# HE UNIVERSITY

# OF MICHIGAN

IMPINGEMENT LOSSESATTHE D.C. COOK NUCLEAR POWER PLANT 

## OFFACTORS RESPONSIBLE AND POSSIBLE IMPACT ON LOCAL POPULATIONS

DURING

## 1975-1982WITHA DISCUSSION

NANCYJ. 

### THURBER and DAVID

### .A JUDE

. 

### Special Report No. 

### 115 of the 

### Great Lakes Research 

### Division

IriIMPINGEMENT LOSSESAT 

### THE D. C. COOK NUCLEAR POWER Pk DURING 1975-1982 WITX A DISCUSSION OF FACTORS RESPONSIBLE AND POSSIBLE IMPACTON LOCAL POPULATIONS

Nancy J. Thurber and David J. Jude

Special Report No. 115 

### of the Great Lakes Research Division Great Lakes 

### and Marine Waters Center The University

### of Michigan 2200 Bonisteel Blvd. Ann Arbor, MI 48109

1985

### TABLE OF CoNTEbITs

LIST Cl? FIaJIZeS

# ............................................................ iv LIST OF 

### .LEs 

# ............................................................. v LIST OE'APPENDICES

# . .. 

# ........................................................ Vll I.ION 

# ............................................................... 1 M.IXS 

# .................................................................... 2 ReSULTS AND

DI.SI. 

# ..................................................... 5 

### species CcII(pOsition

# ................................................... 5 Seasonal Ab.a. 

# .................................................... 45 rSnpimpd FishCanpared withField-Cawht Fi. 

# ......................... 52 Plant Eff.tS 

# ......................................................... 56 Mitigative 

### Measures for Impirganent

# ................................... 59 S~Y 

# .................................................................... 61 .E 

# ............................................................ 65 

### LITERATURE CI. 

# ........................................................... 67

### LIST OE' FIGURES

2. Species canpositionof 

### the total

### nuaber 

### of fish impiwejduring spring (March, 

### April, 

### May) 1975-1982 

### atthe D. 

### C. Cook Plant, southeastern Lake Michigan.

# .......................................... 39 3. 

### Species composition of 

### the total 

### nunber of fish 

### impinge during 

### surmer (July, August, Septexber) 1975-1982 

### at

### theD. C. Cook Plant, southeastern Lake 

### ~chigan........................................... 40 4. Species camposition of 

### the totalnrraber of fish impinged each 

### year during 19751982

### at 

### the D. C. Cook Plant, southeastern Lake Michigan............................................................. 41 5. Species canpsition 

### of the 

### total nunber of fishcollected in stadard-series fishing each year during 1975-1982 

### at

### the D. C. Cook Plant, southeastern Lake Michigan,

# ........................ 44 6. Species camposition

### of 

### the total nunber 

### of fishimpirged during fall 

### (October,November) 19751982

### at 

### the D. C. Cook Plant, southeastern 

### Lake ~c~gan........................................... 48 

### 7. Species cuaposition 

### of the total 

### nunber of fish impinged during winter (December, January, February) 19741982at

### the D. C. Cook Plant, southeasternLake Michigan.

# ................................... 49



### ivLIST OF 

### TABLES Page 1. Carmon 

### and scientific

### names, and total estimated 

### nunber 

### of each species impingedduring 1975-1982 at the 

### D. C. Cook 

### Nuclear 

### Power Plant, 

### southeastern Lake ~chigan............................... 6 2. 

### Nunber of fish impirged on 

### the D. C. Cook Plant traveling 

### screens during 1975.......... 

# ................................................. 8 3. Weight (kg) of fish impinged on 

### the 0. C. Cook Plant traveling 

### screens 

### in 1975................ 

# ....................................... 9 4. Estimated 

### nunber of fish impinged on 

### the D. C. ,CookPlant 

### traveling screens 

### in 1976..........................................e.. 10 5. Estimatedweight (kg) of 

### fish impinged on 

### the

### D. C. Cook Plant traveling 

### screens in 1976...... 

# ....................................... 11 6. Estimated

### nu&= of fish impinged on 

### the D. C. Cook Plant traveling 

### screens in 1977....................... 

# ...................... 12 7. Estimated weight (kg) 

### of fish impingedon 

### the 0. C. Cook Plant traveling 

### screens in1977............................................. 13 8. Estimated nunber of fish 

### impiwed on the 0. C. Cook Plant traveling 

### screns 

### in1978............................................. 14 9. Estimatedweight (kg) of fish 

### impinged on the 0. C. Cook Plant traveling 

### screens in 1978.................... 

# ......................... 15 10. Estimated nunber 

### of fish impinged on 

### the D. C. Cook Plant 

### traveling screens 

### in 1979

# ............................................. 16 11. Estimated weight (kg) 

### of fish impinged on 

### the D. C. Cook Plant 

### travelixq 

### screens 

### in 1979.

# ............................................ 17 

### 12. Estimated nunber 

### of fish impirged on 

### the D. C. Cook Plant traveling screens 

### in 1980............................................. 18 13. Estimatedweight (kg) of fish impinged on 

### the D. C. Cook Plant traveling 

### screens in 1980............................................. 19

14. Estimated 

### nunber of fish impixqed on the D. C. Cook Plant traveling 

### screens 

### in 1981...........................................-.. 20 15. Estimated weight (kg) of fish impinged on the D. C. 

### Cook Plant traveling 

### screens 

### in 1981

# ............................................. 21 16. Estimated nunber of fish impirqed on theD, C, Cook Plant traveling screens in 1982......... 

# .................................... 2217. Estimated weight (kg)

### of 

### fish impirged on the 

### D. C. Cook Plant traveling screens in 1982............................................. 23 18. Monthly water volme (inmillions of cubic meters) 

### punped through the condenser circulating water system of the Cook Plant, southeastern Lake Michigan fran 1975 to 1982.

# .......................... 26 19. 

### Number of fish caught by standard series trawling, gillnetting, 

### and seining in 

### D. C. Cook Plant study areas, southeastern Lake Michigan, 1973.................................................... 

### 27 

### and seining in 

### D. 

### C. Cook Plant 

### study areas, southeastern Lake Michigan, 

### 1974.................................................... 28 

### and seining in 

### D. 

### C. Cook Plant 

### study areas, southeastern Lake Nichigan, 

### 1975.............1...................................... 29 

### and seining in

### D. C. Cook Plant study areas, southeastern 20. 

### Nunber of fish caught 

### by standard series trawling, gillnetting,

21. 

### Nunber of fish caught 

### by standard series trawling, gillnetting,

22. 

### Mnnber of fish caught 

### by stardard series trawling, gillnetting, Lake Michigan, 1976.

# ................................................... 30 23. Nuuber of fish caught 

### by standard series trawling, gillnetting, and seining in

### D. 

### C. Cook Plant study 

### areas, southeastern Lake Michigan, 

### 1977.................................................... 31 24. 

### Nrmber of fish caught 

### by stamiard series trawling, gillnetting, 

### and seining in 

### D. C. Cook Plant studyareas, southeastern Lake Michigan, 1978.

# ................................................... 32 

### 25. 

### Nmkrof fish caught by 

### standard series trawling, gillnetting, 

### and seining in 

### D. 

### C. Cook Plant study 

### areas, southeastern Lake Michigan, 

### 1979.................................................... 33 26. 

### Nudber of fish caught 

### by stardard series trawling, gillnetting, and seining in 

### D. 

### C. Cook Plant study areas, southeastern Lake Michigan, 1980.

# ................................................... 34 27. 

### Number of fish caught 

### by standard series trawling, gillnetting, and seining in 

### D. 

### C. Cook Plant study areas, southeastern LakeMichigan, 1981.................................................... 35 and seining in 

### D. 

### C. Cook Plant study areas, southeastern 28. Nunber of fish caught by standard series trawling, gillnetting, Lake Michigan, 

### 1982.

# ................................................... 36 29. Iake Michigan water temperatures (C)measured at the St. Joseph Municipal Water Plant.................................................. 43 30. A canparison between two periods 

### of the percent change in volune 

### of water pmped 

### and nunber of fish impiqed annually at the D. C. Cook Plant....................................................... 57
viApperdix Page 1. Lake Michigan 

### water temperatures recorded dailyat theSt. Joseph municipal water plantduring 1975.................................... A-1 2. LakeMichigan water temperatures recorded dailyat

### the St. Joseph municipal water 

### plant during 1976.................................... A-2 3. Lake Michigan

### water temperatures recorded dailyattheSt. Joseph 

### municipal water plantduring 

### 1977.........,.......................... A-3 4. Lake Michigan water 

### tempratures recorded dailyatthe St. Joseph 

### municipal water plant during 

### 1978.................................... A-4 5. Lake Michigan 

### water temperatures recorded dailyatthe St. Joseph municipal 

### water plantduring 1979.................................... A-5 6. Lake Michigan water temperatures recorded dailyat 

### the St. Joseph 

### municipal water plant during 

### 1980.................................... A-6 7. LakeMichigan 

### water tanperatures recorded'dailyat 

### the St. Joseph 8, LakeMichigan water temperatures recorded dailyat

### the St. Joseph 9. Length-frequency histogram of alewives impinged during 1975 municipal water plantduring 1981.................................... A-7 

### municipal water plantduring 1982.................................... A-8


### at 

### the Cook Plant, 

### southeastern hkeMichigan.................. 

# ......A-9 10. Length-frequency histograms of alewives caught during 1975field sampling at 

### the Cook Plant, 

### southeastern hkeMichigan.

# . . . . . . ....

# ..

# . .A-10 11. Length-frequency histograms of alewives impinged during 1976 at 

### the Cook Plant, 

### southeastern Lake Michigan........ 

# ................A-ll 12. Length-frequency histograms of alewives caught during 1976 field sampling atthe Cook Plant, southeasternLake Michigan....... 

# ........ A-12 13. Length-frequency histograms of alewives impinged during 1977 at the Cook Plant, southeasternLake Michigan...... 

# ..................A-13 14. Length-frequency histograms of alewives caughtduring 1977 field sampling at 

### theCook Plant, southeasternLake Michigan........ 

# .......A-14 15. Length-frequency histograms of alewives impinged during 1978 at the Cook Plant, southeasternLake Michigan.

# .... ...

# .. . ...

# .. ..

# . .. .A-15 16. Length-frequency histograms of alewives caught during 1978 field sampling atthe Cook Plant, southeastern Lake Michigan............... A-16

vii17. -*-frequency histograms of alewives impinged during 1979 at the Cook Plant, southeastern Lake ~chigan........................A-17 18. kngth-frequency histogrms of alewives caught 

### during 1979 field sampling at the Cook Plant, southeastern Lake 

### Michigan..........,....A-l8 19. 

### mth-frequency histograms of alewives 

### impingedduring 1980 at the Cook Plant, southeastern Lake Michigan. , 

# . . . . .

# . 

# ..

# .. 

# .. .



# . ...

# .... .A-19 * 20. bngth-frequency histograms of alewives caught 

### during 1980 field sampling at the 

### Cook Plant, southeastem Lake 

### Michigan.............,.A-20 21. 

### qth-frequencyhistograms of alewives impinged during 1981 at the 

### Cook Plant, southeastern 

### Lake 

### Michigan.............,...,,....,A-21 22. Length-frequency histograms of alewives caught 

### during 1981 field 

### sampling at 

### theCook Plant, southeastern Lake Michigan,

# .

# . . .. ... ,



# .. .. .A-22 23. Length-frequency histograms of alewives impinge3 

### during 1982
24. Lengtfi-frequeq histograms of alewives caught during 1982 field


### 25. Letqth-frequency histograms 

### of spottail shiners impinged during c at the Cook Plant, southeistern Lake Michigan.

# .. .... . .

# .. .

# . . . .. .

# ... ..A-23 sampling at the Cook Plant, southeastern Lake 

### Michigan.....,..,......A-24
1975 at 

### the Cook Plant, southeastern Lake 

### Michigan...................A-25 26. Length-frequencyhistograms 

### of spottail shiners caught 

### during 1975
27. 

### Length-frequencyhistograms 

### of spottail shiners 

### impinged during field sampling at the Cook Plant, Southeastern Lake Michigan.........A-26
1976 at 

### the Cook Plant, southeastern Lake 

### Michigan...............,...A-27 28. Length-frequency histograms of spottail shiners caught 

### during 1976 field sanpling at the Cook Plant, southeastern Lake Michigan.........A-28 29. Length-frequency histograms of spottail shiners impinged during 1977 at 

### the

### Cook Plant, southeastern Lake Michigan...... 

# ............. A-29 30. Length-frequency histograw of spottail shiners caught during 1977
31. Length-frequencyhistograms 

### of spottail shiners impinged 

### during field sampling at the Cook Plant, southeastern Lake Michigan......,..A-30
1978 at the Cook Plant, mutheastern Lake Michigan.. 

# ................. A-31 32. Length-frequency histograms of spottail shiners caught during 1978
33. Length-frequencyhistograms 

### of spottail shiners impinged during
34. Length-frequency histograms of spottail shiners caught during 1979 field sanpling at 

### the Cook Plant, southeastern

### Lake Michigan,.

# ....... A-32
1979 at the Cook Plant, southeastern Lake Michigan...................A-33 field sampling at the Cook Plant, southeastern Lake Michigan..... 

# .... A-34


### viii35. Length-frequency histograms 

### of spottail shiners impinged during 1980 atthe Cook 

### Plant, southeastern Lake Michigan.... 

# ............... A-35 36. Length-frequency histograms of spottail shiners caught during 1980 field sampling atthe Cook Plant, southeastern Lake Michig

### an......... A-36 37. Length-frequency histograms of 

### spottail shiners impinged during 38. Iength-frquency histograms of spottail shinerscaGht during 1981 1981at the 

### Cook Plant, 

### southeastern Lake Michigan.... 

# ............... A-37 field smpling 

### at 

### theCook Plant, 

### southeastern Lake Michigan.........A-38 39. Length-frequency histograns 

### of spottail shiners impinged during 1982 

### at

### the Cook Plant, southeastern Lake Michigan...................A-39 40. Length-frequency histograms of 

### spottail shinerscaught during 1982 field sampling at

### theCook 

### Plant, southeastern Lake Michigan.........A-40 41. Length-frequency histograms 

### of trout-perch impinged during 1975
42. Length-frequency histograms 

### of trout-perch caught during 1975 field at 

### the Cook Plant, 

### SoutheasternLake Michigan.................. ......A-41 sampling 

### at the Cook Plant, southeastern Lake 

### Michigan...............A-42 43. Length-frequency histograms of 

### trout-perch impinged during 1976 at 

### the Cook Plant,

I

### southeastern Lake Michigan..

# .

# . .. .

# .... 

# ..

# . .. ..

# .. 

# .. . .A-43 44. Length-frequency histograms of trout-perch caught during 1976 field
45. Length-frequency histograms of trout-perch impinged during 1977 samplirrg at 

### theCook Plant, 

### southeastern Lake 

### Michigan...............A-44
at theCook Plant, southeastern Lake Michigan.

# . .

# .. ... ...

# ...... . ..

# .. .A-45 46. Length-frequency histograms 

### of trout-perch caught during 1977 field
47. Length-frequency histograms of trout-perch impinged during 1978 smpling at 

### the Cook Plant, southeastern Lake Michigan.... 

# ...........A-46
at 

### the Cook Plant, 

### southeastern Lake Michigan.

# .. ..

# . 

# . .. .

# . ... .

# .... . . .. .A-47 48. Length-frequency histograms of trout-perch caught during 1978 field sampling 

### atthe Cook Plant, southeastern Lake Michigan.... 

# ...........A-48 49. Length-frequency histograms of trout-perch impinged during 1979 at 

### the Cook Plant, southeastern Lake Michigan.............. 

# .......... A-49 50. Leng~-frequency histograms of trout-perch caught during 1979 field sampling atthe Cook Plant, southeastern Lake Michigan......... 

# ......A-SO 51. Length-frequency histograms of trout-perch impinge3during 1980 at the Cook Plant, southeastern Lake Michigan..

# . .. . .. 

# .. .

# ... . . .

# ..

# ..

# ...A-51 52. Length-frequency histograms of trout-perch caught during 1980 field sampling at 

### the Cook Plant, southeastern Lake Michigan.. 

# ..

# ......

# .....A-52


### ix53. 

### mgth-frequencyhistograms of trout-perch impingedduring 1981 

### at the 

### Cook Plant, southeastern LakeMichigan............ ............A-53 

### 54. kngth-frequency 

### histograms 

### of trout-perch caught during 1981 

### field sampling at the 

### Cook Plant, southeasternLake Michigan.

# .

# . . . . . 

# ..... . . .A-54 55. 

### Length-frequency histograms of trout-perch impinged during 1982 

# . at the 

### Cook Plant, southeasternLakeMichigan.. 

# . . .. . . . . .. 

# ... . 

# ... . .. . .A45 56. 

### Length-frequency histograms of trout-perch caught during 1982 

### field -ling at the Cook Plant, SoutheasternLake Michigan...............A-56 57. 

### Length-frequency histograms of yellowperch impingedduring 1975 

### at the 

### Cook 

### Plant, southeastern

### LakeMichigan........................A-57 58. 

### Length-frequency histograms of yellowperch caqhtduring 1975 

### field -ling at 

### theCook Plant, southeasternLakeMichigan...............A-58 59. Length-frequency 

### histograms of yellow perch 

### impinged during 1976 

### at the 

### Cook Plant, soutkastemLakeMi~igan........................A-59 60. 

### Length-frequency histograms of yellowperch caughtduring 1976 

### field sampling at the Cook Plant, southeastern LakeMichigan...,...........A-60 61. 

### Length-frequency

### histograms of yellowperch impingedduring 1977 

### at the 

### Cook Plant, southeaste-m Lake Michigan.,......................A-61 62. 

### Length-frequencyhistogramsof yellowperch caughtduring 1977 

### field sanpling at the

### Cook Plant, southeastern LakeMichigan...............A-62 63. 

### Length-frequencyhistqramsof yellowperch impinged during 1978
64. 

### Length-frequencyhistograms of yellowperch caughtduring 1978 

### field at the 

### Cook Plant, southeasternLakeMichigan........................A-63 

### sanplingat theCook Plant, southeasternLake Michigan...............A-64 65. 

### Length-frequency histogramsof yellowperch irnpiwd during 1979
66. 

### Length-frequencyhistograms of yellowperch caughtduring 1979 

### field at the 

### Cook Plant, southeastern LakeMichigan.....,..................A-65 

### sampling at the

### Cook Plant, southeasternLakeMichigan...............A-66 67. Length-frequency 

### histograms of yellowperch impingd during 1980 

### at the

### Cook Plant, southeasternLake ~chigan........................A-67 68. 

### Length-frequencyhistograms of yellowperch caught during 1980 

### field
69. 

### Length-frequencyhistograms of 

### yellowperch impingedduring 1981 

### sanpling at the 

### Cook Plant, southeasternLake Michigan...............A-68


### at the 

### Cook Plant, southeasternLake 

### Michigan........................ A-69 70. 

### Lewth-frequencyhistograms of yellowperch caught during 1981

### field sampling at the

### Cook Plant, southeastern Lake Michigan............... A-70

X71. kngth-frequency histograms of yellow perch impinge3 during 1982 at 

### the Cook Plant, southeastern 

### Lake Michigan................., 

# ...... A-71 72. kngtbfrequencyhistograms of yellow perch caught during 1982 field sanplirq at 

### the Cook Plant, 

### southeasternLake Michigan.......... 

# ..... A-72 73. Length-frequency histograms of rainbow 

### melt impinged during 1975 

### at the Cook Plant, southeastern Lake Michigan.

# ...................... .A-73 74. Lmgth-frequency histograms of rainbow melt caught during 1975 field sampling at the Cook Plant, 

### southeastern Lake Michigan.... 

# ..... A-74 75. mth-frequency histograms of rainbow 

### melt impinged during 1976 at 

### the Cook Plant, southeastern Lake Michigan.. 

# ..................... .A-75 

## . 76. Length-frequency histograms of rainbow 

### melt caught during 1976 field sampling at 

### theCook Plant, southeastern Lake Michigan.........A-76 77. Length-frequency histograms of rainbow 

### melt impinged during 1977 atthe Cook Plant, southeastern Lake Michig

### an........................ A-77 78. Length-frequency histograms of rainbow melt caught during 1977 field sanpling at 

### theCook Plant, southeastern Lake Michig

### an......... A-78 79. Length-frequency histograms of rainbow 

### melt impinged during 1978 at 

### the Cook Plant, Southeastern Lake 

### Michigan............~..... 

# ...... A-79 80. Length-frequency histograms of rainbow 

### melt caught during 1978 field sampling at 

### the Cook Plant, 

### southeastern Lake Michigan.

# ........ A-80 81. Length-frequency histograms of rainbow 

### melt impingd during 1979 at 

### theCook Plant, 

### southeasternLake Michigan.................. 

# ......~- 81 82. Length-frequency histograms of rainbow 

### melt caught during 1979 field sampling at 

### the Cook Plant, southeastern Lake Michigan,.... 

# .... A-82 83. Length-frequency histograms of 

### rainbow 

### melt impinge3 during 1980 at 

### the Cook Plant, 

### southeastern Lake Michigan........ 

# ................ A-83 84. Length-frequency histograms of rainbow 

### melt caught during 1980 field sampling at the Cook Plant, southeastern Lake Michigan.

# ........ A-84 85. Length-frequency histograms of rainbow 

### melt impinged during 1981 at 

### the Cook Plant, southeastern Lake Michigan....... 

# ................. A-85 86. Length-frequency histograms of rainbow melt caught during 1981 field sanpling at the Cook Plant, southeastern Lake Michigan......... A-86 87. Length-frequency histograms of rainbow smelt impinged during 1982
88. Length-frequency histograms of rainbow melt caught during 1982 at the Cook Plant, southeastern Lake Michigan

# ........................ A-87 field samplillg at the Cook Plant, southeastern Lake Michigan

# ......... A-88


### xi

### INTRODUCTION The Donald C. Cook 

### Nuclear Power Plant 

### 1s a 2,200 My utilityon the southeastern shore of Lake Michigan 

### near Bridgman, Michigan. Unit 1(1,100 MU), which began operation in 1975, 

### requires 2.7 x 10 

### liters/- cooling 6 6 water, while Unit 2, also 1,100 Mu, 

### uses 3.6 x 10 liters/min. Though Unit 2 began operation 

### in 1978, sustained pumping for 

### a month or longer at full capacity did not occur until 1979. 

### cribs located 686

### m offshore fn 7.3 

### m of 

### water, and heated 

### water (witha calculated

### maximum AT of 12.1°C) 

### isdischarged through two slot-jet discharge 

### structures located 366 

### m offshore in 5.5 

### m of watet. With

### two 

### units operating, water velocity 

### at the intake crib

### is 0.4 

### m/s. mximm water velocity 

### is 1.8 

### m/s within the intakepipe. To prevat erosion and scour, a riprap bed (approximately 6 ha) of crushed limestone 0.1-1.0 

### m indiameter was deposited around the intake and discharge 

### structures during plant construction. Cooling 

### water enters through three intake

Within the screenhouse, trash 

### bars 6.6 

### an apart prevent large debris from entering the forebay. Within the forebay, vertical traveling 

### screens impinge trash 

### and fishtoo largeto

### pass through the 9.5-pilm-bar mesh screens. organisms (mostly fish 

### larvaeand eggs, and zooplankton) are entrained with the cooling water and 

### pass through the condensers. "impingement" 

### and "entrainment," "entrapment" in

### this report refers tofish entering the forebay through the intakes. entrapment because of thepossibility that not all fishwhich enter the forebay are eventually impinged. To summarize, entrainment 

### refers tothose organisms present in the cooling water that pass through the traveling screens Smaller


### In addition tothe 

### terms Impingement is distinguished from

1and condensers, 

### and are discharged back into the lake. Allfishwhich enter the forebay and cannot 

### pass through the traveling screens are 

### considered tobe entrapped. 

### is considered impinged when it 

### is caught 

### on the intakevertical traveling 

### screensand 

### sluiced intoplant 

### trash baskets. Some entrapped fishmay make 

### their way back to

### the lake. A fish



### This report 

### containsannual 

### estimates and species composition 

### of fish impinged 

### at the 0. C. Cook Plant 

### and c-es thrm with

### similardata for field-caught fish

### for 1980-1982. 

### Also 

### discussed are 

### smasonal and yearly 

### trends infish

### abundanceand anviromental 

### and plant opuation

### effects 

### on rates of fish impingement. 

### discusses similar

### results from 1975-1979. A previous report 

### (!Churber 

### and Jude 1984)

METHODS
Fish 

### and debris 

### from the traveling screms were 

### reparatd by Cook Plant personnel. Allfish

### were bagged, labeled with date 

### and time, 

### and than frozen. University 

### of Michigan 

### personnel collected

### and weighad allfrozen fish; 

### a 24-h sample was savad 

### every fourth day anb 

### sorted by 

### species and 

### size. When many fish

### of the samsizewere collected in fourth-day samples, 

### a subsample composed 

### of up to 30 fish

### war randomly 

### selected and romafning 

### fishwere weighed 

### and discarded. Allsavad fishwere 

### measured to the nearest millimeter (total length), weighed tothe nearest gram, 

### and sexed; stomachs 

### were examined for presence 

### of food. damgo were alsorecordd. 

### Condition of gonads, presence 

### of disaasa, or physical Fourth-day samples 

### (number and weight 

### of fish) 

### and weight of all fish impinged 

### on interim days were used to estimate totalmonthly Fmpingament
2losses by species. samples 

### was used topartition the actual monthly weight of fishimpinged into weight 

### estimates by species, according tothe formula: Percent species composition (byweight) of fourth-day

where: 

### = Estimatedmonthly weight 

### of fishimpinged for a given species; EW

e Monthly weight of Fourth-day impingement samples for a given sW

pW

TW species;


### = Monthly weight of fourth-day impingement samples, all fish combined; 

### and 

# - Total monthly weight of all fish impinged (includesfourth-day and interim days).

* Number of fish impingedper mOnth 

### was then estimated using

where: En 

### = Estimated totalnumber of fishimpinged each month for a given species; and
=Mean weight per fishof a given species, calculated for each species from number and weight of fishof each species impinged infourth-bay samples for a given month. Offshore 

### standard-series field samples were collected by gillnet and bottom trawl from four stations: 6-m and 9-m stations 

### atWarren Dunes State Park, about 11km south of the Cook 6-m and 9-m stations 

### at theCook Plant and

3Plant. Fish were seined from the beach zone at two stations near the Cook Plant (onenorth 

### and one south 

### of theplant), 

### and at one station at Warren Dunes State Park. Gill nets 160 x 1.8 

### m were set at offshore stations once per month for approxhately 12h during daylight 

### and 12 h during the night. adjusted 

### to catch par 12 h to standardizedata (Judeet al. 1979). composed 

### of 12 

### panels 

### of netting 

### as follows: followingmesh sizes 

### (barmeasure)

# - 1.3 

### cm, 1.9 

### cm, and 2.5 

### cm; 15.2-m sections 

### of mesh sizes 3.2-7.6 

### cm by 0.6-cm intenmls; and a finallS.2-m section

### of 10-cm mesh. bottom. Catch was Nets were 7.6-m sections 

### of each of the

All gill nets were set parallel to shore 

### on the
Duplicate, 1O-min bottan tows were taken monthly both day and night at offshore stations, using a semi-balloon, nylon trawl having a 4.9-m haadrope and a 5.8-m tootrope. The 

### body and cod endweecanposed respectively

### of 1.9- 

### cm and 1.6-cm 

### bar mesh, while tha cod 

### and intulinu was 0.7-cm bar mesh. All trawl hauls were made at 

### an average speed of 5 km/h, i.e., at a fixed rppl using the University

### of Michigan's R/V MYSIS. The trawl was towed parallel to shore following the 6- or 9-mdepth contours; one haul was taken north to south 

### and the other 

### south 

### to north at 

### each depth contour. Beach seining was usually conducted during periods 

### of reduced wave height using a nylon seine 38 x 1.8 

### m witha 1.8 x 1.8- bag; the entire seine had 0.64-cm bar 

### mesh. The 

### seinewas first stretchd perpMdfcular to the shoreline

### and then pulled parallel to shore 

### a distance 

### of 61

### m. Duplicate, non-overlapping samples were taken in this mannet both day and night once each month at beach stations. The seine was pulled against the current or

4southerlywhen 

### no current was detectable. the 

### seine against the

### current, seining

### was done with the 

### current. When it was 

### too difficult 

### topull
Field-caught fishwere 

### processed inthe same

### manner as impinged fish. For 

### a more detaileddiscussion

### of field-sampling methods, 

### see Jude et 

### al. (19791, Tesar et 

### al. (19851, and Tesar and Jude (1985). Common and scientific names 

### of fishdiscussed 

### inthis paper are presented

### inTable 1.

RESULTS AND DISCUSSION SPECIES COMPOSITION The number of fishimpinged annually

### at theCook Plant during 1975-1982 ranged 

### from 53,190 (1,833.34 kg) fish

### in 1977

### to2,307,654 (71,208.81 kg) fish 

### in 1980 (Tables 2-17). Percent 

### contributions that each species made 

### to each year's total catch were averaged for 1975-1982; the fishmOst often impinged was thealewife (68%of 

### total catch). Following

### inorder of abundancewere spottail shiner (1021, yellow perch (9%),trout-perch (5%),

### rainbow smelt (4%), 

### and slimy sculpin (2%). Though averaging 

### less than 1% over all years, bloaters 

### increased innlmrber during the study period and ranged from 0.02 to 4%of eachyear's 

### total. None of the other 

### less c~lpmon

### species ever 

### constituted

### more than 0.9%

### of the

### total number of fishimpinged 

### inany 1year during 1975-1982 (Tables 2-17). 

### inhighest 

### numbers, rank order of the other species varied from year 

### toyear. During 1975-1982, 61 species

### weze impinged (Tables 2-17). Nineteen species
wereimpinged every year for all 8 years 

### of the study, while 22 species were impinged during 4 years 

### or less and were considered

### rare. Except for alewife, whichwas always impinged

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## -"
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### 2 cpl cywrpm -mm- 

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1: 

### 2 CI Ql 1Z+U7mNNN+QwO

111 

### .... ~O?(qO-OOO' 000000~00 0 00005 ~00060~ D 01 mmomLnwo-- womw m

1 cymmmmm--+

### In genecal, species compositionof impinged fishreflected fish abundance 

### in the 

### nearshorearea 

## (<lo-m depth) tempered by the unique vulnerability of certain species to 

### the impingementprocess. Differences inspecies composition among years could usually be attributed to fluctuations inyear-
. class strengthamong themost abundant species, 

### or seasonal differences in periods 

### of maximum

### or minimum pumping levels. Because both 

### units were operatingduring 1978-1982, theseyears should be considered separately

### from 1975 

### to 1977 when only one 

### unit was operating. An overviewof the

### data (Fig. 1) shows that during one-unit operation, 1975-1977, impingemurt of alewives was 

### around 100,000 fish (Tables 2, 4, 61, 

### and volume of coolingwatar 

### pumped through the plant was also consistent, around 1.2 x 10 m /yr (Table 18). During these years, alewife populations 

### in the lake fluctuatedaccording to 

### our indexdata, frm

### about 42,000 fish in standard series catches in1975, to 137,000 in1976, and back to 56,000 in 1977 (Tables 19-28). Thus, it appear& that although alewife populations varied 

### a great deal inLake Michigan, these variationsdid not increase impingement substantiallyduring 1976 when alewife abundance was highest of the 3years in Lake Michigan. 93

All variables changed in the next 5years of operation (1978-1982) as 93 Unit 2doubled 

### plant prcpaping rates 

### from around 1.2 x 10 

### m /yr to 2.3- 2.8 x 10 

### m /yr (Table18). Alewife populations inthe lake exhibited 

### a catastrophic dacline starting in 1980 (Tables 21-28), while iarphgement rates increaseddramatically in the 1980s (Tables 2-17). causal mechanisms isdifficult because of the many Varying factors. 

### For example, even though total volume 

### of cooling water increased'twofold

### from 1977 

### to 1978, impingement lossesdid 

### not riseproportionally. 93
Sorting out possible

This seeming

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36anomaly can be partially explained by lowpumping rates during April and by 1978, which is the usual time of 

### maximum impingement of alewife. These low pumping rates in the spring thus led to substantially reduced total impingement losses in 1978when compared to other years 

### of two-unit operation when spring pumping rates were "average" during this period. A second example of the difficulty in explaining changes is related tophysical conditions in the lake (water temperature, storms, currents) interactingwith thediffering behaviors of age-groups of alewives (Appendixeslo, 12, 14, 16, 18, 20, 22, 24). decline 

### in populations of alewife in Lake Michigan (Judeand Tesar 1985). However, a different group 

### of fish 

### in a different month in each of the 3 years The peak years 

### of impingement, 1980-1982, occurred 

### in spite of a general 

## ---_ --------- - 

### -

c__ 

# -------- ____L-- IIs_lll.__l.ll-

was responsible for a substantial proportion 

### of total numbers 

### and biomass 

### of fish impinged 

### in each of the 3years. In 1980, largenumbers 

### of adults--w-s-e.-2 L& *--" I--.--LII---^-- 1_(---___.._-- "~- i# A bw impinged inApril-May (Appendix 191, in1981, yearlings impinged during May- _____________I_-------- June (Appendix 21) was thedauinant group intotal 

### losses, while for 1982, 

### -
yearlings and adults impinged in June (Appendix23) comprised thehighest fraction of losses. t Therefore, it appeared that physical factorswhich resulted in -...---...-- Il..-----_II_I---^----- ,. concentrating certain age-groups of alewives or making themmore susceptible to impinganent because 

### of high pumping rates during these periods 

### of susceptibilitycould explain much of the variability inimpingement rates observed. Alewives illustrateat least two 

### of these conditions. As nearshore water warms during spring, fish follow the warm-water 

### mass and concentrate 

### near shore (Wells 1968, Jude et al. 1979, Tesar and Jude 1985). *Ir __-I-- __-------_ 

# -. - 1 I_ 

### ----- ___I

-__1_ I-?.)

I ------_lll.

- - ___ L.- --- - -- -

~ -- 

### If theplant

-+- _- 

# - -_I-_ 

# %i i operates at or near
__l.__II_xIIII ___^_ capacity
__ 

### and without substantial -.- interruption _l_l__.__._ during April -

# - and May, largenumbers of fish of many species are impinged, but alewives
-=----__.-,----,____I"___ . ,..- . .. ...- .... ..... ..,-.. -- --- - 37dominate the 

### loss. This was the

### case 

### in 1975 

### (one-unit operational) and 1980 (both 

### units operational) (Tables 2, 12); during both years 

### alewives accounted fir 

### over 759 of 

### the 

### total impingement 

### loss (Fig. 2). 

### were similar during 1978

### and 1980 (2.4 x 10 

### vs. 2.8 x 10 

### m 1; 

### however, volume pumped during April-y 1978 was 

### low, while 

### in 1980 it was high (Table 18). alewife

### losses (0.2 million) 

### cwpardwith 1980 (1.8 million) 

### evm though pumping 

### volumes for theyear 

### were camparable and alewife

### populations in Lake Michigan 

### had declined 

### over that period. occurred among 

### species c~mp~n in 

### nearshore watu during 

### late

### sumnu through autumn, particularly 

### spottail 

### shiner, rainbow smelt, and trout-perch (Fig. 3). Despite thedeclining

### populations 

### of alewivos 

### in Lake Michigan during the

I____ 

### -_-_ I_IIIc -- - ____Ix_-_ I I - 1980s, 

### alewives continued 

### tobe impingd 

### in large

### quantities, and they 

### even-
__--I-- 

### ____- ”------- -- 

### --- -_I----- - 

### --- began 

### to

### comprise 

### a larger fraction of impingamsnt 

### lossesover this

### period (1980-1982) 

### compard withthe 

### earlier years, 3975-1979 (Fig. 4). Clupeids, in general, may be particularly vulnerable 

### toipppfnganent. throughout Lake Michigan, 

### alewives were the

### most 

### oft- impingd species (Benda 

### and Gulvas 1976, Sharma and 

### Freanan 19771, while gizzard shad 

### were 

### most often impingd 

### atplants in

### southunLake 

### Huron and Lake Erie (Be and Routcooper 1976, Eisele 

### and 

### Malaric 1977). Gizzard 

### shad and threadfin 

### shad were the

### most often impingd fish

### at powu

### plants 

### on 

### southemreservoirs and 

### estuaries (Freeman and Sharma 1977, 

### Loar et 

### al. 1977). Yearly pumping 

### volumes 9 93



### The reduced flow in spring 1978resulted 

### inconsiderably 

### lower total

High impingement 

### losses in 1978

1_________^_--- -”

_I_--- 

## __ Atwater intakes *--------- I_ I----

## __ L__ - ‘ t.^--.o---

By 1980, both 

### units were operating at fullcapacityfor axtended periods of 

### time. Volume 

### of cooling water pumped annually during 1980-1982 was notably higher than during any previous (Table 18). Beside 

### t??e decline 93 year and leveled off around 2.7 x 10 

### m /yr in alewife populations, there were 

### a few other

# 60- d 7 

### 3 

## m 

# a40- W 

# > 

# - J

# 20- W


# 1975

# n

1976

# n

1977 1978 

# n

1979 1980 1981 

## 1982

Figure 

### 2. impinged during spring (March, April, 

### May) 1975-1982 

### at the D. C. 

### cook Plant, southeastern 

### Lake Michigan. 

### months 

### of steadily rising water temperature. Species composition of the total number 

### of fish Spring was defined 

### as

39

# %loo60- 4 

# in’40- n



## i

# 20- 

# a W


# 1975 

# 1976 1977 1978 1979 1980 

# 1981 1982
Figure 3. Species composition 

### of the total number 

### of fish impinged during summer (July,August, September) 

### 1975-1982 at the D. 

### C. Cook 

### Plant, southeastern Lake Michigan. Summer was defined as months 

### of maximum average temperature.
40Lr, 

### LL 

## 0



# a40


# 20 W 

# a 

# H
n 

# n n n



# 3 1979 I980 1981 

# I 

# 1982

Figure 4. impinged each year during 

### 1975-1982 at the D. C. 

### Cook Plant, southeastern 

### Lake Michigan. Species composition 

### of the total number 

### of fish

41notable shifts

### in species composition of fishimpinged during these years that 

### were 

### more closelyrelated 

### tofishpopulation 

### changes inthe lake 

### than to changes 

### in cooling 

### water flows. 

### In 1980

### and 1981, therewas 

### more than

### a twofold 

### increase

### innumber of yellow perch wingad annually (Fig. 4), probably reflecting the increasing

### abundanceof yellow perch 

### as alewife, 

### a suspected 

### predator 

### of yellow perch 

### larvae, declined (Pig. 5, Tables 19-28; Jude 

### and Tesar 1985). Rainbow 

### malt populations 

### also increased during the -I___. _cI

---w -_b__- __I------ 

### -

- -

### - - early 1980s 

### in _l_l 

### response tothe ---.----- alewife decline, - 

### and 

### rainbow smelt 

### were 

### also

_.____L.- impinged in dramatically higher 

### numbers during 1980-1981than during 

### earlier years (Pig. 4, Table 

### 11, 

### as well

### as being abundant 

### in fieldcatches (Fig. 5, Tables 19-28). During 1975-1979 (one 

### unitoperation), 

### an average 

### of 160 salmonids was impingd annually. these years. An average of over 1,000 salmonids was impingedannually over 1980-1982 (Tables 12, 14, 16). 

### Most of these fishwere 

### juvenile chinook Lak8 

### trout was the

### most camonly impinged salmonid during



### salmon (875

# - probably nmlyplanted) in1980, 

### adultand juvenile lake 

### trout (517 fish) 

### in 1981, 

### and adult 

### coho salmon (530 fish) 

### in 1982. mingernurt 

### losses for most species declindduring 1982, mOst notably 

### for 

### rainbow smelt, trout-perch, 

### and bloaters. Lake-wid8 

### populatfon f

### luctwtfonsmay have b.m partially

### responsible (Judeand Tesar 1985)

## ,but much of thedecline innumber of fishimpinged canprobably be attributed

### to local 

### water 

### teqmratur8s, which wereunusually warm during July-September 1982 (Table 29). (Appendixes 1-8), the thermcline was relatively stable

### and intersected the 

### Because thu8was only 

### one notable upwelling during thistime



# . bottom faroffshore. Many species concentrate at or near the thermocline
-_____- 

### ---- , 

## -__-_____ -

42

### Table-29. Lake Michigan water temperatures (C)

### measured at the St. Joseph Municipal Water Plant; intake depth

# - 5.8 

### m. Data are monthly means 

### of the daily average 

### of maximum and minimum temperatures. Month Year Jan 

### Feb Mar Apr 

### May Jun Jul 

### Aug Sep Oct Nov Dec 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1973-

1982 0.5 1.2 

### 1.3 1.1 1.1 

### 1.7 1.3 3.0 0.9 1.2 1.3 0.6 1.1 

### 1.1 2.1 1.1 

### 1.4 

### 1.8 2.4 1.2 0.7 1.4 4.2 7.1 10.6 17.9 18.8 19.7 16.4 15.7 9.7 4.1 3.7 7.5 

### 11.3 14.9 17.2 16.5 16.2 13.3 9.2 3.0 2.1 5.4 10.9 16.2 19.5 15.5 17.3 14.5 10.9 4.1 5.4 9.6 

### 11.0 16.7 19.2 20.5 18.0 14.6 8.3 2.0 3.5 8.7 12.4 14.7 18.6 18.5 15.9 

### 12.1 8.5 2.5 1.5 5.6 10.2 13.7 14.1 17.9 18.4 14.0 10.1 

### 3.1 2.6 6.6 10.6 14.1 18.0 19.5 17.3 14.5 10.3 5.4 2.4 5.9 9.8 14.3 16.7 16.4 15.2 12.4 7.2 2.6 3.2 8.2 

### 9.8 15.4 14.8 19.2 18.2 12.0 8.5 3.6 

### 1.8 6.3 10.7 13.7 18.5 20.1 

### 18.5 14.4 8.9 5.8 3.0 7.1 10.7 15.1 17.6 18.4 17.2 13.8 9.2 3.6

43

# 360 n


# a40 W 

# > 120 W 

# a 

# d
n



# 1978 

# 1
I98

# I n 

# I
1982

Figs-e 

### 5. Species composition 

### of the total number 

### of fish collected in standard-series fishing each year during 1975-1982 at 

### the 

### D. C. Cook Plant, southeastern Lake-Michigan.-

44(Brandt 1980, Brandt et al. 19801, 

### and thus 

### were probably concentrated 

### at depths greater than the intake depth during the 

### late surmer months of 1982. 

### ___-___- -

-* II ^^ __^_ _-__I __I -- 

## - _I___

Over a period of several days 

### inMay 1980, more 

### than half of the alewives ‘appeared

### tohave been dead 

### before they

### wereimpinged. These fish

### are easily distinguished from fishthat were alive when impinged for three 

### reasons. They
are emaciated, the 

### scales and skin grayish and dull, and many are limp

### and compressed. 

### In contrast, newly impinged fish

### are often 

### alive when they enter the trash baskets, 

### and 

### most samples are placed 

### in freezers within 5-6 hr of being impinged, thus preserving their 

### color and 

### form. Alewives which were already dead appeared 

### inimpingement 

### samples immediately following unusually high impingement rates in April and May 1980. 

### Because there was 

### no corresponding 

### increase in thenumbet of dead 

### alewives washed up 

### on the beach 

### or collected 

### inour May field 

### sanples, the impinged 

### alewives probably died in the forebay from 

### starvationand 

### stress caused by wercrowdfng. During 1981

### and 1982, both dead fishand debris from all impingement samples processed in the lab

### were weighed 

### and recorded. There was 

### no recurrence of the high proportion of dead fishthat appeared 

### in 1980. Of the 

### total weight of impinged fish samples 

### inboth 1981and 1982, weight of dead fishwas about 12. samples 

### in 1981

### and 2%

### in 1982. Trash weight equaled 32 of the weight 

### of impinged fish

SEASONAL ABUNDANCE Number of fish impinged per month at the Cook Plant varied seasonally (Tables 2-17). impinged during winter. 

### Most fish were impinged during April through October; few were Each year was characterized by a month of peakimpingwent during June or July, 

### and often another (usually secondary)pa in spring (April, May) or fall (September-November). Though factorsinfluencing impingement overlapped over seasons 

### and yeats, the

### dynamics contributing toheavy impingement losses differed fran season.to 

### season. During spring, many fish

### are impinged 

### as they

### move shoreward seeking warm water. Warming of Lake Michigan 

### water during April 

### ischaracterized by 

### a 

### narrow band 

### of warmer, inshore 

### water, separateand 

### distinct 

### from colder, offshore

### water. Forrpation of apronounced 

### and 

### persistent thstmdl bar separating inshore 

### and offshore 

### water 

### masses (Huang 1969, Mortimer 1973), may ' 

### act as a 

### barrier, concentrating fishin

### a 

### narrow band of 

### warm, nutrient-rich 

### water close to.shore. A therm1bar 

### was present within 2 or 3 km of shore duringperiods 

### of high impingement 

### losses in April 1975and 1980. High fish impingemat ratesduring this 

### time may have 

### resulted from 

### increased activity 

### and movement of fish

### and higher densities 

### of fish 

### inshore. 

### In June 

### and July, impingement lossesmay 

### be quitehigh 

### as fish

### mova shoreward 

### to spawn. Among 

### the 

### more abundant species, alewife, spottail 

### shiner, yellow perch, and trout-perch 

### spawnduring 

### these months. Numbers 

### of fishimpinged during these months may also

### k strongly influenced by upwelling, whichincreases fishactivity

### and 

### causesmy fish

### tomove shoreward seeking preferred 

### warmer temperature (Wells 1968, Emery 1970, Jude et al. 1979). Rainbow smelt 

### and bloater, whichprefer cold water (Wells 1968, Jude 

### et al. 19791, may accompany cold, upwelled 

### water inshore. Exceptionally high inpinganent 

### losses during July 1978coincided withthree periods of strong upwelling (Appendfr 41, while

### incontrast during summer 1982 a low frequency of upwelling resulted in low impingement 

### losses. Autumn impingement losses may be attributableto increased movement of fish as water temperatures
46become isothermal 

### and fishme offshore toward deeper water. In addition, impingement of largenumbers of young-of-the-year (YOY) fish occurs as they attain a 

### size which

### canbe retained by traveling screens. Species composition of impingement losses alsochanged seasonally (Figs. 2, 3, 6, 7). This was particularly notable for alewives, which comprised over 801 

### of spring losses, nearly 601

### of summer losses, about 251of 

### falllosses, and about 8%of winterlosses. impingement losses was YOY and yearling yellow patch; trout-perch 

### were also
common in collections. Though winter impingement losses 

### were 

### low, spottail shiner, yellow perch, 

### and rainbow smelt 

### were allimpinged frequently; evidently these species remain nearshore or forage frequently nearshore during winter. The 

### largest component of 

### autumn

*g 

### The biology of indiiridual species is 

### an important factor determCrun seasonal patterns in impingement 

### rates. Thepreference 

### of alewives for warm water accounts 

### for their high density inshore. Peak impingement of alewives usually 

### occurred during June 

### or July, when alewives moved inshore to spawn. In late SUPPPBT or autumn there was 

### an increase 

### in impingement of YOY alewives, which by this 

### time were largeenough (250 

### m)tobe retained by traveling
screens (Appendices 9, 11, 13, 15, 17, 19, 21). Spottail shiner preference for shallowdepths and warm 

### water (Wells 1968, Jude et al. 1979) affected spottail shiner impingement rates. spottail shiners increased inMarch and April 

### as spottail shinersmoved shoreward seeking warmer, inshore water. impingement of spottail shiners during May and June was low (Tables 2-17); field data indicated spottail shiners were mostly inshore of the intake depth (9m) (Tesar et al. 1985, Tesar and Jude 1985). Impingement of Except for 1980and 1981,

Impinged spottail shiners
$7

# 5100 - LL LL 

## 0
n

# 80
U 

# 8 W 0 

### Q 

# z 3 

# 560
m 

# a40 W 

# > 

# - G a20 

# B
n



# 1975 1976 

# m n

1977 1978 1979 1980 1981 n



# I982

Figure 

### 6. Species composition of the total number 

### of fish impinged during fall (October, November) 1975-1982 at the 

### D. C. Cook Plant, southeastern Lake Michigan. Fall was defined as months of steadily falling water temperature.

# ..

w 

# a 

# $! 60 n m 

# a40 7 

### 3
W 

# > I- 

# - a J

# 20 W N LL 

# 1975 1976 1977 1978 1979 1980 1981 

# 1982

Figure 

### 7. impinged during winter (December, January, February) 

### 1975-1982 at the 

### D. C. Cook Plant, southeastern Lake Michigan. was defined as months 

### of minimum average water temperature. Species composition 

### of the total number of fish Winter

49were generally >SO 

### mu (Appendices 25, 27, 29, 31, 33, 35, 37, 39). The minimum 

### siteretained by thetraveling screens was generally 50

### mm. 

### 'Incontrast, field-caught 

### spottail shiners included 

### a large component 

### of YOy fish which 

### were recruited toour seining gear (Appendices 26, 28, 30, 32, 34, 36, 38, 40). Peak spawningfor spottail shiners occurs inJuly (Jude 

### et al. 19791, when they 

### alsobegin their post-spawning migration offshore, Large 

### late 

### summer impingement 

### losses of spottail 

### shinersduring 1978-1980 

### were probably 

### due toincreased activity 

### and offshoremovement during 

### these months. Impingement of 

### adult spottail shiners during October was presumed tobe related totheir offshoremigration which 

### takes them past the influence 

### of the intakes. A 

### similar event 

### occurred in 1975-1977 for YOY 

### spottail 

### shiners which by this time 

### were largeenough tobe retained 

### on the traveling screens (Appendices25, 27, 291, A few spottailsremained 

### inshore allwinter. Winter impingement 

### rates seemed to

### be directly

### related 

### towater temperature, since 

### rates increased when water 

### tauperatureinthe

### area 

### rose to3.C 

### or above, but there 

### were exceptions. spottail 

### shiners was probably afmctedby attraction tothe 

### warm-water plume, winter storms, 

### and ice cover. Beside water temperature, winter impingementof

Impingement

### of trout-perch began toincrease 

### in April, becomfng high in June 

### and July. continues throughout I-. highly variable, but it appear@ tocoincide with upwelling 

### or storms. 

### In June, trout-puch 

### move inshore for spawning, which Impingemaat of trout-perch during 

### summer was Impinged fish 

### wwe generally 80-150 

### am in length. Over 50,000 trout-perch
wereimpinged during July 1978, which was the highest impingement loss of trout-perch for a month insupp~per(Appendices 41-56). During 

### most years, impingement losses tapered off during late 

### summer and rose again 

### in September
50Or October 

### as offshore trout-perch migrations placed fish

### inthe 

### influence of the intakes. A few trout-perch were impinged during winter. nopingernant 

### of yellow perch increased slightly

### inMarch 

### and April, 

### as inshore water temperatures warmed in spring. occurred during 

### June through September, except for 1975. after the spawning 

### season (lateMay-early 

### June) for yellow perch, their midto-late su1p1p8t abundance evidently reflected post-spawning migrations 

### into the vicinity of the

### intake area after spawning 

### in other 

### areas of the lake (Jude et 

### al. 1979, 

### Dorr 1982). There 

### is 

### some evidence that impingement of yellow perch during slt"mrr increased sharply after 

### storms (Lifton 

### and Storr 1977; personal observations). Septembar and continued 

### tok impinged during falland winter, showing that at least sane fishremained 

### inshore through 

### most of the

### winter (Appendices 57- 72). Peak impingement of yellow perch Because this

### was

Young-of-theyear yellow per& were firstimpingad in

Impingement of 

### rainbow melt usually peaked during spring, 

### most often during April and Uay. 

### area as they migrate 

### inshore to spawn (Jude et 

### al. 1979). rkinbow 

### smelt prefer cold water 

### (Wells 1968, Jude 

### et al. 19791, they

### move offshore during

### months of warm-water temperatures

# . Impingement of rainbow smelt during the slll~mer usually occurred when cold, upwelled water 

### allowed rainbow smelt 

### tomove shoreward. rainbow smelt were impinged during smer. were impinged in Septembuand October (Appendices 73-88). During these months, rainbow 

### smeltmove past the intake Because adult

During 1978 through 1981large numbars of Young-of-theyear rainbow smelt

Fish impingement during 1980 through 1982 was distinguished by extremely large

### numbers exceptionally of fish impinged during April-June, beginning with the high losses which occurred during April 1980. 

### Losses were highfor most spades during 

### thesemonths, particularly 

### for almives. my yellow 

### perch were impinged during 

### June of these years, although 

### not in previous years. Winterimpingemant losses were exceptionally high during 

### January

### and ~ecemb.t 1981. 

### The 

### species impingd 

### at this 

### time wue 

### species 

### most likelyto be found 

### inshore during

### winter; ..go, spottail shinu, yellow 

### parch, 

### troutperch (Decunber only), 

### and 

### rainbow smelt.
IMPINGEDFISH COMPAREDWITH FIELD-CAUGFTFISH In 

### general, species that 

### were 

### most abundant in fmpingamnt collections (Tables 2-17) ware 

### alsomost abundant 

### in field 

### catches (Tables 19-28). Spottail 

### shiners camprisai

### a highupercentage 

### of fieldcatchos (231of all fish caught 

### in 

### standard series fishing 1975-1982, 

### Tesar and Jude 1985) 

### than of impingemant 

### losses (10%of total). Though spottail shiners wue locally abundant, khey apparently ware 

### not attractd totho intake 

### structureand may evan have avoidd the 

### area; they 

### were most abundant inshore 

### of the intakes (Tesar and 

### Jude 1985). Sculpins wereimpfnged 

### in muchhigher numbers 

### than would be predicted frao field catches. 

### (Dorrand Miller 1974, 

### Dorr and Jude 1980) 

### observed that sculpinswere found 

### inmuch highudensities in the ripraparound 

### intake structures 

### than 011 adjacent 

### sand; their 

### propensity 

### for hiding 

### in dark places and their nocturnal Benda and 

### Gulvas (1976)and our divers

activitypattunsprobably 

### increased their susceptibilitytoentrapment. The relationshipamong fish impingement losses, field abundance, 

### and volume 

### of 

### water 

### circuhtdthrough the plant varied with species. An 

### analysis
was conducted usingmultiple correlation to determine if significant relationships existed anmg these threa variables: fishimpingeamit losses,

52fieldabundance of fish, and volume of water circulated through theplant. 

## me total weight of alewives impinged over 5-day periods, corresponding with the 

### same 5-day periods in which our eight field sampling tripsper year were performed during 1975-1982, was used for the first variable. alewives gillnetted at stationsinthevicinity of the intakes was the second variable, and volume of cooling water circulatedduring those periods 

### was used
as the thirdvariable. three variables for 

### alewives. impingement 

### rates and the latter 

### two variables was alsopositive, but 

### less strongly so, possiblybecauseyellow perch may be less randomly distributed throughout the area (G. 

### Godun, unpublished manuscript, Great Lakes Research Division, University of Michigan, Ann Arbor, Mi&.). abundance 

### was a better predictor 

### of impingement 

### loss than volume of cooling water pumped. The number 

### of

There was a Strongpositivecorrelation among these The relationship between yellow perch

For both species, field

A second analysis was doneby pooling data within a year, providing eight data points. predicted impingement (C. Madanjian, unpublished manuscript, GreatLakes Research Division, University 

### of Michigan, Ann Arbor, Mich.). Annual field abundance of 

### alewives was negatively correlated with annual impingement loss. Part of the reason for thisfindinghas alreadybeen discussed, and involves the high impingement 

### rates during 1980-1982 during the time when alewife populations lakewi.de were declining dramatically. and not pooling data) of colnparing impingement losswithfieldabundance indicate that fishimpingement 

### at any given time 

### isprobably related tothe In this case, 

### volume of cooling

### water pumpedmore precisely

These two methods (pooling

momentary abundance necessarily reflect of fishinthe vicinity of the intakebut may not seasonal or yearly changes inthe inshore abundance of

53certain 

### species. impingment losses (Tables 2-17) were compared withfieldcatches (Tables 19- 28). Annual 

### bpingment losses among other abundant species more closely followed field abundancebut often shoud 1or 2years 

### when the two variables were not correlated. Annual ippPingernMt losses 

### of trout-perch during onrunit operation (1975-1977) (Tables 2-71 

### and rainbow 

### smlt during 

### two-unit operation (1978-1982) (Tables 8-17) 

### wue nagatively correlatd withannual field abundance of 

### these 

### two species 

### (Tables 21-28) The differencesmay 

### be partially 

### explained by limitations 

### of field 

### sampling, 

### because only samples during one 24-h puiodeach month, but this explanation alone 

### is inadequate. Young-of-theyear fish

### were often 

### more abundant in field 

### catches 

### than they 

### were in impingemant samples, 

### because they 

### ware most likely to

### be inshore of the 

### intakes and 

### because they 

### uuetoo small to

### be impinged. The years 1980 through 1982 held 

### some especially sharp contrasts, particularly for alewives, which daclindprmcipitously 

### in field abundance during this

### time (Tables19-28, Fig. 1; Jude and Tesu 1985) but which continued tobe impinged inextremely large

### numbus (Tables 12-17). other spedes, particularlyyellow perch, whichrespond& positively to the alewife docline, Md toa 

### lesser extent, 

### slw sculpin

### and 

### rainbow smelt, were more abundant during these yaars 

### thanpreviously 

### in both fiU 

### and impingemsnt samples. 

### Blortur wermrelatively abundant infield catches during 1980-1982, particularly 1981, perbaps resulting 

### from several intense 

### upwellings during June 

### and July, 1981 (Appendb7). high during this 

### time, 

### as it was in 1978-1979, but both fmpingaaent losses (Table 16) and field abundance (Table 28) declined 

### in 1982. Field abundance This was particularly 

### trueof alewives 

### when y-ly

gear type

Several

Impingement of 

### bloaters u8s meptioMlly -

54and population changes among all species is discussed 

### in detail 

### in Tesar et al. (1985), Tesar 

### and Jude (1985)

## ,and Jude and Tesar (1985) Disproportionatelyhigh entrapment rates may Occur when fishare attracted 

### to the riprap or the intake structures. temperature changes also 

### increasehorizontal or vertical movements of fish, which 

### can lead to decreasedfish avoidance of the intake structureand increased impingement 

### losses. which 

### are attracted to the riprapand apparentlyprefer that substrateover the flat, featureless 

### sand bottom which characterizes field sampling stations. Sculpins, in particular, as confirmed by project divers (Dorrand Jude 19801, reside 

### on the riprap almost exclusively. yellowperch around the intakes (Dorr and Jude 19801, 

### and yellowperch, sculpins, johnnydartef, spottaii shiner, and ninespine sticklebackmay use the riprap as spawning substrate (Dorr 1982). Weather or water

Sculpins 

### and yellowperch are examples of fish

Divers 

### also observedaggregations

### of

Trout-perch 

### and rainbow smelt, however, are mles of fishwhich are 

### Evenwhen present inshore, not normally attracted to the intakes

### or riprap. theymay not be impinged in largenumbers 

### unless weather or water temperature changes OCCUT. attracted to the intakes, increases when fish activity increases. spring warming of inshorewater, fall overturn, upwelling, 

### and storms 

### are all Entrapmeut 

### of all fish, even 

### thosewhich normally are Spawning,
conditions which increase fishmovement through the 

### area of the intakes. Upwelling 

### can force fish tome upward in thewater column (Emery 19701, which increases their 

### chances of entrapment. during storms, but may seek shelter in the lee of 

### an intake structure (Lifton and Storr 1977). reduce fish awareness and avoidance of the intake structure and current. Fish

### not only 

### aremore active
Turbidity and turbulence associated with stormsmay also6 Two-unit operation increased cooling 

### water flow rate Fran 2.7 x 10 iiters/min to 6.1 x lo6 liters/min 

### (USAEC 1977) 

### and, during certain

### times of theyear, increased fish impingement substantially over impingement during one-unit operation. In ma&ing comparisons 

### of imphaanent 

### rates, 1977 was 

### not considerd

### because 

### so few fishwere impingd canpard with theprecaiing 2 years. 

### Because 1977was 

### a year 

### of one-unit opuation, 

### its-1usion should # contributeto

### a 

### more conservative 

### estimate

### of the differences

### between one-unit and two-unit operation. Initial years 

### of two-unit 

### operati=, 1978

### and 1979, are compared separately 

### fran 1980-1982 

### because Unit2 pumping during 1978-1979 was 

### erratic, especiallyduring the spring, 

### a keyhigh puiod of impingamnt loss. 1980

# . The fulleffect 

### of sustain& 

### two-unit Mingwas 

### not obs.rved until

The largest percat increase in impingement losses for 

### spottail shiner, trout-perch, 

### and rainbow 

### smelt occurred in 1978-1979 (Table 30). 

### increase was probably 

### a 

### direct 

### result of the 

### plant pumping 

### schedule which 

### This


### increased pumping 

### rates dramatically when Unit 2 cam

### on linein 1978. Howevet, monthly pumping volumes were 

### erraticand seldom involved more than three pumps for any utddperiod 

### of time during spring and early SIJLPPML: 

### of these 2 years, which resultd in 

### lower impingment rates 

### for fish usually abundant during these 

### months. In contrast, volume 

### of 

### water pumpd during July-Decembrt, 1978-1979 Was high (Table 18) Md ItmpbgglUlt 10SS.S alWng 

### species which were abYndant during thesemonths 

### were substantial (Tables 8- 11). spring and early surmper months of 1980 through 1982 (Table 181, with Both units were opuatingat nearly fullcapacityduring 

### most of the

56

### Table 30; 

### change in volume 

### of water pumped and number of 

### fish impinged annually 

### at the 

### D. 

### C. Cook Plant. Comparisons are among years of one unit operation (1975-19761,years when two units operated sporadically (1978-19791, and years 

### of full two unit operation (1980-1982). The year 1977 was not included because volume pumped was exceptionally low and not considered characteristic 

### of full one unit operation. See text for full explanation. A 

### comparison between two periods 

### of the percent

Comparison 1975-1976 1978-1979 1975-1976 to 1978-1979 to 1980-1982 to 1980-1982 Volume 

### of wdter pumped 87 15 114 Major 

### fish sDecies Alewife 97 374 Spottail shiner 577 -35 Yellow perch 114 463 Trout-perch 303 -64 Rainbow smelt 1,226 112 832 342 1,103 12 2,721

57concomitant high impingement losses (Tables 12-17) among species (especially 

### alewife and yellow perch) which 

### are normally abundant during 

### these months. when theperiod 1975-1976 (consistent one-unit operation) was compared with theperiod 

### of consistent 

### two-unit operation (1980-1982), 

### a 1141 

### increase in volume of 

### water pwqed 

### was acconpiniedby increased impingomat losses among major 

### species ranging 

### frm 342% 

### to 2,7211 (Table 30). Trout-puch ware M exception; losses declincd during 1980-1982. 

### Tesar 1985, Teuu

### and Jude 1985) 

### show& trout-perch declined substantially in Field abundance

### data (Jude and

1982 

### compared to 

### earlier yeart, possibly due to increasdlpredation by the burgeoning yellow perch population. Data from 1980 

### to 1982 indicate that full

### two-unit operatian can 

### result in srtremely largonumbers 

### of fish impingd in 

### a 

### short period 

### of time. In 19808 ovu 1million fishwere *bgdl during a 3-wk pUid

### inApril and May. 

### Zion Station, a nuclear powerplant in Illinois 

### (LakeMichigan) experienced a 

### similar influx

### of alewives during May 1975 (Kitchel 1975). Heavy impingement losses may possibly affect 

### local abndance of 

### iupactd species, especially in cmrihinrtion withtotal impingemant 

### losses southern 

### basin 

### of Lake Michigan. within the 

### Jensen et 

### al. (1982) estimated that water withdrawal boughallintakes 

### an Lake Michiganreduced alewifebiomass by nearly 31, 

### basd 

### on 1975 

### data. Many fishimpingd 

### at the Cook Plant during peak periods in1978 through 1982 were YOY or yearlings whichhad not spawned (Appendices 15-23). detrimsntal

### bocause of their high production potential (R8go 1979). 

### Losses among this age-group might be particularly
Rag0 (19791, in calculating production forgone due 

### toentrainment and impingement

### of larval and adult fish, indicates that most production forgone 

### results from losses among 

### post-larvae tl.'rr%gh yearlings. Through 1981, over80% of alewifeproduction forgonewas attributable to entrainment 

### (P.J. Rago, unpublished 

### ms); however, impingement of YOY and yearlings contributed significantly- to 

### rainbow smelt losses and dominated yellowperch production forgone (Rag0 1979). If alewives continue todecline in abundance and 

### are replaced inshore by other species, impingement lossesmay became increasingly important to total production forgone. Jensen et al. (1982) felt that the biomass of fish impinged on Lake Michigan had more impact on stocks 

### of abundant species thandid entrainment of 

### larvae. by the high predation pressure on alewifeby salmonids (Stewart et al. 1981; unpublished

### data, Great Lakes 

### Research Division). rainbow smelt, were impinged during 1983 and 1984, and yellow perch were very abundant in gill nets set at Cook Plant stations for radiologicalmonitoring (E. Mallon, pusonal cammunication, 0. C. Cook Plant, Bridgman, Mich.). 

### His prediction is confounded

Few alewives, but many

MITIGATIVE MEASURES FOR IMPINGEMEHT There are several structuralor functionalmodifications 

### of the intake systemwhichmight reduce

### or eliminate impingement 

### and -evenentrainment 

### of fish. Engineering and economic constraints

### of most of these alternativesare discussed 

### at length by IMPC (1979). Bimber et al. (1984)discuss the effectiveness 

### of several alternatives inreducing entrainment. Perhaps the

### most favored system is fine-mesh, wedge-wire screens. Intakes 

### of this type currently installed at the J. H. Campbell Plant eliminated impingement and reduced entrainment for some species (Jude et al. 1982, Zeitoun et al. 1981). Smaller mesh sizes (mesh size

### of Campbell screens is 9.5 

### mm>might reduce entrainment further, but not substantially (Schneebergerand Jude 1981). Smaller mesh size, however, requiresmre

59frequent cleanbg 

### and reduces flow (IMPC 1977). The suitability of this technology 

### for a plant with cooling water requirements 

### as large

### as Cook's is 

### stillunproven. 

### Because 

### of the low flow velocities cbaracteristic

### of 

### this system, construction would require

### an intake field substantially larger 

### than currently

### exists at the Cook Plant, 

### resulting 

### in a significantly larger riprap


### area which

### would provide substantial spawning habitat. \ 

### This could 

### result in 

### an actual increase in 

### entrainumt of larvae 

### of certain 

### spmcies, 

### such 

### as yellow 

### perch 

### (Judeet

### al. 1982) 

### and possibly lake trout, which

### would be 

### attracted to the 

### area. A 

### barriu net which surrounds the intake 

### structure.andptWoritS fish entraporit was 

### used with apparent success 

### at Won Station, Lake Michigan (Kitchel 1975) 

### and 

### in Lake 

### Erie (J. 

### Gulvas, personal comunication, Consumeirs Power 

### corqwurY, 

### Jackson, MI). The 

### S-cm stretch-nnsh 

### net was installedduring April-Nwuubu 

### and appearad 

### tobe effactivo inreducing Fmpingeut8nt of 

### adult ,alewives. Nanticoke Plant inLake Ontariohelped 

### reduce inpingment lossesby 64-845 A fine-mesh

### knthic 

### a8t placad 

### around the intake

### at

### Ontario Hydro's
(Poster 1981). Tne 

### net was 

### not sizrseloctivebut was species-selective, deterring emerald 

### shiner, 

### rock bass, spottail shiner, trout-perch, white 

### bass, and yellow parch more affoctivoly 

### thanalewife 

### and samothu species. The 

### barrier 

### net was 

### not rocOmDIILdd, 

### howaver, 

### because it was vulnuable towave action and 

### ice scour, 8 drawbackwhich should 

### not be a problem if the 

### nets were 

### rapovd smasonally. 

### A 

### barriu net is 

### a possibility for the Cook Plant, but a 

### more 

### carotul stwiy 

### should be macia of the effectiveness and &tmance raquirenants of the netswhich have been tried in the Great Lakes. Otherpossibilities for alleviating impinganent losses include operational strategies which

### would requireno structural changes in the

60intake. The most effective approach would be to

### curtail volume of water pumped through theplant duringmonths 

### of maximum impingement. Over 801 of all fish

### were winged from April through July, though 

### most YOY 

### were impingrd 

# . from August through October. During 

### two-unit operation, 

### an average 542 

### of annual impingement losses have occurred in 1month, June, while the secondlargest losses 

### usually occurred inMay. through theplant duringMay-July should 

### result inimpingement of 

### less biomass, while curtailment during September

### and October should 

### result infewer YOY impinged. A lower volume of 

### water pumped could be achieved by scheduling refueling 

### and maintenance during these months. reducing power output by the plant would 

### result ina AT exceeding the ma~~imupp AT 

### of 22 OF+ 1*F

### for Unit 1

### or 17 OF + 1 OF

### for Unit 2 specified by 

### Nuclear Regulatory Commission enviromental technical specifications. plume effects 

### (IMPC 19771, as wellas those of others (Kelso

### and Minns 19751, indicate 

### no biological reason why a compromise'could 

### not be reached 

### toreduce fishimpingement losses at the plant. zooplankton, benthos) 

### would also have tobe taken into consideration. Curtailment of volume of water pumped

Reducing volumepumped without



### Our analyses of

Impact on other biota (phytoplankton, Reducingflow

### at night might alsoreduce impingement. Though we made no 

## x diel studies, there 

### is some evidence From other plants that more fishare
' impinged atnight (Benda

### and Houtcooper 19761, 

### and 

### more fish 

### larvae 

### are

entrained atnight at the Cook Plant (Bimbet et 

### al. 1984).

The D. C. Cook Nuclear Power Plant 

### isa two-unit, 2,200 mW utility located on the shores of southeastern Lake Michigan. The plant began Unit 1operation 

### in 1975, and Unit 2 came 

### on line 

### in 1978. Both 

### units together 

### require 6.3 x 

## lo6 literdmin for cooling 

### water which

### isdrawn fram 

### three intakes 

### located 

### in about 7 

### m of 

### water. firstwith 6.60- trash

### bars, then with 9.5- 

### bar mesh traveling 

### screens. Juvenile and adult fish

### too large 

### topass through the 

### screens are retained, removed witha jet 

### spray, and sluiced 

### into larger baskets. Plant personnel bagged and froze

### all fish, 

### and University of 

### Michigan personnel processed samples 

### of all fish

### in 1975

### and samples from every 

### fourth day in 1976-1982. These data were

### used 

### togenerate inpingemant 

### losses for all species 

### on a monthly and 

### annual basis. losses with 

### our concurrently collected field samples 

### and with the totalvolume 

### Water entering the

### plant is screened



### In addition, wecompud trends inimpingement

Of 

### -tu pumpd through the

### plant. Annual Imphgemmt 

### losses at theD. C. Cook Plant over 1975-1982 ranged froid 53,190 (1,833.34 kg) fish

### in 1977 

### to2,307,654 (71,208.81 kg) 

### in 1980.' Each yeat was characterizedby a

### month of peak impingemalt during

### June 

### or July 

### and often a 

### secondary peak in spring (April-May). comprised over 682 

### of the 

### total 

### loss, spottail 

### shiner 102, yellow perch 92, trout-perch 52, rainbow 

### smelt 42, 

### slimy 

### sculpin 22, while 55 

### less conwn species made up the

### ranaU.ng loss 

## (e%). Pooled 

### over years, alewife

During 

### consistemt 

### two-unit operation in 1980-1982, 

### an average 

### of over 1,000 

### salmonids was impingeper year. percentage of 

### losses varied each year from juvenile chinook salmon in 1980 

### to lake 

### trout in 1981, and 

### adult coho salmon 

### in 1982. The fishcomprising the highest

During May 1980, we recorded a largenumber of previously dead alewives in impingement 

### collections. We felt these fishentered the forebay during the

62high impingement events in lateApril and May and died inthe forebay from stress

### and overcrowding. 

# - The variability among years inimpingement losses was a function 

### of abundance of 

### various age-groups of fishin the lake and their behavior during major physical events (thermal bar, storms, strong current). A second important factor was pumping rate, 

### and whether maximumpumping rates occurred during certain key months when fishwere particularly susceptibleto impingement. 

### In addition, during the early 1980s, alewives 

### suffered a dramatic declinein Lake Michigan, with several 

### species (yellowperch, rainbow smelt, bloater) increasing in response tothe decline. However, alewives stillcomprised a high percentage 

### of the 

### losses in 1980-1982, whichis partially related tohigh prrmping rates in the spring and persistenceof the thermal bar. alewives now comprise a substantially 

### lower percentage of the catch. More recent data collected by power plant personnel suggest that

As yellow perch, rainbow 

### rmelt, and bloaters increased

### in abundance

### inLake Michigan, they alsowere impinged inhigher numbers. Biology and behavior were important determinants of the susceptibilityof 

## >c individual species toimpingement. spawning 

### and feeding, 

### and in

### response totemperature, brought different Seasonal and diel

### movements because of species atdifferent times into the influence 

### of the intakes. which decreased the avoidance capabilities 

### of fish, such asdarkness, storms, Any factors

or high currents, 

### caused increased impingement of species in the vicinity of the intakes. Alewives were particularly susceptible

### as they

### moved shoreward in spring and concentratedwithin thethermal bar seeking warmwater. Persistence of the bar led to impingement 

### of largenumbars 

### of alewives and other species each spring. The preference of spottail shiners for nearshore
63areasreduced their Fmpingement susceptibility, while other species, 

### such as sculpins 

### and johnny 

### darters, preferred the riprap 

### around the intakes and were impinged 

### in largenumbers 

### as a consequence. movement nearshore 

### of cold water species, 

### such as lake trout, bloaters, and rainbow 

### smelt. related toupwelling frrquurcy. Upwellings resulted in the

Their impingerpmt 

### losses during sumpdt appaared tobe directly

Unit2 

### became fully

### opuational in 1978, but consistentpumping 

### rates were not 

### maintained until 1980. 

### unit operation) was 

### compared with 1980-1982 (consistent 

### two-unit operation), a 114%increase 

### involume 

### of water pumped 

### was accompanied by 

### increased impingement losses among 

### major species ranging 

### from 342%to 2,7211. 

### unit opuation

### resultd in tho impingement of over 1million fishduring 

### a 3= wk period in April-Wy, 1980. When thoperiod 1975-1976 (consistent oneFull 

### two-

\ In general, species that were most abundant in field catches 

### wae

### also most abundant ininpingamant collections, withalowifo dauinant 

### in both. Spottail 

### shiners comprised 

### a higher proportion 

### of fieldcollections 

### than impingement losses 

### because they 

### werecancentrated inshore 

### of the intakes 

### and may have wenavoided them. Other species, 

### such as sculpins, comprised 

### a low percentage 

### of fidd

### catches, but wue 

### attractd 

### to thoriprap and impinged 

### in high 

### numbers. Production forgone estimates (Rag0 1979) showed that over 801 

### of the production 

### loss for alewife was attributabletoentrainmat. YOff 

### and yearlings contributed significantlyto

### rainbow zmcrlt losses 

### and dominatedyellow perch production forgone losses. Impingeanent 

### of

Reduction inimpingement losses could be obtained by installation

### of wedge-wire screens, but cost constraints, biofouling, and operational

6Lfeasibility in shallow water may preclude their use. troublesome, may 

### be another mitigative device useful in curtailingimpingement losses, particularly if 

### barrier 

### net 

### use targeted 

### known periods 

### of high impingement losses (e.g., 808 by number of allfish

### was usually impinged in April-July). 

### most of which would require 

### Nuclear Regulatory conmission approval. would include curtailment of volume of water pumped through theplant during high impingementperiods. Schedulingrnaintenance 

### and refueling during these months 

### would accomplish that. Decreased volume could alsobe attained by increasing the AT of the cooling water. documented higher impingement

### rates, would alsoresult in lowered impingement 10s

### sa. Barrier 

### nets, although

Another avenue of approach involves changes in plant operation, This

Reduced flow atnight, a period 

### of

Collection and processing of impinged fishwas a labor intensive effort and we thank the many people who carefullypried loose rotted alewives, debris, 

### dune grass, and 

### sticks, and who meticulously recorded 

### reams of data for thisreport. We appreciate the cooperation wereceived from 

### Jon Barnes in the early days and more recently Eric Mallon and Tom Kreisel of the Cook Plant staff. To all those Cook Plant personnel who exercised care inbagging impinged fishwe extend our thanks. We particularly thank Frank Tesar, John Dorr 111, Tim Miller, Paul ago, Greg Godun, Don Efnhouse, Dave Bimber, Rich Palacios, and Mike Enk for their substantial contributions tothe collection and processing of samples and for several computer programs which efficiently crunched 

### our massive datasets. Russ Moll is thanked for his thoughtful and

65

### vw helpful review. their many talents in text processing 

### and figurepreparation. We 

### thank Bey McClellan 

### and Steve Schneidetr for final report refinements and publication. Pam Mansfield, Xeang 

### Tin, and Mary Sweeney contributed

66

### LITERATURE CITED
Benda, 

### R. S., and J. A. Gulvas. 1976. Post-operational effects 

### of the Palisades nuclearpower plant. R. W. Mc Farlane, eds. Thermal Ecology Symposium, Instituteof Ecology, Univ. Georgia, Augusta, 

### Ga. Pages 243-250 

### &G. W. Esch and
Benda, 

### R. S., and W. C. Ifoutcooper. 1976. Impingement studiesat 16 electrogenerating plants inMichigan. Pages 291-315 

### & L. D. Jmsen, ed. Third National Workshop

### on Entrainment and Impingement. Inc., Melville, N.Y. EcologicalAnalysts, Bimber, 0. L., M. Perrone, Jr., L. S. Noguchi, 

### and D. J. Jude. 1984. Field distribution

### and entrainment 

### of fish larvaeand eggs at theDonald C. Cook Nuclest Power Plant, southeastern LakeMichigan. 105. Great Lakes Res. Div., Univ. Mich., Ann Arbor, Mich. 320pp. Spec. Rep. NO. Brandt, S. B. 1980. Spatial segregation

### of adult 

### and young-of-the-year alewivesacross a thumcline

### in LakeMichigan. Trans. Amer. Fish. Soc. 109:469-478. Brandt, S. B., J. J. Magnuson, and 

### L. B. Crowder. 1980. Thermal habitat partitioning by fishes in Lake Michigan. Can. J. Fish. Aquat. Sci. 37: 1557-1564. 

# . Dorr 111, J. A. 1982. Substrate and other environmental factors in reproduction

### of theyellow perch 

### (Perca 

### flavescens) Univ. Mich., AnnArbor, Mich. Ph.D. thesis, 276 pp. Dorr 111, J. A., 

### and D. J. Jude. 1980. SCUBA assessment of abundance, spawning, and behavior of fishes insoutheasternLakeMichigan near the Donald C. Cook Nuclear Plant, 1975-1978. Mfch. Acad. l2:345-364. Dorr 111, J.A., and 

### T. 3. Miller. 1974. Undemater operations in southeasternLake Michigan

### near the Donald C. Cook Nuclear Power Plant during 1973. Pages 465-475 

### &E. Seibel and J. C. Ayers, eds. The biological, chemical 

### and physical character 

### of Lake Michigan 

### in the vicinity 

### of theDonald C. Cook Nuclear Plant. Spec. Rep. No. 51, Great Lakes Res. Dfv., Univ. Mich., Ann Ubor, Mich. Eisele, P. J., 

### and J. F. Malaric. 1977. A conceptual model 

### of causal factors regarbfng gizzard shad 

### runs at steam electric power plants. 298

### & L. D. Jensen, ed. Impingemant. Ecological Analysts, Inc., Melville, N.Y. Pages 291- FourthNational Workshop

### on Entrainment and Emery, A. R. 1970. Fish and crayfish mortalitiesdue to an internal seiche in GeorgianBay, Lake Huron. J. Fish. Res. Board Can. 27:1165-1168.

67

### Fostar, J. R. 1981. The efficiency of 

### a benthic net and chain 

### curtain in diverting fish. Pages 261-271 

## in P. B Donand J. T. 

### Johnson, 

## as. Advanced intake technology for power

### plant cooling systems. U.S. Fish 

### and Wildlife Service, 

### Washington, D.C. Freeman 111, R. F., 

### and R.K. 

### Sharma. 1977. Survey of fishimpingement 

### at power

### plants in theUnited States: Volume II. National Lab. Publ. ANL/ES-56. Argonne, Ill. 328pp. theoretical 

### and 

### obsuvational modal 

### study. Spec. Rep. 

### No. 43, Great Lakes Res. 

### Div., Univ. nich., Ann Arbor, Mich. Inland waters. Argonne Huang, C. K. 1969. 

### The thermal 

### current structure in Lake Michigan

# - a
Indianaand Michigan Powu 

### Campany (IMPC)

# . 1977 Report

### on the 

### inpact of 

### coolingwater use 

### at the Donald C. 

### Cook 

### Nuclear Plant, Mi&. Wat. 

### Res. Corn. Ind. Mi&. Power 

### Co., Fort Wayne, 

### Id. 194pp. Submitted 

### to
I rdiaM

### and Michigan Power Company 

### (IMPC). 1979. Supplemantal 

### report demonstrating compliance with 

### section 316(b) 

### of the

### clean water act. Submitted 

### toMich. Wat. Res-. Corn, Ind. Mich. Power Co., 

### Fort Wayne, Ind. 129pp. 

### Jensen, A. L., 

### S. A. Spigarelli, and M. M. names. 1982. Use of 

### conventional fishery models 

### toassess 

### entrainment and impingement 

### of threm Lake Michigan fish species. 

### Trans. Amer. Fish. 

### Soc. 111:21-34. Jude, D. J., 

### and F. J. Tesar. 1985. Recent 

### changes inthe forage ffsh

### of Jude, D. J., F. J. Tesar, J. C. 

### Tamlinson, T. J. Miller, N. J. Thurber, G. G. 

### Godun, and J. A. 

### Dorr 111. 1979. Inshore Lake Michigan fish 

### populations 

### near the D.C. Cook 

### Nuclear Power Plant duringpreoperational years

# - 1973, 1974. Spec. Rep. 

### No. 71, Great Lakes Res. Div., Univ. Mich., Ann Arbor, Mich. 529 pp. Lake Michigan. Can. J. Fish. Aquat. Sci. 42:1154-1157. -

Jude, D. J., C. P. 

### Madanjian, 

### P. J. Schneeberger, H. T. Tin, P. J. Mansfield, T. L. Rut-, G. 

### E. Noguchi, and G. R. Eieufelder. 1982. Adult, juvenile and larval 

### fish

### populations in the vicinity 

### of the 

### J. H. Canpbell Powu Plant, 1981, with 

### special

### reference to the effectiveness

### of wdge-wire 

### screens indecreasing 

### entrainmant and impingemuit. Spac. Rep. No. 96. Great Lakes Res. Div., Univ. Mich., Ann 

### Arbor, Mi&. 519 

### pp. Kelso, J. R. M., and C. 

### A. Minns. 1975. Sumner 

### distribution of the 

### nearshore fish camunity 

### neaf a thermal generating 

### station as determined by 

### acoustic census. J. Fish. Res. Board 

### Can. 32:1409-1418. Kitchel, M. 1975. Screen monitoring study. Pages 237-260 Operational environmental monitoring 

### in Lake Michigan 

### near 

### Won Station, July 1974 through June 1975. Vol. IV. Annual Report 

### toComonwealth Edison Co., Nalco 

### Environmental Science, Northbrook, Ill.Lifton, W. S., and J. F. Storr. 1977. The effect of environmentalvariables on fish impingement. Pages 299-311 in L. D. Jensen, Ed., Proceedings of the Fourth National Workshop on Entrainment and Impingement. Ecological Analysts, Inc., Melville, N.Y. Loar, 3. M., J. S. Griffith, and K. D. Kumar. 1977. An analysis of factors influencing the impingement of threadfin shad at power plants in the southeastern United States. Pages 245-255 

### & L. D. 

### Jensen, ed. Fourth mtional workshop on Entrainment and Impingement. Ecological Analysts, Inc., Melville, N.Y. Mortimer, C. H. 1973. Lake hydrodynamics. Mitt. Theoret. Verein. Limnol. 20:124-197. Rago, P. J. 1979. On the calculationof production forgone due to entrainment and impingement 

### of fishes at the Donald C. Cook Nxlear Plant. of the clean water act. Volume 

### I. Ind. Mich. Power Co., Fort Wayne, Ind. 129 pp. Supplemental report demonstrating compliancewith section 316(b)
Schneeberger, P. J., and D. J. Jude. 1981. Use of fish larvamorphometry to predict exclusion capabilities of small-mesh screens at cooling-water intakes. Trans. mer. Fish. SOC. 110:246-252. Sharma, R. K., and R. F. Freeman. 1977. Survey

### of fish impingement at power plants in the United States: Volume I. National Laboratory publicationANL/ES-56. Argonne, Ill. 218 pp. The great lakes. Argonne Stewart, D. J., J. F. Kitchell, and L. B. Crowder. 1981. Forage fish and their salmonid predators in Lake Michigan. Trans. 

### mer. Fish. SOC. 110:751-763. Tesar, F. J., and D. J. Jude. 1985. Adult and juvenile fishpopulations of inshore southeastern Lake Michigan near the D. C. Cook Nuclear Power Plant, 1973-1982. Spec. Rep. No. 106, Great Lakes Res. Div. Univ. Mich., Ann Arbor, Mich. 94pp. Tesar, F. J., D. Einhouse, H. T. Tin, 0. L. Bimber, and D. 3. Jude. 1985. Adult and juvenile fish populations near the D. C. Cook Nuclear Power Plant, southeastern Lake Michigan, during preoperational (1973-74)and operational (1975-79) years. Spec. Rep. No. 109. GreatLakes Res. Div., Univ. Mich., Ann Arbor, Mich. 341 pp. Thurber, N. J., and D. J. Jude. 1984. Impingement losses at the D.C. Cook Nuclear Plant during 1975-1979 with a discussion of factors responsible and relationships to field catches. Spec. Rep. No. 104, Great Lakes Res. Div., Univ. Mich., Ann Arbor, Mich. 99 pp.

69u.S. Atomic Energy Comnission (USAEC). 1373. 

### Final environmental statanent related 

### to operation

### of Donald C. Cook Nuclear Plant 

### units 1and 2. Docket 

### nor. 50-315 

### and 50-316. 

### Directorateof Licensing, US. Atan. 

## mer. Ccarm., Washington, D.C. 327 pp. Wells, L. 1968. 

### Seasonal depth distribution

### of fish

### insoutheasternLake Michigan. Fish. Bull. 67:l-15. Zeitoun, I. H., 

### J. A. 

### Gulvas, 

### and D. 

### E. Roatabaugh. 1981. Effectiveness 

### of fine 

### mesh cylindrical wedgc-wire screens in reducing entrainment 

### of Lake Michigan ichthyoplankta. CM. J. Fish. Aquat. SCi. 38:l20-125.

70

## 30 6 28

# I 1975 2u 22 

# - 20 18 

# = 16 

## u Y W 3 

# & lU 

# E 12 +8 e W 

# = 10


## 6 

# u 2 

## 0 JAN 

### FEB MAR APR MAY 

### JUN 

### JUL AUG 

### SEP OCTNOV 

### DEC 

### MONTH Appendix 

### 1. the St. 

### Joseph municipal water plant during 

### 1975. was 6 

### m. Lake Michigan water temperatures recorded daily at Intake depth

A- 1

## 30 28 26 

## 2u 22 20 

## 10 16 ltl 

## 12 10

0 

## 6 

# u 2 

## I976

u I I I I u I I I I I I 

### JAN 

### FEB MAR APR 

### MAY JUN JUL AUG 

### SEP OCT 

### NOV 

### DEC 

### MONTH Appendix 

### 2, Lake 

### Michigan water temperatures recorded 

### daily at the 

### St. 

### Joseph municipal water plant during 1976, 

### Intake depth was 

### 6 

### m.

A- 20 

### u Y W 3 

# + a 

## a a W (L 

### I: 

### w c 

## 30 28 26 

## 2u 22 20 18 16 

## 14 12 10

8 

## 6 tl 

## 2 

# 1977

Ol I I I I 1 I 1 I I I I I 

### JAN 

## FEB MAR 

### APR MAY JUN 

### JUL AUG 

### SEP OCTNOV 

### DEC 

### MONTH Appendix 

### 3. the St. 

### Joseph municipal water plant during 1977. 

### was 6 

### m. Lake Michigan water temperaturks recorded daily at Intake depth

A-3c. 

### u Y W 3 #- 

## a 

## a a W Q. 

## z WI

## 30 28 26 

# 2u 22 20 18 16 

# ltl 12 

## 10

8 6 

# u 2 

## I978


# ii

JAN'FEB'MAR'APR'MAY *

### JUNJUL 

### 'AUG-SEP-OCT~NOV'DEC MONTH Appendix 4. 

### Lake 

### Michigan water temperatures recorded daily at the 

### St. 

### Joseph municipal water plant during 1978. 

### Intake depth vas 

### 6 m.

A- 4n 

## u Y W 

### => t 

### a 

## a a w Q 

### x Wt

## 22 20 18 16 

## 11 12 

## 10

8 

## 6 tl 

## 2 0 I JAN 

## FEB MAR 

### APR MAY JUN JUL AUG 

### SEPOCT NOV 

### DEC 1 I 1 I I I I I I I I I 

### MONTH Appendix 

### 5. Lake Michigan water temperatures recorded daily at the St. 

### Joseph municipal water plant during 1979. was 6 

### m. Intake depth

A- 5n 

## u Y W 

### => 

### c 

## a a 

## a W 

## e 

## z W t 

## 30 

## 28 26 2u 22 

# 20 18 16 

## ltl 12 10



## 8 6 

## 1980 

# -

I



# P

Ol 1 1 I 1 a I I I I I I 1 

### JAN 

### FEEMAR APR 

### MAY 

### JUN JUL AUG 

### SEP OCTNOV 

### DEC 

### MONTH Appendix 

### 6. was 6 

### m. Lake Michigan water temperatures recorded daily at

e 

### the 

### St. Joseph municipal water plant during 1980. Intake depth

A-6

## 30 

## 28 26 24

n 

### u V W 

## ac 3 t 

## a a w 

### e 

## r W I- 

# -

VI I 8 I I I I I I I I I I 

### JAN

## FEE MAR APR MAY JUN 

### JUL AUG 

### SEP OCT NOV 

### DEC 

### MONTH Appendix 7. 

### the St. 

### Joseph municipal water plant during 1981. 

### was 6 

### m. Lake Michigan water temperatures recorded daily at Intake depth

A-7n 0 Y W 3 

### c 

## oc W 

## e 

## r WJ

## a 

## a 30 

## 20 26 

## 2u 22 20 18 

## 16 ltl 12 10

8 6 

## li 

## 1982



# tc

I I I I I t I I I I 

### JAN 

## FEB MAR APR MAY JUN 

### JUL AUG 

### SEPOCT NOV 

### DEC 

### MONTH 

# .

Appendix 

### 8. Lake Michigan water temperatures recorded daily at the St. 

### Joseph 

### municipal water plant during 1982. 

### Intake depth was 6 

### m.

A-

### aJAN

.............................

4000" 

## FEB

.............................

I-

......................... NOV MAR

L



### .... 4000 28ow

12000 MRY

4000 4m

# t-

........................... 

### SEP L


### I

......... 

### DEC 

# 1 rn ..... 4mn 1-- 

# . ?OO 3513 c 

### 13u L-- 

# --- 3U IUU TOTAL LENGTH 

## (!In) Appendix 

### 9. Length-frequency histograms 

### of alewives impinged 

### during 1975 

### at the 

### Cook Plant, southeastern Lake 

### Michigan.

A- 91200 

### JUN 

### zoo
1200 3600 

# 3.2400 H LL 0 IA 1200



### a w m x 3 

### z 12000

8400 7200 6000



### OCT NOV 

### 210 O~....'...'"...~"'~'.... 

### 10 

### 60 110 

### 160 TOTAL 

### LENGTH (MM) Appendix 10. 

### during 1975 

### fieid sampling at the 

### Cook 

### Plant, southeastern Lake 

### Michigan. Length-frequency 

### histograms of alewives 

### caught

A-iO

# 5 n LL LL 0 W I= 1 Z 

### a m 1200 1200 6ww 4800 3600 2400 1200 9600

1200

L 

### 200 

### TOTAL LENGTH (MRI 

### 250 Appendix 11. 

### during 1976 at 

### the Cook Plant, southeastern Lake 

### Michigan. Length-frequency histograms 

### of alewives impinged

A-11

# wl 1976 WR
4000



### JUL



# m H L LL. 0 K W S m



### SEP 1 

### OCT
a000 NOV 

## 60 110 

### 160 210 

# or'

. ' ' ' . ' ' . ' . . ' . . . 

### 10 TOTRL 

### LENGTH 

### (MI?) Appendix 12. 

### during 1976 

### field sampling at the Cook 

### Plant, southeastern Lake 

### Length-frequency histograms of alewives caught Michigan.

A-12

### TOTAL LENGTH (IWl 

### Appendix 

### 13. during 1977 at the 

### Cook Plant, southeastern 

### Lake Michigan. 

### Length-frequency histograms 

### of alewives impinged

A-13

# lmk1977 APR



# s w LL LL 0 W S => 

### z a m 2400

lzwl 1200



### 160 TOTAL 

### LENGTH (RM) 0 

### 10 

### 60 110 96M 8400 

# Ii

4m 3800 2400 1200 NOV 

### 210 Appendix 14. 

### during 1977 

### field sampling at 

### the 

### Cook Plant, southeastern Lake 

### Michigan. Length-frequency histograms 

### of alewives caught

A-144000 4000

JUL 

### --. . 

# - 

# - FEE -.. ........................... 

# -

4000 4ooo 4000 4ooo So00 

### 50 100 

### 150 200 

### 250 TOTAL 

## LENGTH (MI11 Appendix 15. during 1978 at 

### the 

### Cook Plant, 

### southeastern Lake Michigan. Length-frequency histograms 

### of alewives impinged

A-15

### APR



### JUL 1200



### mw RUG

Ln H LL LL 0

1200 NOV 

## 60 110 

### 160 210 0 

## TOTAL LENGTH ~tlfl) 

### 10 Appendix 16. 

### during 1978 

### field sampling at the Cook 

### Plant, southeastern Lake Michigan. Length-frequency histograms 

### of alewives caught

A-16

### TOTAL LENGTH (MMI 

### Appendix 17. 

### during 1979 at 

### the Cook Plant, 

### southeastern Lake Michigan. 

### Length-frequency histograms 

### of alewives impinged

A- 17NOV rooQ 0 

### 10 

## 60 110 

### 160 

## 210 TOTRL LENGTH (flfll 

### Appendix 18. 

### Length-frequency histograms 

### of alewives caught during 1979 

### field sampling at 

### the Cook 

### Plant, southeastern Lake 

### Mi

### chi

### gan1 JRN 

### FEB



# - SEP OCT NOV 

### DEC 12000 12000 12000 

## 80 130 180 

## 230 TOTAL 

### LENGTH (Mnl 

## 30 Appendix 19. 

### during 1980 at the Cook Plant, southeastern Lake Michigan. Length-frequency histograms 

### of alewives impinged

A-19160 960 800 640 480 320 160 800 640 480 320 160 960 8w) 640 480 320 160 1280 1120 960 a00 640 480 320 160 320 160

TOTRL 

### LENGTH (MI71 

### Appendix 20. 

### during 1980 field sampling at the Cook 

### Plant, southeastern Lake 

### Michigan. Length-frequency histograms of alewives caught

A-2012000 1- 12000 12000 IOsOOO 36(#w 84w)ll 72ooo 60000 48000 36000 2m 12000 108000 84OoO 060000 36m 324000 

# 5 96000
L 7Moo 

# f5-


# = 12OOO 84ooo 72000 6M100 48000 36000 24000 12000 12000 12000 12OM 12000 12000 

### 20 

### 70 120 

### 170 

### 220 TOTRL LENGTH (flfll 

### Appendix 21. 

### Length-frequency histograms 

### of alewives 

### impinged 

### during 1981 at 

### the Cook 

### Plant, 

### southeastern Lake 

### Michigan.

A-218110

# t

___ 

### SEP 

# -

Appendix 22. during 1981 

### field sampling at 

### the Cook 

### Plant, southeastern Lake Michigan. Length-frequency histograms 

### of alewives caught

A-22Bowl

# mb1382 

# - FEB

L ...................... i JAN



### m

# t

.........................

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

# - 

# - SEP i. 8aM 101,019



## .... RUG

......................... 

### OCT NOV 

### DEC 30 

### 80 130 180 

### 230 TOTAL 

### LENGTH (BRI Appendix 

### 23. 

### Length-frequency histograms 

### of alewives impinged 

### during 1982 

### at the 

### Cook Plant, southeastern Lake Michigan.

A-23210

## c

OCT m- NOV 244

# -

0 

### 110 

### 160 

### 210 TOTAL 

### LENGTH (tltll 

## 60 10 

# .

Appendix 24. 

### during 1982 

### field sapling at 

### the Cook 

### Plant, southeastern Lake Michigan. Length-frequency histograms of alewives caught

A-24-- 

## TOTAL LENGTH (flfll Appendix 

### 25. impinged during 

### 1975 at the 

### Cook Plant, southeastern Lake Michigan. 

### Length-frequency histograms 

### of spottail shiners

A-25NUV 

# I 60 110 

### 160 TOTFlL 

## LENGTH (MR) Appendix 26. 

### caught during 1975 

### field sampling at the Cook 

### Plant, southeastern Length-frequency histograms of spottail shiners Lake Michigan.

A-262400 2000 16w) 

### ma 800 40 

### m 400 40 

### JUN 400 -. 

### JUL 400 400 800 400 800 40 eo0 400



### 30 

### 80 130 TOTAL 

### LENGTH tllfl) 

### Appendix 27. 

### Length-frequency histograms 

### of spottail shiners impinged during 1976 at the Cook Plant, southeastern 

### Lake 

### Michigan.

A-27160 

## no 160

800 640 480 320 160 1440 1280 1120 960 800 640 480 320 160
160



### NOV 

### 10 

## 60 110 160 b 0; 

### TOTRL 

### LENGTH (Rfl) 

### Appendix 28. 

### Length-frequency histograms 

### of spottail shiners caught during 1976 

### field sampling at the 

### Cook Plant, southeastern Lake Michigan.

A-28c

720 540 560 480 400 320 240 160 80 400

80 80 80 80 80 320 240 160 80 80

# c NOV 80 

## DEC

30 

## 80 

## 130 TOTAL LENGTH (11) Appendix 29. 

### impinged during 1977 

### at the Cook Plant, southeastern Lake 

### Michiuan. Length-frequency histograms 

### of spottail shiners

A-291977 FIPR 400

400



# "t I
t- I

L NOV !- 

### 10 60 110 

### 160 

# 4-

0: 

## TOTRL LENGTH (tlfl) 

### Appendix 30. 

### caught during 1977 

### field sampling at the Cook 

### Plant, southeastern Lake Michigan.Length-frequency histograms 

### of spottail shiners

A-308W'

### rooo8000 MFiR 4000 8000

# - JFlN 

# - FEB 

# -

c

L 4000 8000

# - 

# - APR
L 4000 8000

# - MAY 

# -

c 4000 48000 44000 

## 5 40000 36000 LL 32000 28000 0 

### a 

## # 24000 

### f20000 

# = 16Ooo 12000 8000 4000 8000 4000 8000 L 

# - - RUG L 4000 8000 

### SEP 4000

# - - OCT 4000 8000 NOV 4000 

## DEC 

## 30 80 130 TOTAL 

### LENGTH (l'lfl) 

### Appendix 31. 

### impinged during 1978 

### at the Cook 

### Plant, southeastern Lake 

### Michigan. Length-frequency histograms of 

### spottail shiners

A-311978
800- 

### APR 

# -

JUN 7

c 800 1600 800
800

# F r 

### NOV 110 160 TOTAL 

### LENGTH (tltll 

## 60 0' 

### 10 Appendix 32. 

### caught during 1978 

### field sampling at 

### the Cook 

### Plant, southeastern Length-frequency histograms 

### of spottail shiners Lake 

### Michigan.

A-321600 800 800 800 

# I FEB flRR 3200 24M 1600 800 800

8w 3200c 2400 16M 800

L 4800 4aao 3200 2400

eoa 1600

3200
1600 800 800 NOV 

## DEC 800



### 30 80 130 

### TOTAL LENGTH (flfl) 

### Appendix 33. impinged during 1979 at 

### the Cook 

### Plant, southeastern Lake Michigan. Length-frequency histograms 

### of spottail shiners

A-33

# Boot 1979

800

### i

### NOV



# or 10 

## 60 110 

## 160 400

# p TOTAL 

### LENGTH UTI1 

### Appendix 34. 

### Length-frequency histograms 

### of spottail shiners caught during 1979 

### field sampling at the 

### Cook Plant, southeastern Lake Michigan.

A-34

# IMUL 1980
16M JRN

L 

## FEB 

# -

L 4 

# L
3200 MQY

L JUL I 1- cn n L LL 0 RUG 1600 17600 16000 14400 tzs00 11200 36w1 8000 6400 4800 3200 1600 3200 1600 NOV 1600 1600 

### 20 

### 70 

### 120 170 TOTAL LENGTH ~fllll 

### Appendix 35. 

### impinged during 1980 

### at the Cook 

### Plant, southeastern Lake Michigar.. Length-frequency 

### histograms 

### of spottail 

### shiners

A-35x v) H LL LL 0 U w G 

## 5 z 1980 APR 

# -

2m 2400 2m 16iw 1200 800 400 400 2000



## SEP OCT NOV -. 

### 10 

### 60 110 

### TOTRL LENGTH 

### (MMI Appendix 

### 36. caught during 198G 

### field sampling at the Cook 

### Plant, southeastern Lake Michigan.Length-frequency histograms 

### of spottail shiners

A-36I v) H LL LL 0 w 

### a 

### m 

# 5 z 1981
2400 1200 2400' 

### JAN 

## FEB RAR APR tzoo 2400 tloo 2400 1241

1241 2400 1200 2400 /. 

## OCT

90 

## NOV 

## DEC 140 

## TOTAL LENGTH tl'll'l) 

### 190 Appendix 

### 37. impinged during 

### 1981 at the Cook Plant, southeastern Lake Michigan

# . Length-frequency histograms 

### of spottail shiners

A-37800 400 8w 400 800 400 800 ¶-

L 

### NOV 400

0 

## 60 

## 110 160 Length-frequency histograms 

### of spottail shiners 

### 10 TOTAL LENGTH 

### ttlfll Appendix 38. 

### caught during 1981 

### field sampling at the 

### Cook Plant, southeastern Lake Michigan.

A-30

### c

nm= 

## rrm FEB



# - RUG 7. 

### JUL

12mt2Da## mIZM \ 

# - SEP



# . OCT 

### NOV 

## DEC 

# - - 1 

# - - - 

# - -
Appendix 39. Lengthimpinged during 1982 

### Michigan. frequency h 

### at the 

### Cooki stograms 

### of spottai Plant, southeastern

### 1 

### shiners

, Lake

A-35

### TOTAL 

### LENGTH ttlfll Appendix 

### 40. caught during 

### 1982 field sampling at the 

### Cook Plant, southeastt Lake Michicran.Length-frequency histograms 

### of spottail shiners I

I



### zrn

### JAN ftQ 200 200- I LU 

# - - tlRR APR 

# - 4 flAY 200 

### JUN 200 

### JUL 200



### .

## -- 200

### I1400

# 't

290

# c 10 

## 6R 110 

### TOTAL 

### LENGTH (llll) 

### 160 Appendix 41. 

### during 1975 at 

### the Cook Plant, 

### southeastern Lake Michigan. 

### Length-frequency histograms 

### of trout-perch impinged

A-4120

20

20

20

10 0 

# so 100 1

# so TOTAL LENGTH 

## (mi Appendix 42. Length-frequency histograms of trout-perch caught during 1975 field sampling at the Cook 

### Plant, 

### southeastern Lake 

### Michigan.

A-42

# - 160

# - 1976 JAN

c

160 

## FEB 160



# - NOV 

# - 160

I



### OEC 160 

### 10 

## 60 110 

### TOTQL LENGTH IMR) 

### 160 Appendix 43. 

### during 1976 

### at the Cook 

### Plant, southeastern Lake 

### Michigan. 

### Length-frequency histograms 

### of trout-perch impinged

A-43

# "Ot 1976 

### 1

200 160 

# ':I

40
F 

# "i

c

L

c 40 80

0 NOV 

# so 100 

## 150 TOTAL LENGTH 

### (Ill71 

### Appendix 44. 

### Length-frequency histograms of trout-perch caught during 1976 

### field sampling at the Cook 

### Plant, southeastern Lake Mi

### chigan

# .
A-44120

## z 1977 

### JAN 

# --- 120 120 240 

### FE0 

## z 1977 

### JAN

120 240- 120 240 

### APR 

# - tlAR
'

120 240 120 

# ?-------

120

I- hitr 240 I20 IS60 1440

# - - -
- 960- 840 720 600 480 360

# - 240

# - 120t- 

# -

- - 

# . nuu 

## SEP

240 120 240 120



### 1 TOTQL 

### LENGTH (l7fl) 

### Appendix 45. 

### during 1977 

### at the Cook Plant, southeastern Lake Michigan. Length-frequency histograms 

### of trout-perch impinged

A-4540 80 40 80

# - APR 

# - 

# -

40

40 80 40

# - 80

# - 1 

# -



# . i

tmv 

# I
1.u v 

### t 

### 100 

## 150 TOTAL 

### LENGTH 

## tnn) 

# so 01


### Appendix 46. 

### Length-frequency histograms of trout-perch caught during 1977 

### field sampling at the Cook 

### Plant, southeastern Lake Michigan.

A-46JAN
JOOE 

### FEB

Boo 400 BM RAY 

# - JUN 400- 56Do

L 

### NOV

400 8M L 

### DEC 400 

### 10 

## 60 110 

### 160 

## TOTAL LENGTH VIfll 

### Appendix 47. 

### Length-frequency histograms 

### of trout-perch impinged during 1978 

### at the Cook 

### Plant, southeastern Lake Michigan.

A-4740-

40 

### JUN 1978 

# - APR

J=

c .I NOV



### -- TOTFlt 

### LENGTH (tlfll Appendix 48. 

### Length-frequency histograms 

### of trout-perch caught during 1978 

### field 

### sampling at the Cook 

### Plant, southeastern Lake 

### Michigan.
A-48NOV 2110 ___ 

### DEC 

### 10 

## 60 110 

### 163 

### TOTRL LENGTH (RM) Appendix 49. 

### during 1979 

### at the Cook Plant, 

### southeastern Lake 

### Michigan. Length-frequency histograms 

### of trout-perch impinged

A-498

NOV 20I

# too 150

a TOTAL 

### LENGTH (flnl 

## 50 Appendix 50. 

### Length-frequency histograms of trout-perch caught during 1979 

### field sampling at the Cook Plant, southeastern Lake Michigan.

.
A-53I v) H LL LL 0 w z 3 

### z a m 'ODJRN 

### - 

# -

2000

c I
I

# F

400
2000 1600 1200 800

L


### TOTFlL 

### LENGTH (IlM) 

### Appendix 51. 

### during 1980 at the 

### Cook Plant, southeastern 

### Lake Michigan. Length-frequency histograms of trout-perch impinged

A-5140 

### I980 bDD 80 44

80 40
120 80 40 240

160 120 80 4u 40 NOV



### 20 70 120 170 TOTAL LENGTH 

### (Rfll 

### Appendix 52. 

### Length-frequency histograms of trout-perch caught during 1980 

### field sampling at the Cook 

### Plant, southeastern 

### Lake Michigan.

A-52400

### 1 

# -1981 JAN 800- 

## FEB 4oa 800c

4aJt 

### em 440

400 

### em L

~ ~ 

# - NOV 400- 800



## 30 

## 80 

## 13u TOTAL 

## LENGTH (nM1 

### 180 Appendix 53. 

### Length-frequency histograms 

### of trout-perch impinged during 1981 

### at the Cook Plant, 

### southeastern Lake 

### Michigan.

A-5360 48 36 24 

## n 24 12 

### n 0 

### 20 

## 70 120 170 TOTAL LENGTH 

### (llfl) 

### Appendix 54. 

### Length-frequency histograms 

### of trout-perch caught during 1981 

### field sampling.at the Cook 

### Plant, southeastern Lake Michigan

# .

A-54L 

### NOV 

# - DEC 

# - 20-



## 60 110 

### 160 TOTAL LENGTH 

### (MIV Appentiix 55. 

### during 1982 

### at the Cook 

### Plant, southeastern Lake Michiaan

### Length-frequency histograms 

### of trout-perch impinged

A-55

### c I6 

## n 8 o4 4 

## OCT NOV 

## 20 

## 70 120 170 4 0

# - TOTRL LENGTH (tlnl 

### Appendix 56. 

### Length-frequency histograms of trout-perch caught during 1982 

### field sampling at the Cook 

### Plant, southeastern Lake Michigan

# .

A-56I VI H LL LL 0 W S 3 

### z a m

.. ...T 

### .... .................. 

## 30 80 

### 130 180 230 

### 280 330 380 TOTRL LENGTH 

### (flfl) Appendix 57. 

### Length-frequency histograms 

### of yellow perch impinged during 1975 

### at the Cook 

### Plant, southeastern Lake 

### Michigan.

A-5780-

720 640 580 480 

### roo 320 210 160 80 --_rr..

### . . . . . . . . . . . . . . . w RAY

80


### a
80
80

0 

### 1 TOTAL LENGTH 

### (Rn) Appendix 58. 

### during 1975 

### field sampling at the Cook 

### Plant, southeastern Lake Michigan. Length-frequency histograms 

### of yellow perch caught

A-50200 200 200 200 200 200 400 

### m 2ooo le00 16UU 1400 1200 1000 800 600 400 2wl 1800 1600 1400 1200 loo0 800 600 400 200 200 200



## 30 

## 80 130 180 

### 230 

### 280 

## 330 

## 380 TOTRL LENGTH (Mtll 

### Appendix 59. 

### Length-frequency histograms 

### of yellow perch impinged during 1976 

### at the 

### Cook 

### Plant, southeastern Lake Michigan.

A-59

## "E 18 32- c 1976 

# - APR 

# - 

# - a .,. 1 48 32 

### le

16 32c 

# - OCT 

# - -
c IS

# t NOV



### Appendix 60. 

### Length-frequency histograms of yellow perch caught during 1976 

### field sampling at the Cook 

### Plant, southeastern Lake Michigan.

A-b3120

# f:1977 

### FEB

JUN 720 6ua 480 360 210 120 120 120 360 240 120 120 120 sg..................... 

## DEC 

## 30 80 130 180 230 

## 280 330 380 TOT% 

### LENGTH Ulfll 

### Appendix 61. Length-frequency histograms 

### of yellow perch impinged during 1977 

### at the Cook 

### Plant, southeastern Lake Michigan.

A-61L

L 

### roo 360 320 280 244 200 180 120 80 40 129 80 40



### Appendix 62. 

### during 1977 

### field sampling at the 

### Cook Plant, 

### southeastern Lake 

### Length-frequency histograms of 

### yellow perch 

### caught Michigan.

A-62

# 5 H LL LL 0 

### a W 

### a E= 3 

### z JAN

flAY 

# I

2400



# =I
“L

-4w

### SEP 400
m 

### OCT

................

TOTAL LENGTH Wl) 

### Appendix 63. 

### Length-frequency histograms 

### of yellow perch impinged during 1978 

### at the Cook 

### Plant, southeastern Lake Michigan.

A-6316 8 16 8 32 24 16 8 104 96 88 80 72 64 56 48 10 32 24 16 8 16 8 64 56 48 44 32 24 16 8 24 16 0 16 

### e 0 TOTAL 

### LENGTH (Rfl) 

### 1 Apgendix 64. 

### during 1978 

### field sampling at the Cook 

### Plant, southeastern Lake 

### Michigan

# . Length-frequency histograms 

### of yellow perch caught

A-64-i v) H LL LL 0 U w 

### r= 3 

### z m L

4w

### I-

.... 

### JUL 800 400 4800 4000 3600

# E 3200

# c B88E 28M

# E 2400 

### L888 L 2000

### I1200 1600

# E
-

L 400 800 400 80U 400



### 30 80 

### 130 180 

## 230 280 330 380 TOTAL LENGTH 

### (MI) Appendix 65. Length-frequency histograms of yellow perch impinged during 1979 

### at the Cook Plant, southeastern Lake Michigan.

A-651979 W
80- i 

### APR
tlAY II

I

I

L I

c IBo

### OCT 

# - 80

# -

0

# - NOV 

## 60 110 

### 160 

### 210 260 310 

## 360 ....' 

### 10

- 

### TOTAL 

### LENGTH (l'lfll Appendix 66. 

### during 1979 

### field sampling at the Cook 

### Plant, southeastern Lake 

### Michigan. Length-frequency histograms 

### of yellow perch caught

A-664000

# - - DEC t... 

### TOTRL LENGTH 

### [Rll) 

### Appendix 67. 

### Length-frequency histograms 

### of yellow perch impinged during 1980 

### at the Cook 

### Plant, southeastern Lake Michigan.

A-67

### roo

### 11980

I cn H LL LL 0 LJ I= 3 2 

### a 

### m roo 4100 40#1 3600 3200

800 400 

### SEP roo 

### OCT 

# - 400- 

# - NOV 

### 20 70 120 170 

### 220 270 320 TOTAL LENGTH 

### (MR) Appendix 68. 

### during 1980 

### field sampling at 

### the Cook 

### Plant, southeastern Lake Michigan. Length-frequency histograms 

### of yellow perch caught

A-6812000

FIPR 

# - - FEB

12m

# - - MAY



### Izooo
12000
tzoco lM[w 181,821



# - - JUL 

### RUG SEP OCT ................................. 

# - 

# - - 

# - - - NOV 12000

### !-

c 

### DEC
2 

## 30 80 130 

### 180 230 280 

## 330 380 TOTRL LENGTH (flfll 

### Appendix 69. Length-frequency histograms 

### of yellow perch impinged during 1981 at the Cook 

### Plant, southeastern Lake Michigan

# .

A-69

# 8 H U U 0 W m I 

### a 

# 1 l98* APR flRY 400



### RUG 400
L



### NOV



## 30 

## 80 130 

## I

# ao 230 280 330 .................................. 

### TOTAL 

### LENGTH (fltl) 

### Appendix 

### 70. during 1981 

### field sampling at the Cook 

### Plant, southeastern Lake Michigan, Length-frequency histograms 

### of yellow perch caught

A-73f 

### 1982 JAN 400
L
400- 400- 

# - nRR



# ...

OCT 4011



### ..........................

NOV 400 

## DEC

40 

## 90 140 190 

### 240 290 

## 340 390 TOTAL 

## LENGTH Appendix 71. 

### Length-frequency histograms 

### of yellow perch impinged during 1982 

### at the Cook Plant, southeastern Lake Michigan.

A-71

### TOTAL 

## LENGTH (fftll tom

### I- E

Appendix 

### 72. during 

### 1982 fieid sampiing at the 

### Cook Plant, southeastern Lake Michigan. Length-frequency histoZjrams 

### of yellow perch caught

A-72

# 801 1975 80- 

## - 

# - FEB an.-’ . 160 80 

# I 240 160 80 80 !

JUN

80 80 ~-

# - SEP r ............................

80 

### DEC v ........... 

### 10 

### 60 110 

### 160 

### 210 260 TOTAL LENGTH 

### (flfll 

### Appendix 73. 

### Length-frequency histograms 

### of rainbow 

### smelt impinged during 1975 

### at the 

### Cook 

### Plant, southeastern Lake Michigan.

A-73a

80 40 480

380 320

240

## c

JUL

3U IUU IUW 

### 200 25G TOTAL 

## LENGTH Mfl) 

### Appendix 74. 

### during 1975 

### field sampling at 

### the Cook 

### Plant, southeastern Lake 

### Michigan. Lensth-frequency histograms 

### of rainbow smelt caught

A-7480 60 40 20 20 40 20 140 120 1w 80 60 40 20 120 1w 80 60 

### a 20 20 40 20 40 20 20 40 20 20 40 20



### 10 

## 60 110 

### 160 

### 210 260 TOTAL 

### LENGTH Wltl) 

### Appendix 75. 

### Length-frequency histograms 

### of rainbow smelt impinged 

### during 1976 

### at the Cook 

### Plant, southeastern Lake Michigan.

A-7596 80 64 40 32 16 32

L

48 32 16 0 

# so 100 

## 150 200 250 

## TOTAL LENGTH (flfll 

### Appendix 76. 

### Length-frequency histograms 

### of rainbow smelt caught during 1976 

### field sampling at 

### the Cook 

### Plant, southeastern Lake 

### Michigan.
A-7520 20 40 20 60 44 20 40 20 20 120 100 80 60 40 20 20 20 160 140 120 100 80 60 40 20 20 20



### 10 

### 60 110 

### 160 210 

### 260 TOTAL LENGTH (I'll71 

### Appendix 77. 

### Length-frequency histograms 

### of rainbow smeit impinged during 1977 

### at the Cook 

### Plant, southeastern Lake 

### Michigan.1977 

# 1

JUN 

# I 520 

# 1

SE? 40 80 40



### TOTRL 

## LENGTH (tlnl 

### Appendix 78. 

### during 1977 

### field sampling at the Cook 

### Plant, southeastern Lake Michigan. Length-frequency histograms of 

### rainbow smelt caught

A-78I m H LL LL 0 W I= 3 

### z a m

800- JRN



# -

. 

### OCT c ............................ 

### FE0 800 

### tlRR 8w



### ..

JUN 800 Bw)(1 7240 6400 5600 4840 4ooo 32W 2400 1600 800 5600 4800 4000 32W 2400 1600 800

a- 

# - F 

### SEP

................. NOV 800 

## DEC 800 

### 10 

### 60 110 

### 160 

### 210 260 TOTRL 

### LENGTH (fltll 

### Appendix 79. Length-frequency histograms 

### of rainbow smelt impinged during 1978 

### at the 

### Cook Plant, southeastern Lake Michigan.

A-796M !- 200 

# ?jg7* 

### APR -. . . . .. 400 200 

### JUN



# . - . . . . . .



## SEP OCT NOV 

### 100 

### 150 

## 200 

## 250 '..'.....''.'.."''....*.' 

### TOTAL LENGTH (RR) 

## 50 Appendix 80. 

### during 1978 

### field sampling at 

### the Cook 

### Plant, southeastern Lake 

### Michigan

# . Length-frequency histograms of rainbow smelt caught

A-33

### FEB

............................ 800 800

c

2400 1600 800 8W

L NOV

............................ 

# t..

.................... 

### DEC 

### 10 

## 60 110 

### 160 210 260 

### TOTRL LENGTH (MM) 

### Appendix 81. impinged during 1979 

### at the Cook Plant, southeastern Lake Mi

### chigan

# . Length-frequency histograms 

### of rainbow smelt

A-a1

### JUN

TOTAL 

### LENGTH (MMI 

### Appendix 82. 

### during 1979 field sampling at the Cook 

### Plant, southeastern Lake Michigan, Length-frequency histograms of rainbow smelt caught

A-82I v) H LL 

### w8ow)

IA 0 

# - APR

............. .j JRN

4ww48000-- L



# - MRY

.............. ...

4ow- 

# - RUG 8ooo-..
................... L

L

L 4000 8oM 

### OCT 41100

# - 8oM

# - NOV 

### DEC 4aw 

### 20 70 120 170 

### 220 TOTRL LENGTH (flfl) 

### Appendix 

### 83. impinged during 1980 at the Cook 

### Plant, southeastern Lake 

### Michisan. 

### Length-frequency histograms 

### of rainbow smelt

A-03I v, n LL. LL 0 w S 3 

### z a a



### 10 

## 60 110 160 

### 210 TOTAL LENGTH 

### IMM) 

### 260 Appendix 84. 

### Length-frequency histograms of rainbow smelt 

### caught during 1980 

### field sampling at the Cook 

### Plant, southeastern Lake Michigan

# .

A-04I v) H LL LL 0 w m 

### z a 

# 5

# *r-

- _.... HAR I ..
............................

4m- 

# - SEP OCT 

# *-

D 4ooo-

D 

### NOV

............................ 

### 4moc 

### DEC 

### 30 

## 80 130 180 

## 230 TOTAL 

### LENGTH 

### (IYfl) 

## 280 Appendix 85. Length-frequency histograms of rainbow smelt impinged during 1981 at 

### the Cook 

### Plant, southeastern Lake 

### Michigan.

A-05L 

## SEP 200 400 200 400 2m

0 

### 10 

## 60 110 

### 160 

### 210 TOTAL 

### LENGTH (MH) 

### 260 Appendix 86. Length-frequency histograms 

### of rainbow smelt'caught during i981 

### field sampling at 

### the Cook 

### Plant, southeastern Lake Michigan

# .

A-86

### JAN

...... 

### FEB tlAR 241 

### 4a 200



### ........... 

### JUN 200 UIO 

### JUL 200 440 

### RUG 241 440 

### SEP 200 440 

### OCT 2a UIO


## DEC 200



### 40 

### 90 140 

### 190 240 TOTAL LENGTH 

### (RMI Appendix 87. 

### impinged during 1982 

### at the Cook 

### Plant, southeastern Lake Michigan. Length-frequency histograms of rainbow smelt

A-07l60 320 WIO 320 lW 320 

## SEP 160 320 

### OCT 

### la 3211 /.............. 

### NOV 

### 10 

## 60 110 

## 160 210 260 TOTAL 

## LENGTH (fltll 

### Appendix 88. 

### during 1982 

### field sampling at the 

### Cook Plant, southeastern Lake Michigan. Length-frequency histograms of 

### rainbow smelt caught



### A-88 P L