2 0.1 Enchy traeldae 6 0.2 Enchytraeldae 2 0.1 Enchytraeldae 10 0.4 42 1.5 Caenidae 120 5.1 Caeni dae 25 1.4 Caenidae 50 1.7 Caenidae 0.6 Ephemeridae 13 0.5 Ephemeri dae 19 ' O.8 Ephemeridae 21 . I .2 Ephmer idae 17 90 5.0 347 11.7 Chaobori dae 170 6.1 Cboobor idae 420 17.7 Chaoborldae .

Chaoboridae 2.6 Ceratopogonidae 57 3.2 Ceratopogonidae 38 I.3 Ceratopogonidae 19 0.7 Cer atopogonidae 61 947 34.1 Chironcaldae 981 41.4 Chironomidae '1,121 62.5 Cttronomidae 1,672 56.2 Chironomidae 50 2.8 Others 574 20.6 Others 100 4.2 Others f

N Others Total 32 1.1 2,976 100 Total 2,780 100 Totat 2,371 100 Total I,804 500 N

LG5 inD JM.B 420 17.7 1. Paranals f r f c f 260 14.4 l

i 1. Cladotanvtarsus 594 20.0 1. Paranals frfc!. 808 29.1 1. CtaaDQr.us Aufst.IttPJils 256 14.2 15.2 2. cladotanvtarsus 202 7.3 2. CJAcatanvtarsus 275 11.6 2. Cladotanytarsus

2. Paranth frict 452 170 6.1 3. fx annis frfcl 260 11.0 3. Paratandlass , 244 f3.5

3. Chact,9t.us gunctinennis 349 11.7 3. Chaoborus nunctinennis 149 8.5 227 7.6 4. chtronomus 153 5.5 4. flats 10cnunis 227 9.6 4. Eolyggdijas

4. Ect.yggallum 4.5 5. Ers11AUms 149 6.3 5. Procladtus- 111 6.2

5. fAlrCaptus 189 6.4 5. Procladtus 124 90 5.0 157 5.3 6."Paratend gas 103 3.7 6. folygsdllum 128' - 5.4 6. Chaetsrus nunctinennfa

6. ferattralkei 120 5.1 7. Hals satdalls 86 - 4.8

7. Preciatlas 155 5.2 7. Mferochtron<wue 94 + 3.4 7. CacDJs 4.4 2.4 86 3.6 8. Paraklef f er f atla 80

8. Auln2r_tjus alsueil 149 5.0 8. Polvendt f um 67 8. Elitochtronomus 57 3.2 59 2.0 9. Caents 42 .5 9. Ealttfnyla complex 57 2.4 9. N!crochtronraus

( 9. N213 carun t s 10. Limnodritus glasaredlanus 34 1.2 10. Crysischtronemus 38 I.6 10. Ealpomyla complex 55 3.0

10. Caents 50 1.7 l 10. Tanvtarsus 34 1.2 l

l I

I l

.a