ML20079N371

Environ Monitoring Program 1976 Annual Rept

ML20079N371
Person / Time
Site:	Monticello
Issue date:	12/31/1976
From:	Hopwood A ST. CLOUD STATE UNIV., ST. CLOUD, MN
To:
References
RTR-NUREG-1437 AR, NUDOCS 9111110184
Download: ML20079N371 (40)

Text

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+ v.. -A MONTICELLO NUCLEAR GEN PLANT 9 ATTACHME1!1 2 MONTICELLO NUCLEAR GENERATING PLANT ENVIRONMENTAL MONITORING PROGRAM 1976~ ANNUAL REPORT AOUATIC-MACROINVERTEBRATES (Comparison. of Benthic Macroinvertebrate Populations Within and Outside of the Effluent-Plume From the NSP Monticello Generator) 1 (2.2) '

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Prepared for Northern States Power Company Minneapolis, Minnesota-by -

Alfred ~J. Hopwood, Ph.D.

-Department of Biological-Sciences:

--St.-Cloud State University'

.St. Cloud, Minnesota 2.2-1

~'

-9111110184 761231 PDR. NUREQ

- )' 1437-C PDR~

. _ ._ . - . - _ _ > . . _ _ _ ~ _ _ _ _ . _ . _ . . - _ _ - ..-_._. _

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2.2 AQUATIC-MACROINVERTEBRATES 2.

2.1 INTRODUCTION

2.2.1.1 Proiect Obiectives ,

The_ objective _of this study was to determine the effect the power plant effluent on benthic macroinvertebrates beldV the power plant' discharge by comparing samples from affected and

.-unaffected areas in the Mississippi River.

2.2.2 MATERIALS,AND METHODS Concrete artificial substrate samplers were placed in physically similar' locations inside and outside of the discharge plume as -

shown in Figure 2.2-1. _The control transect,-located 370 meters

. upstream from the power plant intyke structure, consisted of Stations CI, CII,andCIIIa'frEf$$$fromlefttorightfacing downstream._ The experimental transect, consisting. of Stations EI, EII, EIII, and EIV,=was located 490 meters downstream from theLdischarge canal. Each station consisted of four samplers.

Organisms were allov .d to colonize the samplers over a period of- ,

30 days. Af ter this period, the macroinvertenrates were - collected from.the blocks and taken to'the' laboratory for. sorting, counting,.

-and' identification to the lowest taxonomic level.

Sorting wasfdona in 8"1x 8" shallow plastic trays illuminated from underneath. Each tray _was divided into sections so one-half ~

or one-fourth of -the' originni sample could be sorted.

The sorted samples were identified and counted abaultaneously-by counting the entire sorted sample or-a fraction. The numbers of invertebrates 2.2-3

___a__ . - _ _ . _ - . . _ _ - . - . .__.__.m_,,_._. .._

l in each sample were projected by multiplying the actual counts by their respective fractional denominations.

Artificial substrates were operated from April 30, .,/6 to November 22, 1976, roughly equivalent to the ice-free period on the river. Environmental conditions over the substrates were observed on days when the blocks were handled and weekly during the 30-day sampling period (Tables 2.2-2 and 2.2-3). Water flow velocity was measured with a Gurley Model 665 Direct Reading Current Meter. Air and botton temperatures were recorded with a YSI Model 42 SC Telethermometer. Current velocity and bottom water temperatures were taken at a depth of 0.11 m from the river bottom.

2.2.3 RESULTS The collection overall contained 54 groups identified to the lowest possible taxonomic level (Table 2.2-1). Mayflies were composed of 12 genera, none of which were distinguishable to species. Diptera were represented by five f amilies with one species each in Tipulidae and Rhagionidae. The families Psycho- i didae and Simuliidae each had one genus. Midge larvae and pupae {

were discernable to the trfbal level. Trichoptera were composed of nine families and 22 genera. Twenty of the caddis flies were identified as species. The order Plecoptera was represented by six genera, five taken to the species level. There were small numbers of occasional appearances of odonatan, coleopteran insects, and the limpet Ferrissia sp.

Numbers of caddis flies collected at each station arc listed in Table 2.2-4 through 2.2-10. Hydropsyche dominated the Trichoptera 2.2-4 l

w and the overall macroinvertebrate biomass. Hydropsyche phalerata numbers were highest in May and September samples, sugger. ting that a winter population of larvae became adults in May and June,

' and a summer group became adults in late September and October after peak numbers were attained in September. Hydropsyche cf.

bifida populations showed dynamics similar to those of H. phalerata, with peak numbers in May and August.

The apparent responses of Trichoptera to the effects of the effluent plume varied seasonally, probably due to the buildup of larvae and pupae and their subsequent removal from the river as adults. A comparison of the trichopteran standing crop at taated and unheated stations in 1975 and 1976 is shown in Tables 2.2-13 through 2.2-19.

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Numbers of mayflies collected at each station are listed in Table 2.2-11. From May through September, Stenonema, Ephemerella, and Paetis predominated, Ephemerella becoming the dominant form in November. Effects of the effluent plume on mayfly populations varied taxonomically and seasonally (Tr:ble 2.2-20) . There were generally larger numbers of larvae in stations outside the plume compared with. stations included in the plume, e.g., Ephemerella and Pseudocloeon were consistently more numerous in the control samples than in the experimental samples. In so.ne months, numbers of certain genera were higher at heated stations, e.g.,

Stenonema.in May, October, and November; Tricorythodes in June,

-July, and August; Stenacron in July and August; and Potamanthus in August, September, and November.

Numbers of dipterans collected at each station are listed in Table 2.2-12. Midge larvae, the most frequently encountered 2.2-5

\

specimens in most samples, were most abundant in May and least numerous in November. Numbers of larvae built up in alternate months, i.e., May, July, and September, and declined in June, August, and November at control stations. A different numerical

(.hdistrfbutionoccurredatstationsaffectedbytheeffluent.

Midge populations started from a peak in May, declined in June, then increased through July and August to a peak in September.

Numbers declined more slowly during October and November in the heat plume than at unaffected stations. Chironomini pupae were most numerous in October, an exception in the cyclic abundance pattern, which was otherwise similar to that of the larvae.

The Simulium population began to rise in July, reached peak numbers in August, then declined gradually through the autumn at stations not affected by the plume. Pupae were not present in the May and June samples and were low in number during July, August, and September. In October pupae numbers increased ,

eightfold along with the continued decline of larvae which had begun in September. In the heat plume, pupae were present in small numbers in May and October and were absent in other months.

A comparison of numbers of dipterans in areas within and outside the effluent plume is given in Table 2.2-21.

Counts of Plecoptera, Coleoptera, Lepidoptera, and Odonata are reported in Table 2.2-22. Stonefly larvae and the adults and immature stages of Coleoptera appeared sporadically. Larval Lepidoptera and Odonata were encountered occasionally.

e 2.2-6 )

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j m . m . . ~ . , . ~ . . -

~a# . eau a u 44.~w #- , sA 4 2 a- m-- _ mu- - a . . . - .. u_ = .* ~ r._--.

4 2.2.4 DISCUSSION During 1976 the effort expended and information available on classification of certain groups culminated in the expansion of the-taxonomic identification of the sampled caddis flies to the species level. Thus, for example, numerical and gravimetric data listed for the genus Hydropsyche in past years are now sepa-rated corresponding to six species. It is readily seen, in Tables 2.2-4 through 2.2-10, that Hydropsyche is composed pre-dominantly of H. phalerata and H. cf. bifida, the latter probably consisting of more than one species commonly called "the bifida group." Among the remaining hydropsychid groups, H. cf. cunnis was present most consistently in numbers several orders of magni-

.tudes less than the two dominant-species. H. orris appeared in May, then July through November, and the others appeared occasion-ally-in Autunn.

. The Hydropysche population structure and all others are explainable

- according: to the law of tolerance; i . e., H. phalerata and H. cf.

bifida are' successful, having had their environmental' requirements more optimally l supplied by the complex of conditions present at- .

.the site.of collection,.g. cf. cuanis having less-than optimal conditions- for the species indicated by . their relative degree of success, ani g. orris, g. betteni, - and H. cf.-haceni approaching the111mits of: tolerance in that habitat. The addition of the effluent from the NSP'Monticello Plant.into the Mississippi River may cause changes'in' population levels, since ' the effluent con-stitutes an alteration of at least part of the total environmental complex vithin-which each species has a degree of success.

2.2-7

The effect of the effluent was assessed by comparing the mean number of insects per squa ce mater of artificial substrate in the water affected by the effluent with uhe same parameter in parts of the study area not affected by the effluent. River flow during the period of study typically fluctuated, so at low flow the effluent plume spread over more stations in the downstream transect (E) than at high flow. Table 2.2-3 lists the stations included in comparative analyses as being affected by the effluent.

Stations not listed were included with the controls. Affected stations were so designated if, according to position and tempera-ture reading relative to other stations, the station was affected for three or more weeks of the 30-day sampling period.

Ratios computed on 1976 data according to the formula:

x = mean nudber of insects per m2 at stations in the clumey , y 1 = mean number of insects per m 2 at stations outside the plume are listed in Tables 2.2-13 through 2.2-19 for Trichoptera :

Tible 2.2-20 for Ephemeroptera and Table 2.2-21 for Diptera-Tables 2.2-14 through 2.2-18 also compare numbers and ratios for the years 1975 and 1976.

In comparing years, it was noted that, with a few exceptions, in 1975 insects were more numerous in the heated zone than in the unaffected areas, and in 1976, insects were less numerous in the heated zone compared with the unheated zone. For example, the heated zone in June and July of 1975 produced more Cheumatopsyche than the same months in 1976. This was also true for Oecetis in September and October, and for Psychomyia in October. The reversal in effect, from a positive impact by the effluent upon 2.2-8

Y insects in previous years to a negative one, is probably due to the extraordinarily low flow during 1976 (Table 2. 2-23 ) . Shallow, slowly-flowing water is much more affected by solar hetting than deeper, rapid areas, thus, solar heating and the power plant dis-charge plume could interact at low flow to bring about a combina-tion of conditions (perhaps not simply temperature-relatad) which could limit populations; for example, low flow results in shallow depth and decreased current velocity. Depth, in turn, complexly affects such things as lighting of the bottom, availability of gases exchanged at the surface, and the organisma used as food by the insects. Decreased current velocity directly a'ffects insects by decreasing the " physiological richness" (Hynes 1970) of the water in terms of food and gases, and by decreasing its capacity to carry away metabolites. A comparison of the dis-charge values for 1975 and 1976 shows that the threshold below which reduced numbers of insects can be expected lies in the range between approximately 3,000 to 1,100 cfs i., the summer months, However, the sigaificance of such impact at low flow is minor, since the river area affected by,the plume is small and recovery of populations in the plume area should take place rapidly from drift and the surviving population. A passage zone existed at low flow on the left side of the river, indicated by temperature readings on the experimental transect across the effluent plume.

Moreover, since some insects (Cheumatonsyche, Oecetis, Psychomyia, Potamanthus, Tricorythodes, Stenacron, Stenonema, and the Chironomini) did net respond negatively to river conditions below the power plant discharge in 1976, the overall effect at other trophic levels should have been minor. For example, as shown by 2.2-9

1 i

i The effect of the effluent was assessed by comparing the mean number of insects per square meter of artificial substrate in the l water affected by the effluent with the same parameter in parts of the study area not affected by the effluent. River flow during the period of study typically fluctuated, so at low flow the effluent plume spread over more stations in the downstream

. r3 transect (E) than at high flow. Table 2.2-3 lists the stations included in comparative analyses as being affected by the effluent.

Stations not listed were included with the controls, affected stations were so designated if, according to position and tempera-ture reading relative to other stations, the statien was affected for three or more weeks of the 30-day sampling period.

Ratios computed on 1976 data according to the formula:

x = mean number of insects per m 2 at stations in the clume

,y 1 = menn number of insects per m 2 at stations outside the plume are listed in Tables 2.2-13 through 2.2-19 for Trichoptera :

Table 2.2-20 for Ephemeroptera and Table 2.2-21 for Diptera:

Tables 2.2-14 through 2.2-18 also compare numbers and ratios for the years 1975 and 1976.

In comparing years, it was noted that, with a few exceptions, in 1975 insects were more numerous in the heated zone than in the untffected areas, and in 1976, insects were lecs numerous in the heated zone compared with the unheated zone. For example, the heated zone in June and July of 1975 produced more Cheumatopsyche than the same months in 1976. This was also true for Oecetis, in September and October, and for Psychomyia in October. The reversal in effect, from a positive impact by the effluent upon 2.2-8

7 insects in previous years to a negative one, is probably due to .

the extraordinarily low flow during 1975 (Table 2. 2-23) . Shallow, slowly-flowing water is much more affected by solar heating than deeper, rapid areas, thus, solar heating and the power plant dis-charge plume could interact at low flow to bring about a combina-tion of conditions (perhaps not simply temperature-related) which could limit populations; for example, low flow resu.'.ts in shallow depth and decreased currant velocity. Depth, in turn, complexly affects such things as lighting of the bottom, availability of gases exchanged at the surface, and the organisms used as food ,

by the insects. Decreased current velocity directly a'ffects insects by decreasing the " physiological richness" (Hynes 1970) of the water in terms of food and gases, and by decreasing its capacity to carry away metabolites. A comparison of the dis-charge values for 1975 and 1976 shows that the threshold below which reduced numbers of insects can be expected lies in the range between approximately 3,000 to 1,100 cfs in the summer months.

However, the significance of such impact at low flow is minor, since the river area affected by the plume is small and recovery of populations in the plume area should take place rapidly from drift and the surviving population. A passage zone existed at low flow on the left side of the river, indicated by temperature readings on the experimental transect acroes the effluent plume.

Moreover, since some insects (Cheumatoosyche, Oecetis, Psychomyia, Potamanthus, Tricorythodes, Stenacron, Stenonema, and the Chirunomini) did not respond negatively to river conditio6s below the pewer plant discharge in 1975, the overall effect at other trophic levels should have been minor. For example, as shown by 2.2-9

._ . 7 t

Andersen (1972), fish feed on insects by size grouping with a lack of selectivity for food species and are able to range within and outside the effluent plume while feeding.

It is clear that events in the life cycles of the species present are altered in time (accelerated) in that part of the river affected by the effluen , although the mechanism by which this occurs is not fully understood.- This is best seen in the 1976 data on Diptera (Table 2.2-21). In May and June midge larvae in the unheated zone outnumbered those within the plume. At the same time, the pupae in the plume were more numerous than the sante. forms outside the plume, -indicating that the pupal stage was_being reached _ earlier in tha heated zone. By July, an emergence, one of many in a series since February or March, according to Lager (1976) and Hopwood (1975), occurred in the heated zone. This is indicated by the drop in numbers of pupae between June and July in the heated zone compared with unheated areas in the river.

2.2.5

SUMMARY

Assessment of the effects of the effluent from the Monticello-Generating Plant upon Mississippi River benthic macroinvertebrates continued during the ice-free period of May through November,

'1976. As in previous years, concrete artificial substrate samplers were placed in sets of four on the river bottom at three-stations along an. upstream transect and at four stations in a downstream transect. Samples were taken.at intervals of 30 days. In all, 196 samples.were taken. Invertebrates were sorted to the lowest taxonomic level and counted. Weighing of each sample was nearly complete at the time of this report.

2.2-10 l

'hh.

Twenty Trichoptera species were identified. The Ephemeroptera -

were composed of 12 genera, none of which were distinguishable to species. The Diptera were represented by five families with one species each in Tipulidae and Rhagionidae. The families Psychodidae and Simuliidae each had one genus. Midge larvae and pupae were separated and were discernable to the tribal level (Chironomini).

Raw dat -

'e converted to organisms per square meter of sub-strate anc comparison of populations in the ef'_Auent plume was made against the normal river population.

Cheumatopsyche, Oecetis, Psychomyia, fotomanthus, orythodes, Stenacron, Stenonema, and the Chironomini popul' sere greater in the effluent plume, but other insects were less numerous in the downstream stations than in areas not touched by the effluent plume.

Insect populations in the aested zone in 1976 were amaller than in 1975, probably attributable to the effects of extraordinarily low river flow in 1976.

Insect life cycles appeared to be accelerated in the heated zone.

2.2.6 ACKNOWLEDGEMENTS Studies in the biology of the invertebrates of the Mississippi Riv7r require many hours in the field, often during inclement weather. New information is revealed.froa biological samples only through many hours of laboratory work. I owe deep grati-l 2.2-11

7> l tude to Graduate Research Assistant Wayne F. Sarappo and for the .

technical assistance of Erik Englebretson, Dennis MCGovern, and Roger Ramthun, who worked on this project.

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.2.2.7 LITERATURE CITED Andersen, Robert A. 1972. Food habits, length-weight relations, and conditions of the shorthead redhorse, Moxostoma macrolepidotum (Lesueur), and the carp, Cyprinus carpio L.,

collected from the Mississippi River near Monticello, Minnesota. Master's Thesis, St. Cloud State University, 111 pp.

{ Hopwood, Alfred J. 1975. Analysis of flying aquatic insects collected by light-trap samplers. pp. 129-34, 145-85 IN Environmental Monitoring and Ecological Studies Program for -the Monticello Nuclear Generating Plant, Monticello, Minnesota, 1974 Annual Report. Northern States Power Co. ,

. Minneapolis.

Hynes, H. B. N.

1970. The ecology of running waters. Univ.

Toronto Press, Toronto.. 555 pp.

Lager, Thomas M.- 1976. The effect of a thermal discharge on the macroinvertebrates in the Mississippi River near '

Monticello, Minnesota. Master's Thesis,.St. Cloud State

. University. 112 pp.

4

=

2.2-13

Figure 2.2-1. Map of the Mississippi River and the Monticello Nuclear Generating Plant showing locations of transects for macroi.nvertebrate sampling in 1976.

• )

Control , ,f, Transect

0 Intake o "

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l P1 ant ----> *

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r N o l N 'O f

A,M r Co 31ing Tovars (

Nr ]

Discharge }

Canal r

}

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1 l

N H1

% Experimenta1 0 60 120 Transect Scale-Meters

/

2.2-15

Table 2.2-1. Macroinvertebrate taxa captured on artificial substrate samplers .

in the Mississippi River near the NSP Monticello Nuclear Generator during 1976.

Phylum Arthropoda Class Insecta Order Ephemeroptera Family Potamanthidae . . . . . . . Potamanthus sp.

Family Baetiscidae . . . . . . . . Baetisca sp.

Family Siphlonuridae . . . . . . . Isonychse sp.

Family Tricorythidae . . . . . . . Tricorythodes sp.

Family Caenidae. . . . . . . . . . Caen.is .

Family Ephemrellidae . . . .. . . Ephemer na sp.

Fan.ily Leptophlebiidae . . .. . . Leptophlebia sp.

Family Heptageniidt.e . . . . . . . Stenonema sp.

Stenoacron sp.

lieptagenia sp.

Family Baetidae. . . . . . . . . Baetis sp.

Pseudocloeon sp.

Order Odonata Family Coenagrionidae. . . . . . . Argia sp.

Enallagma sp.

Order Plecoptera Family Perlidae. . . . . . . . . . Perlinella sp.

Neoperla clymene (Newman) .

Aaroneuria abnormis (Newman)

Aaroneurialycorias(Newman)

Acroneuria ruralis (Hagen)

Paragnetina media (Haiker)

Phaaganophora cavitata (Pictet)

Family Periodidae. . . . . . . . . Isoperla orata Frison Order Coleoptera Family Elmidae . . . . . . . . . . StensInr:s sp.

&abiraphia vittata (Melsheimer)

Cptioserous fastiditus (Le Conte) 2.2-17 I . _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ .

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Table 2. 2-1 (Continued) .  !

l Order Trichoptera Family Hydropsychidae. . . . . . . Macronena zebmtwn (Hagen)

Hydropeyche phaterata Hagen Hydropsyche cf. cuania Ross Hydropsyche cf. bifida Banks Hydropsyche Cf. hageni Banks Hydropsyche betteni Ross l

Hydropsyche orris Ross 3 Cher

atopsyche sp.

Chewnatopsyche cf. minuscula (Banks) j Family Hydroptilidae . . . . . . . Leucotrichia pietipes (Banks) l Hydroptila albkornis Hagen l Family Philopotamidae. . . . . . . Chimarm socia Hagen I Chimarr2 obscum (Walker)

Family Polycentropodidae . . . . . Neureclipsis crepuscularis (Walker)

Polycentropus Cf. cinereus Hagen

@ctiophy!ar sp.

Family Psychomyiidae . . . . . . . Psychomyia flavida Hagen Family Glossosomatidae . . . . . . Protoptila cf. maculata (Hagen)

Family Leptoceridae. . . . . . . . Decetis avara (Banks)

.c vug Ceraclea menticus (Walker)

Family Limnephilidae . . . . . . . Pseudostenophylar uniformis Betten Family Helicopsychidae . . . . . . Helicopsyche borealis Hagen Order Lepidoptera Family Pyralidae . . . . . . . . . Pamrgyractis sp.

Order Diptera Family Tipulidae . . . . . . . . . Antocha saricola Osten Sacken.

Fami]y Psychodidae . . . . . . . . Psychoda sp.

Family Chironomidae. . . . . . . . Tribe- Chironomini Family Simuliidae. . . . . . . . . Simulium sp.

Family Ragionidse. . . . . . . . . Atheri variegata Walker Phylum Mollusca Class Gastropoda Order Basommatophora Family Ancylidae . . . . . . . . . Ferrissia sp.

2.2-18

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Table 2.2-2. Water flow velocity and temerature of macrotnvertebrate sampling stations in the Gississippi River netr the NSP Monticsila Nuclear Gener2 tor during 1976.

STATIONS Da te CI CII CII El EII EIII EIV Flow Temp. Flow Temp. Faow Temp. Flow Temp. Flow Teg . Flow Teep. ' Flow Temp.

(m/sec) (DC) (m/sec) (DC) (st/se:) (OC) (m/sec) (DC) (m/sec) (OC) (m/sec) (DC) (si/sec) (OC) 30 Apr. 1.25 12.8 1.25 12.8 1.25 12.8 1.00 12.8 1.00 15.5 1.00 16.1 1.00 17.6 6 May 1.00 11.1 1.00 11.1 I.00 11.1 1.29 13.3 1.29 15.0 1.29 17.0 1.29 17.8 14 May -

16.6 -

15.6 -

16.6 -

20.0 - 20.5 -

21.8 -

22.0 21 May 1.10 18.3 1.10 18.3 1.10 18.3 0.70 18.3 0.70 18.5 0.70 20.0 0.70 22.3

' 25 May -

19.9 - 19.9 D~ 19.9 - 21.0 -

21.5 -

23.5 -

25.0 4 June -

22.5 -

22.5 -

22.5 - 23.5 -

24.0 -

24.5 - 24.0 11 June - 26.9 - 26.9 -

26.9 -

28.0 -

29.0 -

27.5 -

27.0 18 June 1.00 20.0 1.00 20.0 1.00 20.0 0.50 19.0 0.50 21.0 0.50 17.5 0.50 18.0 24 June 0.65 22.2 1.30 22.2 1.30 22.2 0.30 21.7 0.60 25.6 0.40 25.0 0.30 25.0 2 July 0.80 24.0 0.80 24.0 0.80 24.0 0.75 24.5 0.80 25.0 0.75 26.0 0.75 26.0=

9 July - 26.5 -

26.5 -

26.5 - 26.5 -

28.5 -

29.0 - - 28.0 y 16 July 1.45 23.8 2.05 23.4 2.30 23.4 c.80 23.0 1.50 24.0 1.10 26.5 0.45 26.9 u 23 July 0.40 26.5 J.75 27.0 0.90 27.0 0.40 21.5 0.55 28.8 0.25 29.5 0.15 30.0 h 30 July 0.50 26.5 0.70 26.1 0.70 26.5 0.35 26.5 0.55 28.0 0.35 28.9 0.10 29.0 6 Aug. 0.45 25.0 0.75 24.9 0.75 25.0 0.35 25.1 0.50 24.9 0.30 25.0 0.10 25.0 13 hg. 0.50 25.1 0.70 24.5 0.65 24.8 0.30 24.9 0.45 27.5 0.25 27.0 0.10 27.0 20 Aug. -

26.0 -

26.0 -

26.0 - 25.0 - 29.5 -

28.0 -

28.5 23 Aug. 0.65 25.9 0.75 25.8 0.60 25.8 0.34 26.5 0.24 29.5 0.25 27.5 0.20 27.8 27 Aug. 0.75 23.0 0.75 23.0 0.75 23.0 0.30 25.0 0.30 28.0 0.30 26.0 0.20 26.0 3 Sep. 0.40 21.5 0.65 21.0 0.65 21.5 6.15 26.0 0.15 26.0 0.20 25.5 0.10 24.5 10 Sep. 0.60 20.0 0.90 20.0 0.70 20.0 0.25 24.0 0.30 25.0 0.20 22.5 0.15 23.0 17 Sep. 0.40 19.0 0.80 19.0 0.90 19.0 0.20 22.0 0.20 22.0 0.20 21.0 0.10 21.0 22 Sep. 0.45 15.0 ~0.50 15.0 0.64 15.0 0.03 16.5 0.04 18.5 0.25 17.0 0.15 18.0 1 Oct. 0.45 18.3 0.90 18.5 0.70 18.5 0.25 20.0 0.40 20.5 0.30 20.0 0.25 21.0 8 Oct. 0.85 9.0 0.85 9.0 0.85 9.0 0.10 11.0 0.05 12.0 0.05 11.5 0 12.0  ;

15 Oct. 1.70 8.0 1.80 8.0 1.40 8.0 0.10 9.0 0.40 12.0 0.20 12.0 0.e0 13.0

?? Oct. 0.40 4.0 0.50 4.0 1.20 4.0 0.15 4.0 0.40 6.5 0.15 8.0 0.10 9.0 l

, 9 Oct. 9.55 6.0 1.00 66.0 0.50 6.0 0.20 7.0 0.30 9.0 0.30 9.0 0.25 10.0 5 Nov. 0.80 3.0 0.90 3.0 0.95 3.0 0.50 3.5 0.50 5.5 0.40 8.5 0.25 9.0 12 Nov. -

1.0 - 1.0 -

1.0 -

1.0 -

1.0 -

3.0 -

8.5 19 Nuv. 0.55 2.0 0.60 .

2.0 0.90 2.0 0.20 2.0 0.40 3.0 0.20 7.0 0.05' 9.0 22 Nov. 0.60 0 0.60 0 0.60 .0 -

0 0.25 1.0 0.25 4.5 0.10 s

12.0

Tabl.e 2.2-3. Macroinvertebrate sampling stations in the filssissippi River included in the effluent plume from the NSF Monticello fluclear Generator during 1976.

1 Sampling Period Stations Included in the Effluent Plume April 30-May 25 EIII, EIV May 25-June 24 EII P

y Jun$24-July 23 EII, EIII, EIV E J . 23-August 23 EII, EIII, EIV August 23-Septe:nber 22 EII, EIII, EIV September 22-October 22 EII EIII, EIV October 22-November 22 EIII, EIV

-. ....._a--... -

.Q

4 r, z&

Table 2.2-4. Total projected numbers of irichoptera captured on artificial substrates in the Mississippi River near the NSP Monticello Nuclear Generator during May,1976. '

STATION Species CI CII CIII El EII EIII EIV Macronema zebratwn 2 2 8 44 24 5A 14 Rydropsyche phalerata 918 3562 1046 1912 1110 3228 2902 R. cf . e: e rts 2 20 24 4 2 H. cf. bifida 558 3370 2532 2264 3986 3380 4066 H. cf. hageni H. betteni H. orris 2 2 2 2 4 Cheumatopsyche sp. 142 38 1028 264 118 116 C. cf, minuscuta 2 122 12 Leucotrichia pictipea Rydroptila albicornia Chinarra socia 8 12 4 C. obscura 28 12 8 16 Neureclipsis crepuscularis Polycentropus cf. cinereus 2 2

%ctiophyla: sp. 8 4 2 Psychomyia flavida 82 106_ 58 44 40 36 21 2 Protoptsta cf. maculata 22 22 26 104 22 24 6 Decetia avara Ceractea mentieus 8 8 28 20 32 20 Pseudostenophylax unifomis 2.2-21

Table 2.2-5. Total projected numbers of ~Trichoptera captured on arti-ficial substrates in the Mississippi River near the NSP Monticello Nuclear Generator during June,1976. '

STATION-Species CI CII CIII EI E!! E!II EIV Nacronem zebratw 12 24 24 2 10 4 14 Bydropsyche phaterata 1030 1856 1470 290 1702 1106 500 H. ef. cuania 4 4 14 6 16 68 H. cf. bifida 2198 3126 3848 1182 1784 658 474 H. cf. hageni ,

H. betteni H. orris Cheumtopsyche sp. 28 28 222 214 C. cf. minuscula Leucotrichia pictipaa Hydroptila albicornia Chimrra occia C, obscura 4 2 4 4 .14 ._

Neurectipais av.puscularis Polycentropus cf. cinereus Nyctiophyla: ep.

Psychcrmgia. f7avida 122 204 100 160 42 284 Procoptila cf. maeutata 142 80 8 ' 38 12 30 Decetic avara Ceraclea mentieus Pseudoetenophyla: unifamia l

l 2.2-22

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

Table 2.2-6. Total projected numbers of Trichoptera captured on arti-ficial substrates in the Mississippi River near the NSP .

Monticello Nuclear Generator during July,1976.

STATION Species CI CII CIII EI EII EIII EIV L eronema zebratum 276 132 382 180 108 102 130 Bydropsyche phaIemta 1996 1084 1500 1882 4206 410 682 R. cf. cuania 130 25 21 0 136 84 108 84 R. cf. bifida 2170 1165 3954 448 280 138 250

8. cf. hageni R. betteni R. orris 5 18 4 2 Cheum topsyche sp. 506 170 296 820 51 8 294 270 C. cf. minuscula 14 Leucotrichia pictipes p,,

Rydroptila albicorni.s Chimarra socia C. obscum 58 64 86 102 44 24 22 -

Neureclipsis crepuscular's Ptycentropus cf. cinercus 2 i@ctiophyla sp.

Psychmjdaflavida 88 42 74 168- 4 10 190

!. Protoptila cf. maculata 482 13 106 12 26 130 208 Decetis avara 2 2 2 Ceraclea mentieus Pseudostenophyla: unifo mia 2 2.2-23

4 Table 2.2-7. Total projected numbers of Trichoptera captured on arti-ficial substrates in the Mississippi River near the NSP Monticello Nuclear Generator during August,1976.

STATION Species -

CI CII CIII EI E!! EIII EIV I Macronema zebratum 288 142 128 16 34 12 12 Hydropsyche phalemta 5520 5098 4048 2968 6170 5860 792 l

H. cf. cuanis 72 66 76 114 154 122 68 l H. cf. bifida 2108 5124 11032 110 186 182 64 H. cf. hageni H. betteni H. orris 2 12 2 4 Chem:atopsyche sp. 1364 468 524 688 558 582 390 C. cf. minuscuta 4 8 a8 38 32 Leucotrichia pictipes Hydroptila albicornia Chimrra socia C. obscura 220 18 36 cJ 54 16 24 Neureclipsis crepuscularis 8 Potycentropus cf. cinereus 44 Itgotiophyla sp. 6 Psychargia .ftavida 4 20 Protoptila cf. macula +x 4 12 Decetis avara 8 Cemetea mentieus 4 4 Pseudostenophyta: unifo mis 2 2.2-24

n . - . .. .- ~. - . - . - - - . _ . . - - . . - - -

t Table 2.2-8. Total = projected numbers of Trichoptera captured on arti-ficial substrates.in the Mississippi River near the NSP -

Monticello Nuclear Generator during September,1976.-

i STATION Species t CI CII CIII El EII EIII =EIV Macmnema zebratum 192 12 6 2 6 Rydspsyche phaterata' 4660- 5970 2532- 2626 5280 3602 222 R. - cf. cuania 66 58 62 60 98 54 36 R. cf. bifid 2 _

3802 4146 5174 58 596 80 48 R. cf. hageni.

R. betteni R. orria 4

- Chaumacopsyche sp. 2500 582 430 468 1606 746 338-C. Cf. minuscuta 14 144 28 16 44 26 Leucotrichia pictipes- 2 RydroptiZaiaZbicornia ' 12- 4 _14 8 22 16

- Chimrm~ socia .

C.cobse:au 694- 68 40- 10 < 3 6 -- 32 .16 .

-Neureatipsis crepuscutaria .6'.

. Potycentropus cf. cinereus l0. 4 32 352 .

. NyctiophyEa= sp. - 4 .

Psychemyia flavida - .38 10 42. 4 2

. ProtoptiZa ' cf. moulata 96~ 102 2 Decetis avara 4 6 6 104 152 74 14-Cemetea mentieus 4 2 3g 4 PseudoatenophyZOx unifamis 2.2-25

4 c,- Table 2.2-9. Total projected numbers of Trichoptera captured on arti-ficial. substrate _in the Mississippi River near. the NSP Monticello Nuclear Generator during 0ctober,1976. ..

STATION Species CI CII CIII E! EII EIII EIV Macronema zebratum-Rydropsyche phalerata 790 884 308 ~652 1564 1302 114 H. Cf. cuania 20 24 4 6 14 4

. R. cf. bifida 1348 1178- 1980 34 114 64 52 R. cf.-hageni' H. betteni 6 26 R.~ orria- 2 Cheumatopsyche sp. 922 512 490 178 342 466 294

c. cf. minuscuta 14 26 36 26 44 50 j Leucotrichia pictipea 2 .l

- Hydroptila albicornia 222 72 120 28 220 80 72 t l

Chimarra socia 4 l

. C obscura- 18- 22 6 '4 8 Neureatipsis crepuscutaria- -

Polycentropus cf. cinereus 2 ^4 8 4 14 88

- Nyctiophyta: sp. :2 Psychomyia flavida 12- 6 4 2 2

,- 1 Protopeita ef, maeutata 132 240 60- 2 30 i-oecetis avara- -14 10- 6 56 206 382 22 Ceractea mentieus 6 6 2 '8' Pseudostenophyta: uniformie Heliopsyche boreatie 2 I

2.2-26

[ .- -- si

__ . . . _ . . - . _ ,,_.....,_~,.._,-....._.,_.._.,_..._,........m._, _ - _ . , . . . , , . . -

Table 2.2-10. Total projected numbers of Trichoptera captured on arti-ficial substrates in the Mississippi Rivt.c near the NSP Honticello Nucinar Generator during November,1976.

STATION Species -

CI CII CIll El EII EIII Elv 1%~ronema zebrgen Hydspapohe phalerata 105 136 75 87 242 3F

d. cf. cuanis 8 3 6 1 4 R. ef. bifida 200 254 420 16 17 30 H. cf. hageni H. betteni ') \

H. orrie 1 Cheumatepayche sp. 125 51 51 80 169 103 w

C. cf. minuccula 23 5 4 17 Leucotrichia pictipea Nydroptita albicornia 37 P1 54 53 30 Chburra socia C. obac:au 2 1 Neureclipsia crepuscularia Poiycentrepus cf. cinereus 1 1 34 Nyctiophyla: ep.

Psychmyla flavida Protoptila cf. maculata 4 6 Ceoette avara 6 2 9 118 90 6 Ceracica mentieus 3 5 2 10 5 Pseudentenoph '~n unifornie 2,2-27 4

Table 2.2-11. Total projected numbers of Ephemeroptera captured on artificial substrates in the Mississippi River near the NSP Monticello Nuclear Generator during 1976.

STATION Species CI CII CIII El EII E!!! EIV 12 4 Hay Potxnanthun 12 88 4 4 20 4 12 Jaonychia 64 28 84 48 20 32 Ephencrella 40 84 36 44 48 204 96 104 Stenonema 4 24 16 8 8 8 Reptagonia 48 32 100 12 8 116 Baetis 20 544 948 1124 440 1980 320 348 Pocudoctocon 2 2 June Potananthua 10 22 8 8 Joonychia 12 8 18 26 20 126 7Picorythodca 4 8 10 70 22 6 6 4 EphemereIIa 22 2

Leptophlebia Rhithrogena 4 ggQ 42 ]Qg ]Qg gg $4 Stenonema 1Ag 32 60 106 68 16 40 Baetis 6 464 354 204 330 70 240 Pacudoolocon 362 46 2 July Baetisoa 8 20 22 42 2 Iconychia 50 30 330 510 Tricorythodes 78 20 34 368 164 '

l 4 26 Caenia 2 2 36 76 206 110 62 24 18 EphemereI7c 160 2 2

( Leptophlebia 2 104 31 8 106 42 72 396 92 Stenonema 26 2

Stenacron 62 60 230 726 31 2 78 Baotis 114 220 700 1670 1892 2218 996 316 Pacudoolocon 4 24 8 32 18 Nobcmanthus Aus st Isonychia 48 52 4 36 40 24 16 20 4 264 200 196 248 Tricorythodes 28 14 16 8 Cacnia 188 156 232 72 24 24

.)hemereIIa 176 1860 360 200 274 Stenancru 720 132 16 4 66 Stenaeron 36 58 208 328 272 84 12 Baetis 52 172 160 Pacudooloeon 2100 2848 2552 748 2.2-28 su

y-Table 2.2-11 continued. ,

STA170N l Species CI CII CIII El EII EIII EIV September Potamanthus 36 2 8 36 20 Isonychia 132 50 56 4 16 Tricorythodes B 2 4 2 Caents 2 6 rphemeretta 92 340 16 4 32 28 6 scenonema 748 552 21 2 448 68 412 128 Stenaeron 104 6 32 42 Baetis 32 30 64 16 Pseudoctocon 1556 1454 592 92 34 148- 10 October Potamanthus 2 4 28 Joonychia 32 32 8 4 4 Tricorythodeo 2 Ephemeretta 252 96 44 24 32 40 32 stenoncma 80 100 24 72 30 108 76 Stenacron S 12 8 8 Baetia 4 8 2 8 4 Pseudoolocon 132 100 56 24 8 20 November Potamanthus 2 2 10 6 Isonyohia 4 Lpeneretta 52 22 6 4 14 28 Parateptophlebia 2 stenancma 2 2 2 10 20 Stenacron 2 2,2-29

Table 2.2-12. Total projected numbers of Diptera captured on arti-ficial substrate in the Mississippi River near the NSP Monticello Nuclear Generator during 1976.

STATION Species CI CII CIII El EI! E!!! EIV May Chironomini larvae 4160 2976 3024 16848 3680 2400 3888 .

Chironomini pupae 64 64 52 56 32 144 180 )

simulium larvae 64 72 28 64 32 20 i simulium pupne 4 June Chironomini larvae 588 792 1090 408 476 Chironomini pupae 2 2 4 simutium larvae 6 24 36 10 20 simatium pupae July Chironomini larvae 948 2048 2040 792 2304 2160 1400 Chironomini pupae 20 12 4 36 38 24 14 simatium larvae 86 372 238 60 16 14 16 sinutium pupae 20 August Chironomini larvae 1048 1232 1268 2192 1380 1468 2920 Chironomini pupae 12 24 24 simazium larvae 1C4 -768 416 52 24 16 Simulium pupae 16 September Chironomini larvae 2376 1696 796 4596 2144 2736 2792 Cnironomini pupae 64 2 20 16 16 64 simulium larvae 496 180 440 24 Simutium pupae 20 12 Antocha saricola 4 2 16 October Chironomini larvae 940 832 580 2332 3520 3888 1808 Chironor..ini pupae 148 88 80 44 52 76 28 Simulium larvae 288 336 372 12 20 8 4

'simatium pupae 76 24 152 6 32 November Chironomini larvae 88 40 34 264 2232 392 Chironomini pupae 6 2 8 Simulium larvae 34 40 22 2 2 simulium pupae 5 12 24 2.2-30

r l

l I

Table 2.2-13. 2 Comparison of mean number of Trichoptera per m from heated and unheated stations in the Mississippi River near the NSP Monticello Nuclear Generator during May, 1976. Ratios were computed using data from unheated stations as a base.

Unheated Heated Taxa Stations Ratio Stations Haemnema sebmeum 3 1:9.67 29 Rydropsycha phatemta 1535 1:1.66 2554 R. cf. cuanto 13 0 R. Cf. bifida 1794 1:1.73 3103 H. orris 2 1:1.50 3 Choumtopsyche ap. 50 1:1.96 98

c. cf. minuscuta 34 0 Chimrm socia 2 1:0.50 1

c. obscura 0 10 Potycentropus cf. cinereus 1 0 W ociophylax sp. 3 1:0.33 1 Payohonest: fTavida 68 1:1.56 106 l

ProcoptiZg cf. meutata 19 1:0.68 13 j Cemalea mentieus 4 1:5.60 22 l

l l

2.2-31

h -

Y Table 2.2-14. Comparison of mean number of Trichoptera per2m from heated and unheated stations in the i

Mississippi River near the NSP Honticello Nuclear Generator during June,1975 and 1976.

Ratios were computed using data from Lnheated stations as a base.

1975 1976 Taxa Unheated Heated Unheated Heated Stations Ratio Ratio Stations Stations Stations w

" Macronema 24 1:1.77 43 17 1:0.47 8 Hydmpsyche 2901 1:1.19 3456 3764 ~1:0.78 2918 M H. phaZemta 1210 1:1.17 1418 H. Cf. cuania 2 1:6.50 13 H. cf. bifida 2548 1:0.58 1487 Cheumtopsychs 283 1:2.06 582 6 1:30.83 185 Chimrm 16 0 1 1:3.00 3 C. obscum Psychomyia flavida 11 1:1.99 22 118 1:0.30 35 ProtoptiZa cf. meuZata -

62 1:0.52 32 oecetis 16 1:1.00 16 i

. . - . , ~ . __ _m

y. o U

2 Table 2.2-15. Compa'rison of mean number of Trichoptera per m fmm heated and unheated stations in the Mississippi River near the NSP Monticello fluclear Generator during July,1975 and 1976.

Ratios were computed using data from unheated stations as a base.

1975 1976 Taxa Unheated Heated Unhea ted Heated Rati Rati Stations Stations Stations Stations u

• 242 1:0.92 222 202 1:0.47 94 w Macmnem 3069 1:0.57 1736 Hydspsyche 1380 1:1.15 1587 1472

& 1346 1:1.09 w H. phalemta 104 1:0.74 77 H. cf. cuanis 1614 1:0.12 186 H. cf. bifida 5 1:0.60 3 H. orris 312 1:u.610 191 376 1:0.80 300 Cheumcopsyche 373 1:0.80 300 C. sp. 3 0 C. cf. crinuscula 62 0 65 1:0.38 25 Chirm ra 1 0 Polycentwpus cf. einexus 76 1:0.75 57 Psychc=yia fIavida 128 1:0.79 101 Pmtoptila cf. meuZata 1 1:1.00 I

, Decetia avam 0 1 Pseudostenophytax uniforw:e

. l, Table 2.2-16. Cortparison of mean number of Trichoptera per m2 from heated and unheated stations in the

?tississippi River near the NSP Monticello Nuclear Generator during August,1975 and 1976.

Ratios were computed using data from unheated stations as a base. i 1976

^

1975 Taxa Unheated 88

' Unheated Heated Ratio R3ti Stations Stations Stations Stations 120 1:0.13 16 426 1:0.70 298 M2cmnem 7573 1:0.50 3779 4007 1:1.29 51 51 3562 Rydropsyche 3674 1:0.97 R. phalemta 68 1:1.41  %

R. cf. cuania 3828 1:0.03 120

. H. cf. bifida 3 1:0.67 2 N H. orris 273 1:1.22 333 637 1:0.72 456 b

Cheumatopsyche 634 1:0.67 425 l 4 C. sp. 3 1:11.00 33 C. cf. nrinuscula 1:0.42 231 61 1:0.43 26 548 2 chimrm 0 Neureclipsis crepuscularsia 3 0 12 0 2 IbZycentmpus 3 1:0.96 3 0 ,

f.5yctiophylax 21 1 1:6.00 6  !

Psuchomyia 0 1:3.00 .3 0 35 1 Piotoptila 0 2 Oecetis avaru 1 1:1.00 1 CemcIca mentieus 0 1 Pseudostenophytax uniformis

+

t 1

_,.,s.. . _.. e . ~ -. - . ~...,:.s,a . %

1

-- __-___ _-_- __ ____________-_ - - _______________-___ __________ - _ - 1

w.

Table 2.2-17. Compdison of mean number of Trichoptera per m from heated and unheated statior.s in the Mississippi River near the NSP Monticello Nuclear Generator during September,1975 and 1976. Ratios were computed using data from unheated stations as a base.

1975 1976 Taxa Unheated Heated Unheated Heated

1. 'O Rati Stations Stations Stations Stations M2emnem 0 1 58 1:0.03 2

" Hydspsyche 1003 1:1.19 1191 7374 1:0. 18 2782 w H. phalerata 3656 1:L.29 2529

• 52 1:1.GJ 52 H. cf. cuanis H. Cf. bifida 3645 1:0.06 201 H. orrie 1 0 Chewutopsyche 293 1:1 359 1027 1:0.75 767 Cheumtopsyche sp. 976 1:0.77 747 C. cf. minuamla 52 1:0.37 19 Leucotrichia pictipes 1 0 HydmptiZa 0 16 8 I:1.38 11 crimrm 17 1:0.80 16 223 1:0.10 23 Neta'eclipsia crepuscularis O 2 Eblycentmpus cf. cinereus 0 47 Nyctiophytax 1 0 1 0 Feychorrgza 15 1: 0.31 5 25 1:0.08 2 Pmtoptila 87 1:3.88 339 55 1:0.02 1 oecetie 2 1:5.20 10 4 1:16.75 67 Cemclea mentiens 2 1:2.00 4 4

e

o!

f 2

Table 2.2-18. Conparison of mean rumoer of Trichoptera per m from heated and unheated stations in the  !

Mississippi River near the N5P Monticello Nuclear Generator during October,1975 and i 1976. Ratios were computed using data from unheated stations as a base. l i

1975 1976 .

Unheated- Heated *' I[nheated Heated Ratia Ratic Stations Stations Stations Stations  !

Macmnem 0 1 ~

1 0.74 1346 Hydmpsyche 1003 1:1.19 1191 1824 H. phalemta 550 1-2.26 1242 H. cf. cuanis 12 120.83 10 +

H. cf. bifida 1252 L-0.oe 96 l H. betteni 9 g o* .. O [

w H.onds 1 0 o

g Cheumtopsyche - 293 1:1.22 359 555 1:0.90 '498  !

C. sp. 534 1:0.86 459  !

$ C. cf. minuscula 21 1:1.86 39 t Leucotrichia pictipes 1 \

,l Hydmptila 0 16 115 1:1.35 155 Chimrm 17 1:0.98 16 14 1:0.36 4 5

C. socia 1 *t- O f C. obscum 13 1

0.38 5 t Iblycentropus cf. cinereus 2 1:22.0 44  :

vgeliophylax 1 0 1 0 Psychorrgia 15 1:0.31 5 6 1:0.33 2  :

! Protoptila _ 87 1:3.88 339 120 1:0.15 18  !'

oecetts . 2 1:5.20 10 8 1:31.75 254 CemcIsa mentteus ,

t 3 1:1~33 4 Helicopeyche borealts 9 - T 1

1 i

a.

I . . s .w. . ....% a. wen 4 sh e e sr. s- . ;vg r-4 , ,n V E f

t 2

Table 2.2-19. Comparison of mean number of Trichoptera per m from  :

heated and unheated stations in the Mississippi River near the NSP Honticello Nuclear Generator during November,1976. Ratios were computed using data from '

unheated stations as a base.

Unheated Heated Taxa Rati Stations Stations >

Bydropsycho phaterata 88 1:1.32 116

h. Cf. cuanis 5 1:0.21 2 H. t.f. bifida 253 1:0.08 20 l H. betteni 8 0 Chetanatopsychs sp. 63 1:1.79 113 C. cf, minuseuZa 8 1:0.88 7

r RydroptiZa aIbioornis 16 1

2.13 34 chuarra obscura 1 o

Polyoentropus cf. cinereus 0 14 Protoptsta cf. mo4Iata 3 0 oscetis avara 5- 1:8.00 '40 4

L caractea acntieus 3 1:0.67 2 l

11 1_ ) ~

,r 1

l 2.2-37

.. .~D I

2 Table 2.2-20. Comparison of mean number of Ephemeroptera per m from heated and unheated stations in the Mississippi River near the NSP Monticello Nuclear Generator during 1976.

Ratics were computed using data from unheated stations as a base.

d Unheated Heated Taxa Ratio Stations Stations May Pbtananthus 0 2 Jeonychia 27 1:0.37 10 rphemeretta 37 1:0.59 22 1:2.19 stenonema 36 79 Rep,tagenia 13 1:0.15 2

..[ Baetia Pacudoolocon 28 698 1:1.86 1:0.53 52 372 June Potananthus 0 0 Joonychia 9 1:0.78 7 Tricorythodes 6 1:3.67 22 Ephemeretta 32 1:0.16 5 Leptophlebia 0 0 Rhithrogena 1 0 stenonem 122 1:0.74 90 Bastia 33 1:1.73 57 Pacudoctocon 227 1:1.21 275 July Baetiaca 10 1:0.10 1 Isonyohia 30 1:0.25 10 Tricorythodes 104 1:2.68 279 Caenia 8 1:1.00 8 rphemeretta 115 1:0.25 29 LeptophIcbia 1 1:1.00 1 Stenonema F20 1:1.12 143 Stenacron 1 1:7.00 7 Baetia 288 1:0.19 56 Pecufooloeon 1412 1:0,24 34 3 August .Potamanthua 6 1:2.67 16 Jaonychia 29 1:0.76 22 Tricorythodes 66 1:2.71 179 Caenia 3 1:2.00 6 Ephemerella 135 1:0.10 13 stenonema 601 1:0.39 232 Stenaeron 3 1:6.33 19 Bastia 186 1:0,16 29 Pseudooloson 1718 1:0.06 107 2.2-38

Table 2.2-20 continued.

Unheated Heated Taxa Ratio Station Station September Potamanthus 11 1:1.66 18 Isonychia 67 1:1.06 4 Tricorythodca 2 1:1.00 2 0 2 Caenia 98 1:0.19 18 rphemeretta stenoncim 544 1:0.32 '74 29 1 :0.'/7 22 stenacron Baotia 35 1:0,11 4 Pseudoctocon 1026 1:0.02 53 0 14 October Potamanthus 20 1:0,10 2 Jaonychia 0 1 Tricorythoaae Iphemervita 109 1:0.47 44 stenonema 57 1:1.00 107 Stenacron 0 12 Bastia 3 1:2.0 0 Paeudoetoeon 80 1:0 . .'. 5 12 November Potamanthus 1 1:7.0 7 0 2 Isonychia 18 rpherrerutta 22 1:0.82 0 1 Parateptophlebia Stenor:cma 2 1:7.0 13 s 0 1 Stenacron 5-t 2.2-39

Table 2.2-21. Compari:en of mean numbar of Diptera per m2 from heated i and unheated stations in the Mississippi River near the I NSP Monticello Nuclear benerator during 1976. Ratios w6te computed using data from unheated stations as a base, Taxa Unheated Ratio Heated Station Station 1

May Chironomini larvae 2822 1:0.93 2620 Chironomini pupae 50 1: 2.70 135 '

Simlium larvae 38 1:0.58 22 '

Simulium pupae 0 2 ,

June v 'ronomini larvae 686 1:0.58 397 Cr.i Anomini pupae 1 1:3.00  ;

Simulium larvae 18 1:0.94 1.7

- July Chironomini larvae . 1214 1:1.34 1629 Chironomini pupae 15 1:1.40 21 Simutium larvae 158 1:0,08 13 Simulium pupae 4 0 August Chironomini larvae 1196 1:1.34 1602 Chironomini pupae 3 1:4.00 13 Simulium larvae 279 1:0.05 13 Simulium purse 4 0 September Chironomiri larvae 1352 1:1.58 2131 Chironomini pupae 24 1:0.92 22 Simuliwn larvae 310 1:0.02 7 Simulium pupae 9 0 October . Chironomini larvae 653 1:4.70 3072 Chironomini pupae 88 1:0.49 43 Simulium larvae 277- 1:0.03 9 Simulium pupae -70 1:0.15 11 November Chironomini larvae 45 1:24.31 1094

. Chimnomini pupae 2 1:2.00 -4 Simultuar 1arvae 27 1:0.04 1 Simulium. pupae 11 0 2.2-40

u. _ ._..._ _ .._ _ _ _ _ . . . . _ , _ . . . _ , - - _ . . _ . - . . _ _ - -

9 iabb 2 2-22. Total projected numbers of Plecoptera. Coleoptera, Lepidoptera and Odonata from artificial substrates in the Mississippi River near the 14SP Montice11o Nuclear Generator during 1976.

STATION CI CII CIII El EII EIII EIV May Plecoptera 4 Acroneuria abnomia 8 8 4 4 4 Paragnetina media Jooperla orata 24 16 16 12 4 12 Coleoptera 8 20 8 8 4 44 16 Steno! mis adult 4

stencZmia larvae 8 optionenus fastiditus June Plecoptera 8 6 4 2 8 8 Paragnetina media Lepidoptera 2

Parargymatie Coleoptera 2 2 6 22 6 26 StencImia adult 2 2 StencImia larvae 2 Optioservus larvae 8 2 2 2 14 2 July Plecoptera 2 Paragnetina media 4 Acroneuria abnormic Lepidoptera 8 2 16 Parargyractie .

Coleoptera 2 18 StensImis aduit 2 10 14 8 6

SteneInia 1arvae 2 Optioservus Tarvae 4 Ferriceia August Piecoptera 20 16 Paragnetina media Acroneuria abnormie 4 4 8 Phaaganophora capitata 4 2 Acroneuria r:traIia Lepidoptera a 22 Parargyractie Coleoptera 4 32 16 8 4 4 4 SceneImis adult 4- 8 6 StensIria larvae 2 optioservua 1arvae Odanata 2 Argia 2.2-41

I l

y N.

e Table 2.2-22 continued.

1 STATION >

L CI CII CIII El E!! EIII EIV l'

September Plecoptera Paragnetina media 12 4 4 -

Aeroncuria abnomic 4 ,

Neoperta olymenc 4 Lepidoptera  !

Parargyractic 4 2 16 8 2 2 \

,oleoptera i Stenntmis adult 60 4 6 3 Stensimis larvae 4 Dubiraphia vittata 4 October Plecoptera Paragnetina media 4 Partinetta 12 8 8 8 4 Coleoptera

.. Steneimis 8

Odonata Enattagma 4 November Plecoptera Pertinetta 2 4 10 2 Lepidoptera Parargyractia 2 2 k

e i

2.2.-42

ps;n l

I Table u.2-23. Comparison of monthly average ., ,1 Mississippi River flow (cfs), Mays 4 through November 1975 and 1976.

From records of Northern States Power Company, Minneapolis.

Discharge (cfs)

Month 1975 1976 May 23220 3815 June 9000 2397 July 11000 1852 August 2680 1203 September 2940 1052 October 3000 1151 November 3000 1331

• At Monticello, Minnesota 2.2-43

_-___- - _ - _ - _ - - _ - _ _ - _ _ _ - -