Argonne National
                Laboratory
Radiological and Environmental ANL/ES-109
Research Division        March 1981
Argonne National Laboratory
Argonne, Illinois 60439
                United States
                Environmental Protection
                Agency
                Region 5
Great Lakes National
Program Office
536 South Clark Street
Chicago, Illinois 60605
                                                  EPA-905/3-81-001
                An  Assessment  of  the Impacts
                of  Water Intakes on  Alewife,
                Rainbow  Smelt,  and  Yellow  Perch
                Populations  in Lake Michigan
Do not WEED. This document
shouldberetainedmtheEFA
Region 5 Library Collection.

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                                    DISCLAIMER

     This  report has  been reviewed  by  the Great  Lakes National  Program Office
and  the  Enforcement  Division, Region  V, U.S.  Environmental  Protection Agency,
and was  approved for  publication.  Approval  does  not signify that the contents
necessarily   reflect   the  views  and   policies   of  the   U.S.   Environmental
Protection  Agency,  nor  does  mention  of  trade  names  or  commercial  products
constitute endorsement or recommendation for use.
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                                                         ANL/ES-109
                                                         EPA-905/3-81-001
                                                         March 1981
              ARGONNE NATIONAL  LABORATORY
                9700 South  Cass Avenue
               Argonne,  Illinois   60439
     AN ASSESSMENT OF THE IMPACTS OF WATER  INTAKES
ON ALEWIFE, RAINBOW SMELT, AND YELLOW  PERCH POPULATIONS
                   IN LAKE MICHIGAN

                          by

            S. A. Spigarelli, A. J. Jensen,
                   and M. M. Thommes
   Radiological and Environmental Research Division
     Interagency Agreement No. EPA-IAG-78-D-X0322
           Project Officer:  Gary S. Mil burn
       U.  S. EPA Region V, Enforcement Division
     Interagency Agreement No. EPA-IAG-79-D-F0819
           Project Officer:  Vacys J. Saulys
    U.  S.  EPA, Great Lakes National Program Office
                                    y.S. Environmental Protection Agency   M
                                    Region 5, Libracy (PL4&J)             J
                                    77 West Jackson 0oufevar
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 U,S.  Environmental  Protection Agency

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                                   FOREWORD
     The  U.S.  Environmental Protection  Agency was  established to  coordinate
administration of  the  major Federal programs  designed to protect the  quality
of  our  environment.   An important part  of the  Agency's  effort involves  the
search  for information  about  environmental  problems, management techniques,
and new technologies to  optimize  use  of the nation's  land and  water resources
and minimize the threat  pollution poses to  the welfare of  the /American  people.

     The  Great  Lakes  National  Program  Office (GLNPO)  of  the United  States
Environmental  Protection  Agency,   was  established  in  Region   V,  Chicago  to
provide a  specific focus on water  quality concerns of  the  Great Lakes.   The
Great Lakes  National  Program Office  provides funding  for studies  to  address
Great  Lakes  specific   environmental   concerns   and  to  help  fulfull   U.S.
commitments under the U.S.-Canada Great Lakes Water  Quality  Agreement of 1978.

     This  report   provides  an   analysis  of  fish  loss  data generated  by  the
electric  power  generating  industry.    It  is  a  pioneering  effort  to  utilize
water-body wide  assessment techniques  to address single  industry  impacts  on
specific  natural  resources.   We hope that  the information  and  data contained
herein will  help  planners and  managers of  both  the  electric power  generating
industry  and regulatory  agencies  make  better decisions  for carrying  forward
their responsibilities.


                                      Madonna F. McGrath
                                      Di rector
                                      Great Lakes National Program Office

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                                   ABSTRACT

     A large volume  of water is withdrawn  from  Lake Michigan for cooling and
other industrial and municipal purposes.  Potential ecological impacts of such
withdrawals  have  caused  concern.     This   study   estimates   the  impacts  of
entrainment  and impingement  at  water intakes on  alewife, smelt,  and yellow
perch  populations  of  Lake  Michigan.   Impingement  and  entrainment estimates
were  based on  data  collected  by  utilities  for 316(b)  demonstrations  at 16
power plants.   Two conventional  fishery stock assessment models,  the surplus
production  model  and  the  dynamic   pool  model,  were  applied to  assess  the
impacts.    Fisheries   data  were applied  to  estimate  the model  parameters.
Movements  related  to   spawning  and  seasonal  habitat  selection   cause  high
variation  in impingement  and  entrainment over time and location.  Impingement
and  entrainment rates  were  related to geographic location,   intake  type and
position,  and volume of water flow.   Although the  biomass  impinged and numbers
entrained  are  large, the proportions of the  standing stocks   impinged and the
proportions  of  the eggs  and larvae entrained  are small.  The  reductions in
biomass assuming full  flow at all intakes and our  estimates of biomass in 1975
are  predicted  by the models  to  be:   2.86% for  alewife,  0.76% for smelt, and
0.28% for yellow perch.

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                               TABLE OF CONTENTS

                                                                           Page
LIST OF FIGURES	    ~lm~

LIST OF TABLES	       x

ACKNOWLEDGEMENTS	    xi i i

SUMMARY	      xv

INTRODUCTION	       1

ACQUISITION AND DEVELOPMENT  OF  DATA BASE	       3
    Sampl ed Power PI ants	       3
    Unsampl ed  Intakes	       7

IMPINGEMENT ESTIMATES	       9
    Alewife Impingement  -  Sampled  Intakes	       9
    Al ewi fe Impi ngement  -  Lakewi de	      11
    Rainbow Smelt Impingement - Sampled  Intakes	      15
    Rainbow Smelt Impingement - Lakewide	      17
    Yellow Perch Impingement -  Sampled Intakes	      18
    Yellow Perch Impingement -  Lakewide	      18

ENTRAPMENT ESTIMATES	      19
    Alewife Entrairiment  -  Sampled  Intakes	      19
    Al ewi f e Entrai nment  -  Lakewi de	      20
    Rainbow Smelt Entrainment - Sampled  Intakes	      22
    Rainbow Smelt Entrainment - Lakewide	..      24
    Yellow Perch Entrainment -  Sampled Intakes	      25
    Yel 1 ow Perch Entrai nment -  Lakewi de	      26

FACTORS AFFECTING IMPINGEMENT AND ENTRAINMENT	      27
    Effects of Intake Type	      27
        Al ewi f e	      27
        Rainbow Smelt	      31
        Yel 1 ow Perch	      40
    Effects of Flow and Geographic  Location	      40

DEVELOPMENT OF THE MATHEMATICAL MODELS	'.	      44
    Surplus Production Model	      44
    Dynamic Pool Model	      51

ESTIMATION OF BIOLOGICAL AND FISHING PARAMETERS	      56
    Surpl us Producti on Model	      56
        Alewife	      56
        Yel 1 ow Perch	      57
        Smelt	      59
    Dynamic Pool Model	      61
        Alewife	      61
        Yel 1 ow Perch	      62
        Smel t	      64

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ESTIMATION OF POWER PLANT-RELATED PARAMETERS	      64
    Surplus Production Model	      64
        Alewife	      66
        Yel 1 ow Perch	      66
        Smelt	      66
    Dynamic Pool  Model	      67
        Al ewi f e	      68
        Yel 1 ow Perch	      68
        Smel t	      68

SIMULATION OF IMPINGEMENT AND ENTRAPMENT IMPACTS	      69
    Al ewi fe	.,	      70
    Yel 1 ow Perch	      75
    Smel t	      78

DISCUSSION OF MODELING RESULTS	      81

REFERENCES	      90

GLOSSARY OF TERMS	      93

APPENDIX A	      96
    Plots of Daily Impingement and Entrainment Densities at  Sampled
    Power Plants

APPENDIX B	     162
    Estimates of Proportions Impinged and Entrained during
    1975 at Sampled Power Plants Based on Designed Water Flows  Using
    the Surplus Production and Dynamic Pool Models and  Calculated
    Coefficients of Impingement and Entrainment

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                                LIST OF FIGURES

                                                                           Page

 1.   Map  of Lake Michigan  showing  the  locations of  sampled  power plants
     and  statistical  districts	    6

 2.   Mean  annual  densities of  impinged  alewife at  each  sampled  intake
     (1975)	   28

 3.   Mean  annual  densities of  entrained  alewife  eggs  at each  sampled
     intake  (1975)	   28

 4.   Mean  annual densities  of entrained alewife  larvae at each  sampled
     intake  (1975)	   30

 5.   Mean  annual  densities of  impinged  smelt  at  each  sampled  intake
     (1975)	   30

 6.   Mean annual  densities  of  entrained smelt  eggs  at each  sampled intake
     (1975)	   34

 7.   Mean  annual  densities of  entrained  smelt  larvae  at each  sampled
     intake  (1975)	   34

 8.   Mean  annual  densities of  impinged  yellow  perch at  each  sampled
     intake  (1975)	   42

 9.   Mean annual  densities  of  entrained yellow perch  eggs at each  sampled
     intake  (1975)	   42

 10.  Mean  annual  densities of  entrained  yellow  perch larvae  at  each
     sampled intake (1975)	   43

 11.  Relationship between total number of alewife impinged  and  total  flow
     (1975)	   43

 12.  Relationship  between  total  number  of alewife  eggs  entrained  and
     total flow  (1975)	   45

 13.  Relationship  between  total  number  of alewife  larvae  entrained  and
     total flow  (4975)	   45

 14.  Relationship between  total  number of  smelt  impinged and total  flow
     (1975)	   46

15.  Relationship between total number of  smelt  eggs entrained and  total
    fl ow (1975)	   45

16. Relationship  between  total  number  of smelt  larvae  entrained  and
    total  flow  (1975)	    47

17. Relationship between total number of yellow perch  impinged and  total
    flow (1975)	    47
                                      Vll

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18. Observed yields and yields predicted by surplus production model  for
    alewife in Lake Michigan	    58

19. Stock  production  curves   for   alewife  in  Lake  Michigan  at  five
    different levels of water withdrawal considering  only  the impact of
    impingement	    58

20. Observed yields and yields predicted by surplus production model  for
    yellow perch in Lake Michigan	    60

21. Observed yields and yields predicted by surplus production model  for
    smelt in Lake Michigan	    61

22. Impingement  impact of  increased  water  withdrawal  on  biomass  of
    alewife in Lake Michigan (1975)	    72

23. Impingement  impact   of   increased  water  withdrawal   on  maximum
    sustainable yield (MSY)  of alewife in Lake Michigan (1975)	    72

24. Entrainment  impact of  increased  water  withdrawal  on  biomass  of
    alewife in Lake Michigan (1975)	    73

25. Entrainment  impact   of   increased  water  withdrawal   on  maximum
    sustainable yield (MSY)  of alewife in Lake Michigan (1975)	    73

26. Combined  entrainment  and  impingement  impact  of  increased  water
    withdrawal on biomass  of alewife in Lake Michigan (1975)	    74

27. Combined  entrainment  and  impingement  impact  of  increased  water
    withdrawal  on  maximum  sustainable  yield (MSY)  of alewife  in  Lake
    Michigan (1975)	    74

28. Combined  impingement  and  entrainment  impact  of  increased  water
    withdrawal on biomass  of yellow  perch in Lake  Michigan	    77

29. Combined  impingement  and  entrainment  impact  of  increased  water
    withdrawal on MSY of yellow perch in Lake Michigan	    77

30. Impingement impact of  increased  water withdrawal  on biomass of smelt
    in Lake Michigan (1975)	    79

31. Impingement  impact   of   increased  water  withdrawal   on  maximum
    sustainable yield (MSY)  of smelt in Lake Michigan (1975)	    79

32. Entrainment impact of  increased  water withdrawal  on biomass of smelt
    in Lake Michigan (1975)	    80

33. Entrainment  impact   of   increased  water  withdrawal   on  maximum
    sustainable yield (MSY)  of smelt in Lake Michigan (1975)	    80

34. Combined  entrainment  and  impingement  impact of  water  withdrawal  on
    biomass of smelt in Lake Michigan (1975)	    82
                                     vm

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35. Combined entrainment  and impingement impact  of  water withdrawal on
    maximum sustainable yield (MSY) of smelt in Lake Michigan (1975)	    82

36. Relation  between  estimate  of  population  biomass  and  estimate of
    proportion of  biomass standing  stock  impinged for yellow  perch in
    Green Bay (1975)	    85

37. Observed and predicted yields  for yellow perch  in  Green Bay (1960-
    1977)	    85

38. Combined  entrainment  and  impingement   impact  of  increased  water
    withdrawal  on biomass of yellow perch in Green Bay	    88

39. Combined  entrainment  and  impingement   impact  of  increased  water
    withdrawal  on  maximum sustainable  yield  (MSY)  of yellow  perch in
    Green Bay	    88

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                                LIST OF TABLES
                                                                           Page

    Summary Tab!e	xvi i i

1.  Intake  sampling  and  design  characteristics  of  16  sampled  power
    plants on Lake Michigan	     5

2.  Locations  and  design flows  of  unsampled  water  intakes  on  Lake
    Michigan	     8

3.  Estimated  total  number  and  biomass  of  alewife,  rainbow smelt,  and
    yellow  perch  impinged each  month at  all  16  sampled  power  plants
    (1975)	    10

4.  Estimated  total  number  and  biomass  of  alewife,  rainbow smelt,  and
    yellow  perch  impinged annually  at each  of  the sampled  power  plants
    on Lake Michigan (1975)	    10

5.  Mean weights  (g)  of alewife impinged  each  month  at 15  power  plants
    on Lake Michigan (1974-1976)	    12

6.  Estimated  total  numbers  and biomass  (kg)  of alewife,  smelt,  and
    yellow  perch  impinged  at  sampled  power  plants,   unsampled  power
    plants  and  municipal/industrial  intakes  on  Lake  Michigan,  assuming
    design flow operation  (1975)	    13

7.  Estimated  total  annual impingement of alewife at all  water  intakes
    within  each  statistical  district on Lake Michigan  (1975),  assuming
    design flow operation  at all intakes	    14

8.  Comparison of  estimated  maximum annual  impingement and entrainment
    values  (1975) with  observed  annual  values for Edgewater Power  Plant
    (1975-1976),  Inland Steel  (1976-1977),  and U.S.  Steel/Gary  (1976-
    1977) water intakes	    14

9.  Mean weights (g) of smelt  impinged each  month at 15 power plants on
    Lake Michigan (1974-1976)	    16

10. Estimated  total  annual  impingement  of  rainbow  smelt  at  all  water
    intakes within  each  statistical  district on  Lake  Michigan  (1975),
    assuming design flow operation at all  intakes	    17

11. Estimated  total  annual  impingement of  yellow  perch   at  all  water
    intakes within  each  statistical  district on  Lake  Michigan  (1975),
    assuming design flow operation at all  intakes	    19

12. Estimated total numbers  of  alewife, rainbow smelt,  and yellow  perch
    eggs and larvae entrained  each  month  during the sampling periods at
    all   15   sampled   power   plants;   estimated  annual   totals  by
    extrapolation to full year for each plant (1975)	    21

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 13.  Estimated  total  numbers of alewife, rainbow  smelt,  and yellow perch
     eggs  and larvae  entrained  during  the sampling periods at each of the
     15  sampled power plants; estimated annual  totals by extrapolation to
     full  year  for  each  plant  (1975)	    21

 14.  Estimated  total  numbers of alewife, rainbow  smelt,  and yellow perch
     eggs  and  larvae entrained  at  sampled  power  plants,  unsampled power
     plants,  and municipal/industrial   intakes  on  Lake  Michigan,  assuming
     design  flow operation (1975)	    23

 15.  Estimated  total  annual  entrainment of  alewife eggs and larvae at all
     water intakes  within  each statistical  district  on  Lake  Michigan
     (1975)  assuming  design  flow operation  at  all  intakes	    23

 16.  Estimated  total  annual  entrainment of  rainbow smelt  eggs  and larvae
     at  all  water  intakes within each   statistical   district  on  Lake
     Michigan (1975)  assuming design flow operation at  all  intakes	    25

 17.  Estimated  total  annual entrainment of yellow perch eggs  and larvae
     at  all  water  intakes within each   statistical  district  on  Lake
     Michigan (1975)  assuming design flow operation at  all  intakes	    26

 18.  Statistical  comparisons between  lakewide monthly mean  impingement
     densities  of alewife,  smelt,  and  yellow  perch for  intake  locations
     and types	    29

 19.  Statistical  comparisons  between   lakewide annual  mean  entrainment
     densities of each species-life stage for intake  locations  and types.    29

 20.  Statistical  comparisons of the monthly  mean densities  (number/1000
     m3) of  impinged  alewife between  dissimilar and similar  intakes  that
     are   "adjacent"   to   each   other.     Underlined   densities   are
     significantly higher  (a = 0.05)	    32

 21.  Statistical comparisons of  the monthly mean densities  (number/m3)  of
     entrained  alewife eggs between dissimilar and similar  intakes  that
     are   "adjacent"   to  each   other.     Underlined   densities   are
     significantly higher  (a =  0.05)	     35

 22.  Statistical comparisons of  the monthly mean densities  (number/m3)  of
    entrained alewife larvae between dissimilar and similar  intakes  that
    are   "adjacent"   to  each   other.     Underlined   densities   are
    significantly higher  (a =  0.05)	     36

23. Statistical comparisons of  the monthly  mean densities  (number/m3)  of
    impinged  smelt  between dissimilar and  similar  intakes  that  are
    "adjacent"   to  each   other.   Underlined densities  are  significantly
    higher (a = 0.05)	     37

24. Statistical comparisons of the monthly  mean densities  (number/m3)  of
    entrained  smelt eggs between dissimilar and similar intakes that are
    "adjacent"   to  each   other.    Underlined densities  are  significantly
    higher (a  = 0.05)	    33
                                       XI

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25. Statistical comparisons of the monthly mean densities (number/m3) of
    entrained  smelt  larvae  between dissimilar and  similar  intakes that
    are   "adjacent"   to   each   other.      Underlined   densities   are
    significantly higher (a = 0.05)	    39

26. Statistical comparisons of the monthly mean densities (number/m3) of
    impinged yellow  perch  between dissimilar  and  similar  intakes that
    are   "adjacent"   to   each   other.      Underlined   densities   are
    significantly higher (a = 0.05)	    41

27. Total catch, pound  net effort  (number of lifts),  and catch per unit
    of effort for alewife in Lake Michigan, 1960-1977	    57

28. Total catch, trap  net  effort (number  of lifts),  and catch per unit
    of effor for yellow perch in Lake Michigan, 1960-1977	    57

29. Total catch, pound  net effort  (number of lifts),  and catch per unit
    of effort for smelt in Lake Michigan,  1960-1977	    59

30. Growth of alewife in Lake Michigan	    61

31. Fecundity of alewife in Green Bay as a function of length	    63

32. Age structure of alewife in Lake Michigan	    63

33. Estimates of alewife parameters for dynamic pool model	    63

34. Standard length  (mm) of yellow perch at the end of each year of life    63

35. Age  structure   of  yellow  perch   population   in   Lake  Michigan  at
    Ludi ngton	    63

36. Estimates of yellow perch parameters for dynamic pool model	    64

37. Estimates of smel t  parameters for dynamic pool model	    64

38. Comparison  of  commercial alewife  catch  from district  WM1 in Green
    Gay and observed impingement at Pulliam Power Plant  during 1975	    83

39. Residual  sums  of  squares for fit of  surplus production  model  to
    al ewi fe catch and effort  data	    83

40. Total catch, trap  net  effort  (number  of lifts),  and catch per unit
    of effort  for yellow perch in Green Bay, 1960-1977	    86

41. Power plant  related parameters for impact  of Pulliam Power Plant on
    yellow perch populations  of Green Bay  (surplus  production  model)	    86
                                     XII

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                                ACKNOWLEDGMENTS

     The authors wish to thank the following people  for  their  contributions  to
this study and to the preparation of the report:

Dr. Ishwar Murarka, Electric Power Research Institute, Palo  Alto,  California.

Ms. Deborah  Bodeau, Environmental  Impact Studies  Division,  Argonne  National
    Laboratory.

Mr. Richard  Freeman,  Environmental  Impact  Studies Division,  Argonne  National
    Laboratory.

Ms. Patricia Tyrolt, Radiological and Environmental  Research Division,  Argonne
    National  Laboratory.

Mr.  Gary  Milburn,  Enforcement  Division,   Region  V,  U.S.   Environmental
    Protection Agency, Chicago, Illinois.

Mr.  Vacys  Saulys,  Great  Lakes  National   Program  Office,  Region  V,   U.S.
    Environmental Protection Agency, Chicago,  Illinois.

Mr. Howard Zar,  Enforcement Division,  Region V, U.S. Environmental  Protection
    Agency, Chicago, Illinois.

Dr. Richard  Hatch,  Great  Lakes  Fishery Laboratory,  U.S.  Fish  and  Wildlife
    Service,  Ann Arbor, Michigan.

Dr.  LaRue Wells,   Great  Lakes  Fishery Laboratory,  U.S.  Fish  and  Wildlife
    Service,  Ann Arbor, Michigan.

Dr. Edward Brown,  Great  Lakes  Fishery  Laboratory,  U.S.  Fish  and  Wildlife
    Service,  Ann Arbor, Michigan.
                                    xm

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                                    SUMMARY

     Two factors  related to  water intakes  have  indicated  the  potential  for
impacts  on  Lake  Michigan  fish  populations:   (1)  the present  annual  water
withdrawal  (capacity) equals  ~260% of the total  inshore  (depth <10 m) volume
of Lake  Michigan,  and  (2)  very  large numbers of  fish  are entrapped by water
intakes.  This  study estimates the numbers  (and  biomass)  of alewife, rainbow
smelt,  and yellow perch  that  were entrapped in 1975 by  all  water intakes on
Lake  Michigan  and  assesses the  impacts  of  these losses  on the  three  fish
populations.

     Impingement and  entrainment  data collected by utilities preparing 316(b)
demonstrations were  assembled into a  computer  data base  by Argonne National
Laboratory.    Based on  the  data  collected between  1974 and  1976  at 16 power
plant intakes, annual estimates  were  made of the  losses  of adults, eggs, and
larvae at sampled and unsampled water intakes on Lake Michigan.

     Impingement  and entrainment  of   the  three  species   are  highly variable
processes in time and space, primarily because of population  movements related
to spawning and seasonal habitat selection.

  -In 1975  the lakewide  impingement  of  alewife  was ~1.5 million kilograms;
   about 70%  of  this total  was  taken at  conventional power  plant intakes.
   Based on'previous  estimates of alewife standing crop biomass, water intakes
   impinged a  maximum of 1.2% of the 1975  standing  crop of  alewife.   Water
   intakes on  the western  shore  of Lake Michigan  and  canal intakes impinged
   the highest densities (number/unit flow) of alewife.

  -Lakewide  smelt   impingement   in  1975  was   ~14  thousand  kilograms  and
   represented a  maximum of 0.1%  of  the standing crop biomass;  about 90% of
   the  lakewide  smelt   impingement  occurred  at  conventional  power plants.
   Water intakes  on the western  shore  of Lake Michigan  impinged the highest
   densities of smelt.

  -A total  of ~9.5 thousand kilograms of yellow perch were impinged in 1975 at
   all water  intakes; no estimates of  standing crop  biomass of  yellow perch
   were  available  from  external   sources.   Approximately  60% of  the lakewide
   impingement of  perch occurred  at  conventional  power  plants  and  40%  were
   impinged in Green Bay.

  -At  least  50  billion  alewife  eggs  and  one billion  alewife  larvae  were
   withdrawn in 1975  by all water  intakes on Lake Michigan.  The majority of
   alewife  eggs   and  larvae  were  entrained   on   Illinois,   Indiana,   and
   southwestern  Michigan   shores.    Based  on   the   temporal   patterns  of
   entrainment, it  appears  that  planktonic  alewife young  are  transported by
   counterclockwise  currents  in  the  southern basin  of Lake  Michigan and may
   "accumulate" in the southern end of the lake.

  -Lakewide entrainment of  rainbow  smelt  eggs and larvae  were estimated to be
   400 million and  50 million, respectively.   As  with alewife, smelt eggs and
   larvae  seemed   to be  transported  by  inshore  currents   and  subsequently
   entrained at  "downstream"   intakes,  especially  on the  southern  (eggs) and
   western (larvae)  shores  of  the  lake.   Smelt  eggs and larvae are vulnerable
   to entrainment for a longer time and by more water intakes than are alewife


                                      xv

-------
   eggs and larvae,  primarily because smelt have slower development times.

  -Although yellow  perch  eggs and larvae  may  have been  entrained,  they were
   not identified at most sampled  intakes.   The highest numbers were observed
   at  water  intakes  on  Green  Bay  and  the  southeastern  shore  of  Lake
   Michigan.  Approximately 40 million yellow  perch  eggs  and 2 million yellow
   perch  larvae were withdrawn in 1975 by all water intakes.

     Three  factors  apparently affected the  impingement and entrainment of the
three  fish  species  at  sampled  water intakes:   (1)  geographic  location; (2)
intake type and  location,  and (3) water  flow.   Comparisons of mean densities
(flow  normalization)  of each  species-lifestage between  all  sampled  intakes
grouped by type, indicated that:

  -Canal  and onshore intakes impinge more alewife/um't volume than do offshore
   open bay or offshore porous dike intakes.

  -Onshore  intakes  and offshore  porous  dikes  entrain  more alewife eggs/unit
   volume,  while offshore  open  bays  entrain  higher  densities of  alewife
   larvae.

  -Canal   intakes  impinge higher  numbers  of rainbow  smelt/unit volume during
   the spawning  season  while  offshore  intakes  impinge higher densities during
   other periods.

  -Offshore intakes entrain more smelt eggs and larvae/unit  volume in general.

  -The very heterogeneous distribution of yellow perch tended to confound the
   comparisons  between  intake  types;   however,  if  Green  Bay   intakes are
   excluded,  offshore   open  bay  intakes  seem  to  impinge  high  densities  of
   yellow  perch.    Canal   and  offshore  open  bay   intakes may be  equally
   destructive of perch eggs and larvae.

  -An analysis of the relationships between numbers impinged/entrained and the
   flows  at  sampled   intakes  suggests  that  -50%   of  the   variability  in
   impingement  and  entrainment of each  species-life  stage is attributable to
   flow, with the exception of alewife eggs where no  relationship was found.

     Two mathematical models  were  applied to (1) describe  the  dynamics  of the
impacted fish populations, (2) estimate stock biomass  and mortality associated
with  water  withdrawal,  and  (3)  simulate the  impact  of present  and increased
water withdrawals.   A  dynamic pool  model  and a surplus production model, both
standard  fishery models, were  applied  to assess  the fish stocks.  Different
types of  data were  applied  to estimate the parameters of  the two models:  the
surplus production  model relies on catch and effort  (commercial fishery)  data,
whereas  the dynamic  pool  model  relies  on  life history  data.   The results
obtained using the  different models were quite  similar.

  -Estimates of  standing stock biomass of  alewife  and rainbow smelt obtained
   from the models  are  higher than those obtained from direct  sampling  of the
   populations by the  Fish  and Wildlife  Service, but  the  direct  estimates are
   considered  minimum  values.   Although  the biomass  estimates in this  study
   could  be in  substantial   error  due to  parameter  assumptions  used  in the
   models,  even  large  errors  in estimation of biomass would  not  significantly


                                     xvi

-------
 alter the conclusions about the impacts of water withdrawal.  Standing crop
 biomass estimates are listed below in the summary table.

-Although the entrainment  and impingement coefficients (rates)  were  low at
 most  sampled  intakes,  the  cumulative  impact  of  total  water  withdrawal
 (lakewide)  is approaching  levels where there may be reason for concern.  At
 total  capacity flow  for all  water intakes, alewife  biomass  is reduced ~3%
 and yield to the  fishery is reduced ~4%;  smelt biomass is reduced ~0.8% and
 yield is reduced  ~1%;  yellow perch  biomass is  reduced ~0.3%  and  yield is
 reduced ~0.5%.   The impacts  on  yield to  the  fishery are higher  than the
 impacts on  biomass.

-The  impact  of  impingement  was   found  to  be  larger than  the impact  of
 entrainment, but  entrainment  impact is more  difficult to determine.   The
 impacts of impingement can be assessed using  methods that are identical to
 those applied for fishery  assessment and  the results appear to be reliable.

-If  the  reductions   in  standing  stock  biomass  and  yield   due  to  water
 withdrawal  are evaluated  as  though no other  stresses are  placed  on these
 fish populations, the  impacts are  small.   Alternatively, if  the  combined
 sources of  mortality are  considered  (e.g.,  predation, fishing, and water
 withdrawal), and  if  the liberal  stocking of  salmonid  fishes  is taken into
 account, the  mortality of  alewife  and  smelt  at water  intakes could  be
 viewed as a significant impact on  populations that may already be  stressed
 by predation from stocked salmonids.   Conversely,  the water intake-related
 losses of alewife and smelt biomass can  be viewed as significant losses in
 the production  of salmonid biomass in Lake  Michigan.
                                  xvi i

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                                                       SUMMARY TABLE
x
<
Estimates for 1975 !
Maximum impingement (kg)
Maximum egg entrainment (number)
Maximum larval entrainment (number)
Standing stock biomass (kg)
Surplus production model
Dynamic pool model
U.S. Fish & Wildlife Service
Percent reduction in standing stock
Impingement
Entrainment
Impingement + entrainment
Maximum sustainable yield (kg)
Percentage reduction in MSY
Impingement
Entrainment
Impingement + entrainment
Al ewi f e
Lake
2
7
1

2
2
1

2
0
2
3

3
0
3
Michigan Total
.10
.39
.31

.06
.37
.22

.45
.41
.86
.00

.42
.56
.98
x 106
x 1010
x 109

x 108
x 108
x 108




x 107




Rainbow Smelt
Lake
1
6
8

2
2
1

0
0
0
2

0
0
1
Michigan Total
.86
.15
.28

.53
.47
.37

.46
.30
.76
.50

.71
.46
.18
x lO1*
x 108
x 107

x 107
x 107
x 107




x 106




Lake
1
4
3

1
1




0
7



0
Yellow Perch
Michigan Total Green Bay
.31 x ID1*
.81 x 107
.26 x 106

.07 x 107
.00 x 107
-

-
-
.28
.42 x 105

~ -
-
.47
5.00 x 103
1.20 x 107
2.40 x 106

5.21 x 106
_
-

-
-
0.61
3.50 x 105

-
-
1.03

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                                 INTRODUCTION

     As  of  1975,  the  combined  capacity  for  water  withdrawal   by  all  power
plant, industrial, and municipal water intakes on Lake Michigan  exceeded  1.2  x
1013 gal  (4.8  x 1010 m3) per year;  this  volume  represents ~26Q% of the  total
inshore water  (<10 m deep)  of the lake.   Based on our calculations, all  power
plant intakes  (including Ludington Pump-Storage) have the capacity to  withdraw
4.2 x 1010 m3  per year  (230% per year) while Ludington has  a  capacity  of  2.1  x
1010 m3  per year  (115% per year).   Although  many  intakes  are not  operated
continuously or  at  full  capacity, it is  safe  to  assume that a  volume equiva-
lent to the entire inshore volume is withdrawn by water intakes  in less than  6
months.

     Aside from the  considerations of consumptive water use,  the withdrawal of
such large  volumes  of inshore water  could  have  biological/ecological  impacts
since the  inshore  waters of Lake Michigan  serve  as  spawning areas, migratory
routes,  and   habitats   for  many   species   of  fish  that   have  commercial,
recreational,  and trophic  importance.   Free-swimming adult fishes are subject
to  entrapment  by  water intakes,  and  subsequent  impingement  on  traveling
screens.  Immature fish  (ichthyoplankton) are subject to entrapment  and subse-
quent  entrainment  into  industrial,  utility  or  municipal  process  streams.
Despite efforts to develop  intake  structures that reduce fish impingement  and
entrainment,  no  reductions  in  intake-related   fish   mortalities  have  been
affected  in Lake  Michigan,  except  for  external  modifications such as  the
behavioral barrier placed around the Zion intake.

     Numerous  species of  fish  are  entrapped  by water  intakes  around  Lake
Michigan and the  populations  of many of  these  fishes  have fluctuated greatly
in recent years.  Numerous  factors  influence the dynamics  of fish populations
in  Lake  Michigan, not  the least  of which  are  (1)  predation  by piscivorous
fishes  (salmonids) and  man;  and (2) competition  between  species with similar
niche  requirements.    It has  been  hypothesized  that  the  added mortality of
fishes  at  water  intakes  may   constitute  a  significant  stress   on  some
populations, but  little  effort  has  been expended  to  test  this hypothesis.
CDM/Limnetics  [1]  conducted  a  study which estimated  the losses  of  adults,
larvae and  eggs  of  every fish species entrapped  at  17  power plant  intakes on
Lake Michigan.  These estimates  indicated that approximately 93% of the  total
number of fish  impinged  were  alewife (Alosa pseudoharengus), ~5% were rainbow
smelt (Osmerus  mordax),  and ~0.5% were yellow perch iPerca  flayescens).   The
total  biomass  impinged  of each species was  estimated  to  be 0.06% of  the ale-
wife and  0.07% of  the smelt standing crops in  Lake  Michigan in  1974;  neither
fractional mortality was considered to be stressful.

     The present study was  designed  to  provide  independent estimates  of  lake-
wide  impingement and  entrainment-related   fish  mortalities  and an   initial
assessment  of  the  effects of  this  additional  mortality  on  the  population
dynamics  of  three   economically  important  species:    alewife,  smelt,   and
perch.   These  species were chosen for study because (1)  each is important in
the fisheries  of Lake  Michigan,  (2)  alewife and  smelt are critical forage
species for the huge numbers  of  salmonid  fishes  introduced into  the lake,  and
(3) each  species  suffers large  intake-related  mortalities at  some  or all  of
the water intakes on Lake Michigan.

     The  objectives  of  this  study were  to (1)   collect  extant  data   on fish

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impingement and  entrainment  at sampled power plant  intakes and estimate mor-
talities at  all  unsampled intakes,  thereby  developing a  lakewide data base;
(2) compare species-specific losses between intake types and locations  on Lake
Michigan;  (3)  compare  the  losses  of each  species  with  previous (1975)  and
present  estimates  of population  standing  crop  biomass; and  (4)   simulate the
effects  of  intake-related  fish  mortality on  species'  production,  standing
crop, and yield  to  the  fishery.   In all  calculations,  it  was assumed that all
entrapped adults, larvae and egg die, i.e., a worse case assessment.

     The impact  of  entrainment  and impingement cannot be assessed directly.
To determine the proportion of a population that is impinged or entrained, the
number  or  biomass  of  the  impacted  population must  be  known  or estimated.
Direct estimates of  abundance  are  difficult  and costly for large  populations,
so  a mathematical   model  was  applied  to  estimate  fish  abundances  in Lake
Michigan using  commercial  catch  and effort  data.    Mathematical  models also
were applied to  simulate the impact on standing stocks  and yields  under exist-
ing and increased water withdrawals from Lake Michigan.

     Models applied  for  power  plant assessment  have not been of the same form
as  models   applied  for  assessment  of  the   impact  of  fishing  on  fish
populations.   Models constructed by  persons  with  engineering backgrounds are
often linear compartment types that do not adequately  represent the biology  or
have poorly defined  biological  variables  that are  difficult to estimate.  The
models most  commonly used  by biologists are  of the Leslie-matrix type [2-6].
These models are useful  for  population  projection  and  consider the population
age structure; but  application  requires  estimation  of a large number of para-
meters that are  difficult  to  estimate.   Also, these models require specifica-
tion of  compensation mechanisms  and  this  aspect has  been controversial [7].
Finally, this  approach  requires  good estimates of. mortality  and growth for
early life  history  stages.   Swartzman, Deriso,  and  Cowan [8] have critically
compared several  models applied  for  power plant impact  assessment.    A major
difficulty for workers  in  environmental  impact  assessment is that, typically,
results  are  required at  once  and there is little time  to  gain experience with
different methods.

     In  fisheries  studies  three models have  been  developed for assessment  of
the  impact  of  fishing.   These models were  developed between  the late 1920's
and early  1960's,  a period  of 30 years.   Development  of these models was slow
and it was  accompanied  by  the  development of an understanding of  the problems
of  parameter  estimation and of  how to work with less than a complete under-
standing of how  fish  populations compensate for fishing.   The three models are
usually  termed the  surplus  production model,  dynamic pool model,  and spawner-
recruit model.

     Surplus  production models  relate  the  biomass  and  productivity  of the
stock directly  to yield.   These are  the  simplest  to  develop  and apply, but
many  assumptions  are necessary.   Application  to  laboratory  and  wild fish
populations  indicates that  this type  of model is  useful  for  estimation  of
population  abundance and for  determining  the level  at which  a population  is
being exploited  [9].

     The  dynamic pool  model  is  now  the most  widely  applied  type for  stock
assessment.  This  model  combines data on  growth,  reproduction, and mortality
and  is  both  flexible and easy to apply.  Structurally,  the dynamic pool model

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 is  more readily  understood  than the  surplus  production model, and  it  can be
 expanded  easily  to include  new  information.    Application  of  dynamic  pool
 models  requires  a considerable amount of information  on growth and age struc-
 ture.

     Spawner-recruit models  have been  applied  in power plant impact assessment
 studies  [7],  but they were  developed  for salmon populations  exhibiting clear
 spawner-recruit  relationships,  where  data for  numbers  of spawners  and recruits
 are  obtainable.    For  most  species, estimates of  numbers  of  spawners  and
 recruits are  difficult to  obtain,  and  no  clear  relationship between the number
 of  spawners and  the number of  recruits is detectable.

     In  this   study  both  the  surplus production model  and the dynamic  pool
 model  are  applied to  estimate the biomass  of  the  population, number  of  eggs
 produced,  and  number  of  larvae  produced.   These  estimates  are  applied to
 determine  the  proportions  of each population impinged  and  entrained,  and  then
 to  estimate  coefficients  of  entrainment  and   impingement.    The  models  are
 applied  to examine the  impact on standing  stock,  biomass, and yield  of  fish
 populations due  to  present and increased  rates  of water withdrawal.

     The surplus production  model and dynamic  pool  model  apparently  have  not
 been applied  for power plant assessment but several components of  the dynamic
 pool model  have  been applied [10-13].  Application of  fisheries models for  the
 assessment of  environmental  impact takes  advantage of  the considerable experi-
 ence gained  through the assessment  of the  impact  of  fishing  on fish  popula-
 tions.   Application of  the surplus  production  model  and dynamic pool  model
 together  for   power plant assessment  gives a  degree  of  confidence  in  the
 results  that  is  not attained with application of either model  alone.   The  two
models  are entirely different  structurally and the data  for  parameter estima-
 tion in the two  models  are  entirely  different.   Close  agreement  between  the
 results  of  the  two  simulations  with  different  models  would  constitute
 "independent"  corroboration  of the assessment.

     For  estimation  of  power  plant-related  model  parameters,  full  design
volume  flow  has  been  assumed  and  numbers  and  biomass entrained  or  impinged
have been extrapolated to  design  flow  conditions.


                  ACQUISITION AND  DEVELOPMENT OF  THE DATA BASE

                             Sampled Power Plants

     This  study   relied  exclusively  on  extant  data  provided  by  the  various
electric utilities that conducted  316(b)  studies  and by federal/state  resource
agencies.   Fish impingement  data  initially  were  obtained  for   a  study   of
impingement throughout the United States  [14];  entrainment  data were  obtained
subsequently and  added to  the  data base.  Since  variations  in  daily flow rates
are  common,  especially  at  coal-fired power  plants   that  are  operated in  a
peaking mode,  we obtained daily average  flow  rates  for  each  of  the  sampled
plants  during   their  respective  periods  of  impingement  and   entrainment
sampling.

     The impingement and entrainment data bases  exist  as permanent  batch-only-
accessible  data   sets.    They  reside  within the  large  capacity  pool  of Itel

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7330-12  storage  disc  drives   shared  by  Argonne  National  Laboratory's  IBM
370/195 and  IBM 3033 computer  systems.   Statistical  analyses were  performed
using  the  Statistical  Analysis  System  (SAS  79.2B  version)  [15].    Graphical
output was  achieved  by using  an  interface  (SASMYPLT)  [16]  between the  SAS
package and  the PLOTIN/MYPLOT  [17]  general  purpose  plotting  program.    This
interface,  developed  by the  Radiological and Environmental Research  Division,
results in the production of publishable quality graphics.

     Table 1  summarizes the  design  characteristics  and sampling intervals  for
16  power  plants  and Figure  1  shows  the  locations  of these  plants on  Lake
Michigan.   Unfortunately, neither the  sampling  schedules nor the methods  were
standardized  among  plants.   Most plants were  sampled  for impingement  during
the  major   portion   of   1975,  except  for  Bailly,   Michigan   City,   Campbell,
Palisades,  and  Big  Rock; only  two plants (Zion  and Cook)  were  sampled for two
consecutive  years,   providing   some  temporal  comparison.    The  most   common
schedule was  to collect  an  integrated  sample  (<24  hours)  every  fourth  day;
only one plant  (Cook) was sampled daily  for impingement.   Entrainment sampling
was initiated  in  1975 at all but one  plant  (Big Rock) and continued for  less
than one year  at all  plants  except  Cook, Bailly, Campbell, and  Big Rock where
at least one  full  year of data were collected.   Most plants were not sampled
for entrainment from January  through  March.    The  most  common schedules  of
entrainment sampling  were  every fourth  day or  once  per week, and most  plants
were sampled in the intake stream.

     It is difficult  to evaluate  the  effects of variable methods  on  the esti-
mation of  fish impingement  or  entrainment  as  reported by  the utilities;  we
made  no  attempt to  normalize  data for  these  potential  sources of  variance.
Murarka  et  al.  [18]  compared  various  impingement  sampling  designs   and
concluded that the stratified-systematic scheme is superior to  the systematic-
random sampling scheme  used by most of the utilities on Lake  Michigan.

     Power plant  data sets  that spanned less than  one full year were extrap-
olated to a full year by assuming a  linear reduction from  the  last data  entry
to zero at the end  of  the year and/or  linear  extrapolation  from  zero  to  the
first  data  entry  for  the year.    This  procedure  allowed the  estimation  of
annual impingement and  entrainment values for all sampled  power  plants.

     If samples  were not  collected  daily  (all  plants except Cook), missing
daily values were estimated (interpolated) by means of  the  following  equation:


     Ii+s = (A1 + sR.^) x f.+s for s =  1, 2, .  . ., j-i (j-i  >  0)
where

     „    . AJ - *i
             j • i
                    f or all j > 1 •
    A^ , Aj = observed impingement/entrainment rates  for  the  i   ,  jth  days.
    I.j+s = impi ngement/entrai nment value for (i+s)   missing observation.
    fi+s = water intake flow rate for the  (i+s)th missing  observation.

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en
        Table 1.   Intake  sampling  and  design  characteristics  for  16  sampled power plants on Lake Michigan.
Plant (ID)
Zion (1)
D. C. Cook (2)
Bailly (3)
Michigan City (4)
Pulliam (5)
Kewaunee (6)
Point Beach (7)
Port Washington (8)
Lakeside (9)
Oak Creek (10)
Waukegen (11)
State! ine (12)
D. Mitchell (13)
J. H. Campbell (14)
Palisades (15)
Big Rock (16)
Approx.
MWe
2100
2200
615
715
390
525
1030
400
345
1670
1100
960
415
645
840
75
Intake
Design
OOBa
OOB
PD
CNL
CNL
OOB
PD
CNL
PD
CNL
CNL
PD
PD
CNL
OOB
PD
Maximum Flow
(mVyr)
3.
3.
6.
5.
7.
8.
1.
1.
8.
2.
1.
1.
8.
5.
1.
9.
48
27
70
97
75
22
53
09
73
45
43
65
23
97
19
55
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
109
109
108
108
108
108
109
109
108
109
109
109
108
108
108b
107
Impingement
Sampling Dates
02/28/74-12/31/75
02/01/75-12/30/76
11/07/75-11/10/76
12/03/75-06/28/76
04/04/75-03/22/76
04/01/75-03/17/76
03/04/75-02/28/76
03/03/75-02/25/76
03/07/75-02/06/76
03/04/75-02/27/76
05/12/75-04/28/76
04/05/75-03/30/76
05/03/75-04/27/76
Jan 74-Mar 75
Mar 74-Mar 75
Feb 74-Mar 75
Schedule
every 4th day
daily
every 4th day
every 4th day
every 4th day
every 4th day
every 4th day
every 4th day
every 4th day
every 4th day
every 4th day
every 4th day
every 4th day
24 hrs/week
24 hrs/week
24 hrs/week
Entrainment
Sampling Dates
04/16/75-09/17/75
01/01/75-12/31/75
11/07/75-11/10/76
N/AC
04/09/75-08/27/75
04/01/75-12/15/75
04/18/75-10/31/75
04/15/75-10/28/75
05/20/75-10/29/75
04/17/75-10/30/75
04/16/75-09/03/75
04/05/75-09/04/75
05/03/75-09/20/75
01/29/75-03/24/76
03/27/75-02/03/76
02/07/74-03/19/75
Schedule
I/week
daily
every 4th day
N/A
24 hrs/week
I/week
every 4th day
every 4th day
every 4th day
every 4th day
I/week
every 4th day
every 4th day
24 hrs/week
24 hrs/week
24 hrs/week
Location
discharge/intake
discharge
discharge/intake
N/A
discharge/intake
intake
intake
intake
intake
intake
discharge/intake
discharge
dicharge/intake
intake
intake
intake
        a OOB =  offshore  open  bay;  PD  = porous  dike;  CNL  = canal.
        b All plants operate once-through  except  Palisades which  utilizes  cooling towers.
        c Entrainment  information  reported for  Michigan  City  not  useful  for this analysis.

-------
      PULLIAM
PORT WASHINGTON








         LAKESIDE



      OAK CREEK
           ZION NUC


           WAUKEGAN
                                                            J. H.CAMPBELL
                                                            PALISADES  NUC


                                                        DONALD C. COOK NUC
                                                                          BIG ROCK NUC
          STATE LINE
                                              MICHIGAN CITY


                                          BAILLY
                             DEAN H. MITCHELL
Fig.  1.   Map  of Lake Michigan  showing  locations  of sampled power plants  and
statistical districts.LlJ

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This method  provides  a  weighted  linear  interpolation  between successive obser-
vations on impingement  and entrainment  variables.   The  impingement/entrainment
processes are  approximated by  linear  segments.

     Entrainment  data  for  D.  C. Cook  were  received in  a reduced  form  where
numbers  of  each  fish  group were  reported  as  totals  for  irregular  time
periods.   These  totals  were divided  by the  number  of days  in   the  sample
period,  thereby  producing  average daily  values  for the period.   No  useful
entrainment  data  were  obtained  from   the  Michigan  City  plant;   therefore,
Michigan City  was treated as  an  unsampled  plant  for entrainment calculations.

     Observed,  interpolated,  and  extrapolated  daily  values  were  summed  by
month and year for each sampled  plant.   For  each  of the three species,  numbers
and  weights  impinged,  and  number   of  eggs   and  larvae   entrained   were
calculated.   These totals were  termed  "observed"  values even  though  missing
daily values were estimated by  interpolation  and extrapolation.  Age  classes
or  size distribution  of  impinged fishes  were  not  reported  for   most  power
plants.    Egg  and  larval  categories  were  used  for entrainment  because  no
standard  categories   were  reported by  the  various  utilities.   Some  utility
reports  identified   larval  and  "juvenile"   stages;   in these cases,   both
categories were considered to  be  larvae.

     Egg entrainment  data for D.  C.  Cook were  reported as  a total   for  the
three  species  (i.e.,  no egg  identification  was made).   Species totals  were
estimated assuming 90% of the total  to be alewife eggs, 4%  to  be smelt  eggs,
and  1%  to be  perch   eggs  [19].    A similar problem  was encountered with  the
Pulliam  egg  entrainment  data except  egg diameters  were reported.    In  this
case,  we  estimated  the fractional  species  total  by  assuming ranges in  egg
diameters for  each species during the time periods that  each  would be  expected
to spawn (e.g., smelt eggs = 0.6-1.3 mm, April-May; alewife  eggs = 0.6-1.3 mm,
June-July; yellow perch = 1.6-2.3 mm, May-June).

     Using the "observed" daily  data  for each sampled plant,  we generated the
data base which estimates the monthly  and annual  totals by  fish category  and
by plant for the sampling periods, based  on actual  flows.   An "extrapolated"
data base  was  generated  which estimates  the  maximum  impingement/entrainment
losses as if all  plants had  operated at maximum  (capacity)  cooling  water flow
rate over  the  full  year.   These extrapolations  were based  on the  ratios  of
actual/design  flows.

                               Unsampled Intakes

     Since the impingement/entrainment  data base  only  represents fish  losses
at 16 of the 22 power  plants  on  Lake  Michigan and does  not  include estimates
for  other water intakes sited on  the lake,  we developed a  list of all  other
intakes and  their capacity flows (Table  2).  Assuming capacity  flow  throughout
the  year,  we  estimated  the  annual  impingement 'and entrainment  values  for
unsampled intakes by multiplying the mean impingement and entrainment  rates  at
all  sampled  plants  in the same  region  (statistical  district)  by the  capacity
flows at unsampled intakes.

     Although  we  considered  methods of  estimation that  would account  for  the
influence of intake   type and spatial  heterogeneity  in  fish abundances,  the
extant information on unsampled intakes  [20] is not very  descriptive of design

-------
Table 2.   Locations  and  design flows of unsampled water intakes on Lake  Michigan^20]
Plant Name Plant Type
Lake City Public Water Department
Waukegan Water Utility
Johns-Manville Products
US Steel Works
Johnson Outboards
Abbott Laboratories
City of North Chicago
Great Lakes Naval Station
City of Lake Forest
Fort Sheridan-US Army DFAE
Highwood Water Plant
Highland Water Plant
Village of Glencoe
Mark Dalin temorial Plant
Village of Winnetka
Kennilworth Water Filtration Plant
Wilmette Water Works
City of Evanston Water and Sewer Dept
City of Chicago Dept Water and Sewer
John G Shedd Aquarium
Hammond Water Dept
Lever Bros Co
Whiting Filtration Plant
American-Maize Prod Co
American Oil Co-Whiting Refinery
East Chicago Water Dept
Inland Steel Co
Youngstown Sheet and Tubing
Gary-Hobart Water Corp
Union Carbide-Linde Div
Universal Atlas Cement
US Steel
Midwest Steel
Bethlehem Steel -Burns Harbor
Michigan City Dept of Water Works
American Playground and Device Co
Escanaba Mun Water Utility-Sand Point
Mead Paper Co
Escanaba Generating Station
Gladstone Water Treatment
Gladstone Generating Station
City of Manominee
Inland Lime and Stone Co
City of Mi chi ana
City of New Buffalo
City of Bridgman
St Joseph Water Filtration Plant
City of Benton Harbor Water Dept
South Haven Water Treatment Plant
Holland Water Treatment Plant
Wyoming Water Treatment Plant
City of Grand Rapids
City of Grand Haven Water Treatment Plant
Muskegon Hts Water Treatment Plant
City of Muskegon Water Treatment Plant
Ludington Water Filtration Plant
Ludington Pump-Storage Facility
City of Traverse City
Bayside City Light and Power Co
Medusa Portland Cement
Penn-Dixie Cement Corp
MaHnette Water Works
Green Bay Water Dept
Two Rivers Water and Light Dept
Manitowoc Public Utilities
Manitowoc Power Plant
Sheboygan Water Utility
Edgewater Power Plant
City of Glendale
City of Pt Washington Filtration Plant
City of Milwaukee
North Shore Water Commission
Univ of Wis- Milwaukee- Central Plant
Cudahy Water Utility
South Milwaukee Water Utility
Racine Water Dept
Kenosha Water Utility
MUN
UTI
IND
IND
IND
IND
MUN
MUN
MUN
MUN
MUN
MUN
MUN
MUN
MUN
MUN
MUN
MUN
MUN
MUN
MUN
IND
MUN
IND
IND
MUN
IND
IND
MUN
IND
IND
IND
IND
IND
MUN
IND
MUN
IND
UTI
MUN
UTI
MUN
IND
MUN
MUN
MUN
MUN
MUN
MUN
MUN
MUN
MUN
MUN
MUN
MUN
MUN
UTI
MUN
UTI
IND
IND
MUN
MUN
MUN
MUN
UTI
MUN
UTI
MUN
MUN
MUN
MUN
MUN
MUN
MUN
MUN
MUN
Statistica
District
ILL
ILL
ILL
ILL
ILL
ILL
ILL
ILL
ILL
ILL
ILL
ILL
ILL
ILL
ILL
ILL
ILL
ILL
ILL
ILL
IND
IND
IND
IND
IND
IND
IND
IND
IND
IND
IND
IND
IND
IND
IND
MH1
Mm
Mm
MM
Mm
Mm
Mm
MW2
MM8
MM8
MM8
MM8
MM8
MM3
MM7
MM7
MM7
MM7
MM7
MM7
MMo
MM6
MM4
MM4
MM3
MM3
wm
WML
wm
wm
wm
WM5
WM5
WM5
WM5
WM5
WM5
WM5
WM5
WM5
WM6
WM6
1 Design
(gal/min)
1,389
6,944
1,389
2,244
2,778
11,111
2,431
4,167
2,083
521
278
5,729
1,319
2,222
2,639
311
5,208
16,667
709,023
139
18,055
3,819
1,042
9,028
92,361
11,805
749,997
318,748
20,833
69,120
2,244
568,669
17,361
305,000
5,000
449
1,389
20,833
16,667
1,500
3,600
1,181
5,000
494
1,391
404
4,200
4,167
1,389
4,444
10,903
24,305
5,835
294
7,639
2,082
29,668,626
3,472
13,194
1,795
1,346
1,389
10,764
4
5,555
13,465
9,028
131,956
15,260
4,167
116,367
4,028
3,125
4,514
2,778
15,833
12,068
Flow
(mVntin)
5
26
5
8
11
42
9
16
8
2
1
22
5
8
10
1
20
63
2,684
1
68
14
4
34
350
45
2,839
1,207
79
262
8
2,153
66
1,155
19
2
5
79
63
6
14
4
19
2
5
2
16
16
5
17
41
92
22
1
29
8
112,309
13
50
7
5
5
41
0
21
51
34
500
58
16
441
15
12
17
11
60
46

-------
 and the available  data on  fish  abundances do not  have  the necessary spatial
 definition.   Some sampling of adult fish and ichthyoplankton in inshore waters
 was performed  at each  power plant  required  to  do  316(b)  studies,  but the
 methods  and  periods  of  sampling  were  not  standardized  between  locations.
 Consequently,  utility  data  on fish abundances  could not  be  compared between
 intake  sites and were  not useful for  adjusting impingement/entrainment rates,
 based on  fish  abundance.

     Lakewide  estimates of  impingement  and entrainment-related mortalities of
 alewife,  smelt,  and yellow  perch  are  reported  as  totals  for (1)  all  power
 plant  intakes  excluding the Ludington Pump-Storage  Power Plant;  (2)  all  power
 plant intakes  including Ludington;  (3) all  other  intakes;  and (4)  all intakes
 on  Lake  Michigan.   These  results provide  the  only  estimates  of total intake-
 related fish mortalities  for Lake Michigan, albeit 6 years after the fact.


                             IMPINGEMENT ESTIMATES

                     Alewife Impingement -  Sampled  Intakes

     Impingement  rates  of  alewife at  the 16 sampled power plants were strongly
 dependent  on  time of year and location  in  Lake Michigan.  Maximum impingement
 of  alewife occurred from  May through July,  with  the largest  numbers  (1.93  x
 107) and biomass  (7.03  x  105 kg)  impinged  in May (Table  3).  Approximately 95%
 (1.8 x  107)  of the  May 1975 impingement occurred  at the  Zion plant  and  this
 inordinately high value was  the  direct result of a delay in the positioning of
 a behavioral  barrier (screen) around  the  intake [1]; in  1974,  the  screen was
 in  place  in May  and the  numbers of  alewife  impinged  that month at  Zion was
 -3.8 x  105.    It  is evident  that the high  impingement  rates  in early  summer
 reflect the  inshore  spawning migrations of  adult alewife rather  than seasonal
 changes  in total  cooling water  flow.   Likewise,  the  reductions in  alewife
 impingement  from  December through March  reflect the offshore  movement of the
 alewife population  during early winter.   A small  peak  in  alewife  impingement
 occurred in October  and November  prior to  the winter migration offshore.

     The  annual  total  alewife  impingement at  the  sampled  power  plants  was
 estimated  to  be  2.67  x 107  (9.17  x  10$ kg).   Almost  90% of this  total  was
 impinged at four  of  the 16 sampled  power plants (Table  4):  69%  at  Zion  (1.83
 x 107), 9% at  Port  Washington (2.41 x 106),  6%  at  Oak Creek (1.70  x  106), and
 4%  at Point  Beach  (1.19  x 106).  Figures  A.l.a-A.16.a  (Appendix A)  show the
 daily densities of  alewife impinged at each sampled  plant.   The  maximum daily
 densities  were  <10  alewife/1000  m3  at   all  plants  except  Zion  and   Port
 Washington  where  the   maximum  densities  were  400  and  40  alewife/1000   m3,
 respectively.   Relatively high  impingement  densities  (>0.1 alewife/1000  m3)
were sustained between April  and  November at five  of  the  sampled  plants:
 Zion, Waukegan, Port Washington, Point Beach,  and Kewaunee.   These plants  have
no  common  attributes other than their locations  on the western shore of  Lake
Michigan.    The combination  of  relatively   high  alewife  densities  and total
flows resulted in the  dlsporportionate impingement of alewife  at a few plants
on  the  western shore.   The relatively  low impingement densities at the plants
sited on the eastern shore (Cook, Palisades, Campbell, and  Big  Rock)  probably
reflect  a  general  trend toward lower alewife densities along this shore.

     The  timing of the major influx  of alewife  (rapid increase  in impingement)

-------
    Table  3.   Estimated  total  number  and  biomass  of  alewife,  rainbow smelt,  and yellow perch
    impinged each month  at  all  16  sampled  power plants  (1975).
Total Flow
m3
January
February
March
April
May
June
July
August
September
October
November
December
8.57 x
7.39 x
7.88 x
9.01 x
1.02 x
9.93 x
1.16 x
1.18 x
1.05 x
1.09 x
9.63 x
9.62 x
108
108
108
108
109
108
109
109
109
109
108
108
Al ewi f e
Number
8.08 x
4.82 x
2.47 x
6.08 x
1.93 x
3.83 x
1.69 x
4.75 x
1.06 x
1.77 x
1.94 x
2.15 x
102
102
10"
105
107
105
106
105
105
105
105
10"
Kg
2.10 x
1.20 x
7.46 x
2.53 x
7.03 x
1.09 x
4.48 x
1.40 x
3.00 x
3.74 x
1.92 x
3.86 x

101
101
102
10"
105
105
10"
10"
103
103
103
102
Smelt
Number
1.34 x 10"
1.18 x 10"
3.05 x 10"
1.41 x 105
4.61 x 10"
3.58 x 10"
1.22 x 10s
9.03 x 10"
6.91 x 10"
1.23 x 105
4.61 x 10"
3.48 x 10"
Kg
2.31 x 102
3.18 x 102
1.24 x 103
2.13 x 103
5.23 x 102
4.88 x 102
1.24 x 103
7.33 x 102
4.46 x 102
6.96 x 102
5.42 x 102
1.05 x 103
Perch
Number
6.99 x
2.82 x
3.95 x
5.55 x
7.89 x
1.89 x
2.60 x
1.83 x
2.03 x
6.26 x
2.79 x
1.05 x
103
103
103
103
103
103
103
103
103
10"
10"
10"
Kg
8.20 x 101
6.80 x 101
9.50 x 101
3.56 x 102
5.27 x 102
1.52 x 102
2.70 x 102
1.52 x 102
8.80 x 101
6.27 x 102
4.62 x 102
1.53 x 102
    Total
    observed    1.17  x 1010  2.65 x 107  9.07  x 10s  7.64 x 105  9.63 x 103  1.37 x 105  3.03 x 103

    Estimated
    annual
    total            -      2.67 x 107  9.17  x 105  7.69 x 105  9.77 x 103  1.39 x 105  3.11 x 103
Table 4.  Estimated total number and biomass of alewife, rainbow smelt, and yellow  perch  impinged
annually at each of the sampled power plants on Lake Michigan  (1975).
Total Fl ow
m3
Zion
Cook
Bailly
Michigan City
Pulliam
Kewaunee
Point Beach
Port Washington
Lakeside
Oak Creek
Waukegan
Stateline
Mitchell
Campbel 1
Palisades
Big Rock
Total observed
Estimated annual
total
2.04
1.32
4.71
1.01
3.34
6.70
1.21
5.74
2.64
1.64
9.32
1.02
5.11
4.17
1.22
8.20
1.17


x 109
x 109
x 108
x 108
x 108
x 108
x 109
x 108
x 108
x 109
x 108
x 109
x 108
x 108
x 108
x 107
x 1010

-
Alewife
Number
1.83 x
1.73 x
1.21 x
1.03 x
5.78 x
1.79 x
1.19 x
2.41 x
4.79 x
1.70 x
7.66 x
6.57 x
1.46 x
4.54 x
3.14 x
9.50 x
2.65 x

2.67 x
107
105
105
105
105
105
106
106
10"
106
105
105
105
10"
102
101
107

107
Kg
6.80 x 10s
5.11 x 103
4.52 x 103
N/A
2.46 x 10"
4.84 x 103
3.74 x 10"
6.11 x 10"
1.40 x 103
3.29 x 10"
2.80 x 10"
2.19 x 10"
3.68 x 103
1.10 x 103
1.22 x 101
3.51 x 10°
9.07 x 10s

9.17 x 105
Smelt
Number
5.80 x
4.11 x
7.54 x
3.23 x
7.30 x
1.91 x
1.76 x
7.79 x
1.19 x
4.09 x
9.81 x
8.55 x
3.25 x
5.39 x
1.40 x
1.28 x
7.64 x

7.69 x
10"
103
102
102
103
10"
10s
10"
102
105
103
102
102
102
101
102
10s

105
Kg
2.48 x 103
5.10 x 101
1.70 x 101
N/A
2.73 x 102
4.75 x 102
1.26 x 103
8.95 x 102
2.00 x 10°
3.76 x 103
3.77 x 102
2.30 x 101
4.00 x 10°
1.07 x 101
2.27 x 10'1
2.38 x 10°
9.63 x 103

9.77 x 103
Perch
Number
5.85 x 102
1.28 x 10"
6.66 x 102
2.89 x 102
1.18 x 105
2.40 x 102
2.55 x 102
2.62 x 102
1.80 x 101
1.43 x 103
3.21 x 102
1.24 x 103
5.16 x 102
3.42 x 102
1.10 x 101
1.70 x 101
1.37 x 105

1.39 x 105

6.90
3.97
4.40

2.14
4.00
3.90
2.30
3.00
1.06
3.80
8.20
4.60
7.14
1.13
2.04
3.03

3.11
Kg
x 101
x 102
x 101
N/A
x 103
x 101
x 101
x 101
x 10°
x 102
x 101
x 101
x 101
x 10°
x 10"1
x 10°
x 103

x 103
                                                 10

-------
 In  the spring  was  highly  dependent  on latitudinal  location.   Plants  on  the
 southern  basin  of the lake  experienced initial  high impingement  densities  in
 March  or  April  while  those on the northern basin  experienced  alewife influxes
 during  late  April  and May.   This  apparent locational effect on the  timing  of
 inshore  migrations  is  undoubtedly  linked to  the  different  inshore  warming
 rates  between  north  and  south locations.   The  Pulliam  plant  was  somewhat
 unique  in that  no alewife  were  impinged until  mid-May,  indicating  a complete
 absence of alewife from  southern  Green Bay  between  January and  April,  and  a
 massive influx  in May.

     Although most  plants impinged very few alewife  during  the winter months,
 relatively high and sustained  densities of alewife were  impinged during winter
 at  Port Washington, Waukegan,  and Zion and  less  frequently at other plants.
 Only  the  Pulliam,  Lakeside,  Oak  Creek, and  Big  Rock  plants  did not impinge
 alewife during  mid-winter.   Impingement totals  during winter months  (Table  3)
 were relatively low compared with  other seasons  but the  indication of periodic
 inshore movements  or  continued inshore  residence  by alewife during  winter  is
 rather  enigmatic.   Table 5 summarizes the  mean  weights of alewife  impinged
 each  month  and year  at  the  sampled  plants.   The  mean  weights of  alewife
 impinged  during winter months  were  often  greater than  during  other  months,
 indicating  that the  largest/oldest  alewife  either  (1)  tend to  precede  the
 general population  in  the  spring  spawning migration, or (2) that some larger
 alewife tend to remain/migrate  inshore  during the  winter.   The mean  weights  of
 alewife impinged  during  and after the  major  spawning runs  tended to  decrease
 with  time (May  through   November),  indicating   a  size-related timing  to  the
 spawning  migration or to  inshore  distributions  of alewife.  This  relationship
 may be a  function of size-related  temperature preferences [21] and the natural
 temperature cycle of inshore waters.

     Secondary  peaks in alewife impingement occurred  in  the  fall at  about half
 of  the  sampled  plants  (Figs. A.l.a-A.16.a),  with  no apparent effect  of loca-
 tion  on  the  occurrence  of this  fall   peak.    Beginning  in  September  1974,
 October  1975,   and  September  1976  (Table  5)  the  lakewide mean  weights  of
 impinged  alewife decreased  markedly and remained low  for  2-3 months  each year,
 reflecting the  predominance of very  small  alewife (5-10 g), presumably  young
 of  the year (YOY).   Most plants   that  experienced  fall  peaks  in  alewife
 impingement  showed  concurrent decreases in mean  weights of alewife,  implying
 offshore  to   inshore  movements  by  YOY alewife  at  that time  and  location.
 Lakeside  (Fig.  A.9.a)  and  Zion  (Fig. A.I.a)  impinged  substantial numbers  of
 alewife in the  fall  of 1975,  but  showed minimal  decreases  in mean weights  of
 impinged  fish;  however, Zion  experienced a  major influx of  YOY alewife in the
 fall of 1974.

     Although the evidence  in  Table  5  is   equivocal,   the  lakewide  average
weights of alewife may have increased between 1974 and 1976.  Zion  data indi-
cate an increase  between  1974  and 1975, while  Cook  data indicate a  decrease
between 1975  and  1976.    The  annual  mean weights -of  alewife impinged  at each
plant tended to range between 24 and  37  g,  while those at Pulliam  (42.5 g) and
Oak Creek  (19.3  g) apparently were extreme values.

                        Alewife Impingement - Lakewide

     Based on the  observed impingement  rates at  the 16 sampled power plants,
the maximum  annual  lakewide impingement of  alewife  at  all  water  intakes was


                                      11

-------
         Table 5.   Msan weights (g) of alewife impinged each month at 15 power plants on Lake Michigan,  1974-1976.   Dashes  indicate sampling but
         no  alewife impinged.
ro
Plant (ID)
Zion (1)

Cook (2)

Bailly (3)

Pulliam (5)

Kewaunee (6)

Point Beach (7)

Port Washington (8)

Lakeside (9)

Oak Creek (10)

Waukegan (11)

State Line (12)

Mitchell (13)

Campbell (14)

Palisades (15)

Big Rock (16)

Z Mean Weights
n Plants

Year
1974
1975
1975
1976
1975
1976
1975
1976
1975
1976
1975
1976
1975
1976
1975
1976
1975
1976
1975
1976
1975
1976
1975
1976
1974
1975
1974
1975
1974
1975
1974
1975
1976
Jan

16.2

50.9

32.4

_

45.0

33.1

20.5

-

-

37.2

30.1

105.7
-
_

_

-
_
16.2
44.4
Feb

46.1
5.4
36.7

13.9

.

72.0

34.0

20.3

_

-

53.3

_

23.0
-
_

32.4
-
-
_
39.3
36.2
Mar
41.2
54.6
30.2
43.4

56.5

_

62.0
-

28.2

-

36.8


48.9

_

_
22.7

46.7

-
-
36.9
37.5
52.7
Apr
40.5
44.7
37.6
40.8

43.4
-

27.0

36.6

40.5

3.5

31.7


35.3
41.6


30.7
37.4

43.7

_

40.5
32.9
37.6
fey
39.5
37.0
34.9
30.1

43.8
38.6

29.5

32.2

24.9

23.9

28.1

31.8

37.1

39.1

37.4

30.0

35.6

35.6
32.5
37.0
Jun
35.3
32.8
24.9
24.7

35.9
43.7

32.0

33.9

27.2

28.6

19.1

23.2

29.1

26.9

27.8

38.1

35.7

34.2
29.2
30.3
Jul
28.7
27.9
24.8
25.4

31.5
49.7

31.4

34.6

21.4

38.4

13.0

17.1

24.6

26.1

26.1

35.2

41.3

32.8
28.1
28.5
Aug
28.8
28.9
24.5
22.7

25.1
40.2

28.7

33.3

31.2

28.9

19.3

30.1

16.6

30.0

15.2

29.3

37.8

27.8
28.3
23.9
Sept
22.9
21.1
18.0
6.7

15.5
39.4

28.9

23.8

18.4

32.0

13.4
•~
19.2

37.6

17.9

8.2

_

_

15.6
24.5
11.1
Oct
23.1
18.1
5.2
5.2

6.3
24.7

23.4

6.1

6.5

23.3

14.9

7.6

22.4

6.6

6.4

_

_

14.8
14.4
5.8
Nov
14.8
31.3
23.1
25.1
11.0
24.1
2.7

12.3

5.3

20.7

20.5

18.4

8.3

12.6

2.1

6.4

_

_

10.6
14.0
24.6
Annual Mean
Dec Weights
29.3
32.5
41.4
26.1
23.8

16.2


}
32.1

21.4

27.0

18.6

2.7

41.8

12.0 }

7.4


}


18.4
24.2
26.1
31.6
37.1
29.6
26.2
37.4

42.5

27.6

31.4

25.3

29.3

19.3

26.5

33.6

25.6

24.1

39.0

37.0

26.7
26.8
29.9

-------
 estimated  to be  6.18 x  107  (2.10  x  106 kg)(Table  6).   Since this  estimate is
 based on the assumption  that all intakes  were operated  continuously at maximum
 capacity,  it  is  an  over-estimate  of  the annual  lakewide  impingement.   The
 total observed  flow  at  the  16  sampled power  plants  in 1975  (1.17 x  1010 m3)
 was -58%  of capacity flow  (2.03 x 1010 m3)  and probably  is representative of
 annual  water usage  by  all  conventional  power plants.   Other  intakes  on Lake
 Michigan probably are operated at  or  near capacity flows.   It follows  that the
 actual  lakewide  impingement of  alewife in 1975 was  on  the  order of 1.5 x 106
 kg.   Approximately   70% of  the  annual total  alewife impingement  occurred at
 conventional  power  plants,  despite  the  fact only  43%  of  the  total   flow was
 used  by these  power plants.   The  reasons for  this  anomaly are:    (1)  Zion's
 inordinate   impingement   rate  in 1975  and (2)  the   relatively  low estimated
 density of alewife in the  region of the Ludington Pump  Storage Plant.


 Table 6. Estimated total numbers and biomass (kg) of alewife, smelt, and yellow perch impinged at sampled power
 (1975)'  unsamp1ed  power Plants' and municipal/industrial  intakes on Lake Michigan,  assuming design flow operation
Total Flow
(m3)
Al ewi f e
Number Kg
Smelt
Number Kg
Perch
Number Kg .
 16 sampled power plants    2.03 x 1010  4.53 x 107  1.55 x 106  1.18 x 106  1.55 x 101*   3.13 x 105   6 70 x 103
 Unsampled power plants     3.70 x 108   8.80 x 105  2.35 x 101*  2.77 x W*  3.21 x 102   1.13 x 102   1 14 x 101
 Total conventational plants  2.07 x 1010  4.62 x 107  1.57 x 106  1.21 x 106  1.58 x 101*   3.13 x 105   6.71 x 103

 Ludington P.S. plant       2.11 x 1010  2.53 x 10s  7.50 x 10"  6.03 x 10*  7.56 x 102   1.88 x 105   5.81 x 103

 Total all power plants     4.18 x 1010  4.87 x 107  1.65 x 106  1.27 x 106  1.66 x 101*   5.01 x 105   1.25 x 101*

 Total municipal/industrial   6.51 x 109   1.31 x 107  4.56 x 105  8.53 x 10*  2.07 x 103   1.60 x 10*   6.20 x 102

 Total all intakes         4.83 x 1010  6.18 x 107  2.10 x 106  1.36 x 106  1.86 x 10*   5.17 x 105   1.31 x 10*
      The total  annual  impingement  of alewife  in each  statistical  district  is
given in  Table  7.    The  mean densities  of impinged alewife were  highest  in
Illinois >  WM5  >  WM1;  all  of these  regions  are on the  western side of  the
lake.    The highest  total  volumes  of water are  withdrawn  in districts MM6  >
Indiana   >   Illinois  >  MM8  although   the  highest  numbers  were  impinged  in
Illinois >  WM5  >  Indiana.   Thus,  no clear relationship exists  between  total
flow  and estimated total  alewife  impingement in  statistical  districts.

      The estimates  given  in  Table  7  should  be  interpreted  and   used  with
caution.   In  statistical  districts  where  no  sampling  was  performed  (e.g.,
MM4),  the  observed  density  from an  adjacent  district  (MM3)  was  applied  to
calculate  the   numbers  impinged  (i.e.,  assumed  density  x   flow  =  estimated
number).    In   the   case  of  unsampled  intakes   within  districts  where  some
sampling was performed,  the estimates  seem to be  reasonable.   Table  8  presents
a  comparison   of our  estimates  for  three  intakes  that  were  classified  as
unsampled (i.e.,  the  data were  not  included in  our data  base),  but  actually
were  sampled.   In two cases  (Edgewater  and  Inland Steel) we  overestimated the
observed values  and  in the case  of U.S.  Steel/Gary  our estimate  was less  than
observed.

      Recent estimates  of the alewife  standing crop in Lake Michigan  placed the
minimum  total   biomass at  approximately  122-123  x 106  kg during 1974 and  1975
[24]  and 56.5  x 106  [24]  to  73.8 x  106 kg  [25]  in 1976.   The assumption of  a


                                         13

-------
total   of  1.5  x  106  kg  of  alewife   impinged  at  all   water  intakes  in  1975
indicates  that a maximum  of 1.2%  of the  standing crop was  lost due to  impinge-
ment.    The  reported  54%  decrease  in biomass  between  1975  and   1976 [24]  is
similar to the trend  observed in  impingement density  at the  Cook  plant,  i.e.,
a  mean  impingement   density  of  0.1319  alewife/1000  m3  in  1975  and  0.0912
alewife/1000  m3 in  1976 [19].
               Table 7.  Estimated total  annual impingement of alewife at all water
               intakes within each statistical district on Lake Michigan (1975),
               assuming design flow operation at all  intakes.
District
UM1
WM2
WM3
WM4
WM5
WM6
Illinois
Indiana
MM8
MM7
MM5
MM5
MW
MM3
MM2
MM1
Total Flow
(m3)
7.99 x 108
0
0
2.39 x 109
2.55 x 109
2.51 x 109
6.46 x 109
8.10 x 109
3.42 x 109
7.03 x 108
2.11 x 1010
0
3.32 x 107
1.02 x 108
9.95 x 106
9.08 x 107
Density
(N/m3)
1.73 x 10"3
0
0
7.30 x 10-*
2.94 x 10"3
1.03 x ID'3
6.44 x ID'3
4.88 x 10"*
1.20 x 10"*
1.20 x 10"*
1.20 x 10"*
0
1.16 x lO'6
1.16 x 10'6
1.16 x 10"6
1.16 x 10"6
Number
1.38 x 106
0
0
1.75 x 106
7.48 x 106
2.59 x 106
4.16 x 107
3.96 x 106
4.10 x 105
7.78 x 10"
2.53 x 106
0
3.80 x 101
1.18 x 102
1.20 x 101
1.05 x 102
Kg
5.87 x 10"
0
0
5.39 x 10"
1.90 x 10s
5.01 x 10"
1.54 x 106
1.16 x 105
1.22 x 10"
1.95 x 103
7.50 x 10"
0
1.00 x 10°
4.00 x 10°
4.00 x 10-1
4.00 x 10°
Total all
 intakes
                          4.83 x 1010
6.18 x 107    2.10 x 106
        Table 8.
                Comparison of estimated maximum annual impingement and eptcainment values (1975)
        with observed annual values for Edgewatec Power Plant (1975-1976),LIJ Inland Steel (1976-
        1977),L"J and U.S. Steel/Gary (1977)LZ3J water intakes.
                      Edgewater Power Plant
                      ANL Est.	"	
                                  Obs.
                               Inland Steel
                          ANL Est.	
                                                      Obs.
              U.S. Steel/Gary
          ANL Est.	06T7-
Alewife
Rainbow smelt
Yellow perch
Alewife
eggs
larvae
Rainbow smelt
eggs
larvae
Yellow perch
eggs
larvae
7.7 x 105
2.4 x 101*
88

2.5 x 106
4.4 x 10s

5.7 x 101*
1.0 x 105

0
3.0 x 103
5.2 x 10s
1.8 x lO3
N/A

3.0 x 107
1.8 x 10"

0
3.9 x 10s

N/A
N/A
7.3 x 10s
1.6 x 103
1.9 x 103

7.7 x 109
6.3 x 107

9.9 x 106
2.8 x 106

3.0 x 101*
3.4 x 101*
1.2 x 10s
5.6 x 103
3.9 x 102

1.8 x 108
2.3 x 107

3.0 x 107
3.4 x 106

N/A
N/A
5.5 x 105
1.2 x 103
1.5 x 103

5.9 x 109
4.7 x 107

7.5 x 106
2.1 x 106

2.3 x 101*
2.6 x 101*
7.4 x 10s
6.4 x 101*
>860

N/A
N/A

N/A
N/A

N/A
N/A
      Limnetics  [1]  reported  an  estimated total  of 2.08  x  106 Ibs  (9.41  x 105
kg)  of   alewife  impinged  at  17  power  plant  intakes   on  Lake  Michigan  and
                                           14

-------
 concluded that this  biomass  represents ~0.064% of  the  standing crop biomass,
 as reported by Edsall et al.  [26].   Our estimate of alewife impingement at 16
 plants (9.17 x 105 kg)  is  nearly  identical  to that reported by Limnetics, but
 more recent estimates [24]  of the  1975 standing crop biomass indicate that the
 sampled power plants  impinged a maximum of 0.75% of the total alewife biomass.


                  Rainbow Smelt  Impingement  -  Sampled  Intakes

      In some ways, the  impingement  rates of  smelt  were  dependent on time and
 location  in a fashion similar to  the  impingement  of alewife.  A peak in smelt
 impingement occurred  in April,  presumably  during the  spawning  period,  but
 nearly equal peaks also occurred in  July  and October at  the  sampled intakes
 (Table 3).   The  numerical peak in  October probably reflects the inshore aggre-
 gation of  YOY  smelt,  as indicated  by the  relatively small  increase in total
 weight impinged  that  month.    The  peak in  July  may  have  been related  to
 hydrological  conditions (e.g., upwelling) or  some unknown  interaction between
 smelt   and   other  species,  such  as  alewife.    Although  smelt  impingement
 decreased during  winter months, the decreases were  not  as  pronounced as those
 observed  for alewife.

     The  annual  total smelt  impingement at  the sampled  intakes  was  estimated
 to  be  7.69  x 105  (9.77  x 103  kg) in  1975. Four  plants on the western shore of
 Lake Michigan  accounted for  approximately  94%  of the  total  observed  smelt
 impingement (Table 4):   i.e.,  53%  at  Oak  Creek  (4.09  x  105),  23%  at  Point
 Beach  (1.76 x 105),  10% at Port Washington  (7.79  x lO4), and 8% at Zion (5.80
 x  101*).  In general, proportionately  fewer  smelt were  impinged  at intakes on
 the southern and eastern  shores of  the lakes (Figs. A.l.b-A.16.b).   Maximum
 daily  impingement  densities were on the  order of  <5 smelt/1000 m3 at Pulliam,
 Point   Beach,  and  Oak   Creek;  at  other  plants  the  maximum  densities  were
 generally <1  smelt/1000  m3.

     Relatively  little  or  no  smelt  impingement occurred during  winter  months
 at  6 of the  sampled plants:   Pulliam,  Lakeside,  Mitchell,  Campbell, Palisades,
 and Big Rock.   Evidence of major influxes of  smelt during  the  spawning  period
 was  not as  clear cut as  that  observed with  alewife.  Apparent spawning  peaks
 in  impingement were evident at Zion,  Waukegan, Oak Creek,  State!ine,  Cook,  and
 Campbell  during March  and  April;   and  at  Michigan  City,  Bailly,  Lakeside,
 Pulliam,  and Big  Rock  during  April  and May.   Thus,  no apparent locational
 effect  was  observed for  the timing of  the major  spring impingement of smelt.

     The  mean weights of smelt impinged each month  at each  sampled intake  are
 given  in  Table  9.   The  highest monthly mean weights  (30-50  g)  occurred  either
 in  winter or spring at most plants,  and  often  coincided with  the  initiation of
 spring  peaks in  impingement.    After  spring  maxima,  mean  weights tended  to
 decrease  with  time  and, beginning in  July,  YOY  smelt apparently  predominated
 the  impingement, as  evidenced by mean  weight  ranges between 3 and 10 g  for  1
 to  5 months  in  the late summer and  fall.   The  monthly averages indicate  a
 lakewide  predominance of YOY  smelt during August and  September  1974  and  1975,
 and  in  October 1976.    Although  Zion and Cook data suggest  increases in mean
 smelt  weights  between  1974  and 1976,  lakewide  means indicate a  decrease  in
mean weight  of  smelt  over this period.  Conversely, the  lakewide  mean weights
of  impinged  alewife may have  increased  slightly  between  1974 and  1976  (Table
 5).  Considering the  extensive sampling that is represented  in  these  data,  it


                                      15

-------
Table 9.  Maan weights  (g) of smelt impinged each month at  15  power  plants on Lake Michigan, 1974-1976.  Dashes indicate
sampling but no smelt impinged.
Plant (ID)
Zion (1)

Cook (2)

Bailly (3)

Pulliam (5)

Kewaunee (6)

Point Beach (7)

Port Washington (8)

Lakeside (9)

Oak Creek (10)

Waukegan (11)

State Line (12)

Mitchell (13)

Campbell (14)

Palisades (15)

Big Rock (16)

l Mean Weights
n Plants

Year
1974
1975
1975
1976
1975
1976
1975
1976
1975
1976
1975
1976
1975
1976
1975
1976
1975
1976
1975
1976
1975
1976
1975
1976
1974
1975
1974
1975
1974
1975
1974
1975
1976
Jan

38.4

10.6

21.6

-

28.3

5.4

22.8

19.5

23.2

27.0

30.5

22.7
-
28.3

-

-
-
38.4
21.2
Feb

62.9
18.5
23.6

3.9

.

34.0

17.1

25.5

18.4

19.4

34.3

34.3

33.7
-
-

-
-
-
.
62.9
24.4
Mar
31.1
50.3
9.0
14.4

30.9

_

37.9
24.9

26.8

-

28.8


22.6

35.5

23.8
-

-

-
-
31.1
28.0
27.5
Apr
32.4
32.9
20.5
28.4

42.3
37.6

18.1

43.8

33.4

-

7.1


26.8
26.2


40.7
26.7

35.3

16.6

27.8
27.5
34.6
toy
27.3
.
16.7
8.6

11.9
25.9

17.1

30.2

26.8

28.6

8.8

17.5

31.5

28.7

19.5

-

19.7

22.2
23.2
10.3
Jun
24.8
.
11.1
9.2

7.2
_

18.0

26.9

21.4

11.9

10.3

10.2

19.1

15.3

34.9

-

-

29.9
16.0
8.2
Jul
24.0
11.2
10.2
12.2

3.4
20.5

20.0

32.6

6.4

_

7.8

4.7

13.6

5.7

-

-

-

24.0
13.3
7.8
Aug
15.6
19.5
4.3
19.6

2.8
.

20.1

5.3

5.4

-

8.9

6.9

6.0

6.5

-

-

-

15.6
9.2
11.2
Sept
12.7
21.0
5.0
12.9

_
_

20.0

4.9

7.9

-

H.ff

8.0

-

9.1

-

-

-

12.7
10.2
12.9
Oct
47.9
32.1
1.5
5.2

.
37.7

25.4

4.7

21.5

12.5

14.6

13.2

4.7

7.3

-

-

-

47.9
15.9
5.2
Nov
43.1
37.7
7.2
13.3
_
_
_

24.7

6.3

24.5

14.3

11.2

20.0

61.8

4.8

7.5

_

-

25.3
21.3
13.3
Annual Mean
Dec Weights
52.2
58.2
10.7
13.0
14.6 ,
*
40.0

28.6 i
J
8.5 ,
'
24.8 ,
i
- \
i
16.1 ,
J
47.9 ,
/
6.0 ,
t
8.4 ,
/
28.3 ,
j
.

-

40.3
24.0
13.0
28.9
50.6
12.6
14.1

22.2
37.4

24.7

7.2

11.5

18.2

9.2

22.0

26.9

12.0

20.0

35.3

18.6

27.7
24.2
15.8

-------
appears  that mean  weights of  alewife and  smelt  vary  as  the inverse  of each
other.

                      Rainbow Smelt Impingement  - Lakewide

     Assuming  design  (capacity) flow at all water  intakes  on Lake Michigan, we
estimated  the  maximum lakewide impingement of  smelt to be  1.36  x  106  (1.86 x
104  kg) (Table  6).    Accounting  for  the  less  than  capacity  flows at  power
plants, we  conclude  that  at least 1 x  106 (1.4 x 104  kg)  smelt  were impinged
at all  intakes in 1975.   Recent  studies of smelt  annual  standing crop in Lake
Michigan  estimated  the minimum smelt biomass to  be  13.7 x  106 kg  in 1975 and
11.1 x  106 kg  in 1976  [27].   Assuming 1.4 x 10^  kg to have  been  impinged at
all  intakes  in 1975  and  a stock  of  13.7 x 106  kg, we  conclude that a  maximum
of 0.10%  of  the biomass was  lost due to impingement.   Limnetics  [1] estimated
that 17  power plants impinged  9.17  x  103  kg  of smelt  in  1975, which amounted
to 0.06%  of the estimated 1974  standing crop biomass; our  estimate of 9.77 x
103  kg  for  16 power plants represents  0.07% of  the  estimated  1975 standing
crop.   Approximately 90% of the total annual  impingement of smelt occurs at
conventional  power  plants,  despite  the  fact  that only 43% of the  total  flow
during  the  sampling  period  was   used by  these plants.    The relatively  low
densities  of  smelt  on  the  southern  and eastern  shores  of  Lake  Michigan
probably  result in  low numbers impinged despite  large volumes of  water with-
drawn  by  the  Ludington  Pumped  Storage  Power  Plant and  municipal/industrial
intakes in those  regions.
              Table 10.  Estimated total annual impingement of rainbow smelt at all
              water intakes within each statistical district on Lake Michigan (1975),
              assuming design flow operation at all intakes.
District
UM1
WM2
WM3
wm
WM5
WM6 ,
Illinois
Indiana
MrD
MM7
MM6
MM5
MW
MM3
MM2
MM1
Total all
intakes
Total Flow
On3)
7.99 x 108
0
0
2.39 x 109
2.55 x 109
2.51 x 109
6.46 x 109
8.10 x 109
3.42 x 109
7.03 x 108
2.11 x 1010
0
3.32 x 107
1.02 x 108
9.95 X 106
9.08 x 107

4.83 x 1010
Density
(N/m3)
2.18 x KT5
0
0
1.04 x 10"*
9.31 x 10'5
2.49 x ID""
2.28 x 10'5
1.07 x 10"6
2.86 x 10'6
2.86 x 10'6
2.86 x 10'6
0
1.56 x 10'6
1.56 x 10"6
1.56 x 10"6
1.56 x 10'6

-
Number
1.75 x 10"
0
0
2.49 x 10s
2.37 x 10s
6.24 x 105
1.48 x 105
8.69 x 103
9.77 x 103
1.08 x 103
6.03 x 10"
0
5.20 x 101
1.59 x 102
1.55 x 101
1.42 x 102

1.35 x 106
Kg
6.53 x 102
0
0
2.22 x 103
2.73 x 103
5.73 x 103
6.23 x 103
1.67 x 102
1.22 x 102
1.90 x 101
7.56 x 102
0
1.00 x 10°
3.00 x 10°
3.00 x 10-1
3.00 x 10°

1.86 x 10"
     The  estimated  total  annual  impingement  of  smelt  in  each  statistical
district  is  given in  Table 10.   The mean annual  densities of  impinged smelt
(calculated as the average of all daily observations  at  sampled intakes within
a district)  were highest  in  WM6 > WM4 >  WM5  >  Illinois >  WM1,  indicating the
relatively  high  abundance of  smelt  on the  western  shore of  the lake.   The
apparent  spatial  differences  in smelt distribution  negate the  possibility of
                                       17

-------
establishing a clear relationship between volume of water withdrawn  (flow) and
impingement of smelt among  statistical  districts.   For the same reasons given
in the discussion of alewife data, the estimates of total smelt  impingement  in
each statistical  district should  be  interpreted with  caution.   In the case  of
districts with sampling results, the estimates are expected to be approximate-
ly correct.  Table 8 presents  a comparison  of our estimates  for three intakes
that were  sampled,  but were not  included  in the observed  data  base.   Two  of
the estimates  (Inland  Steel  and U.S. Steel/Gary) were lower  than reported  by
the industries,  while  that  for the  Edgewater  plant  was an order of magnitude
higher than reported by Limnetics [1].

     The reported standing  crop biomass of  smelt decreased ~19% between  1975
and 1976 [27].   A comparison of  the mean  annual  impingement  densities at the
Cook plant between 1975 (0.0029/1000 m3) and 1976 (0.0017/1000 m3) indicates a
decrease of ~40% in  smelt abundance over this period.

                  Yellow Perch  Impingement - Sampled  Intakes

     Numbers of yellow  perch  impinged at the 16 sampled intakes were  greatest
in the late fall-early  winter  (Table 3).  Total biomass of impinged perch was
highest in October, followed  by May  and November.  A  spawning-related peak  of
adults was  impinged in May while  larger  numbers of other  age classes  were
impinged in  the  late  fall  months.   Lowest  numbers   and  biomass  of  impinged
perch occurred in the August-September and January-March periods of  1975.

     The annual  total  perch impingement at  the  sampled intakes was estimated
to be  1.39  x  105 (3.11 x 103  kg) in 1975.   Eighty-five percent of the total
biomass  and  95%  of  the total  number of impinged  perch were  taken  by three
power plants (Table 4); i.e., 85% of  the total number  at Pulliam (1.18 x 105);
9% at  Cook  (1.28 x 10M; and  1% at Oak Creek  (1.43  x 103).   In general,  few
perch were impinged at most plants, except for those mentioned above.  Maximum
.daily  impingement densities were on  the order  of <3  perch/1000 m3  at Pulliam
between  October-December  and  <1  perch/1000  m3  at  Cook  between  October-
November.  At  all other plants, the maximum densities were <0.1 perch/1000  m3
(Figs. A.l.c-A.16.c).  Winter densities of impinged perch were not consistent-
ly low  and  indicate substantial  inshore densities  in winter in some  areas  of
the  lake;  i.e.,  in the southern basin  and  isolated  areas such as  Green  Bay
(Pulliam) and Pigeon Lake (Campbell).

                     Yellow Perch Impingement - Lakewide

     Assuming  capacity  flow  at  all  water  intakes  on   Lake  Michigan,  we
estimated  the  maximum  lakewide  impingement  of yellow perch  to  be 5.17 x 105
(1.31  x  10^ kgHTable  6).    Accounting for  the  less  than  capacity  flows  at
power plants,  we  conclude  that at least 3.5 x  105 (9.5  x  103 kg) yellow perch
were  impinged  in  1975.   To date,  no estimates are  available for the  standing
crop biomass of yellow  perch in Lake  Michigan.

     Approximately 60%  of  total annual  impingement  of yellow perch occurs  at
conventional  power  plants,  while  only 43%  of the  total  flow  during  the
sampling period  was used by  these plants.    Based on the  assumption  that in-
shore yellow perch densities are  similar between  the  Cook  and Ludington  areas,
we  estimate  that  the   Ludington  plant  withdrew  1.88  x 105 yellow  perch  in
1975.   This  value  represents  approximately  36%  of  the  estimated  lakewide


                                      18

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 total.

      The  estimated  annual   impingement of  yellow  perch  in  each  statistical
 district is  given  in Table  11.   The mean annual  densities of  impinged  yellow
 perch (average of all daily  observations at sampled intakes within  a  district)
 were highest in WM1  followed by  MM8  and  Indiana, indicating the relatively
 high  abundance of  perch  in  Green  Bay  and  the  southeastern areas of  Lake
 Michigan.  The  values in Tables  6 and 11 should be interpreted with caution,
 since critical  assumptions  were  made  about  the relative  densities  of  yellow
 perch in unsampled districts.  However, a  comparison of estimated yellow perch
 impingement with observed  values  at intakes  that were classified as  unsampled
 (no data included in  data  base)  shows  very  good agreements in  districts where
 sampling data were included  in the data base (Table 8).
               Table 11.  Estimated total  annual impingement of yellow perch at all
               water intakes within each statistical  district on Lake Michigan (1975),
               assuming design flow operation at all  intakes.
District
WML
WM2
WM3
WW
UM5
WM6
Illinois
Indiana
MM8
MM7
MM6
MM5
MM4
MM3
MM2
MM1
Total all
intakes
Total Flow
(m3)
7.99 x 108
0
0
2.39 x 109
2.55 x 109
2.51 x 109
6.46 x 109
8.10 x 109
3.42 x 109
7.03 x 108
2.11 x 1010
0
3.32 x 107
1.02 x 108
9.95 x 106
9.08 x 107

4.83 x 1010
Density
(N/m3)
3.52 x 10"*
0
0
2.64 x 10'7
3.34 x 10'7
8.67 x 10'7
3.05 x 10"7
1.29 x 10"6
8.91 x 10"6
8.91 x 10'6
8.91 x 10-6
0
2.07 x 10'7
2.07 x 10"7
2.07 x 10"7
2.07 x 10"7

-
Number
2.81 x 10s
0
0
6.31 x 102
8.51 x 102
2.17 x 103
1.97 x 103
1.04 x 101*
3.05 x 10"
1.44 x 103
1.88 x 10s
0
7.00 x 10°
2.10 x 101
2.00 x 10°
1.90 x 101

5.17 x 105
Kg
5.11 x 103
0
0
1.01 x 102
7.90 x 101
1.61 x 102
2.32 x 102
6.64 x 102
9.41 x 102
4.00 x 101
5.81 x 103
0
1.00 x 10°
3.00 x 10°
2.00 x 10'1
2.00 x 10°

1.31 x 10"
                              ENTRAPMENT ESTIMATES

                     Alewife  Entrainment - Sampled Intakes

     The major  periods  of entrainment were May through  August for alewife eggs
and  June through  September  for alewife  larvae  (Table 12).   Peaks  in total
entrainment  at  the sampled  plants  occurred  in  June for both  alewife eggs and
larvae.  Each month,  the numbers of entrained larvae were  one to two orders of
magnitude lower than the numbers of  entrained eggs.   No eggs  were entrained
during the  period  October through March.   No larvae were  entrained during the
months January  through  April.  An estimated total of 1.11  x  1010 eggs and 2.01
x 108  larvae were entrained at the 15  sampled  intakes in 1975.   The sampling
periods  probably were  adequate to estimate  the entrainment of  alewife eggs,
but may  have been  inadequate at  some  intakes to characterize  the late summer-
fall  entrainment  of  alewife  larvae.    Therefore,  the  annual  estimate  of
                                       19

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entrained larvae is almost twice that observed.

     Figures  A.l.d-A.16.d  show  the  time-dependent  nature  of  alewife  egg
entrainment and indicate  peak  densities  >100 eggs/m3 at Bailly, Waukegan, and
Mitchell.   Extremely  low  peak  densities  (<0.01  eggs/m3)  were observed at the
Campbell, Palisades, and Big Rock plants.  Despite substantial  impingements of
alewife at Point Beach, Port Washington, Lakeside, and Oak Creek,  the  reported
densities of  entrained alewife eggs were uniformly  low  at these  plants (<0.3
m3).   This  anomaly is difficult to  explain  in view of  the  fact  that sampled
plants to the north (e.g., Kewaunee) and south  (e.g., Zion) of this  group of
plants showed substantially higher densities of entrained alewife  eggs.

     The initiation of alewife egg entrainment  occurred  1-2 months after the
initial  large  impingements of adults at all but one  plant.   At  Pulliam,  the
initiation of alewife  impingement lagged behind that at other  plants  (late May
rather than April-May) and egg entrainment commenced almost  immediately there-
after.  The typical lag period between  initial high impingement densities and
egg  entrainment indicates  that early  migrants  (inshore occupants)  are  not
completely  gravid  and  become  so while occupying  warmer  inshore waters in the
spring.  Peak larval  densities  (Figs.  A.l.e-A.16.e)  occurred  1-2  months after
peak  egg  densities at most sampled  intakes  on the  western  shore  of  the lake
(except Lakeside,  Zion, and  Waukegan)  while on  the  southern and  southeastern
shores,  the egg and   larval  peaks  were  much  less  separated  in  time.   This
apparent spatial difference may  be  the  result  of (1) accelerated  growth rates
of  immature alewife  in the  warmer  southern basin  and/or (2)  a  net  counter-
clockwise movement of  inshore currents  and ichthyoplankton  in  the  southern
basin of Lake Michigan.  Peak densities  of alewife larvae were  >1  larvae/m3 at
Cook and Bailly, and >0.1/m3 at Zion, Waukegan, and Mitchell.

     The estimated  total  numbers of  alewife  eggs and larvae entrained at each
of the sampled  intakes are given in Table 13.   Intakes  on the southern shore
of  Lake   Michigan   accounted   for  the  majority   of  alewife  eggs  and larvae
entrained  by  the  sampled intakes.    Bailly,  Waukegan,  Mitchell,  Stateline,
Cook, and Zion combined accounted for 96% of the  total alewife  eggs  and 97% of
the total alewife  larvae  entrained  by  the sampled intakes during  1975.  Since
the  intakes on  the western shore  of the lake impinged  the  majority  of adult
alewife,  it follows that  the high  entrainment  densities on the  southern shore
may  be the result  of eggs and  larvae  being  transported by  counterclockwise
inshore currents, and  subsequently  being entrained  by intakes on  the  southern
shore.

                        Alewife Entrainment  - Lakewide
     The maximum  numbers of  alewife eggs  and larvae  entrained  by all  water
intakes  on  Lake Michigan  were estimated  to  be  7.39  x 1010  and  1.31 x  109,
respectively, assuming  capacity  flow at all  intakes  (Table 14).    Under  these
conditions,  conventional  power plants would  account  for approximately 54%  of
the  total  entrained alewife  eggs,  the  Ludington  plant would account  for  8%,
and  municipal/industrial  intakes  for 38%.   The relative percentage distribu-
tion  by plant  type for  alewife  larvae  would be  28%  by  conventional  power
plants,  56%  by  Ludington,  and 16%  by the  municipal/industrial plants.   Since
conventional  power  plants, as  a  group,  typically withdraw  ~50%  of  capacity
flows on an  annual  basis, and most other  intakes are assumed to operate  near
capacity flow,  we estimate that  at least  5  x 1010 alewife  eggs  and  1  x  109


                                      20

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Table 12.  Estimated total numbers of alewife, rainbow smelt, and yellow perch eggs  and  larvae  entrained
each month during the sampling periods at all 15 sampled power plants; estimated annual  totals  by
extrapolation to full year for each plant (1975).
Total Fl ow
(m3)
January
February
March
April
May
June
July
August
September
October
November
1.63
1.83
2.30
5.54
9.07
9.96
1.05
1.06
7.73
6.30
2.67
x 108
x 108
x 108
x 108
x 108
x 108
x 109
x 109
x 10s
x 108
x 108
Al ewi f e
Eggs
0
0
0
8.24 x 105
2.30 x 108
6.17 x 109
3.88 x 109
1.77 x 108
3.41 x 105
0
0
Larvae
0
0
0
0
3.63 x 105
6.28 x 107
5.82 x 107
8.22 x 106
3.56 x 106
1.13 x 105
8.03 x 102
Smelt
Eggs
0
0
1.01 x
5.80 x
2.83 x
3.41 x
0
0
0
0
0

105
107
107
106





Larvae
6.00 x 10°
5.42 x 10"
4.48 x 10"
3.72 x 10"
5.44 x 106
6.55 x 105
2.37 x 106
4.53 x 106
3.72 x 106
2.81 x 106
9.40 x 105
Perch
Eggs
0
0
1.24
0
1.01
5.35
1.26
0
0
0
0

x 10"

x 106
x 106
x 10"




Larvae
0
0
0
0
4.49
1.22
2.96
0
0
0
0



x 105
x 105
x 10"




December         2.19 x 108   0            1.30 x 101   0            4.25 x  10"   0             0

Total observed   7.04 x 109   1.05 x 1010  1.33 x 108   8.98 x 107   2.06 x  107   6.38 x  106    6.01  x  105

Estimated annual
 total                -       1.11 x 1010  2.01 x 108   3.10 x 108   2.71 x  107   6.77 x  106    6.12  x  105
Table  13.   Estimated  total  numbers  of alewife,  rainbow smelt,  and yellow perch eggs and larvae entrained
during  the  sampling periods  at  each of the  15  sampled power plants;  estimated annual totals by
extrapolation  to  full  year  for  each plant (1975).

Zion
Cook
Bailly
Michigan City
Pulliam
Kewaunee
Point Beach
Port Washington
Lakeside
Oak Creek
Waukegan
State! ine
Mitchell
Campbel 1
Palisades
Big Rock
Total observed
Estimated annual
total
Total Flow
(m3)
5.52 x 108
1.30 x 109
6.16 x 108
N/A
1.52 x 108
5.33 x 108
8.08 x 108
3.42 x 108
1.41 x 108
8.93 x 108
4.08 x 108
5.26 x 108
2.24 x 108
3.35 x 108
9.94 x 107
1.07 x 108
7.04 x 109

Mewife
Eggs
4.73
6.21
3.86
N/A
2.93
4.71
4.11
2.70
3.07
6.14
2.93
7.12
1.51
6.48
0
0
1.05
1.11
x 108
x 108
x 109
x 108
x 107
x 106
x 106
x 106
x 106
x 109
x 108
x 109
x 10"

x 1010
x 1010
Larvae
4.39
6.51
3.80
N/A
4.84
6.03
3.31
2.95
6.29
1.59
1.18
2.97
7.41
2.25
7.00
1.05
1.33
2.01
x 106
x 107
x 107
x 10"
x 105
x 105
x 105
x 105
x 105
x 107
x 106
x 106
x 103
x 10°
x 101
x 108
x 108

Smelt
Eggs
4.47 x
7.86 x
4.14 x
N/A
6.87 x
9.85 x
0
1.16 x
0
5.96 x
2.73 x
3.61 x
2.32 x
1.24 x
1.40 x
5.47 x
8.98 x
3.10 x
107
106
105
105
105
105
10"
107
106
1Q5
102
101
102
107
108
Larvae
3.13 x 106
2.91 x 105
2.87 x 10s
N/A
2.52 x 10"
9.45 x 106
1.21 x 106
2.99 x 105
0
4.41 x 105
1.37 x 105
8.07 x 10"
1.34 x 106
• 1.49 x 103
1.30 x 101
1.43 x 102
2.06 x 107
2.71 x 107
Perch
Eggs
N/A
4.05 x 106
1.24 x 10"
N/A
2.32 x 106
N/A
N/A
0
N/A
N/A
N/A
N/A
N/A
0
0
0
6.38 x 106
6.77 x 1Q6

Larvae
N/A
6.37 x
1.42 x
N/A
5.17 x
N/A
N/A
5.64 x
N/A
N/A
N/A
N/A
N/A
0
0
0
6.01 x
6.12 x

10"
10"
105

103





10s
105
                                                    21

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alewife larvae were  entrained by all water  intakes  on Lake Michigan  in  1975.
Table  15   shows  the  estimated  maximum  numbers  of  alewife  eggs  and larvae
entrained in 1975 by  statistical  district.   From these estimates,  it  is  clear
that  the   majority  of  alewife  eggs  and  larvae are  entrained  in Illinois,
Indiana,  and  MM6,  the  districts  with  the  greatest  water withdrawal.   Our
estimates  for  district MM6  (primarily  the  Ludington  Pump  Storage Plant) are
based on  the  assumption that inshore densities  of  alewife eggs and larvae  in
that  district  are  equal  to those  in   district  MM8,   since  no  intakes  were
sampled in MM6.   Our estimation procedure seems  to  yield  reasonable  estimats
for "unsampled"  intakes (not in our data base  but  observations available)  in
districts where sampling was performed (Table 8).

     The  total  number  of  alewife  larvae entrained  at  the  sampled   intakes
(Table 12) represents approximately 1.8% of the total  number of eggs entrained
by those  intakes  indicating a 98% mortality  between egg and larval stages  of
development.    Extrapolation of  these  values to  all  intakes  on Lake  Michigan
(Table 14) also  indicates  a 98% mortality  between egg and  larval  stages.  For
a  number  of  reasons,  thse  estimates may  not  reflect actual  mortality  rates
between the  egg  and  larval  stages  of alewife  in Lake Michigan.   This  crude
approach  assumes that  (1)  power  plant intakes  "sample"   eggs  and larvae  at
equal  efficiencies which may not be true; and (2) the  sampled intakes  provided
unbiased  estimates  of  actual   egg  and  larval  densities  in   Lake   Michigan
waters.   Many studies of  fish population  dynamics  have  shown  that  clupied
species tend  to  undergo  high  mortality rates  during  the  first year  of  life,
and it is usually assumed  that mortality from egg to adult  stages  exceeds 99%.

                  Rainbow Smelt Entrainment  - Sampled  Intakes

     The  major periods of entrainment were  March through  June for smelt eggs
and May through November for smelt larvae (Table  12).  Peaks in total  entrain-
ment  at  the  sampled  plants  occurred  in April for eggs  and in  May and August
for larvae.   No  smelt eggs were entrained  between  July  and  February but  at
least  3  x 101* smelt  larvae  were reported  each  month  except for January.  The
monthly totals for  smelt larvae in Table  12 show a bimodal distribution with
time  (i.e.,  peaks  in  May  and  August)  and  may  indicate  either  (1)   altered
spatial distribution  of larvae  over  time,  or (2) the  existence of two or more
separate  spawning times  lakewide.

     An estimated  total of  3.10 x 108  smelt eggs and 2.71 x 107  smelt larvae
were  entrained at the  15  sampled intakes  in 1975.   The sampling  periods were
not initiated  soon  enough  at some of the southern basin intakes  to adequately
characterize egg entrainment; therefore, the  annual  estimate of entrained eggs
is  approximately three times  the  observed  value.    Larval  entrainment was
adequately characterized during the  sampling periods at  most  of the  sampled
intakes.

     Figures A.l.f-A.16.f  show  the time-dependent nature of smelt  egg  entrain-
ment  and  indicate  peak densities >1  egg/m3 at the Zion  and Waukegan plants  in
April.   Numerous plants  had peak densities  >0.1 egg/m3  (e.g., Cook,  Bailly,
Pulliam,  Kewaunee,  and Stateline).   Extremely low egg densities and total egg
entrainment  were observed at  Point  Beach   and  Campbell,   despite  substantial
impingements of  smelt at these  plants (Table  4).

      Smelt egg entrainment commenced about the same time  as smelt impingement


                                      22

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Table 14.   Estimated total numbers of alewlfe,  smelt, and yellow perch eggs  and  larvae entrained at sampled  power
plants,  unsampled power plants, and municipal/industrial intakes on Lake  Michigan, assuming design flow operation
(1975).
Total Flow
Al ewi f e
(m3) Eggs
15 sampled power plants
Unsampled power plants
Total conventional plants
Ludington P.S. plant
Total all power plants
Total municipal/industrial
Total all intakes
1.97
9.67
2.07
2.11
4.18
6.51
4.83
x 10i°
x 108
x 1010
x 1010
x 109
x 1010
3.66
3.15
3.97
5.85
4.56
2.83
7.39
x 109
x 1Q10
x 109
x IQio
x lo"
xlOio
Larvae
3.40 x 108
2.57 x 107
3.66 x 108
7.30 x 108
1.10 x 109
2.14 x 108
1.31 x 109
Smelt
Eggs
4.06
5.10
4.11
5.99
4.71
1.44
6.15
x 108
x 106
X 108
x 107
x 108
x 108
x 108
Larvae
6.37 x 107
1.54 x 106
6.52 x 107
2.33 x 106
6.75 x 107
1.53 x 107
8.28 x 107
Perch
Eggs
1.67 x
1.20 x
1.67 x
3.08 x
4.75 x
6.49 x
4.81 x
107
10*
107
107
107
105
107
Larvae
2.54 x 106
1.67 x 10*
2.55 x 106
5.28 x 105
3.08 x 106
1.81 x 105
3.26 x 106
                Table 15.   Estimated total annual entrapment of alewife eggs and  larvae  at
                all water intakes  within each statistical  district on Lake Michigan  (1975)
                assuming design  flow operation at all intakes.
District
WM1
WI*E
WM3
WW
WM5
WM6
Illinois
Indiana
MM8
MM7
MM5
MM5
MM4
MM3
MM2
MM1
Total all
intakes
Total Flow
(m3)
7.99 x 108
0
0
2.39 x 109
2.55 x 109
2.51 x 109
6.46 x 109
8.10 x 109
3.42 x 109
7.03 x 108
2.11 x 101°
0
3.32 x 10'
1.02 x 108
9.95 x 106
9.08 x 107

4.83 x 101°
Eggs
Density
(N/m3)
1.44 x 10°
0
0
4.85 x 10-2
9.61 x ID'3
7.01 x ID"3
3.68 x 10°
5.18 x 10°
2.77 x 10"1
2.77 x 10-1
2.77 x 10-1
0
0
0
0
0

_

Number
1.15 x
0
0
1.16 x
2.45 x
1.76 x
2.38 x
4.20 x
9.47 x
2.96 x
5.85 x
0
0
0
0
0

7.38 x
109


108
107
107
101°
101"
108
107
109


101 0
Larvae
Densi ty
{N/m3)
1.99 x 10"*
0
0
7.80 x 10'*
1.66 x 10'3
1.66 x ID"3
1.66 x ID'2
4.19 x ID"2
3.46 x ID'2
3.46 x ID"2
3.46 x ID'2
0
9.47 x 10-8
9.47 x 10'8
9.47 x 10~8
9.47 x 10'8


Number
1.59 x 105
O
o
1.87 x 106
4.24 x 106
4.15 x 106
1.07 x 108
3.40 x 10s
1.18 x 10s
3.68 x 106
7.30 x 108
g
3.20 x 10°
9.60 x 10°
9.00 x lO'i
9.00 x 10°

1.31 » in9
                                                      23

-------
increased  in  the  spring  at  some  plants  (Cook,  Bailly,  Pulliam,  Waukegan,
Stateline, and Big Rock),  but at  other plants it was delayed at least a month
relative  to  the  increase  in  impingement (Kewaunee, Port  Washington,  and Oak
Creek).   Since  a number of  plants  impinged smelt  over  the winter months and
the normal hatching time for smelt eggs ranges from 3-5 weeks, it  is difficult
to determine  if  a  lag period exists  between  inshore  migrations and spawning.
Although egg entrainments typically were confined to less  than three months at
any plant,  larval  entrainment  (Figs. A.l.g-A.16.g) was  spread out  over 6-9
months  at some  plants  (e.g.,  Kewaunee  and  Oak Creek).   This  pattern must
result  from the  transport  of eggs and larvae  spawned  at remote locations and
from the  slow  development  of smelt larvae  into  motile juveniles  that are too
large to  be  entrained.   Thus,  smelt young are  vulnerable to entrainment for
longer periods of time and by more water intakes than are  alewife  young.  Peak
densities of larvae were >0.1/m3 at Zion, Kewaunee, and Mitchell,  and >O.Ql/m3
at Bailly, Point Beach,  Port Washington, and Oak Creek.  Very low  densities of
smelt larvae (<0.0001/m3) were entrained at Lakeside, Campbell, Palisades, and
Big Rock.  Smelt larval  densities  were equal  to or greater than egg densities
at Kewaunee,  Point  Beach,  Port Washington,  Oak Creek,  and Mitchell,  another
indication of  long-range  transport  and  extended  vulnerability  of planktonic
smelt to entrainment.

     The estimated total numbers of smelt eggs and  larvae  entrained at each of
the sampled intakes  are given in Table  13.   Eighty percent of the smelt eggs
entrained by sampled intakes were taken at the Zion and Waukegan plants, while
98% were  entrained  by  five plants in  the  southern basin  (Zion, Cook, Bailly,
Waukegan, and Stateline).   However,   entrainment of smelt larvae  was not con-
centrated in  the southern  basin,  but was  nearly  equal  between   northern and
southern  plants  taken  as  groups.    In  the north,  Kewaunee and  Point Beach
accounted for 52% of the lakewide total  (observed)  and in  the south, Zion, Oak
Creek, Mitchell, Waukegan, and  Port  Washington  accounted for 45%  of the total
entrained smelt  larvae.   This difference between  egg  and larval   distribution
indicates that substantial  smelt spawning may be occurring on the  northwestern
shore of Lake Michigan,  as well  as in the southern  basin.

                         Smelt Entrainment  - Lakewide
     The  maximum numbers  of  smelt  eggs  and larvae  entrained  by  all  water
intakes  on  Lake  Michigan  were  estimated  to be  6.15 x  108 and  8.28 x  107,
respectively, assuming capacity  flows  at all  water intakes  (Table 14).   Under
these conditions  conventional  power  plants would  account for 67% of  the  total
entrained  smelt  eggs,  the  Ludington  plant  would account  for  10%,  and  the
municipal/industrial intakes  would  entrain 23% of  the  total eggs.   The  rela-
tive  distribution of  entrained  smelt larvae  by   plant  type would  be 79%  by
conventional  power   plants,  3%   by    the   Ludington   plant,   and  18%   by
municipal/industrial intakes.  Under normal flow assumptions, we  estimate that
at  least  5  x 108  smelt  eggs  and 5  x  107 smelt larvae  were entrained by  all
water  intakes  on  Lake Michigan in  1975.    The  estimated maximum numbers  of
smelt eggs  and  larvae  entrained in  1975 within  each  statistical district  are
given in  Table  16.   These estimates  indicate that the majority  of  smelt eggs
are  entrained  in  Illinois   while   smelt   larvae   are   heavily  entrained  in
Illinois, Indiana, WM4, and WM6.  The accuracy of  these  estimates is  indicated
by  the  good  agreement  between our estimates  for  "unsampled"  intakes  and
observed data at  those intakes for smelt eggs and  larvae  (Table 8).
                                      24

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            Table 16.  Estimated total annual entrainment of rainbow smelt eggs and larvae
            at all water intakes within each statistical district on Lake Michigan (1975),
            assuming design flow operation at all intakes.
Eggs
District
VIM1
WM2
WM3
wm
UM5
WM6
Illinois
Indiana
MM8
MM7
MM5
MM5
MM
MM3
MM2
MM
Total all
intakes
Total
(m3
7.99 x
0
0
2.39 x
2.55 x
2.51 x
6.46 x
8.10 x
3.42 x
7.03 x
2.11 x
0
3.32 x
1.02 x
9.95 x
9.08 x

4.83 x
Flow
)
108


109
109
109
109
109
109
108
1010

107
108
106
107

1010
Density
(N/tn3)
5
5
2
2
2
7
7
6
2
2
2
0
4
4
4
4


.14 x
.14 x
.52 x
.52 x
.16 x
.57 x
.43 x
.61 x
.84 x
.84 x
.84 x

.94 x
.94 x
.94 x
.94 x

-
ID"3
lO'3
10'3
10'3
icr*
10-5
ID'2
10'3
10'3
10'3
ID'3

10"6
10'6
10'6
10~6


Number
4.10
0
0
6.03
5.51
1.90
4.80
5.36
9.70
3.02
5.99
0
1.64
5.03
4.92
4.49

6.14
x


x
x
x
x
x
x
x
x

x
x
x
x

x
106


106
105
105
108
107
106
105
107

102
102
101
102

108
Larvae
Density
(N/m3)
1.37 x 10-"
1.37 x 10-"
1.03 x 10'2
1.03 x 10"2
3.99 x 10"11
4.45 x 10"3
4.38 x 10'3
1.84 x 10'3
1.10 X 10"*
1.10 x 10'"
1.10 x 10"*
0
1.29 x 10"6
1.29 x 10"6
1.29 x'10"6
1.29 x 10"6

-
Number
1.09
0
0
2.46
1.02
1.11
2.83
1.49
3.77
1.44
2.33
0
4.27
1.31
1.28
1.17

8.28
x 105


x 107
x 106
x 107
x 107
x 107
x 105
x 10"
x 106

x 101
x 102
x 101
x 102

x 107
     The  total  number of smelt  larvae entrained at the  sampled intakes (Table
12) represents  approximately 9% of the total number of  smelt eggs entrained at
                and  indicates  a  91% mortality  between eggs  and  larvae.   From
                lakewide estimates  indicate  an  87% mortality between  egg and
               of development.  These estimates of  mortality  between  egg and
               of smelt  in  Lake Michigan  should be used with  caution,  for the
these  intakes
Table  14,  the
larval  stages
larval  stages
same reason  given  in  the discussion of alewife egg-larvae mortality.

                   Yellow Perch Entrainment - Sampled  Intakes

     Yellow  perch  eggs  were  entrained  between  March   and July,  with  peak
entrainment  occurring  in May  and  June.   Yellow perch  larvae wre entrained
between May  and July, with  major entrainment  in May  and June  (Table  12).  No
eggs or larvae  were entrained between August and February.   An  estimated total
of  6.77  x 106  eggs  and 6.12  x  105 larvae  were entrained  at  the  15  sampled
intakes in 1975 (Table  13).   Two power plants  (Pulliam and Cook)  accounted for
99.8% of the total eggs  and  96.6% of the total larvae entrained by the sampled
intakes.   However, it must  be noted that  a  large fraction  of  the plants that
were sampled  did not identify  (report) perch  eggs and larvae;  therefore, the
actual   distribution  of   immature  perch may  be  somewhat  different than  that
reflected by Table 13.

     Figures   A.2.h-A.16.h   and   A.2.i-A.16.i   show   the   entrainment  rates
(densities)  of yellow  perch eggs  and larvae,   respectively,  at  each  sampled
plant  (only   those  plants   that  identified   perch   eggs  or   larvae  were
included).   Of the  three  plants  that  reported  yellow  perch eggs,  Pulliam
recorded  the   highest   densities   (~0.3   eggs/m3),  followed  by  Cook  (~0.04
eggs/m3), and  Bailly  (-0.001 eggs/m3).  Although every sampled  plant  impinged
some yellow  perch (Table 4),  Pulliam  and Cook  impinged  ~95% of  the  observed
                                       25

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totals.    This  indicates  that minor  entrainment  of eggs  and larvae  probably
occurred  at the majority of plants.

     The  earliest  yellow  perch  egg  entrainment  was  recorded at  the  Bailly
plant  in  March, while at  Pulliam and Cook egg  entrainment started  in  April  to
May  and  peaked  in  May to June.   Yellow perch  were  impinged at variable  rates
prior  to  the egg entrainment and no clear  spawning influx was evident.   Larval
entrainment began >3 weeks after the  initial  appearance of eggs at  each  of the
three  plants that recorded both  eggs  and larvae.   Maximum densities of  larvae
were observed at Pulliam (~0.04 larvae/m3).   The yellow perch larvae entrained
by  Port  Washington  may  have  been  transported  from  the  northwestern shore  by
lake currents.

                       Yellow  Perch  Entrainment  - Lakewide

     The  maximum  numbers  of  yellow  perch  eggs and  larvae  entrained  by  all
water  intakes on  Lake Michigan were estimated to be 4.81 x 107 and  3.26 x  106,
respectively,  assuming capacity  flows at all intakes  (Table 14).    Under  these
conditions,  conventional  power  plants would account  for  ~35%  of  the  total
entrained  perch eggs, the  Ludington  plant would account for 64% of the  total,
and municipal/industrial  intakes for ~1% of  the total.   The relative distribu-
tion of yellow  perch larvae by plant  type would be:   78% by conventional  power
plants,  16%  by  Ludington,  and  6%  by municipal/industrial  intakes.    Under
normal flow assumptions, we  estimate that ~4 x 107 yellow  perch  eggs and  1  x
106 yellow perch larvae  were  entrained by  all  water intakes  on  Lake Michigan
in 1975.

     The  estimated maximum numbers of yellow perch eggs  and  larvae entrained
within each statistical  district in   1975  are given in  Table  17.   These  esti-
mates  indicate  the  the majority of yellow perch eggs and larvae were entrained
in MM6, MM1,  and  MM8.  Unfortunately, no observations were available for

             Table 17.  Estimated total annual entrainment of  yellow perch eggs and larvae
             at all  water intakes within each statistical  district on Lake Michigan (1975),
             assuming design flow operation at all intakes.
District
wm
WM2
WM3
ww
WM5
WM6
Illinois
Indiana
MM8
MM7
MM6
MM5
MM4
MM3
W2
MM1
Total Flow
(m3)
7.99
0
0
2.39
2.55
2.51
6.46
8.10
3.42
7.03
2.11
0
3.32
1.02
9.95
9.08
x


x
x
x
x
x
X
X
X

X
X
X
X
108


109
109
109
109
109
109
108
1010

107
ID8
106
107
Eggs
Density
(N/m3)
1.51
1.51
N/A
N/A
0
N/A
N/A
2.01
1.46
1.46
1.46
0
0
0
0
0
x ID'2
x 10~2





x 10"5
x 10'3
X 10'3
x ID"3





Number
1.21 x
0
0
N/A
0
N/A
N/A
1.63 x
4.98 x
1.55 x
3.08 x
0
0
0
0
0
107






105
106
105
107





Larvae
Density
(N/m3)
3.04 x
3.04 x
N/A
N/A
1.14 x
N/A
N/A
2.29 x
2.51 x
2.51 x
2.51 x
0
0
0
0
0
ID'3
ID'3


ID'5


ID'5
10-5
ID'5
ID"5





Number
2.43 x
0
0
N/A
2.90 x
N/A
N/A
1.86 x
8.56 x
2.66 x
5.28 x
0
0
0
0
0
106



10"


105
10"
103
1Q5





            Total all
             intakes   4.83 x 1010     -      4.81 x 107       -      3.26 x 106
                                       26

-------
intakes  not  included  in  our  data  base;  thus,  no  comparisons  can  be  made
between our estimates for  "unsampled"  intakes and actual observations.

     The total  number  of yellow perch larvae entrained at  the  sampled  intakes
(Table  13)  represents  ~9% of  the  total  number  of entrained  perch eggs  and
indicates a 91% mortality.   From Table 14 a lakewide  estimate  indicates  a 93%
mortality between  egg  and larval stages  of  development.    These estimates  may
not reflect actual mortality  rates between perch egg and larval  stages  in Lake
Michigan.


                 FACTORS AFFECTING IMPINGEMENT AND ENTRAPMENT

                            Effects of Intake Type

     As  of  1975,  three  types  of  water  intakes  were  used  by  the  electrical
utility  industry on  Lake  Michigan:   canals  (CNL),  offshore open bays  (OOB),
and porous dikes  (PD).   Six  of the 16 sampled power plant  intakes are  canals,
four are offshore  open  bays,  and six are porous dikes  (Table 1).  A number of
factors, besides intake  type,  probably  affected the  obsrved impingement  and
entrainment densities at the  sampled  intakes:   e.g.,  flow  rate, location,  and
most  important,  the  local   inshore  densities  of   each   species/1ifestage.
Inshore  densities  of most species are highly  variable in  space  and  no  data
were available  that  would allow corrections of  observed  intake densities  for
spatial differences in fish abundance  (i.e., impingement/entrainment densities
at each sampled  intake could  not be normalized for local abundances).   Despite
these problems, we made  statistical comparisons of the  lakewide mean densities
between the three  types of water intakes.   Intakes of each type were  sampled
in each basin and on each  shore of Lake Michigan.

Al ewi fe
     The  results  of  statistical   comparisons  between  lakewide  impingement
densities at each  type  of  intake are presented in Table  18.   Alewife  impinge-
ment densities  (rates)  tended to be  significantly  higher at  canal  intakes  in
summer,  fall,   and winter,  and  significantly  higher  at  offshore  open bay
intakes  in  spring.  A  similar trend was found  when  all  sampled intakes were
grouped  into  "offshore"  or  "onshore"  locations:     i.e.,   onshore   intakes
impinged significantly  higher numbers of alewife in  summer and winter,  while
offshore intakes  impinged  more alewife in  spring.   Figure 2  shows  the  annual
mean densities of  alewife at each of the sampled intakes, grouped by type.   It
is apparent from  this arrangement of the data that (1) the Zion  plant  experi-
enced an inordinately  high density  of  impinged  alewife compared to other OOB
intakes, and  (2)  excluding  Zion from  the  OOB  group would  result in  canals
having the highest annual mean density.  This  indicates that  the Zion  site was
relatively high  in alewife abundance and that the  OOB intake design  (without
the behavioral barrier-net)  is not  very protective  of alewife.  Figure  2 also
shows  that  the  intakes sited on  the western  and  southern shores  of Lake
Michigan  experience  the  highest   annual  impingement  densities  of  alewife,
regardless of the  intake type.

     A  statistical comparison  of   lakewide  entrainment  densities  of  alewife
eggs and  larvae between intake types  is  presented  in  Table 19.   Canal and
porous  dike  intakes entrained statistically equal  mean  densities  of  alewife


                                      27

-------
   10
   10'
 o
 o
 o
   10
    -2
   10
  10-
    -3
                     X Kewaunee

                     X D. C. Cook
                     x Palisades
                                      x  Port Washington
                Pulliam
                Oak Creek
                Michigan City
                Waukegan
                                     x  Campbell
x Point Beach
X Statelinc

5 JJitchell
X Bailly
x I.ikeside
                                                     x  Big Rock
                  OPEN BRT
                                   CHNHL
                                                POROUS DIKE
Fig.  2.   Mean  annual  densities of impinged  alewife at  each
sampled  intake (1975).   Circles represent means  for  each
intake type.
    10
    10'

  tc
  I—
  •z.
  UJ
   10
   io-
     -3
Zion
D. C.  Cook
                      x Kewaunee
                      ^Palisades
                                      X Waukegan
                                        Pulliam
                                                      X Mitchell
                                                      x Lakeside

                                        Oak Creek
                                        Port Washington  X Point Beach
                                      X Campbell
                   OPEN BRY
                                    CRNflL
                                                 POROUS DIKE
Fig.  3.   Mean annual densities  of entrained alewife  eggs  at
each sampled  intake  (1975).   Circles  represent  means for
each intake type.
                                   28

-------
eggs  while  the  densities  entrained by  OOB  intakes  were  significantly  lower.
Onshore intakes entrained significantly  higher densities  of alewife  eggs  than
those   entrained  by  offshore  intakes.   The  exact  opposite  relationship  was
found   for  alewife  larvae:    i.e.,  OOB  >  CNL  =  PD  and  offshore  >  onshore.
Figures 3  and  4 show  the  mean  annual  densities  of  alewife  eggs  and larvae,
respectively,  entrained  by  each sampled intake.   The apparent high  abundance
of  adult  alewife  on the western shore  of Lake Michigan  (Fig.  2)  is reversed
for  the entrainment of  eggs  and larvae:  i.e.,  canal  intakes  on  the western
shore   (Oak  Creek  and  Port  Washington)  entrained  relatively  few alewife  eggs
and larvae compared to intakes sited on the  southern  shores.
Table 18. Statistical comparisons between lakewide monthly mean impingement densities of alewife, smelt, and yellow perch for
intake locations and types.8
Alewife
tenth
January
February
torch
April
May
June
July
August
September
October
November
December
Intake
Onshore
A
A
B
A
B
A
A
A
A
A
A
A
Location" Intake Type1-
Offshore OOB
A
B
A
A
A
B
B
B
A
A
A
B
AB
B •
A
A
A
B
C
B
B
B
A
B
CNL
A
A
B
B
B
A
A
A
A
A
A
AB
PD
B
B
B
A
B
B
B
B
C
B
A
A
Intake
Onshore
B
B
B
A
B
A
A
A
A
B
B
B
Smelt
Location
Offshore
A
A
A
B
A
B
B
B
B
A
A
A
Intake Type
OOB
A
A
A
B
B
B
B
B
B
B
A
A
CNL PD
B
A
B
A
A
A
A
A
A
B
A
A
A
B
B
B
B
B
B
B
B
A
A
B
Intake
Onshore
A
A
A
A
A
A
A
A
A
A
A
A
Yellow
Location
Offshore
B
B
A
B
B
B
B
B
B
B
B
B
Perch


Intake Type
OOB
B
B
B
B
B
B
B
B
B
B
B
B
CNL
A
A
A
A
A
A
A
A
A
A
A
A
HU
B
B
B
B
B
B
B
B
B
B
B
B
  OOB = offshore open bay; CNL = canal; PD » porous dike.
  t-test  A > B > C.
  AOV
        a = 0.05.
                    Table 19.  Statistical comparisons between lakewide annual
                    mean entrainment densities of each species-life stage for
                    intake locations and types.3
                    Species/Stage
                                       Intake Location13    Intake Typec
OnshoreOffshore  OOBCNLPD"
Alewife eggs
Alewife larvae
Rainbow smelt eggs
Rainbow smelt larvae
Yellow perch eggs
Yellow perch larvae
A
B
B
B
A
A
B
A
A
A
A
B
B
A
A
A
A
B
A
B
B
B
A
A
A
R
C
R

-
                    I OOB = offshore open bay; CNL
                    ° t-test   A > B > C.
                    c AOV   '  « = 0.05.
        canal; PD = porous dike.
      A different approach  to the  same question  regarding  intake-type effects
was applied whereby regional  and temporal differences in  abundance  were elimi-
nated by   comparing  monthly  mean  densities  of  a  species/1ifestage  between
                                          29

-------
    10'
    1-2
  en
  z
  uj
  a
   10
     -U _
   10
     -Si
                      x D. C. Cook
                      X Kewaunee
                      ^ Palisades
                                      X Waukegan
X Oak Creek



X Port Washington






x Pulliam
                                                       x Mitchell
                 x Stateline


                 X Lakeside
                                                      x Point Beach
                                       Campbell
                   OPEN BRY
                                    CHNflL
                                                 POROUS DIKE
Fig. 4.   Mean annual densities of entrained alewife  larvae

at  each  sampled  intake  (1975).   Circles represent means  for

each intake  type.
    101
 co .
 z
 UJ
    1-3
   10-
                      ; Kewaunee
                       D. C. Cook
                      y Palisades
x Oak Creek




X Port Washington   X Point Beach


•





X Pulliara

                •




X Waukegan
                                      X Michigan City




                                      X Campbell
                  Bailly

                X Big Rock


                X Statellne




                X Mitchell

                x Lakeside
                  OPEN BflT
                                    CflNflL
                                                 POROUS DIKE
Fig.  5.   Mean  annual densities of impinged  smelt at  each

sampled  intake (1975).   Circles  represent means  for  each

intake type.
                                  30

-------
"adjacent"  intakes of different  designs.   Tables  20,  21,  and 22  present  the
statistical  comparisons  between alewife  densities  at "adjacent" intakes  that
were  sampled at the same  time.   Alewife imingement densities  (Table  20)  were
significantly  higher in  most months  at four  canal   intakes  (Waukegan,  Port
Washington,  Oak Creek,  and Michigan City)  that were compared with  "adjacent"
intakes of other types.  The  very high alewife  impingement  at  Zion  through  May
1975  is  reflected  in  the  Zion-Waukegan  comparison,  but  the  significantly
higher densities at  Waukegan  from June through December indicate the  relative
efficiency of canal  intakes for entrapping  alewife.

     Two of  the comparisons in Table 20  are between similar  "adjacent"  intakes
(2 canals  and  2 porous  dikes) and they clearly show  that very similar intakes
in  the  same  region  of  the  lake  impinge alewife  at significantly  different
rates at  least eight months  of  the year:  i.e.,  Port Washington >  Oak  Creek
for  8 out  of  12  months,   Stateline  >  Mitchell  for 4 months during  alewife
spawning  runs,  but Mitchell  >  Stateline during 4  months  in fall  and  winter.
No explanation  is  apparent for the  differences between the densities  of  ale-
wife  impinged  at the two  canal  intakes  (Port Washington vs.  Oak Creek)  other
than  the  distance  of ~37  miles  between  them.  The two porous dikes  (Mitchell
vs.  Stateline)  are separated by ~20 miles  and are slightly different  in  that
the  Mitchell  intake extends  further  offshore  and utilizes  an  electric  fish
screen in the intake forebay.

     Tables  21  and  22  present  the1 intake-pair comparisons  for  entrainment
densities  of alewife eggs  and  larvae, respectively.   Only  one canal  and  one
OOB intake entrained consistently higher  densities  of  eggs  (i.e., Waukegan  vs.
Zion  and  Kewaunee  vs.  Point  Beach).    All  other  comparisons were  equivocal
except that  Mitchell's  porous dike  intake  rather  consistently entrained  more
alewife  eggs/unit  volume  than  the porous  dike at  Stateline.    Entrainment
densities of alewife larvae were higher  at  canal intakes in  late  summer,  while
densities entrained by porous dikes may  have  been higher in  early summer.   The
higher densities of  larvae at Mitchell  as  compared to those  at  Stateline  may
reflect the  apparent lakewide difference between offshore and onshore  intakes
(Table 19).

     In  conclusion,  the   results  of  lakewide  and paired  intake  comparisons
indicate that,  with  the  exception of  the  Zion  intake operated without a  pro-
tective net, canal  and onshore PD intakes impinge more alewife  per  unit volume
than OOB or OPD intakes.   Onshore intakes, and  offshore porous dikes  apparent-
ly entrain  more alewife  eggs/unit volume, while  offshore  open  bays  entrain
higher densities of alewife larvae.  These  indications may reflect  the  follow-
ing:  (1) spawning alewife tend to be  anadromous and may seek  harbors,  rivers,
and canals despite reverse flow  characteristics of intake canals;  (2)  alewife
eggs are demersel  (negatively buoyant) but remain  semi-planktonic  and may  be
equally  vulnerable to  onshore  and  offshore  intake  types;  and  (3)  alewife
larvae are  semi-planktpnic and  may concentrate near the  bottom in  offshore
areas where  open  bay  intakes are  located.   The  comparisons  between  similar
"adjacent" intakes indicate the degree of spatial variability  in  abundances  of
adult and young alewife, and  demonstrate the  potential errors associated with
comparisons of this type.

Rainbow Smelt

     Lakewide annual  impingement densities of  rainbow  smelt (Table  18)  indi-


                                      31

-------
           Table  20.   Statistical  comparisons of the monthly mean densities  (N/10003) of impinged alewife between dissimilar and  similar  intakes  that  are  "adjacent"  to
           one  another.   Underlined densities are significantly higher (a =  0.05).
co
ro

Kewaunee vs. Point Beach
04/01/75-02/28/76
OOB
PD
Waukegan vs. Zion
05/12/75-12/31/75
CNL
OOB
Lakeside vs. Port Washington
03/07/75-02/26/76
PD
CNL
Lakeside vs. Oak Creek
03/07/75-02/06/76
PD
CNL
Bailly vs. Michigan City
12/03/75-06/28/76
PD
CNL
Oak Creek vs. Port Washington
03/04/75-02/25/76
CNL
CNL
Mitchell vs. State! ine
05/03/75-03/30/76
PD
PD
January February March April
.00008 .00033 - .00251
.00017 .00001 - .00021
000 .05499
.00582 .00087 .00167 .31192
000 .05499
0 0 .00149 .13458
.00042 .00021 .00131 .12215
0 .00016 .55357 1.21574
0 0 .00133 .13458
.00582 .01064 .00161 .31192
.00032 .00045 0
.00028 0 0
May
.18628
.73129
2.82230
96.09213
.21484
12.90111
.21484
2.77194
.78674
2.14510
2.77194
12.90111
1.38272
2.84351

June
.92340
4.29441
3.54028
2.00108
1.01245
22.08029
1.01245
5.45543
1.55160
2.46038
5.45543
22.08029
1.02870
2.05157

July
.40736
2.84051
1.00764
.25663
6.81306
.25663
3.00166
3.00166
6.81306
.18293
.48243

August
.35052
.73800
.28921
.09750
.05223
.96535
.05223
1.06960
1.06960
.96535
.01530
.01315
September
.17825
.05431
.30037
.13301
.00182
.14267
.00182
.15047
.15047
.14267
.00121
.02828

October
.23001
.28655
.65819
.15247
.00268
.69851
.00268
.01571
.01571
.69851
.00976
.00154
November
.45843
.54113
.15591
.03238
.12590
.27349
.12590
.02490
• .02490
.27439
.66217
.00448
December
0
.00021
.04383
.00286
.01294
.03304
.01294
.00415
.00117
.00244
.00415
.03304
.13175
.00052

-------
cate  that  canal  intakes impinge  significantly  more smelt/unit volume  between
April  and  September,  while  significantly  higher  densities are  impinged  by
porous  dikes  in  late fall,  and  by  offshore open bays  in  early spring.   Off-
shore  intakes,  as a  group, impinge  significantly  higher  densities  of  smelt
from  fall  to  early spring, while onshore  intakes  impinge higher densities  in
April and summer months.  Figure 5 presents the annual mean  impingement densi-
ties of smelt at each sampled intake and clearly indicates  the  relatively  high
abundance of smelt on the western shore of Lake Michigan:   i.e., regardless  of
intake  type,  the  highest  annual densities of  smelt occur  at  intakes on the
Wisconsin and northern  Illinois  shores.   On an annual basis, the mean  density
of  smelt impinged  at canal  intakes  is  substantially higher than those  at OOB
and  PD  intakes,  but this  difference  may  be a result of  the higher number  of
canal  intakes  on the western  shore  of the lake.   The  comparisons of  monthly
smelt  impingement  densities  between "adjacent" pairs  of  intakes  (Table 23)
suggests that  canal  intakes  impinge  significantly  more smelt  than OOB or  PD
intakes throughout most of  the year, with the exception of  late fall  (Zion vs.
Waukegan).   Porous dikes  (Point  Beach vs.  Kewaunee) may impinge higher densi-
ties of young  of the year  in  late  summer.   Comparisons of  similar "adjacent"
intakes  show  consistently  higher  densities  at  Oak Creek  compared  to  Port
Washington  and  seasonal  differences between  Mitchell  and  State!ine:    i.e.,
between June and December  the  onshore porous  dike at State!ine impinged  fewer
smelt/unit volume  than  the  more  offshore  porous dike at Mitchell and,  in  late
winter, the reverse was true.

     Rainbow  smelt   eggs   were  entrained   at  significantly  higher   rates
(densities) by offshore open bay  intakes  and by offshore  intakes as a  group
(Table  19).   The mean annual densities of  entrained smelt eggs (Fig.  6)  were
highest at intakes on the  southern  basin  of Lake Michigan and  apparently  were
highest at OOB intakes.   Unfortunately, the major period of  smelt egg  entrain-
ment (early spring) either  was not sampled by some utilities or was sampled  in
different  years;   therefore,  the  statistical  comparisons  between "adjacent"
intakes were limited  to very few months  (Table  24).  Despite  these  problems,
the  comparisons  do indicate significantly  higher densities  of  entrained  smelt
eggs at OOB intakes (Kewaunee vs. Point Beach and Zion vs. Waukegan).

     Rainbow smelt larvae  also  were entrained at  significantly higher  rates
(densities) by offshore open bay  intakes  and by offshore  intakes as  a  group
(Table  19).   Intakes on the  western shore  and in  the  southern basin  of  Lake
Michigan tended to show the highest  densities of entrained  smelt larvae  (Fig.
7).   Table  25  presents  the  comparisons  of  smelt  larval  densities  between
"adjacent"  intakes and  reflects  the  lakewide  trend of  offshore  open  bays
entraining  higher  densities than canal  or  porous dike intakes.  Although  Port
Washington  entrained  higher densities of  smelt eggs than  did  Oak Creek, the
reverse was  true  for smelt larvae.   Mitchell's porous  dike   (more  offshore)
consistently  entrained  more  smelt  larvae/unit  volume  than did  the  onshore
porous dike at Stateline.

     In conclusion,  the above analyses  indicate that canal  intakes  are  most
destructive of smelt adults during  the  spawning season,  while offshore  porous
dikes  and  open  bays  tend  to   impinge more   smelt/unit  volume  during  other
periods of  the year.   Smelt  eggs  and  larvae  seem most  susceptible  to OOB
intakes and offshore intakes in  general.
                                      33

-------
   10
     -I,
   10
   10-
     _p
   10
     -5
   10
     -6
                      * Zion
                      X D. C. Cook

                      x Kewaunee
                      .1. Palisades
                                      X Waukegan
                                      X Pulliam
                                      X Oak Creek
                                      X  Port Washington
                                                      X Stateline
                                                      x Mitchell
                                      1 Campbell
                                                      u,Point Beach,Lakeside
                   OPEN BRT
                                    CflNRL
                                                 POROUS DIKE
Fig. 6.   Mean annual  densities of entrained smelt eggs at
each sampled  intake  (1975).   Circles  represents  means for
each intake type.
   10-
    •x-3
 in
 z
 UJ
 Q
 Si! 10-"
     -5
   10
   lO'6
x Kewaunee

x Zion
X D.  C. Cook
x Oak Creek



•

x Port Washington

x Waukegan


X Pulliam
                                      X  Campbell
                                                      X Mitchell
                                                      x Point Beach
                                                      x Stateline
                       Palisades
                                                       Lakeside
                  OPEN Bflr
                                    CflNflL
                                                 POROUS DIKE
Fig.  7.   Mean  annual densities of entrained  smelt larvae  at
each  sampled intake (1975).   Circles represent means  for
each  intake type.
                                  34

-------
            Table  21.   Statistical  comparisons of the monthly  mean  densities (N/nt3) of entrained alewife eggs  between  dissimilar and similar intakes that are "adjacent"
            to one  another.   Underlined densities are significantly higher (o = 0.05).
CO
en
January February torch April
Kewaunee vs. Point Beach
04/18/75-10/31/75
OOB ... o
PD ... o
Uaukegan vs. Zion
04/16/75-09/03/75
CNL ... o
OOB ... o
Lakeside vs. Port Washington
05/20/75-10/28/75
PD - ...
CNL . . .
Lakeside vs. Oak Creek
05/20/75-10/29/75
PD ....
CNL - ...
Oak Creek vs. Port Washington
04/17/75-10/28/75
CNL ... o
CNL ... o
Mitchell vs. Stateline
05/03/75-09/04/75
PD ....
PD - ...
toy


0
0


.00587
.00244


0
0


0
0


0
0


3.31866
.09453
June


.01711
.00450


24.34260
1.88130


.01301
.00204


.01301
.00536


.00536
.00204


22.47867
4.71500
July


.56431
.01987


5.81448
Z. 79794


.05450
.03765


.05450
.01754


.01754
.03765
,,.. -„•-_-_, j. um.-_u

5.86174
.82323
August


.09761
.01097


.93701
.15977


.00432
.00053


.00432
.02179


.02179
.00053


.11838
.19407
September


0
0


.01435
o 	


0
0


0
0


0
0


.01220
.00036
October


0
0


_
„


0
0


0
0


0
0


. _
-
November December


..
_


_ _
_


_ _
_ _


_ _
-


_
_


_
-

-------
          Table  22.   Statistical  comparisons of the monthly mean  densities  (N/m3)  of entrained alewife larvae between dissimilar and similar intakes  that  are
          "adjacent"  to  one  another.   Underlined densities are  significantly  higher (a = 0.05).
CO
January February ftorch April
Kewaunee vs. Point Beach
04/18/75-10/31/75
OOB ... o
PD ... o
Waukegan vs. Zion
04/16/75-09/03/75
CNL ... o
OOB ... o
Lakeside vs. Port Washington
05/20/75-10/28/75
PD -
CNL ....
Lakeside vs. Oak Creek
05/20/75-10/29/75
PD ....
CNL - ...
Oak Creek vs. Port Washington
04/17/75-10/28/75
CNL ... o
CNL ... o
Mitchell vs. State! 1ne
05/03/75-09/04/75
PD . ...
PD ....
*y


0
0


0
0


0
0


0
0


0
0


.00025
0
June


0
0


.01927
.00321


.00310
.00005


.00310
0


0
.00004


.08821
.01227
July


.00315
.00019


.07355
.03184


.01177
.00018


.01177
.00002


.00002
.00018


.04038
.00571
August


.00149
.00109


.01658
.00493


0
.00123


0
.00253


.00253
.00123


.01525
.00546
September October


.00441 0
.00129 .00003


.08063
.00250


0 0
.00321 0


0 0
.00770 .00056


.00770 .00057
.00321 0


.00012
.00168
November December


_ _
_ _


_ _
_ _


_ _
-


.. _
.


_ _
_


_ _
_

-------
Table 23.  Statistical comparisons of  the monthly mean densities  (M/1000  m3)  of impinged smelt between dissimilar and similar intakes  that  are  "adjacent"  to
one another.  Underlined densities are  significantly higher  (a =  0.05).
                                January   February
March
          April
May
          June
July    August   September   October    November   December
                                  .00014      .00164   0         0
                                  .00951      .00638     .03850     .12074
            Kewaunee  vs.  Point Beach
              04/01/75-02/28/76
                OOB                           .04948     .04481
                PD                            .08043     .01966
            Waukegan  vs.  Zion
              05/12/75-12/31/75
                CNL                           -          -
                OOB
            Lakeside  vs.  Port Washington
              03/07/75-02/06/76
U>              PD
"-1              CNL
            Lakeside  vs.  Oak Creek
              03/07/75-02/06/76
                PD
                CNL
            Bailly vs.  Michigan City
              12/03/75-06/28/76
                PD
                CNL
            Oak  Creek vs.  Port Washington
              03/04/75-02/25/76
                CNL
                CNL
            Mitchell  vs.  Stateline
              05/03/75-03/30/76
                PD                            .00034     .00010    .00010
                PD                            .00036     .00069    .00079
                                                                 .03899
                                                                 .00990
                                  .00014      .00164   0         0
                                  .02838      .04445     .09196     .73320
                                  .00042      .00018     .00370     .00649
                                  .00042      .00111     .00284     .00449
                                  .02838      .06124     .09001     .73320
                                  .00951      .01068     .03489     .12074
                    .00353
                    .00572
                                                                            .00183
        .01754    .01261
        .01899    .06966
        .01185
        .06159
                                                                                       .00469    .02168    .00385
                                                                                                 .00061"    .00078
                    .00118     .00121   0          0
                    .10360     .10309    .20519     .29830
                    .00118     .00121   0         0
                    .31172     .19883    .69027     .39366
                    .01014     .00016
                    .00763     .00057
                    .31172     .19883     .69027     .39366
                    .10360     .10309     .20519     .29830
                                                                            .00052     .00095    .00121    .00076
                                                                            .00054     .00006    .00016    .00005
.02228
.05637
.23001
.28655
                                                                .00183    .00338
                                                                .00090    .00128
.08779
.18391
                                                              .00144
                                                              .00637
.01459
.05555
                                                     .00398
                                                     .07176
                                       0           .00045      .00188    0
                                         .45350     .00699      .03149     .03948
                                       0           .00045      .00188    0
                                         .21710     .03461      .12181     .08033
                                                                         .00072
                                                                         .00056
                                         .21710     .03461      .12181      .08033
                                         .45350     .00699      .03149      .03948
                                                                .00073    .00026     .00009     .00164
                                                                          .00008     .00005     .00001

-------
Table 24.  Statistical comparisons  of  the monthly mean densities  (N/m3) of  entrained  smelt eggs  between dissimilar and similar intakes that are  "adjacent"
to one another.  Underlined densities  are significantly higher  (a = 0.05).
January February fferch
Kewaunee vs. Point Beach
04/18/75-10/31/75
OOB ...
PD - . .
Waukegan vs. Zion
04/16/75-09/03/75
CNL ...
OOB ...
Lakeside vs. Port Washington
05/20/75-10/28/75
PD ...
CNL ...
Lakeside vs. Oak Creek
05/20/75-10/29/75
PD ...
CNL ...
Oak Creek vs. Port Washington
04/17/75-10/28/75
CNL ...
CNL ...
Mitchell vs. Stateline
05/03/75-09/04/75
PD ...
PD ...
April Ifey
.05362 .01422
.47900 .06609
.62093 .11037
0
.00210
0
0
0 .00048
.00005 .00249
.00681
.00716
June
0
0
0
.00061
0
0
0
0
0
0
0
.00068
July
0
0
0
0
0
0
0
0
0
0
0
0
August
0
0
0
0
0
0
0
0
0
0
0
0
September
0
0
0
0
0
0
0
0
0
0
0
0
October November December
0 - -
0 - -
0 - -
0 - -
0 - -
0
0 - -
0 -

-------
Table 25.  Statistical comparisons of the monthly mean densities  (N/m3)  of  entrained  smelt larvae between dissimilar and similar intakes that are  "adjacent"
to one another.  Underlined densities are significantly higher  (o « 0.05).
January February
Kewaunee vs. Point Beach
04/18/75-10/31/75
OOB
PD -
Uaukegan vs. Zion
04/16/75-09/03/75
CNL
OOB
Lakeside vs. Port Washington
05/20/75-10/28/75
PD - -
CNL
Lakeside vs. Oak Creek
05/20/75-10/29/75
PD - -
CNL - -
Oak Creek vs. Port Washington
04/17/75-10/28/75
CNL
CNL
Mitchell vs. Stateline
05/03/75-09/04/75
PD - -
PD - -
March April May June July
.00046 .02027 .00169 .02555
0 .00053 .00100 0
0 .03555 .00492 0
000
0 0 .00026
000
0 .00021 .00021
0 .00048 .00021 .00286
0 0 0 . 00026
.02996 0 .00117
.00025 0 .00001
August
.01206
.00538
0
0
0
.00149
0
.01518
.01518
.00149
.00365
.00054"
September October November
.03186 .03551
.00180 .00233
0 - -
0 - -
00
.00298 0
00
.00837 .00152
;00837 .00156
.00258" 0
.00012
December
-
-
-
-

-------
Yellow Perch

     The  results  of  statistical  comparisons  for  yellow  perch   impingement
between  intake  types (Table 18)  are  highly affected  by  the disproportionate
impingement density  at the Pulliam  plant (onshore  canal  intakes).  Figure 8
presents  the  annual  perch  impingement densities  at each  sampled  intake and
indicates that, if Pulliam is excluded, offshore open bay  intakes and any type
sited on the southeastern shore of Lake Michigan impinge the highest densities
of yellow perch.  Comparisons of "adjacent" plants (Table  26) indicate the OOB
and canal intakes  impinged  more yellow perch/unit volume  than  do  porous dike
intakes,  and  that  the canal  intake  at Waukegan  impinged  higher densities of
perch than  the  OOB  intake  at  Zion.    No  consistent  differences were observed
between  the  "adjacent" canal  intakes  or  between  the  "adjacent"  porous dike
intakes.

     Yellow perch  eggs were  not identified  at some  and  not  found  at other
sampled  intakes, making a  statistical  comparison difficult.   The  annual mean
density  of  perch eggs  at D. C.  Cook was  similar to  that  at Pulliam (Fig. 9)
despite  the order of magnitude  difference between  perch impingements at these
plants,  indicating that OOB  intakes  might entrain significantly higher  densi-
ties, if inshore abundances were  equal.   Based  on  the very limited  data in
Figure 10, it appears that canal intakes are at least as destructive of yellow
perch larvae as are OOB intakes, if Pulliam is excluded.

                   Effects of Flow and Geographic Location

     Generally, it is  assumed  that the numbers  of  fish impinged or entrained
by  water  intakes   are  directly  related  to  the  water   flow  or  quantity
withdrawn.   A  "perfect"  linear  relationship  between  these variables  (i.e.,
where all  the variability in y is explained  by  the variability  in  x)  would
require  homogeneous distribution of the fish species/life  stage throughout the
body  of  water,  as  well  as  no  site-specific,  intake-related  differences  in
impingement/entrainment rates.   It is  clear  from the preceeding analyses that
neither  of  these  requirements  are true  for  any of the  three  Lake Michigan
species  included in this report.

     Since the  sampling of  power plant intakes  was  planned and executed in a
site-specific  manner,  the  available  data  do  not  provide adequate  representa-
tion  of  the   variables   potentially   affecting  impingement and   entrainment
values:  i.e., a stratified or hierarchal   sampling design  would be  required to
estimate the  individual effects  of intake type, location,  fish abundance, and
flow.   Despite  these apparent problems,  we performed linear regressions (log
observed   impingement/entrainment   vs.   log   observed    flow)   for   each
species/1ifestage to estimate the effects of  flow and to  determine the  feasi-
bility of predicting the effects of future water intakes.

     The  effect  of water  intake flow on  impingement of  alewife  is  shown in
Figure 11.  A strong linear (log-log)  relationship  was found (P <0.0001) and
the results indicate that 66% of the  variability in  impingement (R2 = 0.66) is
associated  with flow.    It  is apparent from  this  plot  that  four  intakes
impinged inordinately high numbers of  alewife:  Zion  (1),  Port Washington (8),
Pull i am  (5),  and  Michigan  City (4).   The  aforementioned effects  of canal
intakes  and western  shore locations  are  substantiated.  This indicates  that a
canal intake sited on the western shore of Lake Michigan or  on Green Bay could


                                      40

-------
Table 26.  Statistical comparisons of the monthly mean densities (N/1000 m3) of impinged yellow  perch  between  dissimilar and similar intakes that are
"adjacent" to one another.  Underlined densities are significantly higher (o = 0.05).
January
Kewaunee vs. Point Beach
04/01/75-02/28/76
OOB 0
PD .00007
Waukegan vs. Zion
05/12/75-12/31/75
CNL
OOB
Lakeside vs. Port Washington
03/07/75-02/06/76
PD 0
CNL 0
Lakeside vs. Oak Creek
03/07/75-02/06/76
PD 0
CNL .00052
Bailly vs. Michigan City
12/03/75-06/28/76
PD .00200
CNL 0
Oak Creek vs. Port Washington
03/04/75-02/25/76
CNL .00052
CNL 0
Mitchell vs. Stateline
05/03/75-03/30/76
PD .00040
PD .00028
February
.00009
.00004
0
.00054
0
.00039
.00020
.00156
.00009
.00013
.00003
.00037
March
0
.00086
0
.00219
.00068
.00201
.00207
.00077
.00052
.00013
April
.00034
.00059
0
.00113
0
.00107
.00029
.00346
.00107
.00113
May
.00014
.00006
.00005
0
0
.00040
0
.00020
0
.00631
.00020
.00040
0
.00027
June
.00054
.00008
0
0
.00002
.00054
.00002
.00010
.00029
.00188
.00010
.00054
.00024
.00097
July
.00086
.00032
.00009
.00010
.00032
.00078
.00032
.00411
.00411
.00078
.00307
.00419
August
.00040
.00027
.00027
.00020
.00010
.00044
.00010
.00039
.00039
.00044
.00437
.00288
September October
.00053 .00029
.00028 .00020
.00108 .00113
.00018 .00009
0 0
.00018 .00007
0 0
.00021 0
.00021 0
.00018 .00007
.00028 0
.00037 .00031
November
.00050
.00018
.00003
.00042
0
.00046
0
.00027
.00027
.00046
.00008
.00005
December
.00017
.00021
.00050
.00006
0
.00020
0
.00105
.00109
.00178
.00105
.00020
.00080
.00004

-------
    10'
   10'
  o
  o
  o
  £10-
   10"
   10
    -5
;
r
:
r
:

r
:
i 	 	 — | 	 	 	 1 	 .
X Pulliam ;
g
X D. C. Cook
* x Michigan City
x Campbell x Bailly
x Oak Creek * Stateline -.
, Mitchell :
Zion g Port Washington ;
KpwaiinoB Waukegan
Kewaunee * Big Rock
* Point Beach
x Palisades —
x Lakeside ~
	 1 	 1 	 i 	
                 OPEN BflT
                                CRNflL
                                            POROUS DIKE
 Fig.  8.  Mean  annual densities of  impinged yellow perch at

 each  sampled  intake (1975).   Circles  represent means for

 each  intake type.
   10"
   10"
 tier3


 in
 z
 LU
 Q
   10
    -5
   10
    -6
                	1



                 OPEN BflT
                     Palisades
                                  X Pulliam
 Port Washington,

x Campbell	
                                CRNflL
                                            POROUS DIKE
Fig.  9.   Mean annual  densities  of entrained yellow  perch

eggs  at  each sampled  intake  (1975).  Circles represent

means  for each intake type.
                               42

-------
   10
    -2
   10
  : 10'
    -3
   10
    -6
   10
    -7
                    x D. C. Cook
                    ^Palisades
                	f

                 OPEN BfiT
                                   x Pulliam
                                   x Port Washington
                                     Campbell
                                 CHNflL
                                             POROUS DIKE
Fig.  10.   Mean  annual  densities  of entrained yellow perch
larvae  at each  sampled intake  (1975).   Circles  represent
means  for each  intake  type.
               LN(A) - -39.259 + 2.555*LN(flow)
     Fig. 11.   Relationship
     between  total number of
     alewife  impinged  and
     total flow (1975).
                  109

                FLOW IM3)
101
                                43

-------
Impinge  ten times  the  number of  alewife  as another  intake  type sited  else-
where.

     The  relationship between flow  and entrainment  of alewife  eggs was  not
significant  (P >  0.6)(Fig.  12).    This indicates  that  the  distribution  of
alewife eggs is more  heterogeneous than  that of adults  and/or  that intake type
has a  pronounced  effect  on  egg entrainment.  As previously mentioned,  intakes
on the southern shore of Lake Michigan  (3,  11, 13, 12)  entrain  relatively high
numbers of  alewife  eggs.   Conversely,  the  numbers of entrained alewife larvae
are related to flow (P <0.003) and 52%  of the variability  can  be  attributed to
flow (Fig.  13).   Again,  intakes  in the  southern basin  (e.g.,  2,  3,  11, 13,  1,
12) entrain the highest numbers of alewife  larvae.

     Impingement  of  rainbow  smelt  is   directly  related  to  water  flow  on  a
lakewide  basis,  despite  locational  differences  in abundance  (Fig.  14).    The
log-log regression  was significant  (P  = 0.0005)  and indicated that  59% of  the
variability was due to flow  (Fc =  0.59).   Water  intakes on the  western  shore
impinged  the highest  numbers  of smelt.  Entrainment  of smelt eggs  and larvae
were   significantly   related   to  variations  in  flow  (Figs.   15  and   16,
respectively).   Forty-two percent  of the variability  in smelt eggs  and 56% of
the variability  in smelt  larvae were  attributable  to flow.   Intakes  on  the
southern  shore entrained relatively  large numbers of smelt eggs while southern
and western intakes entrained large  numbers of larvae.

     Impingement of yellow  perch was significantly related to flow  on a  lake-
wide basis if the Pulliam intake (5) was excluded  (Fig. 17).   Intakes in  Green
Bay (5) and in the  southern basin  of Lake  Michigan (2, 12, 3, 13, 1) impinged
relatively high numbers of yellow perch.

     Figures  11-17  provide  a  measure of predictability  of   the expected
impingement or entrainment  losses   associated  with  anticipated  increases  in
water  withdrawals.   Slightly better predictions  could be obtained  given  the
intake design and location  on Lake  Michigan,  but  accurate predictions are  not
possible  since  the important effects of  (1) spatial heterogeneity in  abundance
and (2) annual  fluctuations in abundance are not quantified.

                      DEVELOPMENT OF MATHEMATICAL MODELS

     The  surplus  production  model  and  dynamic pool  model are  two  different
mathematical models that are  commonly  applied  for assessment of  the  impact of
exploitation on fish  populations.   In  this  study  these models are applied  for
assessment  of  entrainment  and  impingement impacts.   Impingement  impact  is
comparable  to  the impact of  a  fishery and the fishery models can  be applied
with little modification.   Assessment  of  the  impact  of  entrainment requires
more substantial  modification of the models.

                           Surplus Production Model

     In all populations,  biomass  is continually added  by  growth  and recruit-
ment and  lost  through mortality.   Surplus  production  is the amount  of biomass
that can  be removed  from a population  without changing  the population  size:
i.e.,   the  biomass  removed  is   replaced   by   recruitment  and   growth.     In
derivation  of   the  surplus  production model  it is  assumed   that surplus
production is some function of population size.  Surplus production  is assumed


                                      44

-------
 10'fr-
 109-
iio8
 10'
 10b
  10'
              i§u"
                              A2
                            AlO

                           A7
                          FLOW (M3)
                                         101
    Fig.  12.   Relationship
    between  total number of
    alewife  eggs entrained
    and total  flow  (1975).
101
                           LN(AL) « -75.535 + 4.467*LN(flow)
    Fig.  13.   Relationship
    between total number of
    alewife larvae  entrained
    and  total flow  (1975).
                                                 101
                                        45

-------
10b
10s
10d
                                 10
                             A7
                         A8
 107
                              LN(S) = -38.435 + 2.314*LN(flow)


                            J	1	'  	[	'  i
                            10a
                          FLOW  (M3)
101
10"
                 Fig.  14.  Relationship
                 between total  number of
                 smelt impinged and  total
                 flow  (1975).
                           L,(SE) = -65.024 + 3.912 x U(flow)
                            n                n
                 Fig. 15.   Relationship
                 between  total number of
                 smelt eggs entrained and
                 total flow (1975).
                                                  101
                          FLOW (M3)
                                         46

-------
 !07
 10°
SlO5;
 11011:
  10*
  10*
   10'
                    A8 /A3  A2
                    Al4
        Ift(SL) = -63.883 + 3.881*LN(flow)
           109
         FLOW  (M3)
             101
                                              101
                                                      Fig.  16.   Relationship between
                                                      total  number  of smelt larvae
                                                      entrained and total  flow  (1975).
  10V-
  105
 !l03:
  102:
   107
              * 4
                         A12*
                     A3
                      A13
       *14 All
        8AA  A7
             Al6    A 9

             ,,i|A15. i  i
10D
  10a
FLOW (M31
                      10"
                                101
                                        Fig.  17.   Relationship  between
                                        total number of  yellow  perch
                                        impinged  and total flow (1975).
                                           47

-------
to  be  small  at both  high and  low population  sizes.    The  maximum  surplus
production occurs at some intermediate  level  of  population size.

     In  the  surplus production  model  the  change  in yield  (biomass of  fish
caught)  with  respect to  time is  assumed  proportional  to  the  production of
biomass and fishing effort.   If  the  natural  change  in biomass is  described by
the logistic equation,  then the surplus production model is:


     £•*•
where :

    Y = yield in kg
    B = population biomass in kg
    k = population growth parameter
    B^  = environmental  carrying capacity or population  level without  fishing
    E = fishing effort  in standard units
    q = catchability coefficient
    t = time in years.

Under  equilibrium  conditions,  the  relation  between  equilibrium  yield  and
biomass is the parabola


     Ye = kB - £- B2
                00

where Ye is the annual  equilibrium yield.   The  maximum  sustainable yield,  MSY,
occurs  at a biomass level of BOT/2, so  the  MYS is:


                              2kB     kB    kB
     For  each  species  the  parameters of  the surplus  production  model  were
estimated by non-linear least squares using the  approximation:
     Ya(t) = Y(t + 1)  - Y(t)  = qE(t)   /   B(t)dt -  qE(t)  B(t +  1}  + B(t)
                                      t
where Ya is the annual  yield.   The solution to the logistic  surplus  production
model i s :
            B (k - F)
           I oo
fl         k    1
K"  BJk -  F>J(
                                     48

-------
where B0 is  the  estimate of biomass in 1960 obtained  as  1/q  (1960 CPUE)  and F
is the instantaneous fishing mortality coefficient.

     The surplus  production model  can be  modified  easily to model  the  impact
of  impingement.    Let  f^  be the  impingement coefficient  for  the i™  water
intake and  Q^  be the  volume flow  for the  i"1 water intake;  then  the  surplus
production model  can be written as:
     dl.
     jo        \.   •)
     dB=kB -|-B2 -qEB -  7  f QB
                oo            1=1

where the new terms are :

    n = number of water intakes
    1^ = impingement at water intake i at time t
    fj = impingement coefficient at water intake  i
    Q-j = volume flow at water intake i at time t.

     To  apply  the  surplus  production  model  for  assessment  of  entrainments
equations must be developed for egg production and  for  larval  production;  then
larval production  must be related to the  biomass of the standing  stock.   The
number of eggs produced by the population, G, is:


     G =  f    EUB


where HUB  is  the  number of eggs produced  per unit of female  biomass  and  G is
the  number  of eggs  produced by  the population.    The  rate  of  loss of  eggs
through entrainment at water intake i is:
where G' is  the  number  of eggs entrained at time t  and  p.,-  is  the  egg  entrain-
ment  coefficient  at water  intake  i.   Substitution   from  above  gives  the
equation:
Assuming  that,  in the  long  run,  the population  produces  enough eggs  to  just
replace itself, then
                                      49

-------
dB\  _
dt/e
lOB
                  dG1
                  "dt~
where  (dB/dt)e is  the  rate of biomass  loss as a  result of egg  entrainment.
The  amount  of biomass produced is  a  function of the number of  eggs  produced.
The  impact  of  entrainment  on  egg   is  equivalent  to  a  reduction  in  egg
production  by the  population.   The  rate  of biomass loss  resulting from  egg
entrainment,  (dB/dt)e, is
     Now the impact of larval entrainment  on  biomass  production  will  be  deter
mined.  The number of larvae produced by G eggs  is:
    L = (1 -
where  L  is  the number of  larvae  produced from G eggs  and $ is the  mortality
from  the  egg stage to  the larval  stage.   The  relation between adult  biomass
and the number of "larvae produced is given  by the equation
     L = (1 - $


Differentiation of this equation with respect to time gives


     dL _ M    .  EUB  dB
and the  rate  of  change  in biomass resulting from entrainment of  larvae  at  the
i™ water intake, (dB/dt)-j, is


     dB\  _   dL'/dt

where dL'/dt is  the  rate  of larval  entrainment at the water intake.  The  rate
of larval entrainment at water intake i can be modeled with the equation
where hj is the larval entrainment coefficient at water intake i.  Combination
of the above equations for larval entrainment gives the rate of biomass change
resulting from larval entrainment at water intake i as
                                      50

-------
          = W



     Combining the above  equations  for egg and  larval  entrainment gives the
following surplus production  model  for  assessment of entrainment  impact:
     IT
               ic   ?           n            ".
             - *- B2 - qEB -   I

Combining the model  for entrainment and  impingement  impact  gives  the model



     dY
     ~5t
= qEB
     HT     n
     S-  tiw
     dci=   y    i
     dt     -L  pi
                              1=1           1=1           1=1


This  model  was  applied  to  study  the  combined  impacts  of  impingement and

entrainment on  standing  stocks  and  maximum  sustainable yields  of  alewife,

perch, and smelt.


                              Dynamic  Pool  Model


     The  dynamic  pool  model  [28]   provides  a  more  complete  and  detailed

description of the dynamics  of a  population than does  the surplus  production



                                      51

-------
model  [29].   The dynamic  pool  model is  a  reduction!stic model  in  which the
yield from a fishery is broken into its components:  growth, reproduction, and
mortality.   Each of  these components  is modeled  separately,  in as  great a
detail as necessary, and then the components are brought together into a model
for yield.

     The  derivation  of  the  dynamic  pool   model   begins  with   the  identity
relating  the  biomass  of  a cohort  to  the  number  of individuals  and average
individual weight.  The biomass  of a cohort at age x, B(x), is the product of
the  number of  individuals  of  age  x,  N(x),  and  the  average  weight  of  an
individual of age x, W(x)  :


    B(x) = N(x)-W(x).


Differentiation of  this equation  gives the change  in  biomass  with respect to
age as


      " " = N(x) ^Al+ w(x)
The first  term  on the right relates  to  production  and  the second term to the
loss  of  biomass  by  mortality.   Yield  to  a  fishery equals  the loss  due to
fishing:


     £--«"<>

where (dN(x)/dx)p is fishing mortality.  It is usually assumed that
where  F  is  the  instantaneous  fishing  mortality coefficient  and  the yield
equation then becomes


     ^= F N(x) W(x).


To  apply  this  model,  relations for W(x)  and  N(x)  as functions  of age must be
developed.  Assume that fish are recruited into the exploited stock at age x?;
then  if mortality  follows  the  exponential  model,  change  in  cohort  size is
given by the equations:


     f = -MM. xr < x < xc


        = -(F + M)N, x > x  .
                                      52

-------
Solution of these equations gives the mortality  equation


     N(x) = Re"M^xc " xr   'F + M'^x   xc  ,  x >  xv
                                                   r


where:

    M = instantaneous natural mortality coefficient
    xc = age at entry to fishery
    xr = age at recruitment
    R = number of recruits.

     To  model  weight  as a  function of  age,  it  is  usual  to  begin  with  an
equation for length  as  a function of age.  Growth in  length  is  asymptotic  and
can usually be described accurately  by the equation:
     A(x) = a (1 - e'K(x ' xo})
where :
         = length at age x
    &M = asymptotic length
    K = growth constant
    x0 = age when length equals zero  (assumed to be  zero).

The  relation  between  length  and  weight  is   accurately   described  by  the
parabolic growth equation


    W(x) = a £(x)b
where a  and  b are constants.   For simplicity it will  be assumed that  b  =  3.
Substitution of the equation  for  length as a function of  age  into the  length -
weight equation gives the equation for  growth in weight  as
     W(x) = W (1 - e'K(x ' xo))3,
             oo
where W^,  = asymptotic  individual  weight.   This  is  von Bertalanffy's  growth
equation [9].

     Combining  the  above  results  for  mortality  and  growth  gives  the yield
equation:
     * - FWooRe-M(xc ' V - (F


The solution of the equation is
                                  M)(x - *c>(l - e'K(x  ' V)3.
                                      53

-------
                          o  II p-JK(x   - x  )
             -Mfx  - x )  J  Ui6     C    °
     Y = RW e mxc   V  I   J c x u	,_
                          >n    F + M + jK
where:  U0 = 1, Uj_ = -3, U2 = 3, and  U3 =  -1  (integration  constants).

     Modification  of the  dynamic  pool  model  for assessment  of  impingement
impact is straightforward.  The rate  of impingement with respect  to age  (time)
is:
                   W(x).


The mortality equation modified to include the impact of  n water  intakes  is
     N(x) = Re'(M +  .   W(xc - XI} -  (F + M +  .   W(x  -  xc}
where the new term is:  xj = age when fish first become vulnerable  to  impinge-
ment.  The biomass of a cohort subject to impingement loss  is
             -(M +   ?  f 0 )(x    x )   3      Uie"JK(Xc  " XQ)
     B = RW e IM +  .i. fiQi)Uc   V   7   	^	
           oo        1 -1
                                        J"~°  F + M +   J  f1-Qi +  JK



and the yield from the fishery under equilibrium conditions  is


    Ye = FB.

To  apply  the  above  equations  the  number  of  recruits  must  be determined.
Application of the catch equation,
(where  C  is the  annual  catch  from  the fishery)  together  with the  mortality
equation gives:
                                      54

-------
                +   I  f.Q.)ce'M+   .1.
                    ._1  1  1          1-1
     R-
     Additional modifications of the  dynamic pool model  are  necessary  to apply
the model for assessment of entrainment.  The number of  eggs  produced  annually
in a steady state is:


     G = EUB    .
These eggs are subject to natural and entrainment mortality  so  an  equation  for
change in the numbers of eggs is:
where:

    MI = natural mortality coefficient for egg stage.

The number of larvae produced by an initial number of eggs, G(o),  is


                         n
                 -(M,
     L(o) - G(o)e-(Ml +  .
where :

    L(o) = number of larvae produced by a cohort
    G(o) = initial number of eggs produced by a cohort
    A^ = duration of time from spawning to larval  stage  (after yolk  sac  has
              been adsorbed) .

     Larvae are  subject  to  natural  mortality and entrainment mortality;  thus,
the equation for change in the number of larvae is:
where :

    M2 = larval mortality coefficient.

Combining the  above equations for  egg production, egg  mortality, and  larval
mortality gives the following equation for the number of recruits:
                                      55

-------
               -(M   +       PAt   -  (M
     R =  G(o)e'u'l  T   .^  PfV^i  '  m2


where At2 is the duration of time from  first  entry into the  larval  stage to
the young-of-year stage.

     The  impact  of  entrainment  on  standing stock  and yield will be a result of
its impact on recruitment.


                ESTIMATION OF BIOLOGICAL AND FISHING PARAMETERS

                            Surplus  Production Model

     For  the  surplus  production  model   the  catchability  coefficient,  q,
population growth  parameter,  k, and  carrying  capacity, B^,, were  estimated by
non-linear least squares  using the  commercial  catch  and  effort data.   Lake
Michigan  has  been  divided  into  16  fishery statistical districts  (Fig.  1) and
data on  catch and  effort are  obtained  annually  for  each  district.   In  this
study data  for  the years 1960  to  1977  were applied  for estimation  of model
parameters.

     For  each species  the parameters  of  the  surplus  production  model  were
estimated by non-linear least squares using  the approximation


     Y,(t) = Y(t +  1) - Y(t) =  qE(t)   /  B(t)dt *  qE(t)|B(t  +  1}9+ B(t)
                                      t                 L                J

and the solution to the logistic surplus  production  model  is:

                 I/        Pi         If    ~\   -(]r - P\ +
     p(4-\ _      N	 ..  I A         K     1  p  VK.   r l\,

            k.             *~

where BQ is the estimate of biomass in 1960  obtained as 1/q  (1960 CPUE).

A1 ewi f e

     The  major   fishing  methods  applied  for  alewife  were  trawls  and  pound
nets.  Pound  nets  are used more widely  than  trawls;  therefore,  total  effort
was expressed  in terms of pound nets.    Total  effort  in  terms of  a  standard
gear was calculated as


     total effort =      total  catch
                    CPUE with standard gear

where  CPUE  =  catch  per  unit  effort.   The total  catch and  effort data  for
alewife  in  Lake  Michigan  are  listed  in Table  27.   For  alewife the  model
parameters are:
                                       56

-------
    q = 0.00001
    k = 0.30
    BM = 400,000,000  kg.

The fit of  the observed yields to the predicted yields is good in  recent years
(Fig. 18),  and  for  1975 the  observed yield  is close to  the predicted  yield.
In 1963  the model predicts a much  higher yield than  was  observed and  in 1967
the model  predicts a  much  lower yield  than was  observed.   From 1968 to  1977
the  predictions  are  good  except  for  1973  when  the prediction was  somewhat
high.  Substantial  changes have  occurred in the  fishery since 1960  with large
variations  in population size and massive  die-offs.

     The  maximum sustainable  yield  occurs  at  a  biomass  level   of   about
200,000,000  kg   and  is about  30,000,000  kg  (Fig.  19).    The  maximum  observed
catch of 21,959,080  kg  occurred in  1977.   The  alewife  population does  not
appear to  be over-exploited  by  the fishery  but the  level  of exploitation  is
substantial.
 Table  27.  Total catch  (kg),  pound
 net effort (number of lifts), and
 catch  per unit of effort for  alewife
 in Lake Michigan, 1960-1977.
                                      Table 28.  Total catch  (kg), trap
                                      net effort (number of lifts),  and
                                      catch per unit  of effort for yellow
                                      perch in Lake Michigan, 1960-1977.
 Year
Catch    Effort   CPUE
Year
Catch    Effort
                                                                            CPUE
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1057103
1449346
3456625
2448165
5326641
6353358
13155789
19054064
12285364
13330230
15114488
13450181
14076502
16584780
20663696
15961428
17786288
21959808
2621
2327
8501
24582
11546
7425
12118
16742
11462
10050
10203
7599
7767
11872
10131
7730
7918
7931
403.26
622.71
406.58
99.59
461.32
855.60
1085.57
1138.06
1071.77
1326.32
1481.28
1769.92
1812.34
1396.85
2039.52
2064.81
2246.07
2768.55
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1489562
2574813
2039568
2210172
2646878
695885
406440
573967
235669
291719
313820
338270
465686
339997
587902
344354
387206
439831
57444
98958
59269
50186
91459
49878
30426
27501
15364
15719
17628
18324
20050
20372
32909
22946
31864
44057
25.93
26.02
34.41
44.04
28.94
13.95
13.36
20.87
15.34
18.56
17.80
18.46
23.23
16.69
17.86
15.01
12.15
9.98
Yellow Perch

     The  major fishing  methods for  yellow perch  were 2"  gill  nets,  shallow-
trap nets,  fyke nets,  and hoop  nets.   Shallow-trap nets  are  the most  widely
used gear and were selected  as  the standard gear.   The total catch  and  effort
data for Lake  Michigan  are listed in Table 28.
     For   yellow   perch  the   parameter   values   appear  to
substantially  between 1960  and 1977.   The estimates for  1960
                                                        have   changed
                                                       to 1977  (least
                                        57

-------
   1955
              1960
                         1965         1970
                              YEflR
   1975
              1980
Fig. 18.  Observed yields and yields predicted  by  surplus
production model  for alewife in Lake Michigan.
   35r
  30
  25
ft
  20
 3 15
 UJ
  10
                 100           200
                         BIOMflSS (KG X 106)
300
              400
Fig. 19.  Stock  production curves for alewife  in  Lake
Michigan at 5 different levels of water withdrawal  consider-
ing only the impact  of impingement (f - 0.1071  x  10~12);
V0 = 0.0 m'/yr;  Vi = 1.0 x 1010 mVyr; V2 = 5.0 x 1010  m3/yr;
V3 = 10.0 x 1010 m3/yr; V4 = 25.0 x 1010 m3/yr.
                             58

-------
squares) of the population  parameters are:

    k = 0.01
    Bro = 80,000,000  kg
    q = 0.0000001.

But  these  estimates  result in  a substantial  overestimate  of recent  yields.
Better estimates of  yield  from 1965  to 1977 are obtained with  the  parameters:

    k = 0.20
    BM = 14,837,363  kg
    q = 0.0000014.

Observed yields  and predicted yields using these  parameters appear  in Figure
20.   It  appears that the  carrying capacity of  Lake Michigan for  yellow  perch
decreased  substantially between  1960  and 1977.   Yields  have decreased  from
more than 2,500,000  kg  to  less than  500,000 kg.  The model accurately predicts
yields from  1965  to 1977.   At present  the maximum sustainable yield of  about
741,869 kg  occurs  at a  biomass  of about  7,000,000 kg.   A further  analysis  of
the data is necessary to determine the degree to which over-fishing is related
to the observed decrease in commercial catch.

Smelt

     The major commercial  fishing methods for smelt are 1" gill  nets and  pound
nets.   Pound nets  were selected  as  the  standard  gear.    The  total  catch  and
effort data for smelt in Lake  Michigan are listed  in Table 29.


                      Table 29.  Total  catch (kg), pound
                      net effort (lifts), and catch  per
                      unit of effort for smelt in  Lake
                      Michigan, 1960-1977.
                       Year     Catch    Effort     CPUE
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1479932
715538
702333
526710
404620
419599
503533
554953
811191
1125453
923976
588707
312880
393846
774028
527318
983727
331362
4841
2620
2186
2045
959
1124
1087
812
944
641
482
369
177
336
341
208
303
300
305.66
273.02
321.26
257.47
421.91
373.27
462.97
683.44
859.06
1753.72
1914.06
1591.14
1765.69
1171.43
2265.82
2528.01
3237.12
1101.38
                                       59

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                                               OBSERVED
                                               PREDICTED
  1955
             1960
                         1965         1970
                               TFflR
1975
            1980
Fig.  20.  Observed yields  and yields  predicted by  surplus
production model  for yellow  perch in  Lake Michigan.
   2.0
   1.5
  0.5
                                                    OBSERVED
                                                    PREDICTED
      _l	1—1—I	1—I	1	1	1—I  .   I  I
               1960
                           1965         1970
                                TERR
  1975
             1980
Fig. 21.   Observed yields and yields predicted by surplus
production model for smelt in Lake Michigan.
                               60

-------
     For smelt  the  estimates  of the model  parameters are:

    q = 0.0001
    k = 0.50
    BM = 20,000,000 kg.

Again,  it  is  clear  that dramatic  changes have  occurred  in  abundance  (Fig.
21).   The  model fits well  from about  1969  to  1977 but  for earlier years  the
model predicts  much higher yields  than were observed.

     The  smelt population  in  Lake  Michigan is  not heavily exploited by  the
commercial  fishery.   The maximum  sustainable yield  is 2,500,000  kg and  the
observed yield  has  seldom been more than  1,000,000 kg.   The size of  the  smelt
population  also fluctuated widely  between  1960 and 1977.  To accurately assess
the impact  of fishing a  more  detailed  analysis is necessary.

                               Dynamic  Pool Model

     Parameter  estimates  for  the  dynamic pool  model  were  obtained either
directly from the literature  or were calculated from data in the literature.
                         Table 30....Growth of alewife in Lake
                         Michigan.130-1
                         Age    Length (mm)     Weight (gm)
1
2
3
4
5
6
7
97
142
163
175
183
195
204
7.24
22.90
34.67
42.66
48.98
58.88
67.61
A1 ewi f e

     The length, weight,  and  age  data for alewife in Table 30 were reported by
Brown [30]  for  female  alewife in 1964.   The  parameters for growth in terms of
length were found by fitting  the  equation


     *(x +  1) = a (1 - K) + K£(x)
                 oo


by least squares, where:

        + 1) = length at  age  x +  1  (in mm).
The  estimates of  the  growth  parameters are  K =  0.31  and  ia  = 224.   The
relation  between  length  and  weight  for alewife  is  given  by  the parabolic
equation [30]
                                       61

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    Iog10 w = -5-
and the von Bertalanffy growth equation is


    W(x) = 0.11642  (1  - e"0-31 x)3


where weight is measured in kg.  The asymptotic weight  is  W^  =  0.11642 kg.

     To  obtain  the  number of  eggs per  unit of  biomass  a  relation  between
length  and  egg  production  [31]  (Table  31)  was  applied with  estimates  of
average  length  (170 mm)  and average  weight (39.23  g).    The  number  of  eggs
produced  per  kg of female was  estimated as EUB  =  368,000  (14,436  eggs  per
female).
     The  total  mortality rate  for  alewife
structure  data  reported by  Edsall  et al,
mortality  rate  estimated by  least  squares
obtained  with  the surplus  production  model
the fishing  mortality  was estimated as  F  =
larval  mortality  coefficients  were obtained  by calibration
yield  with the  calculated yield.   The  parameter estimates
listed in Table 33.

Yellow Perch
                                        (Table 32)  was estimated from  age
                                          [26].    The  total  instantaneous
                                        is 0.50.    Using  the  estimate of  q
                                         and the  observed fishing  effort,
                                        qE  = 0.06.  The egg mortality  and
                                                           of  the observed
                                                           for  alewife  are
     Much  of  the  biological   data  for  yellow  perch  in  Lake  Michigan  is
summarized by Brazo,  Tack,  and Listen [32].  From the  growth  data in  Table  34
the growth  parameters were estimated as  im = 300 and  K  = 0.45.   The length-
weight relation used was
    log1QW = -5.17 + 3.30 log10Ji
which gives  the  asymptotic weight W,,,,  =  1-° kg.   Length is  in millimeters  and
weight is in grams.

     A  total  mortality  coefficient of  0.36 was  estimated from  the data  in
Table 35.  The number of eggs produced per  unit of biomass  was calculated from
the equation
log10G = -
                      3.451
where a  is  total  length in mm.  The  average length was taken as  200  mm which
gives  17,309  eggs  per  female  on the  average  and  65,316  eggs per  kg  of
female.  The parameter estimates are  summarized  in  Table 36.
                                       62

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Table 31.  Fecundity of alewife,in  Green
Bay as a function of length.1-131-1
Age
2
3
4
Number
18
15
2
Mean Length
160
176
192
Number Eggs
11147
16138
22407
Table 32.
in Lake Mi<
Age
1
2
3
4
5
6
7-8
Age structure of alewife
Relative Number
1000
600
300
120
36
13
3
            Table 33.   Estimates  of alewife parameters for dynamic pool model.
Parameter
Asymptotic weight
Average weight
Ca tenable age
Impingeable age
Age when length is zero
Instantaneous fishing mortality coefficient
Instantaneous natural mortality coefficient
Age at maturity
Growth parameter
Eggs per unit biomass
Egg mortality coefficient
Larval mortality coefficient
Duration of egg stage
Duration of larval stage
Symbol
W»
ava
X
c
XI
X0
F
M
xmat
K
HUB
Ml
M
Flo
Atj
At2
Estimate
0.1164
0.0392
2.0
1.0
0.0
0.06
0.50
2.0
0.30
368,000.0
11.51
5.50
0.10
1.00
Table 34. Standard length (mm) of yellow perch
at the end of each year of life.1-1^
Age
2
3
4
5
6
7
Ludington
O J
162
206
225
252
291
313
159
182
215
235
247
252
Green
?
99
137
173
197
228
251
Bay
if
99
130
159
185
211
227
N.W. Lake
S d-
96
128
154
183
212
                                                        Tabel 35.  Age structure of yellow
                                                        perch population in Lake Michigan at
                                                        Ludington.132-1
Age
1
2
3
4
5
6
7
Relative Number
12
65
619
423
272
138
13
                                             63

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      Table 36.  Estimates of yellow perch parameters for dynamic  pool model
      Parameter
Symbol
Estimate
Asymptotic weight
Average weight
Catchable age
Impingeable age
Age when length is zero
Instantaneous fishing mortality coefficient
Instantaneous natural mortality coefficient
Age at maturity
Growth parameter
Eggs per unit biomass
Egg mortality coefficient
Larval mortality coefficient
Duration of egg stage
Duration of larval stage
H.
"ava
av9
C
XI
X0
F
M
lflfl t
K
EUB
Ml
Mo
Atj
At2
1.0
0.265
3.0
1.0
0.0
0.06
0.30
2.00
0.45
65316.0
11.51
5.50
0.10
1.00
Smelt

     Much  of  the  available   information  on  smelt  was  published  by  Bailey
[33].   Application of the same methods used  for  alewife and yellow  perch gives
the parameter  estimates summarized in Table  37.


         Table  37.  Estimates of  smelt parameters for dyanmic pool model.
         Parameter
   Symbol
   Estimate
Asymptotic weight
Average weight
Catchable age
Impingeable age
Age when length is zero
Instantaneous fishing mortality coefficient
Instantaneous natural mortality coefficient
Age at maturity
Growth constant
Eggs per unit biomass
Mortality coefficient for eggs
Mortality coefficient for larvae
Duration of egg stage
Duration of larval stage
Woo
"avci
X
c
XI
X0
F
M
xmat
K
EUB
Ml
a,
At2
0.03
0.0140
2.0
1.0
0.0
0.03
0.40
2.00
0.56
107337.0
11.51
5.50
0.10
1.00
                  ESTIMATION  OF  POWER PLANT-RELATED PARAMETERS

                            Surplus Production  Model

      In  the  surplus production model  impingement  at the  ith water  intake  is
modeled  as:
                                         64

-------
     dl
         '  W
where :

     I.,-  =  number  of  fish  impinged  at water  intake  i  at time  t
     B = population  biomass  estimated  from  surplus production model.

The  impingement  coefficient can be estimated  as


     f  -  Ali
     fi ' OP" '

Annual  biomass impinged (A!.,-) and volume  flow (Q^) were estimated  from  plant
data.   The  biomass of the  population in  the  lake in 1975 was calculated  from
the  1975  commercial catch and effort  data  and the catchability parameter  which
was  estimated  from  the surplus production  model using  the equation:


     B  = I (1975 CPUE).


     Entrainment of eggs and larvae were modeled as:


     dG' _ „ n r-
     -5T- PiQiG
and
     dL'
     dt~~ hiQiG'
Applying the  same  approach as above  for  impingement,  the following  equations
can be obtained for the egg and larval entrainment coefficients:
          Q.G
and
     h
     hi =
where :

    AG.J = number of eggs entrained annually at water intake i
    AL.J = number of larvae entrained annually at water intake i

The number of eggs produced by the population was estimated as:


     G = EUB   .
                                      65

-------
The  number  of  larvae  produced was calculated  using  the  equation



     L =  (1 -  M,  -    I  p.Q.)G
                1    1=1   n  1

where Mi  is the  natural  mortality  between  the egg  and larval stages.   In  all
calculations it was assumed that Mj_ = 0.99.

A1 ewi f e

     For  alewife  the  catchability coefficient was estimated as q = 0.00001  and
the  catch per  unit of  effort in 1975  was  2064.   The  biomass  in  the lake in
1975 is estimated as:

    B = 206,400,000 kg.

The estimates  of  the  proportion  impinged and the impingement coefficients  are
listed  in  Table   Bl.  (Appendix  B).    The  proportions  of  eggs  and   larvae
entrained and  the egg and larval entrainment coefficients are listed  in  Tables
B2. and B3., respectively.

Yellow Perch
     The  least squares  estimate  of  the  catchability coefficient  for yellow
perch is 0.0000001 but  this  estimate  results in overestimates of catches from
the late 1960 's into the 1970' s.  A better fit of predicted yields to observed
yields for recent years is obtained with q = 0.0000014.  The catch per unit of
effort in 1975 was 15 which gives the 1975 biomass as:


     B = 0.0000014  15 = 10.714,285 kg.


The estimates of the proportions impinged and the impingement coefficients are
listed in Table B4.   The  proportions  of eggs and larvae entrained and the egg
and  larval   entrainment  coefficients  are   listed   in  Tables  B5.  and  B6.,
respectively.

Smelt

     For smelt in Lake  Michigan the catchability coefficient was estimated as
q = 0.0001  and the  catch per unit of effort in  1975 was  2528 giving the 1975
biomass in the lake as
     B =          2528 = 25,280,000 kg.
The  estimates  of  the  proportion   of   smelt  impinged  and  the  impingement
coefficients  are  listed  in  Table B7.    The  proportions  of  eggs  and  larvae
entrained and the egg and larval  entrainment coefficients are listed in Tables
                                       66

-------
R8. and B9., respectively.



                              Dynamic Pool Model



     In the dynamic pool model impingement at the  itn water  intake  was  modeled
as:
       i

        -= W(x)-
The impingement coefficients were estimated as:




         Al,
      1  Q. B





where A!-J  is  the  biomass  impinged annually at water intake  i.  Biomass  of  the

population in the lake was estimated using the equation






              „.   _   .     3  U.e-jK(xc  - xo}
     D — F51/^\^   ™  T *     V   v

       "   »     C    L      -|0   F + M + JK




and the number of recruits was estimated as







     R , (M + F)CeM(xc " XI)
where C is the catch (in numbers) from the fishery.



     Entrainment of eggs and larvae was modeled using the equations
         = W



and the entrainment coefficients were estimated as
     Pi
     h
     hi - TJTT '




The number of eggs produced by the population was estimated as




                                      67

-------
                   B(x)dx
                m
where x»  is  the age  at  maturity and  EUB  is the number  of  eggs  produced per
unit of biomass.

     The number of larvae produced was calculated using the equation
     L =
and the number of recruits produced by these larvae was calculated as
     R =
                   1=1
-(M2+
 I  h.Q.)At
1=1  1  1    ^
All of  the terms in  the  above equations  have  been described  previously.   A
summary of the terms can be found in the glossary.

Al ewi f e

     The yield of alewife  in  1975  was  15,961,428 kg (Table 27) and the number
of  alewife  in the catch  was  estimated as  406,870,000.   The  estimate  of the
biomass of  the  population in the lake  obtained  from the parameters listed in
Table 33 is 237,401,824 kg.  The estimates of the proportions impinged and the
impingement coefficients are listed in Table BIO.  The proportions of eggs and
larvae entrained and the egg and larval entrainment coefficients are listed in
Tables Bll. and B12., respectively.

Yellow Perch
     The yield of yellow perch in 1975 was 344,354 kg (Table 28) and the catch
was  estimated  as   1,299,449  perch.    The  estimate  of  the  biomass   of  the
population  in the  lake  obtained from  the parameters  listed  in  Table 36  is
15,339,617 kg.  The  estimates of the proportions impinged and the impingement
coefficients  are  listed  in  Table B13.   The  proportions of  eggs  and larvae
entrained and the egg  and  larval  entrainment coefficients are listed in Table
B14. and B15., respectively.

Smelt

     The yield in 1975 was 527,318 kg and the number of smelt  in the catch was
estimated as 37,665,712.  The estimate of the biomass of  the population in the
lake obtained from  the  parameters  listed  in Table 37  is 24,697,856  kg.   The
estimates  of the proportions  impinged  and  the  impingement  coefficients are
listed in Table B16.  The proportions of eggs and larvae  entrained and  the egg
and  larval   entrainment  coefficients  are  listed in  Tables  B17. and B18.,
respectively.
                                      68

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               SIMULATION OF IMPINGEMENT AND ENTRAPMENT IMPACTS

     Both the dynamic pool model and the surplus production model  were  applied
to  simulate  the  impact of water withdrawal  on the standing stocks  and yields
to  the  fishery.   The  separate  results obtained  with these  two  models were
similar;  therefore,  only  the results  for  the  surplus production  model  are
reported.   The  impact of impingement was  slightly less with the  dynamic pool
model  because  recruitment  was  assumed  to be  constant.    In  addition,  the
combined  impacts  of  entrainment and  impingement are  difficult  to model with
the  dynamic  pool  model.   In  these respects,  the  surplus  production model  is
somewhat superior to the dynamic pool model.

     Under equilibrium  conditions where dB/dt  = 0, the  biomass equation of  the
surplus production model that includes terms for impingement becomes
          v   7           n
     kB -\-tf- - qEB -   I  f.QjB = 0
and the population biomass as a function of volume flow can  be written  as

                        _  n

         Bk - qE)   B~f  1  Qi
where  f  is an  average impingement  coefficient  for the  water  intakes.   This
equation predicts  a linear  decrease  in the biomass of  the standing stock  as
the volume flow is  increased.

     Under equilibrium  conditions  (dB/dt = 0) the  equilibrium yield from the
population is given by the equation
     Ye = kB --B  -      W'
                oo       1=1

The relation between equilibrium yield and biomass is a parabola.   Application
of the equation dY/dt = qEB shows that equilibrium yield also  is a  function of
fishing effort, i.e.,


          B q        n
     Ye »-E-Oc -   I  WE
      e    K         .=1  i i


Thus,  the  relation  between  equilibrium  yield and  fishing effort  also is  a
parabola.   The maximum sustainable  yield,  MSY, occurs at  a biomass level of
B^/2, and is given by the equation
                                      69

-------
           kB    ?B
where f is the average impingement coefficient.   The maximum sustainable yield
decreases  linearly  as  the volume  flow  increases.   With zero volume  flow  the
MSY is given by kB^/4.

     Equations similar to  those  above were applied to  simulate  the  impact of
larval  and egg  entrainment  on  the  size  of the  standing stock  and on  the
maximum sustainable yield.  For entrainment the  equations are:


         B (k - qE)   (p + h)B     n
                                      Qi
                                  .=1  1
           kB    B (p + h)    n
     MSY = -^ - -^--g	    I  Q
            4        *       1=1  n

where  p  and h are  the average egg  and  larval  entrainment coefficients.   To
simulate the combined  impact of entrainment and  impingement  the  following two
equations were applied:


         Bjk - qE)    (f + p + RJB^    n

     B =      E             E         & Qi


           kB    B (f + p + fi)    n
                                   Al ewi fe

     The  impact  of  water withdrawal  appears  to be largest on  alewife  so the
results for  alewife  will  be given in  greater  detail  than  those for smelt and
yellow perch.   The  equilibrium stock production curve  for alewife under five
different rates  of  water withdrawal  is shown  in Fig.  19.   Only the impact of
impingement  is  modeled in this  figure.   Increasing  the volume of withdrawal
decreases  the  carrying  capacity,  the biomass level  at  which   the  maximum
sustainable yield occurs,  and  the maximum sustainable yield.   The line drawn
through the maxima of the stock production curves is:


           kB    fB     n
     MSY=-f--ir   Jr
                                      70

-------
     The  total  design  volume flow of  all  water intakes  on  Lake Michigan  is
about 4.8 x  1010  m3  per year.  This level of  flow  results  in  slight  decreases
in the carrying capacity and  MSY.   Substantial  increases  in the  volume  of flow
are  necessary to  cause  a large  impact on  yield  and  standing  stock.    The
impacts  of  entrainment, impingement, and  the  combined impacts  of  entrainment
and impingement on alewife are summarized in Figs.  22  to  27.

     The  highest  impingement coefficient  observed  is 0.4331  x  10"12  and  the
average  impingement  coefficient  is  0.1071  x  10" 12.    The  relation  between
standing stock biomass  and volume flow  for these  impingement coefficients are:


    B = 279,266,660 - 0.0001428Q, f = 0.1071 x  10"12
    B = 279,266,660 - 0.0005775Q, f = 0.4331 x  10"12.

Biomass  of  the   standing  stock  decreases  slowly  as  the volume  withdrawn
increases (Fig. 22).  At a volume flow  of 4.8  x 1010 m3/yr  (full  capacity flow
at  all  water  intakes)  the   total  lakewide  impingement  (A!)  of alewife  was
estimated to be 2.1 x 106  kg  (Table 6).  Based  on the  1975  biomass  estimate of
206,400,000  kg,  the  proportion of  the  standing  stock impinged   (Al/Bjc^)  is
0.0102 (or  1.02%).   The proportion  reduction  in  the  standing stock  (Fig.  22)
is calculated from the  equation:

     BN" B
       BN        BN       '

where By = biomass with no water withdrawal.  Assuming  the  average  impingement
coefficient and a flow of 4.8 x 1010 m3/yr, the reduction in  standing  stock  of
alewife was  0.0245  (2.45%).   The  reduction  in the  standing stock  is  greater
than the proportion of the stock impinge^1 because the surplus production model
assumes that  the growth  rate of  the  population  is  a  function of  population
size.   Impingement  reduces  the  biomass  in the lake  until  a level   is  reached
where the  rate  of impingement is balanced by the increased  growth  rate of the
stock.

     The  impact of  impingement  on  the yield  to  the  fishery  also  is  not
large.  The relation between the maximum sustainable yield and volume  flow  is
given by the equations:

    MSY = 30,000,000 - 0.00002142Q, f = 0.1071 x 10"12
    MSY = 30,000,000 - 0.00008662Q, f = 0.4331 x 10"12.

The maximum sustainable yield decreases  slowly  as volume flow  increases (Fig.
23).  Applying the average impingement coefficient the  proportion reduction  in
maximum sustainable  yield  is 0.034  (3.4%)   at  a volume  flow  of  4.8 x 1010
m3/yr.  The impact on yield  is greater than the impact  on standing  stock.

     The maximum  egg  and larval entrainment coefficients  are  0.1712  x 10" 12
and  0.1743  x 10"ltf and  the  average  values  are  0.1756 x  10"13  and 0.2236  x
10" 15.  The relation between  biomass of the standing  stock  and  volume  flow for
entrainment are:

    B = 279,266,660 - 0.0002306Q, p = 0.1712  x 10-12  n = Q.1743 x  10-14


                                      71

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  29


  28


  27


  26

o
- 25
X

- 214
in
LO
£ 23
o
m
  22


  21


  20;


  19
                             	1	1	r

                              No water withdrawal
                          4    '       6
                        VOLUME FLOW  (M3 X  1010)
                                                          10
Fig. 22.   Impingement impact of  increased water withdrawal
on biomass  of alewife in Lake Michigan (1975).  Arrow  indi-
cates total  design flow for all  water intakes in 1975.
                       VOLUME FLOW (M3 X 1010)
Fig. 23.   Impingement impact of  increased water withdrawal
on maximum sustainable yield (MSY)  of alewife in Lake
Michigan  (1975).   Arrow indicates total  design flow for  all
water intakes  in  1975.
                              72

-------
  29


  28

  27


  26
o
- 25
  23


  22


  21


  20


  19'
No water withdrawal
                (pavg) 0.1756 x 10
                            -13
           -12
     4-
                                                            10
                        VOLUME FLOW (M3 X 10'°)
 Fig.  24.  Entrainment impacts  of increased  water withdrawal
 on  biomass of  alewife in Lake  Michigan  (1975).   Arrow indi-
 cates total design flow for  all  water intakes  in 1975.
   31
   27

  23
  19-
  17
                           I      '     I
                          No water withdrawal
                                            (p  ) 0.1756 x 10
                                            v-*j
                                                        -13
                          4    '       B
                        VOLUME-FLOW  (M3 X 1010)
                                    10
Fig.  25.   Entrainment impact of  increased water withdrawal
on maximum sustainable yield (MSY)  of alewife  in Lake
Michigan  (1975).  Arrow indicates  total design flow for all
water intakes in  1975.
                              73

-------
  29


  28


  21


  26


  25

  2il


  23


  22


  21


  20


  19
                  No water withdrawal
                 (f  )  0.1071 x 10
                    *         -17
                 (p  )  0.1756 x 10 1J
                  av£         _1 i:
               v+ (h  )  0.2236 x 10 *
               \. v mm'
+ (p  ) 0.1712 x 10

+ (h  ) 0.1743 x 10"
  1 max'
                      4-
                                                            10
                        VOLUME FLOW (M3 X 1010)
Fig.  26.   Combined  entrainment and  impingement  impact of
increased water withdrawal on biomass of alewife in Lake
Michigan  (1975).  Arrow indicates total design  flow for all
water intakes in  1975.
  31
  27
  25
  23
  21
  19
  17
                        No water withdrawal
       2 .
                          4    '       6
                        VOLUME FLOW (M3 X  1010)
                                                            10
Fig.  27.   Combined  entrainment  and impingement impact of
increased water withdrawal on maximum sustainable yield  (MSY)
of alewife in Lake  Michigan  (1975).   Arrow  indicates total
flow  for all water  intakes in 1975.
                               74

-------
    B =  279,266,660  - 0.00002371Q, p = 0.1756 x  10'13,  h =  0.2236  x  10'15.

The  impact  of entrainment  on  biomass  of the standing  stock  is less than  the
impact of impingement.   Biomass decreases slowly due to entrainment  of  larvae
and  eggs as volume  flow increases  {Fig. 24).   The  reduction in  the standing
stock  resulting  from entrainment of  larvae and eggs  is  0.00407  (0.41%) at  a
volume flow of 4.8 x 1010 m3/yr.

     The  impact  of entrainment on the yield  to  the fishery is also  less than
the impact of impingement.  The relation between the maximum  sustainable yield
and volume  flow,  considering  only  entrainment of eggs  and  larvae, is given by
the equations:

    MSY  = 30,000,000 - 0.00003459Q, p.=  0.1712 x 10'12, h = 0.1743 x  lO'1^
    MSY = 30,000,000 - 0.000003557Q, p = 0.1756 x 10'13, h  = 0.2236 x lO'1*.

The  maximum  sustainable  yield  decreases  slowly   as   the  volume   withdrawn
increases (Fig. 25), and at a volume of  4.8 x 1010 m3/yr the proportion  reduc-
tion in  the maximum  sustainable yield is 0.0056  (0.56%).

     Under  equilibrium  conditions  the surplus production  model predicts that
the impact of entrainment and impingement is additive.  The combined  impact of
entrainment and impingement on  the  standing stock  and the maximum sustainable
yield is given by the following equations:

    B = 279,266,660  - 0.0008081Q, f = 0.4331 x 10'12, p = 0.1712 x 10'12,
        h = 0.1743 x 10"14.

    B = 279,266,660  - 0.0001665Q, f = 0.1071 x lO'*2, p = 0.1756 x lO'*3,
        h = 0.2236 x 10'is.

    MSY = 30,000,000 - 0.0001212Q, f = 0.4331 x 10"12,  p =  0.1712  x 10'12,
        h = 0.1743 x 10'1".

    MSY = 30,000,000 - 0.00002498Q, f = 0.1071 x 10'12, p = 0.1756 x  10"i3,
        h = 0.2236 x 10"15.

At a flow of  4.8 x  1010 m3/yr  the  proportion  reduction in the standing stock
resulting from entrainment  and  impingement  is  0.0286 (2.86%).  The proportion
reduction in  the  maximum  sustainable  yield  resulting from  entrainment  and
impingement is 0.398 (3.98%).

     With observed  volume  flows the entrainment and impingement  coefficients
must be  increased  substantially  for  impingement  and  entrainment to  have a
large impact  on  standing stock  and  yield.   Alternatively,  with the observed
entrainment  and  impingement  coefficients,  a  substantial  increase  in  volume
flow is necessary to produce a large impact.

                                 Yellow Perch
     The  impacts  of entrainment  and  impingement  on  yellow perch  are  not as
large as the impacts on alewife.

     The  impingement  coefficient for  the Pulliam  plant  (Green  Bay)  is much


                                     75

-------
higher  than  those  for  intakes  on  the  main  body  of  Lake Michigan,  so the
average impingement coefficient was  calculated using  the coefficients for the
15 other sampled intakes.

     The average impingement coefficient  for yellow perch in Lake Michigan is
0.6705 x 10~11+ and the highest impingement coefficient is 0.2962 x 10"13.  The
relations  between  biomass,  maximum  sustainable  yield,  and  volume   flow,
considering only impingement are:

    B = 12,265,439 - 0.0000004974Q, f = 0.6705 x lO"1*
    B = 12,265,439 - 0.000002197Q, f = 0.2962 x 10'13
    MSY = 741,869 - 0.0000004974Q, f = 0.6705 x 10"14
    MSY = 741,869 - 0.000002197Q,  f = 0.2962 x 10"^3

     The  maximum egg  and  larval  entrainment  coefficients for  yellow  perch
(excluding Pulliam) are  0.1759 x  10"13 and  0.1431  x 10"15, respectively.  The
average egg and  larval  entrainment  coefficients  are 0.2942 x 10"14 and 0.3883
x 10"16, respectively.  The relation between biomass of the standing stock and
volume flow,  considering only entrainment, are:

    B = 12,265,439 - 0.000001315Q, p_= 0.1759 x 10"13, h_= 0.1431 x lO"^
    B = 12,265,439 - 0.0000002211Q, p = 0.2942 x 10"14, h = 0.3883 x 10"16.

The  relation  between  maximum  sustainable yield and  volume  flow, considering
only entrainment, are:

    MSY = 741,869 - 0.00000002211Q, p = 0.2942 x 10~i\ h = 0.3883 x 10"^
    MSY = 741,869 - 0.0000001315Q, p = 0.1759 x 10"13, h = 0.1431 x lO'1*.

     The combined impact  of  entrainment  and  impingement on the standing  stock
and  maximum  sustainable  yield of  yellow perch  are  given  by  the  equations
below:

    B = 12,265,439 - 0.0000007185Q, f = 0.6705 x 10"l\ p = 0.2942 x lO"14,
        h = 0.3883 x 10"16

    B = 12,265,439 - 0.000003513Q, f = 0.2962 x 10"*3, p = 0.1759 x 10"13,
        h = 0.1431 x 10"15

    MSY = 741,869 - 0.00000007185Q, f = 0.6705 x 10"^, p = 0.2942 x lO"14,
        h = 0.3883 x 10"16

    MSY = 741,869 - 0.0000003513Q, f = 0.2962 x 10'13, p = 0.1759 x 10"13,
        h = 0.1431 x 10"15.

As the volume  flow  increases,  biomass  of the standing stock (Fig. 28) and the
maximum sustainable yield (Fig.  29)  decrease  slowly.   Assuming  the capacity
withdrawal  of  4.8  x  1010  m3  and  the  average  entrainment  and impingement
coefficients,   the  proportion reduction in standing stock of  yellow  perch is
0.0028  (0.28%)  and  the  proportion  reduction  in maximum  sustainable  yield is
0.0047 (0.47%).
                                     76

-------
                                VOLUME FLOW (M3 X 1010)
Fig. 28.  Combined  impingement  and entrainment impact of increased water with-
drawal on biomass of yellow  perch  in  Lake Michigan.   Average and maximum co-
efficients  have  been  calculated  from all  sampled power plants except Pulliam.
Arrow  indicates  total  design  flow for all  water intakes in 1975.
                                                                              [5]
                                VOLUME FLOW
Fig. 29.  Combined impingement and entrainment  impact  of  increased  water with-
drawal on maximum sustainable yield  (MSY) of yellow  perch in  Lake Michigan.
Average and maximum coefficients have been calculated  from all  sampled  power
plants except Pulliam.L5J  Arrow indicates total design flow  for all  water in-
takes in 1975.
                                      77

-------
                                     Smelt

     The  impact  of  impingement  and  entrainment  on  smelt  is  similar to  the
 impact  on  alewife.   The average impingement coefficient is  0.3717  x  10"13  and
 the  highest impingement coefficient is  0.3149  x 10"12.  The  relation  between
 biomass  of  the   standing  stock  and  volume  flow   for   these   impingement
 coefficients  are:

     B = 15,604,000 - 0.000001487Q, f = 0.3717 x  KT13
     B = 15,604,000 - 0.00001259Q, f = 0.3149 x 10'12.

 Biomass of the standing  stock  decreases slowly as  the volume flow  withdrawn
 increases.   At a flow  of  4.8 x lO™ m3/yr, the lakewide  impingement  (A!)  of
 smelt'was  estimated  to  be 1.86 x 101* kg  (Table  6).  Based on  the  1975  biomass
 estimate  of  25,280,000 kg,  the proportion  of the  standing  stock   impinged
 (Al/B1975)  is  0.0007  (0.07%).   The  proportion  reduction in  the standing  stock
 (Fig. 30)  is 0.0046 (0.46%).

     The  impact of impingement  on  yield to the fishery also  is  small.    The
 relation between  the maximum sustainable yield and volume flow  is  given by  the
 equations:

     MSY =  2,500,000 - 0.0000003717Q, f =  0.3717  x  lO'*3
     MSY =  2,500,000 - 0.000003149Q, f = 0.3149 x 10"*2.

 The  maximum sustainable yield  decreases  slowly  as the volume flow  increases
 (Fig. 31).   The  proportion reduction in yield  due to impingement is 0.0071
 (0.71%) at  4.8 x  1010 m3/yr.

     The maximum  egg  and  larval  entrainment coefficients are  0.1519 x  10"12
 and  0.9242  x  10"11+.   The  average egg  and larval entrainment coefficients  are
 0.2208 x 10'13 and 0.2099  x 10'14.  The relation between biomass of the stand-
 ing  stock and volume flow, considering only entrainment, are:

     B = 15,604,000 - 0.0000009672Q, p = 0.2208 x lO'is,  h =  0.2099  x  lO"^
     B = 15,604,000 - 0.000006734Q, p = 0.1591 x  10'12,  h = 0.9242 x 10'llt.

The  impact  of  entrainment  on  standing  stock biomass of  smelt  is less  than  the
 impact of  impingement.  As volume flow increases, biomass decreased slowly  due
 to entrainment  of eggs and larvae  (Fig.  32).    The  reduction  in  the  standing
 stock due to entrainment of larvae and eggs is 0.00298  (0.3%) in 1975.

     The impact of entrainment on yield is  less  than the impact of  impingement
on yield.   The relation between the maximum sustainable yield and volume  flow,
considering  only  the  impact  of  entrainment,  is  given   by  the  following
equations:

    MSY = 2,500,000 - 0.000001683Q,  p.= 0.1591 x 10'12,  h =  0.9242  x  ID'14
    MSY = 2,500,000 - 0.0000002418Q, p = 0.2208 x 10'13, h = 0.2099 x  10"14.

The  maximum  sustainable   yield  decreases  slowly  as  volume   flow  withdrawn
 increases  (Fig. 33).  The  proportion  reduction  in  yield due to entrainment  is
0.0046 (0.46%) in 1975.
                                     78

-------
   16
 „ 15
 o
 5
   13
                           No water withdrawal
                           4           6
                         VOLUME FLOW  (M3 X  1010)
                                                            10
 Fig.  30.   Impingement  impact of increased water withdrawal
 on  biomass of smelt in Lake Michigan (1975).   Arrow indicates
 total  design flow for  all  water intakes in  1975.
    26
    25
    23
    21
    20
                          No water withdrawal
                           4    '      6
                         VOLUME FLOW (M3 X 10!0)
10
Fig. 31.   Impingement impact of  increased water withdrawal
on maximum sustainable yield (MSY)  of smelt in Lake Michigan
(1975).  Arrow indicates total design flow for all water in-
takes in 1975.
                              79

-------
   15
   15
   13
                         No water withdrawal
                          4    '      6
                        VOLUME FLON (M3 X 1010)
                              10
Fig. 32.   Entrainment impact of  increased water withdrawal
on biomass  of smelt in Lake Michigan (1975).  Arrow  indicates
total design  flow for all water  intakes in 1975.
  26
  23
  22
  21
  20
                         No water withdrawal
-H-
                          4     '      6
                        VOLUME FLOW (M3 X 10l°)
                             10
Fig. 33.  Entrainment impact of  increased water withdrawal
on maximum  sustainable yield  (MSY)  of smelt in Lake  Michigan
(1975).  Arrow indicates total design flow for all water in-
takes in 1975.
                              80

-------
      The combined impact of entrainment and  impingement  on  the standing stock
 and  maximum sustainable yield  are given by the equations  below:

     B =  15,604,000  - 0.00001934Q, f = 0.3149 x 10"12, p = 0.1591 x 10'12,
         h  = 0.9242  x lO"14

     B =  15,604,000  - 0.000002454Q,  f = 0.3717 x lO'ia, p  = 0.2208 x 10-13,
         h  = 0.2099  x 10'1£*

     MSY  =  2,500,000 - 0.000004832Q,  f = 0.3149 x lO'*2, p = 0.1591 x 10'12
         h  = 0.9242  x lO'1"

     MSY  =  2,500,000 - 0.0000006135Q,  f = 0.3717 x 10~l3f  p = 0.2208 x 1Q-13,
         h  = 0.2099  x 10'1I+.

 At  a flow  of 4.8 x 1010 m3/yr the proportion  reduction  in  the standing stock
 resulting  from  the  combined impact  of entrainment and impingement  is  0.00755
 (0.76%)(Fig.  34).   The  proportion  reduction in the  maximum  sustainable yield
 resulting  from  entrainment  and impingement is 0.0118  (1.18%)(Fig. 35).


                         DISCUSSION  OF MODELING RESULTS

      Direct estimation  of the  biomass of a fish stock is  difficult and  assess-
ment of  the  impact of  entrainment  and impingement  cannot  be made  without a
model  that  describes  the response of  the population to these  impacts.  Fishery
models can  be  applied for estimation of stock  biomass and also can be  applied
 for  environmental impact assessment after only  slight modifications.   Fishery
models   have been   widely   applied  and  the   assumptions   and  difficulties
 associated  with the  applications  of  these  models are  well  known.

      The impact of  impingement can be assessed just as the impact of a  fishery
 is assessed.   The model for yield  to a fishery is identical  to  the  model  for
 impingement.    For   alewife  the  pattern  of  impingement  during  the year  is
 similar  to  the  pattern  of  catch from the  commercial  fishery  (Table  38).  Both
the  fishery and the power  plants catch alewife  as they move  toward shore.   To
model  the  impact  of entrainment,  more substantial modification  of  the  fishery
models is   necessary,  but  the  modifications  are straightforward and in  this
study the most direct and simplest modifications have been applied.

      The major  weakness in  application of  fishery  models,  as well as other
models,  for assessment  of  environmental  impacts is  the  shortage of data  for
stock  identification  and  parameter  estimation.    For  fisheries  undergoing
dramatic   changes,   such  as  those of  the  Great Lakes,  meaningful   parameter
estimation  is extremely difficult.    Estimation  of  parameters for the  surplus
production models is difficult  because  the parameters  are  not well  defined  and
they  do  not remain  constant over an extended  period  on the Great Lakes.  Both
the  parameters  of the  surplus  production  model are  few  in  number and  all  of
them can  be estimated directly  from catch  and  effort  data.

     Using the available data and varying  parameter values resulted  in similar
fits  of  the model  to  the  observed  catch and  effort data  (Table  39).   For
example,  increasing k from  0.30 to  0.35 and decreasing Bro from  400,000,000 to
300,000,000 for alewife  increases the residual sum of  squares  by  only a small


                                     81

-------
                        4    '      6
                       VOLUME FLON (M3 X 1010J
Fig. 34.  Combined entrainment  and impingement impact of in-
creased water withdrawal on  biomass of smelt in Lake Michigan
(1975).  Arrow indicates total  design flow for all water
intakes in 1975.
 20
                      VOLUME FLOW (M3 X 1010)
Fig. 35.  Combined entrainment  and  impingement impact of in-
creased water withdrawal on maximum sustainable yield (MSY)
of smelt in Lake Michigan  (1975).   Arrow indicates total
design flow for all water  intakes in 1975.
                             82

-------
amount.    Although  the  fit  of  the  model   to  the  observed  data  is  good,  the
individual  parameter estimates might not be of  similar accuracy.
               Table 38.   Comparison of commercial alewife catch from district
               WM1 in Green  Bay  and observed impingement at Pulliam Power
               Plant during  1975.
               Month
Commercial  Catch  (kg)    Observed Impingement (kg)
January
February
March
April
May
June
July
August
September
October
November
December
0
9
13
78
79,655
2,813,451
2,152,849
978,809
564,083
66,441
2
0
0
0
0
0
267
13,375
7,195
3,383
166
86
79
6
       Table 39.   Residual  sum  of  squares for fit of surplus production  model  to
       alewife catch  and  effort data.
                              0.000005
                        0.000010
                       0.000020
       Sum of squares  for K = 0.25
       Bmax
        0.30000000E+09
        0.40000000E+09
        0.50000000E+09
  0.71559846E+15
  0.43346152E+15
  0.27269751E+15
       Sum of squares  for K = 0.30
       "max
        0.30000000E+09
        0.40000000E+09
        0.50000000E+09
  0.58970330E+15
  0.32373584E+15
  0.22241908E+15
       Sum of  squares for K = 0.35
       Bmax
        0.30000000E+09
        0.40000000E+09
        0.50000000E+09
  0.52456825E+15
  0.30174615E+15
  0.28995566E+15
0.49805058E+15
0.32332165E+15
0.24085464E+15
0.25229185E+15
0.18022458E+15
0.26774588E+15
0.19093856E+15
0.34051601E+15
0.76056059E+15
0.13285475E+16
0.12343199E+16
0.11733996E+16
0.70890663E+15
0.58793512E+15
0.52183262E+15
0.31439214E+15
0.31592491E+15
0.41336671E+15
                                           83

-------
     To  apply  the  surplus  production model  for assessment  of the impact  of
entrainment, the  production of eggs  and survival of  eggs  and larvae must  be
estimated.   Survival  of eggs and larvae was  determined from estimates  of  the
number  of  eggs  produced  and  the  assumption  that  the  population  was   in
equilibrium.    The  sensitivity  of  the  estimates  of impact  to  changes   in
survival of eggs and larvae should be investigated.

     The parameter  estimates  for  the  dynamic  pool model are  based  on  entirely
different  kinds of  data  than  those  of  the  surplus  production model.    The
growth  parameters   and  total  mortality  coefficients were  estimated from  age
structure  and  growth data  available  in  the literature.   Age at maturity  and
age at  recruitment into  the  fishery  also were  obtained  from  the  literature.
The  fishing  mortality   coefficient,   F,   was   estimated  from  the   surplus
production  model  parameters as F =  qE.   This  is  the  only connection  between
the two  models.   The larval  and  egg  mortality  parameters were adjusted  under
the assumption that the stocks were in equilibrium.

     In  a  study  such as  this where a mathematical  model  is  applied to  assess
an impact,  there is no direct method to  determine whether or  not  the result is
reasonable.   Therefore,  the applications  of  the  dynamic   pool  and  surplus
production  models  were  kept as  independent as possible so a  comparison  of  the
results  obtained by the two models could be used as  a  basis for evaluating  the
reliability  of  the estimates of impact.   First,  the  surplus production  model
was applied.   Then, the  dynamic  pool model  was applied  using  the value of  F
estimated  from  the surplus  production  model.    All  other parameter  estimates
are independent.   The close  agreement  between  the  results obtained with  the
two models  gives some degree of confidence in the  results.

     Although the  results of  the  two  models  agree,  there might be  substantial
errors  in   the  estimation  of  the population  parameters  in  both  the  surplus
production  and  the dynamic  pool  models.   These errors could produce  an  error
in estimation of biomass  which  would  affect the estimate of  impact.   However,
even  a   substantial  error  in the  estimate  of  biomass  did  not  result in  a
meaningful  change  in the  level  of  impact  on  Green Bay.  The relation  between
the estimate of the  proportion  impinged and  the biomass  of yellow perch  in
Green Bay  is shown  in Fig.  36.  A large  increase  in  the estimate  of population
biomass  decreases   the  level  of  impact  only  slightly.   The  decrease in  the
estimate of biomass produces a larger change  than an increase but decreasing
the biomass estimate by one-half only increases  the proportion  impinged from
less than  0.001 to  0.0015.  Because the  level of  impact is  small,  large errors
of estimation do not change the level  of impact  substantially.

     The U.S. Fish'and Wildlife Service  estimated  the  adult alewife population
vulnerable  to bottom  trawling to  be from 86,000,000 to 131,600,000 kg in 1975
[24].    Using  the   fishery  data  and  the population models  we estimated  the
alewife  biomass in  1975 to  be 206,400,000 kg.   Although our estimate is  nearly
twice as large as  the  estimate  made  by the Fish  and  Wildlife Service,  it is
probably an underestimate of the  total  alewife biomass in  Lake Michigan.   The
commercial  fishery for alewife  is  not   lakewide  and unless  there  is  complete
mixing  of  the  alewife population,  the estimates  obtained  with  the  surplus
production  model should be  low.

     The 1975  rainbow  smelt  biomass in  Lake  Michigan  was  estimated to  be
13,700,000  kg  by  the  U.S.  Fish  and  Wildlife  Service [27].   The  biomass  of


                                     84

-------
                         BIOMflSS (KG X 10s)
Fig. 36.  Relation between estimate  of population biomass
and estimate or proportion of  biomass  standing stock impinged
for yellow perch in Green Bay  (1975).   Arrow indicates esti-
mated biomass in 1975.
                                                        1980
Fig. 37.  Observed and predicted yields  for yellow perch in
Green Bay (1960-1977).
                             85

-------
smelt  in  1975 was  estimated to be  25,280,000 kg in  this  study.  There  do not
appear  to be  lakewide estimates  of the  biomass of  yellow perch  that  can  be
compared  with  out estimate of 15,000,000  kg  in 1975.

     The  lakewide application of the surplus production model assumes  complete
mixing  of stocks within  the  lake.   This  assumption is not valid and to  deter-
mine what influence this might  have on the  results,  the impact of  the Pulliam
Power  Plant  on yellow perch in Green  Bay was investigated.   Catch  and  effort
data for  yellow  perch in Green Bay  are listed  in  Table 40.   The  effort  data
are  in  terms of  lifts of shallow  trap nets.  The  parameter estimates for the
surplus production model  are:

    q = 0.0000015
    k = 0.20
    BOT =  7,000,000 kg

The  carrying capacity of Green  Bay appears to be about 50%  of the  lakewide
carrying  capacity.  The  growth  rates and catchability coefficients  for  yellow
perch are about  the same in Green Bay  and Lake Michigan.

     The  fit of  the model to the observed yield  data in Green Bay  (Fig.  37)  is
similar  to the lakewide  fit (Fig. 20).   In  Green  Bay,  as  in the rest of  Lake
Michigan,  a  large decrease in catch  occurred between 1963 and 1965.   The model
does not  accurately  predict catches prior  to 1965  but  predicts catches  well
from 1965 to 1977.   It would appear that the  decrease in catch is  not related
to  overfishing.    The  stock  production  curve  for Green Bay indicates  that the
yellow  perch population  is  not  over-exploited by the commercial fishery.   The
MSY of  350,000 kg occurs at a biomass  of  about 3,500,000 kg.
Table 40.  Total catch, trap net effort
(number of lifts),  and catch per unit of
effort for yellow perch in Green Bay,
1960-1977.
Year    Catch (kg)
Effort
CPUE
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
695387.63
1031650.56
989950.88
1039157.50
602275.00
243885.56
161835.25
333137.19
121793.81
149966.06
167150.69
112734.44
105107.39
107444.19
358055.94
221815.31
163233.44
265166.50
29096.64
43686.96
28273.39
27513.02
33451.54
32024.59
18713.91
18483.43
11811.77
11871.31
13769.38
13087.94
12353.30
12583.75
18059.01
28387.89
23854.13
26083.35
23.90
23.61
35.01
37.77
18.00
7.62
8.65
18.02
10.31
12.63
12.14
8.61
8.51
8.54
19.83
7.81
6.84
10.17
                    Table 41.  Power plant-related parameters for
                    impact of Pulliam Power Plant on yellow perch
                    population of Green Gay (surplus production
                    model).
                                        Parameter
                                               Estimate
Volume flow (m3/yr)
Biomass impinged (kg)
Proportion impinged
Impingement coefficient
Number of eggs entrained
Proportion of eggs entrained
Egg entrainment coefficient
Number of larvae entrained
Proportion of larvae entrained
Larvae entrainment coefficient
0.774 x 109
0.4979 x 101*
0.9957 x 10"3
0.6427 x 10'12
0.4526 x 107
0.2772 x KT1*
0.1789 x 10'13
0.9102 x 106
0.5574 x ID"3
0.3598 x 10' 1(*
                                      86

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      Applying  the  surplus  production model,  the biomass  of  yellow  perch  in
 Green  Bay in  1975  was estimated as  5,206,666  kg.   Applying  this  estimate  of
 biomass   together  with  the  observed  volume   flow  and  numbers  and  biomass
 impinged  and entrained at  the  Pulliam Power  Plant gave the  parameter estimates
 listed  in Table 41.   The  impingement and entrainment  coefficients are higher
 when  the  impact  on  Green Bay  is  assessed  than  when  the impact  on Lake Michigan
 is  assessed.   This  is expected because  the biomass available  to  the Pulliam
 plant is  considerably  reduced  when  only Green  Bay is under  consideration.

      The  estimate  of the proportion of yellow  perch  in Lake Michigan impinged
 at  Pulliam Power Plant  is 0.4978  x  10"3.   The  proportion of  the  biomass  in
 Green  Bay  estimated  to  be  impinged is  0.9957  x  10"3.   The. yellow  perch
 population  of  Green Bay  in 1975 was  about  5Q%  of  the lakewide estimate  for
 1975.   From the proportion of biomass in the  lake  impinged and the percent  of
 the  population  of  the  lake  estimated  to  be  in  Green  Bay  the  proportion
 impinged  in  Green  Bay  is estimated as 0.4979  x 10"3 which  is  identical to  the
 estimated obtained  using only  Green Bay data.

      Because  the yellow  perch  entrainment  and  impingement   coefficients  are
 high  when Green Bay is considered  separately,  the impacts of entrainment and
 impingement  increase substantially  as volume flow is  increased.  The relation
 between  yellow perch  standing stock  biomass,  maximum sustainable yield, and
 volume  flow are  given  by the equations:

    B = 5,824,315 -  0.00004648Q

    MSY = 350,000 -  0.000004648Q, f5  = 0.1285  x ID'11,  pr = 0.3578  x 10"13,
           h5 = 0.7195  x 10-^.

 As  volume flow  increases  the  standing stock  biomass  and  maximum  sustainable
yield slowly decrease  (Figs.  38 and  39).  At  a flow of 7.74  x  108  m3/yr, the
 reduction in standing  stock of yellow perch  in  Green Bay  is 0.0061  (0.61%) and
 the reduction  in MSY is 0.0103 (1.03%).  Consideration  of Green Bay separately
 from  the  rest  of Lake  Michigan does not result  in a significant change in the
 estimate  of the  impact of water withdrawal.

     The  results  of  this study   indicate  that  the  cumulative  impacts   of
 impingement and entrainment resulted  in relatively small  decreases  in standing
 stocks  and  yields  of alewife, smelt,  and yellow perch in  Lake  Michigan.  The
major source of  uncertainty in the results  reported here comes  from the lack
of  data  for parameter  estimation,  but even large  errors in  estimation would
not  cause a  great  change in  the  estimated  level  of  impacts during 1975.
Although  the   present  level  (capacity)  of   water withdrawal   does  not  reduce
standing  stocks  or yields  of  these species by more than  a  few percent, the
intake-related  losses  should  be  evaluated   in  light of  the  recent  status  of
each population in Lake Michigan.

     The  published estimates of standing stock  biomass  of alewife available  to
trawls  (1967-1978)   [24]   indicate  cyclic   fluctuations  between  40  and  120
million kilograms,  and our  estimates,  based  on the  fishery  indicate a peak
biomass of >206  x 106  kg  in 1975.   Recent estimates of the annual  consumption
of alewife  by  salmonid predators in  Lake Michigan  [34] indicate a maximum  of
30% of  the standing stock  biomass  was consumed  in  1975, a peak year in the
cycle of  alewife  biomass  fluctuations, and  a  maximum  of 100%  in 1977, a year


                                    87

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   6.0
   5.8
   5.6
8
en
u_
0 5.14
en
en

a


  5.2
  5.0
                           No water withdrawal
                         + (h ) 0. 3598 x 10
                                     -14
                                                             10
                         VOLUME FLON (M3 X 109)
Fig.  38.   Combined entrainment and  impingement impact  of in-
creased water withdrawal  on biomass of  yellow perch  in Green
Bay.  Arrow indicates  total design  flow for all water  intakes
on Green  Bay in 1975.
                                No water withdrawal
                        (fJ 0.6427 x 10

                        (p ) 0.1789 x 10"

                        (h ) 0. 3598 x 10"
                          H           6
                        VOLUME FLOW (M3 X 109)
                                                           10
Fig. 39.   Combined entrainment and impingement impact  of in-
creased water withdrawal  of maximum sustainable yield  (MSY)
of yellow  perch in Green  Bay.   Arrow  indicates total design
flow for all  water intakes  on  Green Bay  1975.
                              88

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when estimated  alewife biomass was extremely  low.   Under natural  conditions,
the numbers of predatory fishes are a direct function  of  reproductive  success,
natural mortality  rates,  and food supply.   However, the numbers  of  salmonids
in  Lake Michigan  are  primarily  under  human  control.   Social  pressures  to
increase salmonid  stocking in Lake Michigan have  resulted  in the  stocking  of
-12 million  salmonids  annually since 1973  and projected stocking  rates of  15
million per year by 1985.  The potential effects of  overstocking  salmonids and
overcropping  alewife  are  becoming serious  issues.   The focus of  fish  manage-
ment and research  efforts must be directed toward forage fish management via
allocation   of   forage  production   among   trophic,  commercial,  and  other
interests.   For example, the loss of  alewife biomass due  to commercial  fishing
in  1975 was  approximately 16  x  106  kg.    Assuming  a  limitation  on  available
forage, this  biomass would have  produced -2 x 106 kg  of  salmonids  (assuming a
forage  to  predator conversion  ratio of  7:1).   Similarly, the loss of  alewife
to  water  intakes   (-2  x 106  kg  in 1975) would convert to -280 thousand kilo-
grams of salmonids.

     Estimates of  the  minimum  standing  stock biomass of rainbow  smelt  in Lake
Michigan indicate  fluctuations between  11  and 16  million kg between 1973 and
1978 [27] and -25  x 106 kg in 1975 (this report).  Although salmonid  predation
on smelt is not well quantified,  it was recently estimated as -5.0  x  105 kg  or
20%  of the  1975   standing stock  biomass  [34].    Commercial  fishing  in 1975
harvested  0.5 x 106  kg (2%) and  sport fishing  accounted  for -1.3  x 106  kg
(5.2%).   The reductions   in  standing  stock  of  rainbow  smelt   due  to water
intakes was estimated to be 0.75%.  The status of the  rainbow smelt population
seems to be  partially  related  to  the  status of the  alewife population  and the
level of predation by  salmonids.   Although the  smelt  population has played  a
secondary  role  in  the  trophic  system  of   Lake Michigan  in the  past,  it may
become  a more valuable forage base  if  the  alewife  population  is  depleted  to
the point of  being unable to support the predatory pressure.

     Yellow perch  are  not a  forage  species for salmonids.   The yellow perch
population   in Lake Michigan  has  fluctuated greatly since  1960.    Apparently,
the standing  stock of  yellow perch was -10.7  x 106  kg lakewide  and 5.2 x 106
kg  in  Green  Bay   in  1975.   Neither  population  seems  to be impacted  by the
combined mortalities due to fishing and water  intakes.
                                      89

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                                  REFERENCES

1.   CDM/Li nineties.     1977.     The   lake-wide  effects  of  impingement  and
     entrainment  on the  Lake Michigan  fish  populations.    Report  to CECO,
     NIPSCO, IMPCO, and CPCO.

2.   Saila,  S.  B.  and  E.  Lorda.   1977.   Sensitivity analysis  applied to a
     matrix model  of  the Hudson  River  striped bass population.   In:   W.  Van
     Winkle  (ed.),  Conference  on  Assessing  the Effects of Power  Plant-Induced
     Mortality on Fish Populations.  Pergamon Press, Inc.  p. 311-331.

3.   Horst,  T.  J.   1975.   The  assessment of  impact due  to  entrainment of
     ichthyoplankton.     In:     S.   B.   Saila   (ed.),   Fisheries  and  Energy
     Production:  A Symposium.  Lexington Books, Lexington, Massachusetts,  p.
     107-118.

4.   Horst,  T.   J.    1977.    Effects  of  power  station  mortality  on  fish
     population stability in  relationship  to life  history  strategy.   In:  W.
     Van Winkle  (ed.), Conference  on Assessing  the  Effects of  Power  Plant-
     Induced Mortality on Fish Populations.   Pergamon Press, Inc.  p. 297-310.

5.   Eraslan, A. H. J2t_^l_-  1975.  A computer simulation model for the striped
     bass young-of-the-year  population  in   the  Hudson  River.   ORNL  Publ.  No.
     766.  208 pp.

6.   Van  Winkle,   W.  et  al.   1974.    A   striped-bass  population model  and
     computer programs.  ORNL Report No. 643.  195 pp.
     Van  Winkle,  W.  (ed.).   1977.   Conference  on  Assessing  the  Effects of
     Power  Plant-Induced  Mortality  on  Fish  Populations.    Pergamon  Press,
     Inc.  361 nn.
8.   Swartzman,  G.  L.,  R.  B.  Deriso,  and  C.  Cowan.   1978.   Comparison of
     simulation  models  used in  assessing  the effects  of  power plant-induced
     mortality on fish populations.  Nuclear Regulatory Commission.  155 pp.

9.   Ricker,  W.   E.    1975.   Computation  and  interpretation  of  biological
     statistics  of  fish populations.   Fish.  Res.  Board Can.  Bull.  No.  191.
     382 pp.

10.  Goodyear, C. P.   1977.  Mathematical methods  to evaluate entrainment of
     aquatic  organisms  by  power  plants.    U.S.  Fish  and  Wildlife  Service.
     Topical Briefs on Electric Power Generation No. 3.  17 pp.

11.  Goodyear, C. P.  1978.  Entrainment impact estimates using the equivalent
     adult approach.  U.S.  Fish and Wildlife Service Report.   14 pp.

12.  Barnthouse,   L.  W.,  D. L.  DeAngelis,  and S. W.  Christensen.   1979.   An
     empirical model of impingement impact.  ORNL Publ. No. 1289.  20 pp.

13.  Van  Winkle,   W.,   S.   W.   Christensen,  and  J.   S.   Suffern.    1979.
     Incorporation  of sublethal  effects  and  indirect mortality  in modeling
     population-level  impacts  of a  stress,  with an  example  involving  power-
     plant entrainment and striped bass.  ORNL Publ. No. 1295.  24 pp.


                                     90

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 14.   Sharma,  R.  K.  and R. F. Freeman,  III.   1977.   Survey of fish impingement
      at  power plants  in  the  United  States:   Vol.  I.   The Great Lakes.  Argonne
      National  Laboratory/Environmental  Impact Studies Division Report, ANL/ES-
      56.

 15.   SAS  Institute  Inc.    1979.    SAS  User's  Guide  -  1979  Edition.    SAS
      Institute  Inc.,  Raleigh, North  Carolina.

 16.   Lucas,   H.  F.,  Jr.    1979.    Radiological  and  Environmental   Research
      Division,  Argonne National  Laboratory,  personal  communcation.

 17.   Toohey,  R. E.,  J.  Rundo,   and  T. J.  Kotek.    1978.    A user's  guide  to
      PLOTIN/MYPLOT:    A  general-purpose  plotting  routine  for  use  with  AMD
      graphics.   ANL/RER-78-3.

 18.   Murarka,  I.  P.,  S. A.  Spigarelli,  and D. J.  Bodeau.   1978.   Statistical
      comparison   and   choices   of   sampling  designs   for   estimating   fish
      impingement at cooling  water intakes.   In:  L.  D.  Jensen (ed.),  Proc.  4th
      National Workshop on  Entrainment  and Impingement,   p.  267-280.

 19.   Jude,  D.  J.    1979.   Great  Lakes  Research  Division,  University  of
      Michigan,  Ann Arbor,  Michigan,  personal  communication.

 20.   Lake  Michigan  Cooling  Water  Intake  Technical   Committee.    1973.    Lake
      Michigan intakes:   Report on the  best  available  technology.

 21.   Otto, R.  G., M.  A.  Kitchel, and J. 0.   Rice.  1976.   Lethal  and  preferred
      temperatures of  alewife (Alosa  pseudoharengus)  in Lake  Michigan.  Trans.
      Amer. Fish. Soc. 105, 96-106.

 22.   Werth, R.  J.,  A. R.  Resetar, and R.  C.  Evers.   1977.   Report  to  Inland
      Steel Company,  East Chicago, Indiana/Fish  Monitoring Study:  June  1976-
     June 1977.

 23.   Energy   Impact   Association.     1978.     U.S.  Steel   Corporation,   Gary
     Works/Fish Impingement-Entrainment Study, Summary  Data  Report.

 24.  Hatch,  R.  W.   1979.   Estimation of  alewife biomass  in Lake  Michigan,
      1967-1978.     U.S.   Fish   and   Wildlife  Service,  Great   Lakes  Fishery
     Laboratory, Ann Arbor, Michigan,  Administrative  Report.   31  pp.

 25.  Brandt,   S.  B.    1978.  Thermal  ecology and abundance  of alewife (Alosa
     pseudoharengus) in Lake Michigan.  Ph.D.  Thesis, University  of Wisconsin-
     Madison.226 pp.

26.  Edsall,   T.  A., E.  H. Brown, Jr., T. G.  Yocum,  and R. S. C.  Wolcott, Jr.
     1974.   Utilization  of  alewives by coho  salmon  in Lake Michigan.    U.S.
     Fish and Wildlife  Service,  Great Lakes  Fishery  Laboratory, Ann Arbor,
     Michigan.  15 pp.

27.  Hatch,  R. W.  1979.   U.S.  Fish  and Wildlife Service, Great  Lakes Fishery
     Laboratory, Ann Arbor, Michigan, personal communication.
                                      91

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28.  Beverton, R. J.  H.  and S. J. Holt.  1957.   On  the  dynamics of exploited
     fish populations.  United Kingdom,  Min.  Agric.  Fish.,  Fish.  Invest. (Ser.
     2)  19.  533 pp.

29.  Gulland, J. A.  (ed.).   1977.   Fish population  dynamics.   John Wiley, New
     York.  372 pp.

30.  Brown,  E.  H.,  Jr.     1972.    Population   biology  of  alewives,  Alosa
     pseudoharengus,  in Lake Michigan,  1949-1970.   J.  Fish.  Res.  Board  Can.
     29, 477-500.

31.  Norden,  C.  R.    1967.   Age,  growth  and  fecundity  of  the  alewife (Alosa
     pseudoharengus) in Lake Michigan.   Trans. Amer.  Fish.  Soc.  96, 387-39^

32.  Brazo,  D.  C.,   P.  J.  Tack, and C. R.  Liston.   1975.    Age,  growth, and
     fecundity  of   yellow   perch,  Perca  flavescens,  in Lake   Michigan  near
     Ludington, Michigan.   Trans.  Amer.  Fish.  Soc. 104,  726-730.

33.  Bailey, M.  M.   1964.    Age, growth,  maturity, and  sex  composition of the
     American  smelt  (Osmerus mordax)  of western  Lake Superior.   Trans. Amer.
     Fish. Soc. 93,  382-395.

34.  Stewart,  D. J.  and J.  F.  Kitchell.   Managing  forage  fish  with salmonid
     predators   in   Lake   Michigan   -   past,   present  and  possibilities.
     Unpublished manuscript,  Marine Studies  Center,  University  of Wisconsin-
     Madison.
                                      92

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                               GLOSSARY OF TERMS
 Impingement:    entrapment  of  fishes  by  water  intakes  and  their  subsequent
     removal  from  the  process  stream by traveling  screens.
 Entrainment:    entrapment  of  eggs  and immature  fishes  by  water intakes  and
     their  passage through the traveling  screens  into  the  process stream.
 Ichthyoplankton:   "free-floating"  or planktonic fish life-stages.   Eggs  and
     larvae are included in  this  term.
 Traveling  Screen:   typically  a 3/8"  wire-mesh  screen  located upstream of  the
     intake pumps as a final filter.
 a,b:  parameters in the parabolic length-weight  equation.
 B:  biomass of  the population  at  time  t.
 B^:   environmental  carrying  capacity  in terms  of biomass  (population size
     without  fishing or water  withdrawal).
 B(x) :  biomass  of individuals  of  age  x.
 BQ:  population biomass at some initial time t.
 C:  annual catch from  the fishery in  numbers or kg.
 CPUE:  catch  per unit  effort in the  fishery.
 D:  density of  fish in lake  (kg).
 Dn-:  density  of fish at itn  intake  (kg).
 E:  fishing effort  in  some  standard units such as  lifts of pound nets or trap
     nets.
 EUB:  egg production per unit  of  female biomass.
 f.j:  annual impingement coefficient  for water intake i.
 favg:  average  annual  impingement coefficient for sampled water intakes.
 fmax:  maximum  annual  impingement coefficient for sampled water intakes.
F:  instantaneous fishing mortality coefficient.
G:  number of eggs  produced  by the  population  during a period of  one year, or
     the number at time t.
G'n-:  number  of eggs entrained at intake i at time  t.
AG.J :  number of eggs entrained at water intake i during one year.
G(o):  the initial  number of eggs produced by a cohort.
                                      93

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havg:  average  annual  larval entrapment coefficient  for sampled  intakes.
nmax:  maximum  annual  larval entrainment coefficient  for sampled  intakes.
hf:  larval entrainment coefficient for water intake  i.
I:  number or biomass  of fish impinged at time t.
Aln-:  number or biomass of fish impinged at water intake i during one year.
k:  population  growth  constant in surplus production model.
K:  growth parameter for weight of individual fish.
!,:  length of an individual fish.
£„:  asymptotic length of an individual fish.
£(x):  length of an individual  at age x.
L:  number of larvae at time t or at age x.
L1:  number of larvae  entrained at time t.
AL.J :   number of  larvae  entrained at  water intake  i  during a  period  of one
     year.
L(o):  initial  number  of larvae produced by a cohort.
M:  instantaneous natural  mortality coefficient.
M.J :  mortality resulting from impingement (assumed to = 1).
M-^:  mortality rate of egg stage.
M£:  mortality rate of larvae.
MSY:  maximum sustainable yield.
n:  number of water intakes.
N(x):  number of individuals of age x.
pavg:  average annual  egg entrainment coefficient for sampled intakes.
p.j:  egg entrainment coefficient  for  water intake i.
pmax:  maximum annual  egg entrainment coefficient for sampled intakes.
q:  catchability coefficient for  the  commercial  fishery.
Q-j:  annual  volume flow in m3 at  water intake i.
R:  number of recruits entering exploited population.
                                     94

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t:  time in years.
Atj^:  amount of time from  spawning to absorption  of yolk  sac.
At2:  amount of time from  absorption of yolk sac  to young-of-year  stage.
Uj:  integration constants for the dynamic pool model.
V:  volume of lake.
WM:  asymptotic individual weight for the dynamic  pool  model.
W(x):  weight of an individual at age x.
x:  age.
     age when fish became  catchable by commercial  fishery.
     age when fish re recruited.
     age when fish become  impingeable.
xm   age at maturity.
xQ   theoretical age when  length is zero.
     annual yield from the commercial fishery.
Y:  yield from the commercial fishery at time t.
Ye:  equilibrium yield from fishery.
$:  mortality rate for prerecruit life-stages in  surplus  production  model
                                     95

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                               APPENDIX   A
                DAILY IMPINGEMENT AND ENTRAINMENT DENSITIES
Figs. A.I.a - A.16.1:  Daily densities of each species/life stage at each
                       sampled plant
Figs. A.I.a-A.16.a:  Impinged alewife.
Figs. A.l.b-A.16.b:  Impinged smelt.
Figs. A.l.c-A.16.c:  Impinged yellow  perch.
Figs. A.l.d-A.16.d:  Entrained alewife eggs.
Figs. A.l.e-A.lS.e:  Entrained alewife larvae.
Figs. A.l.f-A.16.f:  Entrained smelt  eggs.
Figs. A.l.g-A.16.g:  Entrained smelt  larvae.
Figs. A.2.h-A.16.h:  Entrained yellow perch  eggs.
Figs. A.2.i-A.16.i :  Entrained yellow perch  larvae.

NOTE:    Figures   for  plants  not  reporting  a   species  group  were  excluded.
     Heavy   solid lines on x-axis indicate  values < appropriate y-axis value.
                                     96

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                      NUMBER  IMPINGED/1000 M3
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-------
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-------
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-------
 Table Bl.   Estimates of proportions of alewife standing  stock  impinged  in  1975  and  power plant impingement  coefficients  calculated  using surplus
.production model.
POWER PLANT I. 0.
1*
7
3
4
5
6
7
R
9
10
11**
12
13
14
IS
16
VOLUME FLOW
0. 34814101E+10
0. 3272900113+10
0.669!*9990E+09
0. 596900 10E+00
0.77470003E+09
0.82170010E*09
0. 1S320000E+10
0. 10942999E+10
0.«!7340006E*09
0.24512000E*10
0. 14324001E*10
0. 16513001E+10
0.82369997E+09
0.ci('690010E»09
0. 11940000E*09
0.95500000B+08
BIOHHS3 I1PIMGED
0. 14693706E+06
0.11590391E+35
O.S7543711E»34
0.20072391E*3'5
0.41357129E*05
0.562966SOE+04
0.38121 164E*3'5
3.94791375E*05
0.31045945E*34
0.510053S9E+05
0.37437020E+OS
0.36548961E*35
0.62559492E+04
0. 15387852E+04
3.12758341E*32
0.47816925E*31
PP3P3RriJM ISPIHGED
0.7347E-03
0.5795E-04
0. 2877E-0'4
0. 1004E-01
0. 2068B-03
0.2815E-0'4
0. 1906E-03
0.4740E-03
0. 1552E-OH
U.2550B-03
0. 1872B-03
0. 1827E-93
0. 3128E-0'4
0.7694E-05
0.6379E-07
0.2391E-07
IIPTHGBNENr COEFFICIEHT
0.21133155E-12
0. 17706607E-13
0.42975148E-13
0. 16813867E-12
0.26692358E-12
0.34256218R-13
0. 12441632E-12
0. 13311432E-12
0. 177730H2E-13
0. 10404161E-12
0. 13067932F-12
0.11066723E-12
0. 17974689E-13
0. 12389839B-13
0.53426878B-15
0.2b035033E-15
                                                                                                                                                        co
                                                                                                                                                        -o
                                                                                                                                                        §
                                                                                                                                                        -o
                                                                                                                                                        o
 *  Zion  (plant  1)  biomass  impinged  in  1975 was 0.9532 x  106.  The value in the table is for 1974.
 ** Waukegan  (plant 11)  biomass  impinged  in 1975 was 0.4536 x 105.  The value in the table  is for 1974.



               Table B2.  Estimates of proportions of alewife eggs  produced in  1975 that were  entrained and power plant entrainment
               coefficients calculated using  the surplus production model.
POWER PLSNT I. D.
1
2
3
5
6
7
8
9
10
11
12
13
14
15
16
VDLTHE PLOW
0.34814001EMO
0.32729001E+10
0.669U9990E+09
0.77470003E*09
0.82170010E*09
0. 15320000E+10
0.10942999E+10
O.B7340006E+09
0.24512000E+10
0. 14324001E+10
0.16513001E+10
0.82369997E*09
0.59690010E+09
0. 11940000E + 09
0,95500000E*08
NUMBER EHTPAINED
0. 14137398E+10
0.17000000E+10
0.42201874E+10
0.43163904E*09
0.47.349856E+08
0.4S735860E*07
0.37325210E*07
0.57972900E+07
0. 92683780E+07
0. 36946424E*10
0.79521971E+09
0.29844595E+10
0. 140^4319E+06
0.0
0.0
PROPOBTION ENTBATNED
0.38416852E-04
0.46195666E-04
0.11467905E-03
0.11729327E-04
0. USfiSSUE-OS
0. 12441814E-06
0. 10142719E-06
0. 14394811E-06
0. 25185000E-06
0.10039793E-03
0.21609230E-04
0.91099468E-OU
0.38272603E-08
0.0
0.!)
ENT. COEFFICIEHT
0.11034888B-13
0. 14114605E-13
0.17129061E-12
0, 15140473E-13
0.15658770E-14
3.31212884E-16
0.92686885E-16
0. 16481355E-15
0. 1027U567E-15
0.70090689E-13
0.13086198E-13
0.98U57538E-13
0.64118980E-17
0.3
0.0
m
a
                                                                                                                                                        m
                                                                                                                                                        o

                                                                                                                                                        a

                                                                                                                                                        73
                                                                                                                                                        i—i
                                                                                                                                                        •z.
                                                                                                                                                        CD
                                                                                                                                                        cn

-------
                     Table B3.  Estimates or proportions of alewife larvae produced in  1975  that were entrained  and  power  plant  entrainment
                     coefficients calculated using the surplus production model.
                       PDWBR  PLANT T.D.
                                                 VOLUHE FLO»
                                                                      NttflBEB  ENTRAINED  PROPORTION ENTRATHED  ENF.  COEFFICIENT
1
2
3
S
6
7
8
9
10
11
12
13
14
15
16
0. 34814001EMO
0.32729001EMO
0.66949990E+09
0,77470003E*09
0.82170010E+09
0. 15320000E+10
0.10942999E*10
0.87340006E+09
0.24512000ff*10
0. 14324001E+10
0.16513001E+10
0.82369997E+09
0.59590010E+09
0.11940000E+09
0.95500000E+08
0.1 597246 8E+ 08
0. 21000000E*09
0.41615264E+08
0.66691250E*05
0.62247200E+06
0.34300350E+06
0.42359631E+06
0. 10956510E+07
0. 24778260E+07
0.51204880E+Oa
O.I»14!»<»900E+07
0. 10098325E*08
0.6156U883E»04
0.73131733E*01
0. 10062328E+02
O.U3403503E-OU
0.570S5301E-03
0.11308512E-03
0.18122648E-06
0. 16915019E-05
0.93207609E-06
0.11510783E-05
0.29773164E-05
0.67332321E-05
0.13914390E-03
0. 11262217E-04
0.27441129E-0»
0. 16729611E-07
0.19872770E-1D
0.27343322E-10
0.12467245E-15
0. 17435688E-14
0.16890966E-14
0.23393090E-17
0.20585376E-16
0.60840408E-17
0.105188498-16
D.34088775E-16
0.27469106E-16
0.97140279B-15
0.68202047E-16
0.33314441E-15
0.28027464E-18
0. 16643853E-20
0.28631724E-20
ro
            Table B4.  Estimates of proportions of yellow perch standing stock impinged in 1975  and power plant impingement coefficients calculated using the
            surplus production model.
POWER PLANT I. C.
1 *
2
3

-------
                      Table B5.  Estimates of proportions of yellow perch eggs produced in 1975 that were entrained and power plant entrain-
                      ment coefficients calculated using the surplus production model.
PCV.EP PLANT I.C.
1
2
1
6
7
g
9
10
11
' 12
13
14
15
16
VOLUME FLCh
G.348140C1E+1C
0.327290016*10
C.t694S<5SCE+C9
0.77470003E+09
C.8217CC1CE+C9
0.153200CCE«10
O.IOV4299SE+10
0.fl734CCCtE+C9
0.2451200CE*10
G.14324CC1E+10
0.165130C1E-UO
0.8236V997E*09
C.5969CCKE*C9
G.119400CCE+C9
C.9550CCCCE+C8
NUfBEP EMRAINED
C.C
o.iaeoocooE+08
C.1356083tE+05
0.^52t^220E+07
o.c
C.C
0.0
C.C
0.0
o.c
C.C
0.0
c.o
c.o
0.0
PROPORTION ENTRAINED
C.O
0.57566285E-C4
0.41585022E-07
0.136tCC72E-C4
0.0
C.C
0.0
0.0
c.o
0.0
C.C
0.0
0.0
0.0
0.0
ENT. CCEFFICIEfcT
O.C
C.17588775E-13
0.62113561E-16
C. 17890886E-13
0.0
C.C
O.C
0.0
O.C
0.0
O.C
C.C
0.0
0.0
c.o
CO
                     Table B6.  Estimates of proportion of yellow perch larvae produced in 1975 that were entrained  and power plant entrain-
                     ment coefficients  calculated using surplus  production model.
                      POhER PLANT  I.C.
                                             VOLUME FLOK
                                                                M*BEfi EKTPJINEO  FPCPCRTION ENTRMNEC   ENT.  COEFFICIENT
                              1
                              2
                              3
                              S
                              6
                              7
                              8
                              9
                             10
                             11
                             12

                             II
                             15
                             16
C.34814CC1E+1C
0.32729001E+10
C.6694999CE+09
0.7747CCC2E*C9
0.8217C010E+09
0.15320CCCE*1C
0.1094299SE+10
0.87340006E+09
0.24512CCCE+1C
0.14324C01E+10
0.165130C1E41C
0.823699S7E+C9
0.5969001CE*C9
0.1194CCCCE+CS
0.9530CCCCE*08
C.C
C.153COCCCE+C6
0.15528816E*05
O.C
0.0
0.0
C.C
0.0
0.0
C.C
0.0
C.C
c.o
0.0
0.46849207E-C4
0.47549856E-C5
0.27871295E-C3
0.0
0.0
C.20591906E-05
0.0
0.0
0.0
0.0
0.0
C.C
0.0
0.0
0.0
0.143142696-15
C.71C22879E-16
0.35976844E-14
0.0
0.0
0.18817406E-16
O.C
0.0
O.C
0.0
0.0
C.C
0.0
o.o

-------
            Table B7.  Estimates of proportions of smelt standing stock impinged in 1975 and power plant impingement coefficients calculated using the surplus
            production model.
>OHE« PLANT I. C.
1 *
2
3
ft
5
6
7
8
9
10
11 **
12
13
14
15
16
VOLUME FLOW
0.348140C1F+10
0.32729001F+1G
0.66949990E+09
0.5<369CC10E*09
0.77470003E409
0.82170010E*09
0.15320000E+1C
0.10942999E+10
0.873400C6E+09
0.24512000E+IC
0.14324001E+10
0.16513001E+IC
0.82369997E+09
0.5969CC1CE+C5
0.11940000E+09
C.95500000E+08
BIOMASS IMPINGED
0.274C9414E+05
0. 11814774E+03
0.29758041E+02
0.20418350E+02
0.87433838E+03
0.69506860E+03
0. 136C7659E+04
0.15913701E*04
0.75266 02 7 E+01
0.55522813E*04
0.27116650E+03
0. 60C69641E+-02
0. 54151020E*01
0.16055583E*02
0. 23694700E*00
0.29822702E+01
PROPORTICN IMPINGtD
0.1096E-02
0.4726E-05
C. 1I90E-05
0. 8 16 7 E- 06
0.3497E-04
0.2780F-04
0.5443E-04
0.6365E-C4
0.30HE-06
0.2221E-03
C.1C85E-04
0.2403E-05
0.2166E-06
0.6422E-06
0.9478E-08
C.1193E-06
IMPINGEMENT COEFFICIENT
C.31492425E-12
0.14439517E-14
C.17779266E-14
C. 13682928E-14
C.45144620E-13
C. 33835632E-13
0. 35529136 E-13
C.58169398E-13
0.34470345E- 15
0.90605095E-13
C. 75723661E-14
0. 145508726-14
C.26296477E-15
C. 10759315E- 14
0.79379229E-16
0. 12491184F-14
             *  Zion  (plant  1)  biomass  impinged in  1974  was  0.4263 x  ID1*.  The values in the table are for  1974.
             ** Waukegan  (plant 11)  biomass impinged  in  1975 was  0.5448  x  103.  The values  in the table are for  1974.
01
                             Table B8.   Estimates  of  proportions of smelt eggs produced in 1975 that were entrained and power plant entrainment
                             coefficients  calculated  using  the  surplus production model.
POWER PLANT I.D.
1
2
3
5
6
7
8
9
10
11
12
13
t /i
14
15
16
VOLUME FLOK
0.34814001E+10
0.32729001E+10
0. 66949990E+09
0.77470003E+09
C.82170010E+C9
0.15320000E+10
0.1094299SE+10
0.87340C06E+C9
0.24512000E+10
0. 14324001E+10
0.165130C1E+10
0.82369997E+09
0.5969C01CE+C9
0.1I940000E+C9
0.95500000E+08
NUMBER ENTRAINED
0.74359936E+C9
0.75200000E+08
0.45243650E+07
0.76767190E+07
0.49827080E+07
0.0
0.24S84fc88E+06
C.C
0.10CC8S56E*06
0.23360851E+09
0.31467616E+08
0.21424140E+07
0.0
C.O
0.0
PROPORTION ENTRAINED
0.55421679E-03
0.56047807E-04
0.33720835E-05
0.57215857E-C5
0.37136942E-C5
0.0
0.18323374F-C6
0.0
C.74598404E-07
0.17411230E-C3
0. 23453322 E-04
0.15967762E-C5
0.0
C.O
0.0
ENT. COEFFICIENT
0. 15919368E-12
0. 17124814E-13
0.50367222E-14
0.73855479E-14
0.45195239E-14
0.0
C. 16744383E-15
0.0
0.3C433417E-16
C.12155283E-12
0.14202950E-13
0.1S385416E-14
0.0
0.0
0. C

-------
                       Table  B9.  Estimates of proportions of smelt larvae produced in 1975 that were entrained and power plant  entrainment
                       coefficients calculated using the surplus production model.
                       POhER PLANT  I.D.
                                                VOLUME FLCV.
                                                                     NUPBER ENTRAINED   PROPORTION ENTRAINED  ENT.  CCEFFICIENT
1
2
3
5
6
7
8
9
10
11
12
13
14
15
16
0.34814001E+10
0.32729001E+10
C.66949990E+09
0.77470003E+C9
0.82170010E+09
0.1532COOCE+10
0.10942999E+10
0.87340006E+09
0.245120GCE+10
0.14324001E+10
0.16513001E+10
0.82369997E+09
0.59690010E+09
0.119400COE+C9
0.95500000E+08
0.11920482E+08
0.244COCOOE+07
0.31374588E+06
0.13520C88E+06
0.101892C5E+C8
0.19427820E+07
C.43C49138E+06
0.0
0. 66567890 E+07
0.18272669E+06
0.10883388E+06
0.98S5877CE+07
0.24795967E+C3
0.14613811E+02
0.5250
-------
                       Table Bll.  Estimates of proportions of alewife eggs produced in 1975 that were entrained  and  power  plant  entrain-
                       ment coefficients calculated using the dynamic pool  model.
PO'dEP PLANT I. D.
1
2
3
5
6
7
8
g
10
-j -j
X -L
12
13
14
15
16
VOLUME FLOW
0.348H001E+10
0.32729001E+10
0.669U9Q90E+09
0.77»70003K*09
0.82170010E+09
0.15320000H+10
0. 10942999E+10
0.87340006E+09
0. 24512000E+13
0.14324001S+10
0. 16513001K+10
0.823699971> + 09
0.59690010E+09
0. 11940000E*09
0.955000008+03
NUMBER ENTRAINED
0. 1i»137398E*10
0.17000000F*10
0.0?20187«E*10
0.mi6390UE+09
0.tt73a9856E*Oq
0.45785860E*07
0. 373252 10E* 07
0. 52972900E+07
0.92680780E+07
0.36946'* 24E+10
0.79S?1971E*09
0.298Ul»595E*10
0. 1UO>?a319E*06
0.0
0.0
PROPORTION ENTPAIHED
0.849871U3E-03
0. 10219573E-02
0.25369711E-02
0.259*8021E-03
0.28I»6'41H9E-0*
0.27524279E-05
0.22438098E-OS
0.3184«729E-05
0.5S715172E-05
0.22210393E-02
0.!»78-T4718E-03
0. 17941117E-02
O.RH65101J5E-07
0.0
0.0
BUT. C3EFFICIEST
3.2H411777E-12
0.3122W838B-12
0.37893525E-11
I).33H')IHQ1Z-12
•5.3i»640900E-13
0.17966208B-H»
0.2050U525E-14
0.36460635E-14
T.22729754B-1'*
0.15505713B-11
0.289*97596-12
0.21781127E-11
0.14184631E-15
0.0
0.3
en
                       Table B12.   Estimates of proportions  of  alewife larvae produced in 1975 that were entrained and power plant entrap-
                       ment coefficients calculated  using  the dynamic pool model.
POWEP PLANT I. D.
1
2
3
5
6
7
8
9
10

i 7
1 U
13
14
1 ^
j. j
16
VOLUME FLOW
0.34814001EHO
0.32729001E+10
0. 669<*9990E*09
0.77470003E+09
0.82170010E+09
0.15320000E+10
0. 10942999E+10
0.87340006E*09
0. 24512000E»10
0.14324001E*10
0. 16513001E+10
0. 823699 97E*09
0.59690010E*09
0.11940000R+09
0.95500000E+08
NUMBER ENTRAINED
0. 15972468E+08
0.21000000l?*09
0.41615264E*08
0.66691250E*05
0.62247200E*06
0. 3430Q350E+06
0.42359631E+06
0. 10956510E*07
0.24778260E+07
0.51204880E+08
0.41444900E»07
0. 10093325E»08
0. 615fi<*883E*04
0.73111733E+01
0. 10062328E*02
PROPORTION ENTRAINED
0.96018799E-03
0. 12624189E-01
0.25017096E-02
0.40091572E-05
0.37423017E-04
0.20619715E-04
0.25464571E-04
0.65865272E-04
0.14895U99E-03
0.30781913E-02
0.2491U672F-03
0.60706260E-01
0.37039846E-06
O.U3963277E-09
0.60439880E-09
E»T. COEFFICIEHT
3.27580492E-14
0.38571858B-13
0.37366804B-13
0.51751040E-16
0.45539710E-15
0.13459335B-15
0.23270155E-15
0.75412402E-15
0.60768134E-15
0.21489724E-13
0. 15087904E-14
0.73699422B-14
0.62003366E-17
0.36820132B-19
0.63340115E-19

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            Table B13.   Estimates of proportions of yellow perch standing  stock impinged in 1975 and power plant impingement coefficients calculated using the
            dynamic pool model.
           PCWER  PLANT  I.  C,
                                          VOLUME FLCh
                                                                BIOMASS  IMPINGED
                                                                                           FRCFGRTKN IPPIfcGEO
                                                                                                                      IMPINGEMENT COEFFICIENT
1*
2
3
5
6
7
8
9
10
11 **
12
13
14
15
16
C.348140C1E4K
0.327290C1E4K
0.66949990E4Q9
0.7747CCC3E+CS
0.82170C1CE40S
0.15320000E+1C
C.1C942999E41C
0.87340006E409
0.24512CCCE41C
0.14324CC1E41C
C.165130C1E+10
C.623699S7E4CS
0.5969C010E409
0.1194CCCCE4CS
C.95500CCOE4C6
0.25S07446E*03
0.96S31714E4-03
0.54530869E+02
0.82189819E+02
0.497££758E+C4
0.44378845E*02
0.43168C45E+C2
0.40887146E+02
0.63109789E+01
0.15i75256E+C3
0.55464066E+02
0. 1C772827E + 03
0.59S53842E+02
O.US22538E+02
C. lie473A7E+CC
0.2578E-C4
O.S646E-04
C.5427E-C5
0.8179E-05
C.4955E-03
0.4416E-05
0.4296E-05
C.4C69E-C5
0.6280E-C6
0.1520E-04
C.5520E-05
0.1072E-04
C.5966E-C5
O.I186E-C5
0.1179E-07
C.74057243E-14
0.2947 3392 E- 13
C. 810567 16E-14
0.105579986-13
0.60297259 E-12
C.28827987E-14
0.3925750 *.£-!+
C.46587591E-14
0.25622111E-15
0.10612584E-13
0. 33425870E-14
C.13015403E-13
C.99956800E-14
C.99371398E-14
0.12345673E-U
            *  Zion (plant 1) biomass  impinged in 1975 was 0.1420  x 10 .   The value in the table is for 1974.
            ** Waukegan (plant 11) biomass impinged in 1975 was 0.6145 x 102.  The value in the table is for 1974.
cr»
                         Table B14.  Estimates of proportions of yellow perch eggs produced in 1975 that were entrained and power plant entrain-
                         ment coefficients calculated using the dynamic pool model.                                               	
                         PChEF  FLANT I.e.
                                                 VOLUME FLCVt
                                                                    MJCBER  ENTRAINED   PPCPORTICN ENTRAINED  EM.  COEFFICIENT
                                  1
                                  2
                                  3
                                  5
                                  6
                                  7
                                  8
                                  9
                                 10
                                 11
                                 12
                                 13
                                 14
                                 15
                                 16
0.34814001t«10
0.32729CC1E+10
0.6694999CE+09
0.774TC003E+09
0.8217CC1CE+CS
G.1532COOCfcUO
C.lC94299Sfc+10
0.8734CCO
-------
                        Table B15.  Estimates  of proportions  of yellow perch  larvae produced  in 1975 that were entrained and power plant
                        entrainment coefficients calculated using the dynamic pool model.
                        POWER PLANT 1.0.
CT>
CO
                                                 VOLUME FICh
                                                                     MJf*EEF EMS/INEC   FfcOPCRTION ENTRAINED   ENT. COEFFICIENT
1
2
3
5
6
7
8
9
10
11
12
i *a
L -j
14
15
16
0.34814CC1E-»1C
0.327290G1E-»10
G.6694999CE+C9
0.7747CCG3E+C9
O.S21700iCE + C<3
C. 1532CCCCE+1C
0.10942999E410
0.87340CC6E+C9
0.24512CCCE+10
0.14324001E+10
0. 165130C1E+1C
0.82369997E4C9
0.5969C01CE4C9
0.1194CCCCE4CS
0.955UOCOCE4Q8
C.C
0.15300COCE+C6
0.15528E16E+05
C.91C21SS4E4C6
0.0
C.C
0.67248S64E+C4
0.0
C.C
0.0
C.C
C.C
0.0
C.C
0.0
o.c
C. 19682158E-C3
0.19976505E-04
C.11709211E-02
0.0
0.0
0.8651C145E-C5
0.0
C.C
0.0
0.0
C.C
0.0
0.0
0.0
0.0
C.tC136671E-15
0.2S837921E-15
0. 15114493E-13
C.C
0.0
0.75C55147E-16
0.0
O.C
C.C
o.c
C.C
C.C
0.0
C. 0
           Table B16.   Estimates of proportions of smelt  standing stock impinged  in 1975 and power plant  impingement coefficients calculated using the dynamic
           pool model.
           POWER  PLANT  I.  C.
                                           VCLUME FLOW
                                                                   BIOMASS IMPINGED
                                                                                                PROPORTION  IMPINGED
                                                                                                                             IMPINGEMENT  COEFFICIENT
I*
2
3
4
5
6
7
8
9
10
11**
12
13
14
15
16
0.34814CC1F*1C
0.32729001E-HO
0.669499<30E + CS
0.5969C010E+0<3
0.7747C003F+09
0.6217CC10E+C9
0.15320000E*10
0.1C942999E+10
0.87340006E+09
0.24512000E+10
0.14324CC1E+1C
0.1651300lE-flO
0.82369997E+09
0.59690010E+OS
0.11940000E+09
0.95500CCOF+08
0.274C9414E*05
0. 11814774E*03
0.29758041E+02
0.20418350E+02
0.87433838E-t-03
0.69506860E*03
0. 13607659E + 04
0. 15913701E+04
0. 75266027E*01
0.55522813E+04
0.27116650E*03
0.60069641E»02
0.54151020E+01
0. 16C55588E+02
0.236S4700E*00
0.29822702E+01
0.1110F-02
0.4784E-C5
0.1205E-05
0.8267E-06
0.354CE-C4
0.2814E-04
C.5510E-04
0.6443E-04
0.3047E-06
0.2248E-03
0.1098E-04
0.2432E-05
0.2193E-OS
0.6501E-0*
C.9594E-08
0.1208E-06
0.31877669E-12
0.14616174F-14
C. 17996769E- 14
C.13850321E-14
C.45696902E-13
C.34249571E-13
C.35963786E-13
C.58881C14E-13
0. 348920 40E- 15
C.91713529E-13
0.76650044E- 14
0. 14728882E-14
C.26618180E-15
C.10890940E-14
C.80350326E-16
C. 12643995E-14
           *  Zion (plant 1)  biomass  impinged in 1975 was 0.4263 x 104.   The value  in the table is for 1974.
           ** Waukegan (plant 11)  biomass impinged in 1975 was 0.5448 x 103.   The value in the table is for  1974.

-------
                    Table B17.  Estimates of proportions of smelt eggs  produced  in 1975 that were entrained and power plant entrainment
                    coefficients calculated using the dynamic pool model.
                    PCWER PLANT  1.0.
                                           VOLUME FLOW
                                                              NUMBER ENTRAINED   PROPCRTICN ENTRAINEC  ENT. COEFFICIENT
1
2
3
5
6
7
8
9
10
11
12
13
14
15
16
0.34814001E+10
0. 327290016+10
0.66949S9CE+C9
0. 774 7000 3 E +09
C.8217001CE+09
0.1532000CE+10
0.10942999E+10
0.87340006E+09
0.24512000E+10
0.14324001E+10
0. 1651300 1E+10
0.82369997E+09
0. 5969001 CE+C9
0.1194COCOE+C9
0.95500000E+08
0.74359S36E+09
0.75 200000 E+08
0.45243650E+07
0.76767190E+07
0.49827080E+07
0.0
0.24584688E+06
0.0
0.10008956E+06
0.23360851E+09
C.31467616E+08
0.2142414GE+07
0.0
O.C
0.0
0. 16500093E-01
0.16686500E-02
0.10039337E-03
0.17034251E-C3
O.UQ56376E-03
0.0
0.54552174E-C5
0.0
0.22209360E-C5
0.51836520E-C2
0.69825049E-03
0.47539070E-04
0.0
0.0
0.0
0.47394 996 E-H
C. 5C983832E-12
0.14995280E-12
C.21988195E-I2
0.13455491E-12
0.0
0. 49851209E-14
0.0
O.SC606098E-15
0. 3fcl88596E-ll
0.42284893E-12
0.57714033E-13
O.C
0.0
0.0
vo
                     Table B18.  Estimates  of proportions of smelt larvae produced in 1975 that were entrained and power plant entrain-
                     ment coefficients calculated using the dynamic pool model.

                                            VOLUME FLOW       NUMBER  ENTRAINED   PROPORTION ENTRAINED   ENT.  COEFFICIENT
                     POWER  PLANT I.D.
                              1
                              2
                              3
                              5
                              6
                              7
                              8
                              9
                             10
                             11
                             12
                             13
                             14
                             15
                             16
0.34814001E+10
0.32729001E+10
0.66949990E+09
0.77470003E+09
0.82170010E+09
0.153200CCE+10
0.10942999E+10
0.87340006E+09
0.245120CCE+10
0.14324001E+10
0.16513001E+10
0.82369997E+C9
0.5969001CE+C9
0.119400CCE+C9
0.95500000E+08
0.11920482E+08
0.244COCCCE+07
0.31374588E+06
0.l35?3C8aE+06
0.10189205E+08
0.1942782CE+C7
0.43C49138E+06
0.0
0.66567890E+07
0.18272669E+06
0.10e83388E+06
0.98-558770E + C7
0.24795967E+03
0.14613611E+C2
0.52509033E+03
0.26450977E-01
0.54142401E-02
0.69618691E-03
0.30000415E-03
0.22609357E-CI
0.43109395E-02
0.95523964E-03
0.0
0.14771093F-01
0.40546176E-C3
0.24149715E-03
0.21958474E-01
0.55021059E-C6
0.32427344E-07
0.11651500F-05
0.75977852E-13
0.16542625E-13
0. 1C398603F-13
0.38725161E-14
0.27515316E-12
0.28139261E-13
0.87292200E-14
O.C
0.60260553E-13
0.28306429E-14
0.14624651E-14
0.26658309F-12
0.92177947F-17
0.2715854PE-17
0.1Z20C512E-15

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              Distribution for ANL/ES-109  (EPA-905/3-81-001)

Internal:

W. E. Massey
W. K. Sinclair
R. E. Rowland
W. J. Hallett
E. J. Croke
M. M. Thommes (10)
S. A. Spigarelli (10)
A. L. Jensen
ANL Patent Dept.
ANL Contract File
ANL Libraries (2)
TIS Files (6)

External:

U. S. EPA, Region V (123)
DOE-TIC  (27)
Manager, Chicago Operations Office, DOE
President, Argonne Universities Association
Radiological and Environmental Research Division Review Committee:
  A.  K. Blackadar, Pennsylvania State University
  A.  W. Castleman, Jr., University of Colorado
  H.  L. Friedell, Case Western Reserve University Hospitals
  R.  E. Gordon,  University of Notre Dame
  R.  A. Hites, Indiana University
  D.  Kleppner, Massachusetts Institute of Technology
  G.  M. Matanoski, Johns Hopkins University
  D.  W. Schindler, University of Manitoba
  W.  H. Smith, Yale University
                                    170

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                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
1. REPORT NO.
  EPA-905/3-81-001
                                                           3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
  An  Assessment of the Impacts of  Water Intakes on
  Alewife, Rainbow Smelt, and Yellow  Perch Populations
  in  Lake Michigan	
                                    5. REPORT DATE
                                     April 1981
                                    6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
  S.  A.  Spigarelli, A. L. Jensen,  and  M.  M.  Thommes
                                    8. PERFORMING ORGANIZATION REPORT NO.

                                     ANL/ES-109
9. PERFORMING ORGANIZATION NAM.E AND ADDRESS
                                                           10. PROGRAM ELEMENT NO.
  Ecological Sciences Section
  Radiological and Environmental  Research Division
  Argonne National Laboratory
  Arqonne. Illinois 60439
                                    11. CONTRACT/GRANT NO.

                                      IAG#EPA-79-D-F0819
12. SPONSORING AGENCY NAME AND ADDRESS
  U.S.  Environmental Protection  Agency
  230 South Dearborn
  Chicago, Illinois  60604
                                    13.TYPE OF REPORT AND PERIOD COVERED
                                     Final
                                    14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
  A large volume of water  is withdrawn from Lake Michigan for cooling  and  other
  industrial and municipal purposes.   Potential ecological impacts  of  such withdrawals
  have caused concern.  This study  estimates the impacts of entrainment  and impinge-
  ment at water intakes on alewife,  smelt, and yellow perch populations  of Lake
  Michigan.   Impingement and entrainment estimates were based on data  collected by
  utilities  for 316(b) demonstrations  at 16 power plants.  Two conventional fishery
  stock assessment models, the  surplus production model and the dynamic  pool model,
  were applied to assess the impacts.   Fisheries data were applied  to  estimate the
  model parameters.  Movements  related to spawning and seasonal habitat  selection
  cause high variation in  impingement  and entrainment over time and  location.   Impinge-
  ment and entrainment rates were related to geographic location, intake type and
  position,  and volume of water flow.   Although the biomass impinged and numbers
  entrained  are large, the proportions of the standing stocks impinged and the
  proportions of the eggs  and larvae entrained are small.  The reductions  in biomass
  assuming full flow at all intakes  and our estimates of biomass in  1975 are predicted
  by the models to be:  2.86% for alewife, 0.76% for smelt, and 0.28%  for  yellow perch.
                                KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
                                              b.lDENTIFIERS/OPEN ENDED TERMS
                                                 c.  COS AT I Field/Group
  Cooling systems
  Water intakes
  Impingement
  Entrainment
  Lake  Michigan
Fishery models
Stock assessment
Alewife
Rainbow smelt
Yellow perch
  13B
18. DISTRIBUTION STATEMENT

  Release unlimited
                       19. SECURITY CLASS {This Report)
21. NO. OF PAGES
    170
                                              20 SECURITY CLASS (This page)
                                                                        22. PRICE
EPA Form 2220-1 (Rev. 4-77)   PREVIOUS EDITION is OBSOLETE
                                           171

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Agency
Great Lakes National
Program Office
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Official Business
Penalty For Private Use
$300
Postage
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335

w
l^^All
                                                                                           Design: USEPA Region V, Graphic Arts Section 1981

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