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.
-------
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.
Printed in the United States of America
Available from
National Technical Information Service
U. S. Department of Commerce
5285 Port Royal Road
Springfield, VA 22161
NTIS price codes
Printed copy: A09
Microfiche copy: A01
-------
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
-------
The facilities of Argonne National Laboratory are owned by the United States Government. Under the
terms of a contract (W-31-109-Eng-38) among the U. S. Department of Energy, Argonne Universities
Association and The University of Chicago, the University employs the staff and operates the Laboratory in
accordance with policies and programs formulated, approved and reviewed by the Association.
MEMBERS OF ARGONNE UNIVERSITIES ASSOCIATION
The University of Arizona
Carnegie-Mellon University
Case Western Reserve University
The University of Chicago
University of Cincinnati
Illinois Institute of Technology
University of Illinois
Indiana University
The University of Iowa
Iowa State University
The University of Kansas
Kansas State University
Loyola University of Chicago
Marquette University
The University of Michigan
Michigan State University
University of Minnesota
University of Missouri
Northwestern University
University of Notre Dame
The Ohio State University
Ohio University
The Pennsylvania State University
Purdue University
Saint Louis University
Southern Illinois University
The University of Texas at Austin
Washington University
Wayne State University
The University of Wisconsin-Madison
-NOTICE-
This report was prepared as an account of work sponsored by
an agency of the United States Government. Neither the United
States Government or any agency thereof, nor any of their
employees, make any warranty, express or implied, or assume
any legal liability or responsibility for the accuracy, com-
pleteness, or usefulness of any information, apparatus,
product, or process disclosed, or represent that its use would
not infringe privately owned rights. Reference herein to any
specific commercial product, process, or service by trade name,
mark, manufacturer, or otherwise, does not necessarily con-
stitute or imply its endorsement, recommendation, or favoring
by the United States Government or any agency thereof. The
views and opinions of authors expressed herein do not
necessarily state or reflect those of the United States Govern-
ment or any agency thereof.
U,S. Environmental Protection Agency
-------
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
-------
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.
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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.
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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 11I 1I 1 1 1I . 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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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
-------
NUMBER IMPINGED/1000 M3
NUMBER IMPINGED/1000 M3
vo
o
o
33
T)
JO
3D
c:
ci
o
o
o
m
n
_Ulil I I I I I I
LD
C
no
a
p
n
n
o
o
m
CD
3D
"D
IE
X)
c:
CD
en
m
~
m
n
-------
NUMBER IMPINGED/1000 M3
NUMBER IMPINGED/1000 M3
o
o
IV)
o
o
o
rv>
O
to
m
CD
33
-o
33
UD
CO
m
n
O)
CD
cn
LD
C
-5
CD
x.
3D
-------
NUMBER IMPINGED/1000 M3
NUMBER IMPINGED/1000 M3
vo
UD
3D
ID
LD
m
T)
o
o
o
m
o
o
o
CO
LD
C
fD
Ol
Q
m
-------
NUMBER IMPINGED/1000 M3
NUMBER IMPINGED/1000 M3
o
o
XI
3)
~D
33
X
C
LD
m
a
o
o
o
<
a
m
n
-------
NUMBER IMPINGED/1000 M3
NUMBER IMPINGED/1000 M3
3D
~D
3)
en
m
-
o
n
a
m
n
"D
33
t_
c:
3D
c:
en
o
n
o
<:
a
m
n
-------
NUMBER IMPINGED/1000 M3
rn
en
"D
3D
3D
c
en
LD
m
a
n
a
m
NUMBER IMPINGED/1000 M3
o o
-------
o
CO
NUMBER IMPINGED/1000 M3
m
CD
3D
~o
3D
m
"D
a
m
n
NUMBER IMPINGED/1000 M3
-------
NUMBER IMPINGED/1000 M3
NUMBER IMPINGED/1000 M3
o
I
UJ
33
D3
o
n
o
a
rn
n
CD
cn
cn
D
CD
cn
m
-------
NUMBER IMPINGED/1000 M3
NUMBER IMPINGED/1000 M3
o
en
m
CO
3
3D
3D
~0
ID
3D
-------
NUMBER IMPINGED/1000 M3
NUMBER IMPINGED/1000 M3
3D
ID
3D
~0
33
3D
C
cn
oi
m
~
o
n
rn
n
CO
CD
ui
o
ru
LD
C
-i
fD
n
3:
<
\
LO
3D
-------
NUMBER IMPINGED/1000 M3
NUMBER IMPINGED/1000 M3
33
ID
33
"D
33
<
33
C.
CD
CD
n
UD
cn
cr
cn
2
rn
' I ' "I"1I I 11
-------
NUMBER IMPINGED/1000 M3
NUMBER IMPINGED/1000 M3
o
00
m
CD
XI
ID
D
"D
DO
XI
c
Cl
c_n
m
~o
a
n
a
m
n
m
ro
X)
-D
DO
X)
<
Xi
(X
CD
CD
n
a
m
(-1
-------
Figure fl. 9.b LRKESIDE/SMELT
10'
10
o
o
o
D
UJ
CD
10
-1
QZ
LU
CO
10"
10
-3
10
A
-14
0 365
JRN FEB MRR flPR MRT JUN JUL RUG SEP OCT NOV DEC
Figure H.lO.b DHK CREEK/SMELT
0 365
JflN FEB MRR HPR MHT JUN JUL RUG SEP OCT NOV DEC
109
-------
NUMBER IMPINGED/1000 M3
NUMBER IMPINGED/1000 M3
rn
CD
3D
-D
3
L_
c:
3D
~
in
m
~D
o
n
o
o
o
O)
CD
3D
r\j
cr
-------
Figure fl.13.b MITCHELL/SMELT
10 M I I I I I I M I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I II I I I I I I I I I
10'
10
10'
o
o
o
n
LiJ
o
10'
or
UJ
CQ
10
10
-2
-3
10"
f\tt\{\ I
I I I I I I I I I I l_l_ I I I I I I Jl ll I . ,1, ,
0 365
JflN FEB MflR RPR MflY JUN JUL RUG SEP OCT NQV DEC
Figure fl.m.b CRMPBELL/SMELT
o
o
o
a
LU
O
102
10
10°
10
-1
cc
LU
CQ
10
-2
10
10"
-3
fl!
0 365
JflN FEB MRR RPR MflY JUN JUL HUG SEP OCT NOV DEC
111
-------
NUMBER IMPINGED/1000 M3
NUMBER IMPINGED/1000 M3
o
o
ro
33
33
33
T3
3)
33
-------
NUMBER IMPINGED/1000 M3
NUMBER IMPINGED/1000 M3
o
ro
O
ro
t
UD
C
-3
TO
p
r\j
o
p
n
n
o
o
-a
m
ID
n
3D
ID
3D
C
XI
C
CD
LD
m
~D
O
n
o
ro
UD
C
-I
n>
r-u
o
-o
m
3J
-------
NUMBER IMPINGED/1000 M3
NUMBER IMPINGED/1000 M3
o
ru
m
CD
3D
T3
30
33
<
o
o
o
n
a
m
n
CO
CO
en
o
oo
LD
C
m
CD
3D
~D
33
C
CD
LT>
m
"D
o
n
a
m
n
o
o
o
ro
UD
c
-1
LO
n
CD
33
n
IE
-------
NUMBER IMPINGED/1000 M3
NUMBER IMPINGED/1000 M3
o
ro
o
0)
-n
m
CD
33
-
H
CT
o
n
o
a
m
n
ID
c
-j
CD
"D
m
XI
CI
Cl
en
m
"D
o
o
m
n
-------
NUMBER IMPINGED/1000 M3
NUMBER IMPINGED/1000 M3
CTl
O
m
CD
XI
c
CD
in
m
o
n
a
m
CD
LTI
LD
C
CD
X)
CO
n
ti
o
ID
X)
LO
X
\
-<
-o
X)
-o
DO
X)
<
ui
m
"D
o
o
n
rn
n
o
to
o
ru
O
(JO
-J
CD
CD
m
X)
n
n
-------
NUMBER IMPINGED/1000 M3
NUMBER IMPINGED/1000 M3
o
o
o
ru
3)
3D
-0
XI
cz
CD
in
m
-a
o
o
a
m
n
OJ
en
en
LD
C
-J
0)
33
p
n
a
D
o
33
m
m
m
3D
n
<_
ID
m
CD
3
33
3)
X)
~D
33
XI
CD
LT>
m
a
CD
o
a
m
n
o
ru
UD
C
-5
ft)
U3
O
X)
is;
m
en
3)
n
-------
NUMBER IMPINGED/1000 M3
NUMBER IMPINGED/1000 M3
O
O
O
nj
00
3D
"D
ID
3D
<
3D
C
3D
ru
n
<
no
ID
n
m
CD
ID
"D
ID
ID
C
(D
o
n
I I [JJITT] 1 I I I Illlj 1 I I I Illlj
o
o
LO
C
(D
3D
m
en
ID
-------
NUMBER IMPINGED/1000 M3
NUMBER IMPINGED/1000 M3
33
ID
33
TJ
3D
C
CD
cn
m
"D
O
n
a
m
n
J
IL
I I 11 111 1 III
LD
C
fD
33
n
XI
2
"0
CD
m
<
TJ
3D
ID
33
~D
ID
3D
C
CD
a
m
n
UJ
n
33
n
IE
-------
10'
10'
10
10°
Figure R.15.c PRLISRDES/T.PERCH
I I I I I I I I I I I I! I I I I I I I I I I I I I I I ! I
o
o
o
LU
CJ
£10
-1
en
UJ
OQ
10
_p
10
-4:
LJl
365
JflN FEB MRR RPR MRY JUN JUL RUG SEP OCT NOV DEC
Figure R.lG.c BIG ROCK/T.PERCH
o
o
o
10'
10'
10'
CL.
10'
10'
10"
10'
0 365
JRN FEB MRR RPR MRY JUN JUL RUG SEP OCT NOV DEC
120
-------
NUMBER ENTRRINED/M3
NUMBER ENTRRINED/M?
ro
X)
~0
30
(Jl
rn
"D
o
n
a
m
n
o
o
o
U)
LD
C
-j
CD
rv>
Q.
a
o
n
a
a
CD
cr>
en
m
CD
XI
XI
"D
a
n
a
m
n
o
o
LO
C
-5
CD
m
CD
cn
-------
NUMBER ENTRfllNEO/M3
NUMBER ENTRRINED/M3
c_
XI
T)
30
3D
CZ
CD
in
m
~
a
m
n
CO
CD
cn
o
o
ID
C
-*J
CD
ID
Ul
D.
rn
cn
CD
3
ID
X)
CZ
CD
Ul
m
~D
a
o
a
rn
n
o
o
LD
C
CD
XI
CO
CL
CD
CD
-------
NUMBER ENTRfllNED/M3
NUMBER ENTRRINED/M3
ro
CO
XI
z
m
CD
3D
33
3D
"D
3D
<
XI
CD
cn
m
z
a
a
rn
o
CD
XI
Q.
-a
CD
m
n
m
CD
CD
cn
m
CD
3D
-o
33
3
3D
<
XI
cz
Cl
Kl
"a
CD
n
a
m
n
CD
C
n>
3D
CD
a_
m
2:
3D
Z
m
m
x
3D
r~
m
m
CD
CD
cn
-------
NUMBER ENTRfllNED/M3
NUMBER ENTRHINED/M3
C
o
J_
X)
z
Tl
m
CD
D3
3D
33
JO
33
(_
cz
lz-
(_
CZ
XI
CD
CO
m
o
i
-z.
o
o
m
n
CO
CO
- i C
3 o i !-* >- i-' t
I I 0 0 0 0 0 0
"
: :
-
-
-
r - *, ^^^ ;
;_-^ ~*~^>" ~-
r~*^23* -
'~~^*~~*^ :
; :
:
;
-
_
:
:
c_
XI
z
-r\
m
CD
2
D
30
^ ^
c -°
n
P 33
co
C
~7"
1
XI
m ,
en ^
a *~
m
\
? Xi
5 CT
-T]
m !3]
CD U
CD
LO
O
O
1
CD
m
n
CO
01
en
"! ° o o o o o
pj ^ o -- ru (jo .c
: '"' ' ' ' ' ' :
- -
_
: -
; 2
'-
' '-
.
'- '-
-
^^^S^. '-
^~3jj^. '-
r= :
.
.
: :
-
-
_
: , i iiiml t t IIMH| _ n] , , , | ,| ,:
LD
C
~i
n
33
CO
a.
-Q
0
3D
1
s:
X)
CO
X)
rn
2:
-n
m
rn
CD
CD
en
en
-------
Figure R.10.d ORK CREEK/flLEWIFE EGGS
1Q4M ! I I , , ! I I , , , M , , MM MM ., , I I
10d
10'
10
10'
CE
cc
cc
UJ
03
10
-1
10
-2
0 365
JRN FEB MflR RPR MRT JUN JUL RUG SEP OCT NOV DEC
Figure fl.ll.d WRUKEGRN/RLEWIFE EGGS
10 M i i i i i i i i i rn i i i i i i i i i i i i i i M i i i i i i i i i i i ) i i i i i i i i i i i i i i i i i M
rn 1 r\
-------
10'
Figure fl.12.d STHTELINE/RLEWIFE EGGS
I I I II I I I I I I I I I I I I I I I I I I I I I I I I M I I I I I I I I I I I I I
d
CC
\
LU
CC
LU
CO
10'
101
10°
10-
1Q'?I ' ' , i i 'Ill I '
0 365
JflN FEB MRR RPR MRT JUN JUL RUG SEP OCT NOV DEC
10'
103
10'
101
10'
Figure R.13.d MITCHELL/RLEWIFE EGGS
I M I I I I I I I I I I I I I I I I I I M I I I I I I I II I M I I I I I I I I I I M I I I I I I I M
CC
DC
DC
LU
CD
10
-1
10
-2
0 365
JRN FEB MHR RPR MRY JUN JUL HUG SEP OCT NOV DEC
126
-------
NUMBER ENTRfilNED/M3
NUMBER ENTRRINED/M3
ro
c
o
3D
Z
m
DO
2
3D
ID
3D
3D
3D
(_
Z
[
r
3D
CD
Ul
-D
O
n
i
0
a
rn
n
CO
CD
en
D O > 1 !- 1 H
~ - ° ° ^ ^ '
: :
: :
-
;
"
-
"
^
_
.
: :
:
; :
:
-
_
1 1 1 1 Mill 1 1 1 1 Mill III' Mill 1 1 1 1 lll.l 1 1 1 I Mill | | , | |||T
- c
D
<= o
c_
3D
~n
m
CO
2
3D
3)
~n
LD 3D
c -a
-J 33
re
3D
2
> 3D
cn <
D.
(_
~U (
3D -Z.
1-
co
3D (_
CD d
m r~
3D
r~ 3D
rn a.
2: c~i
rn
rn m
Cl ~D
o
o
1
z
a
a
rn
n
CO
CD
cn
3 O >- > ^- f i
i i O O O O O
PO >-' O i-* f\) 01 ,r-
; i I i i iiiij 1 i i i iiiij 1 i i i mi 1 i i i mi| 1 i i i ini| 1 i iimn
; :
; :
; :
; :
'
_
;
-
~
- :
~_
. _
_
;
; :
; :
_
; :
; :
; :
; :
- 1 '
-n
LD
C
}
a>
3D
^
.
d
n
3D
-D
CD
rn
r~
3D
rn
2:
m
m
CD
-------
NUMBER ENTRRINED/M3
o o i-^ > -' >
i i O O O O
\J> o " r\j a)
II I I Mill 1I I I Mill 1I I I INI 1I I I Mill 1I I I Mill 1TT
m
CD
J3
33
33
-o
33
ro
oo
cn
m
"0
o
o
a
m
n
ID
cn
Q.
CD
Cl
33
O
n
PC
\
3D
r~
m
0
CD
<_n
I I [ I III 1
-------
NUMBER ENTRRINED/M3
NUMBER ENTRfllNED/M3
ro
10
m
"0
o
n
o
i
ru
O
o
D
F1
LD
-i
re
r\j
CD
a
n
o
o
a
DD
<
D
cr
cn
en
m
~a
o
n
a
m
n
O
o
O
t\)
o
a)
LD
Ml
O
33
33
XI
-------
NUMBER ENTRRINED/M3
NUMBER ENTRRINED/M3
GO
o
C
~o
(_
DD
m
m
CD
3
U
ID
DD
T3
^
XI
<
(_
cr
z
c_
C3
r~
DD
Cl
c_n
m
0
n
i
~z.
o
<
a
rn
CO
CD
cn
3 O O » i-" >-
I i I 0 O O O
LO ru i o i-> ru co
: ' ' "' ' '' ' ' """' ' ' """l ' ' ""':
-
.
-_ '-
'-
-
_
; :
- ~-
- ~-
- -
-
1 1 1 1 1 1 1 M 1 t 1 1 M 1 I 1 1 1 1 1 M III 1 1 t 1 1 1 1 ll 1 1 I ! ! 1 1 l! 1 ! 1 1 1 M I
n
f
-i
D
cn
a>
-o
r~
r~
DD
s
\
X)
m
2:
~n
m
i
ID
m
XI
ID
DD
cr
cn
a
m
n
o
o
o
ru
o
LO
LD
C
-1
n>
D
uo
(D
00
Xi
DD
ID
-------
NUMBER ENTRRINED/M3
NUMBER ENTRRINED/M3
3D
33
3D
~0
ID
ID
CD
O
n
CD
m
n
T-T
o
o
I I I I I
LD
-J
ro
re
-a
D3
m
n
1C
3D
ID
3)
3D
-Q
ID
3D
<
3D
C
CD
LA
m
-a
a
o
O
o
O
ru
O
en
re
ix
m
^
rn
rn
m
s:
D
3D
-------
CO
no
Tl
m
GO
3D
~D
JO
XI
CD
o
o
|
a
rn
n
co
en
en
NUMBER ENTRRINED/M3
NUMBER ENTRRINED/M3
o
o
o
ro
o
OJ
LD
CD
CD
m
en
ID
<
ID
o
O)
m
CD
ID
3)
ID
C2
Cl
Ln
m
~
a
n
o
rn
n
a)
CO
en
o
o
o
IX)
O
a)
LD
c
-i
ro
03
O)
O
33
CO
X
\
ID
XI
m
-------
NUMBER ENTRRINED/M3
NUMBER ENTRfllNED/M3
CO
CO
o
>
-------
NUMBER ENTRfllNED/M3
NUMBER ENTRRINED/M3
co
GO
XI
3)
3D
~a
DO
3D
c
en
c_n
m
~
o
o
o
a
m
n
CO
en
en
o
ro
UD
c
-J
CD
LO
re
33
<
3D
3D
cr
CD
o
o
ao
en
en
O
O
o
0)
LD
-^
CD
3D
no
CD
in
i
XI
m
\
3D
r~
m
«C
3D
-------
NUMBER ENTRRINED/M3
NUMBER ENTRRINED/M3
CO
en
c
o
c_
X)
rn
CD
3D
3)
XI
3)
<
c
2
l_
r~
3D
CD
CO
m
o
o
1
a
a
m
n
00
en
on
3 O O '-' *-* '-' f-
i I i 0 0 0 0
CO IV) ^ O i-» !\J CO
-
'
; :
; :
-
-
-
-
-
-
.
-
; :
; \
' ,, _ , iMiiil iiml , :
-n
UD
C
CD
XI
on
ro
X)
00
u
a
rn
oo
XI
1
m
z:
~n
m
r~
X)
33
3D
m
c
o
(_
3D
m
CO
3D
3D
-o
JO
_<
cr
0-
i
r -
3D
cr
Cl
en
m
a
n
i
o
CD
m
o
oo
en
on
3 O O >-- i i i--
do A> ± °0 °. ^ 9,
1 1 MIMI 1 1 1 1 I'll j | II I 1 Illj 1 Illl Mil 1 1 1 1 Mill 1 1 1 1 1 III
t ~
; :
-
- I
-
: :
; :
; :
: :
: , , , , ! | | ri|ii:
U3
C
3D
u±
n>
o
X)
CD
m
i
30
m
m
3D
m
-------
NUMBER ENTRfllNED/M3
co
CTl
c
o
3D
m -
CD
3
3D
3D
3D
"D
3D
<
b
~z_
c:
3D
t^
CD
cn
rn
~o
a
n
i
0
a
n
CO
cn
cn
D o o >- !- >- -
i i l O O O C
at nj i- o ru
. ' ' ' 1 ] ' ' ' ' ""1 1 | ' ' 1 1 "I
'
;
-
-
:
"
; :
_
-
; :
: :
-
-
i , , , :
D
OD
C
-i
re
3D
cn
re
CD
CD
o
n
\
3D
1
m
-n
rn
r~
3D
3D
rn
-------
NUMBER ENTRRINED/M3
NUMBER ENTRRINED/M3
o
-, 01
o
U)
o
I
ru
o
o
m
CD
u
31
X>
-o
3)
CO
<_
cr
ci
a
r>
a
m
n
oo
CD
en
UD
-j
(D
p
n
n
o
o
m
CD
X)
"D
3)
X)
<
cr
en
m
TJ
o
n
a
m
n
o
o
LD
C
CD
D
a
z
\
rn
en
(D
-------
10
10'
Figure fl. 3.f BRILLT/SMELT EGGS
10
-l
a
LU
cc
cc
10"
cc
LU
CO
10"
0 365
JRN FEB MflR flPR MRT JUN JUL RUG SEP OCT NOV DEC
Figure H. 5.f PULLIRM/SMELT EGGS
10-
a
LU
cr
cc
10"
QC
LU
QQ
10
-3
10"
10
-5
A
0 365
JRN FEB MflR RPR MRY JUN JUL RUG SEP OCT NOV DEC
138
-------
NUMBER ENTRflINED/M3
NUMBER ENTRflINED/M3
o
o
CO
vo
c_
X)
m
CO
3D
"D
D3
XI
CD
LO
rn
-a
C3
n
a
U)
CT
cn
1
CD
CD
m
3D
n
\
en
CT
cn
m
CD
3D
~0
s
CD
n
C3
m
n
ID
-S
ro
cn
-h
3D
CI
m
rn
cn
3
m
rn
ci
en
LO
-------
NUMBER ENTRRINED/M3
NUMBER ENTRRINED/M3
-PS.
O
o
~n
rn
CD
2
D
3D
~D
31
ID
CD
CO
rn
TJ
o
n
0
a
m
n
cu
en
Ul
m
01
m
L. J
CO
m
CD
ID
3]
o
a
m
n
0
O
o
ID
n>
XI
o
3D
3D
CO
CO
m
m
CD
CD
CO
-------
NUMBER ENTRRINED/M3
NUMBER ENTRRINED/M3
o
o
i
Ul
"0
3D
3D
cn
co
m
"D
o
o
o
<
o
go
o
ro
o
o
CO
05
cn
ID
c
XI
cz
;*
m
cn
3D
z
X
cn
CD
CD
CO
c
0
(_
~n
m
CO
3
33
33
3D
3
<
C_
d
z
c_
c:
i
3D
CD
3
o
n
i
z
<
o
n
CO
CD
cn
3 o o o o >± ±;
1 i I i i O C
ji c u> ru ^ o ^
1 ' ' 1 ' ' ' "'"1 ' ' ' ' ""1 ' ' ' ' ""i ' ' " ""1 ' ' <""L
-
-
*^^»«
- :
' -
'- '-
'-
: :
.
:
-
:
: i( L| t , ,,
m
UD'
o>
33
i i
O
-b
0
n
3D
i 1 1
m
;s;
X
CO
^
rn
r~
i
5
CD
CO
-------
NUMBER ENTRHINED/M3
NUMBER ENTRHINED/M3
ro
m
D3
3D
33
3D
"D
3D
<
3D
c:
CD
CO
m
TJ
O
n
CD
m
n
oo
CD
01
o
o
OD
-i
CD
CD
ID
CO
3D
C
CD
a
n
to
en
en
o
a)
ID
C
CD
HD
cn
3D
CD
CD
c_n
-------
NUMBER ENTRRINED/M3
NUMBER ENTRRINED/M3
o
CO
^Jl l_^ <^f l_J I^_J
I I I I i O O
Q ui cC u) ru i-- o i
3D
2
"n
m
CO
3D
33
3D
~D
on
3
3D
(_
Z
L_
cz
33
CD
C/1
m
a
o
o
a
m
n
CO
CD
cn
: ' ' '"' ' ' :
; :
; - :
;
.
:
-
;
-
-
:
.
: :
:
"
-
: :
_
-
-
: , ! ! , , :
;n
LD
C
n>
3D
en
~*
3D
cn
a
CO
cn
m
i
rn
o
CT
CO
, , I I , 0 0
<-" j= LD ru i o
3D
-z.
TI
m
CO
3D
3J
3D
ID
3D
<
(_
2
C
|
3D
Cl
CO
rn
~0
o
n
i
z.
o
» ~~-
: -
' '-
-
.
.
-
*
-
-
:
:
; :
; :
; i
*
-
: , , , , , :
-n
^
ra
3D
IP
-h
n
3D
ID
00
m
r~
i
CO
m
I
rn
Cl
CO
-------
10
Figure fl.lB.f BIG ROCK/SMELT EGGS
10
-1
DC
LJJ
CD
1 ID"3
10
10
-14
0 365
JRN FEB MflR HPR MRY JUN JUL RUG SEP OCT NOV DEC
144
-------
Figure R. t.g ZION/SMELT LflRVflE
10 UI I I I I I I I I I I I I II I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I M I I I I I I
10
I io-i
UJ
DC
LU
CQ
10'
10
-3
10
-14
0 365
JflN FEB MRR RPR MHY JUN JUL HUG SEP OCT MOV DEC
Figure H. 2.g D.C.COOK/SMELT LRRVflE
10
10'
CC
cc
10
-1
cc
UJ
10
10-
-3
0 365
JflN FEB MRR HPR MflY JUN JUL RUG SEP OCT NOV DEC
145
-------
NUMBER ENTRfllNED/M3
NUMBER ENTRRINED/M3
_
XI
2
m
CD
D
3)
3D
TO
3D
3D
<
XI
CD
cn
m
o
n
O
cL
CO
CD
en
I I I I Illll I III
LD
C
-1
o>
m
CD
3D
DO
Xi
;
3D
-------
o
NUMBER ENTRRINED/M3
o o
NUMBER ENTRfllNED/M3
O
o
o
ru
3D
3D
-o
33
D
;
3D
C
CD
m
~D
o
n
a
m
n
U)
en
ui
ro
3D
UD
3D
n
LT>
3D
3D
T|
m
aa
3D
~D
33
3D
3D
Cl
_
m
TD
D
n
a
m
n
CO -
CD r
en
o
o
o
[\J
LD
C
-j
tu
CT)
LD
m
s:
3D
CO
3
3D
33
3D
rn
-------
00
t_
XI
CD
X>
DO
X>
13
DO
U
Cl
Ln
m
~o
o
n
2
O
m
n
NUMBER ENTRRINED/M3
NUMBER ENTRRINED/M3
O
03
O
O
O
ru
LO
CD
CD
X)
CD
LD
(-0
a
XI
<
Xi
O
XI
"D
ID
cn
m
"D
o
no
o
o
o
ro
LD
C
CD
p
f°
LO
"D
O
XI
LO
n:
-------
10'
10
10'
Figure fl.10.g OflK CREEK/SMELT LRRVRE
d
CC
10
-1
cc
LU
CO
10
ID'
-3
0 365
JflN FEB MflR RPR MHY JUN JUL HUG SEP OCT NOV DEC
Figure R.ll.g WflUKEGRN/SMELT LRRVRE
10 ui i i i i i i i i i i i i i M i i i i i i i
10'
10'
10
-1
cc
LU
CD
10-
10'
365
JRN FEB MRR RPR MRY JUN JUL HUG SEP OCT NOV DEC
149
-------
NUMBER ENTRfllNED/M3
NUMBER ENTRflINED/M3
en
o
rn
CD
XI
ID
ID
D
ID
3D
cr,
01
m
13
o
n
a
m
o
00
en
o
i
CO
o
o
I 1 1 I I 11
o
IV)
o
LD
-J
CD
do
LO
ID
DO
DD
m
"n
m
DO
33
ID
ID
-o
UJ
3D
i.
3D
CZ
Cl
_
m
13
D
o
a
m
o
o
ru
O
o
O
IV)
LD
ra
3D
Xl
3D
-------
NUMBER ENTRRINED/M3
NUMBER ENTRRINED/M3
tn
c
0
3D
z.
~n
rn
03
3
33
3D
-o
ID
2
3D
<
(_
,_
cr
i
33
cr
o
en
m
~°
o
o
1
z
o
a
n
CO
CO
3 O O O >- >
I I i i O O O
c o) r\j i- o *-» ru
1 1 1 1 M llj 1 1 1 I 1 1 Ml 1 1 1 1 1 1 1 II 1 1 1 1 1 1 1 II 1 1 1 1 1 ] III 1 1 1 I 1 1 1 1
-
; :
; \
-
; , :
; :
.
;
-
: :
-
1
.
.
.
.
.
:
; :
-
-
1 1 1 1 1 1 1 ll 1 I 1 1 1 T 1 ll 1 1 1 1 1 I III 1 1 1 1 M 1 ll 1 1 1 1 1 1 III 1 1 1 1 t 1 II
LD
c
-i
n
3D
, ,
en
LD
3D
r~
CO
a
m
CO
en
m
r~
i
i
33
ro
ro
rn
en
c
o
3D
~n
m
CO
3D
33
3D
"0
ro
2
3D
-<
(
^
CT
I
33
C
tn
rn
"D
o
n
z
o
a
n
CO
en
3 O O O ' i i-^
i i i i O O O
j= LO ro > o - nj
. ' ' ' '""i ' ' " ""1 ' ' ' "'"1 1 "1 ' ' ' ""i
.
: !
; :
:
-
;
; ;
.
-
: :
-
: ;
'
"
-
.
-
.
.
:
-
-
.
, 1 , I I Mini , i , ,,,,,1 , , , mill , i , innl ,7
-n
LD
-I
CD
33
|r;
LD
n
ro
CD
m
i
\
en
<
i ' i
i
-H
r~
ro
ro
3D
m
en
-------
10'
Figure fl.lG.g BIG ROCK/SMELT LflRVflE
10
-1
LU
CC
LU
CD
10
10'
10'
-2
0 365
JflN FEB MflR RPR MflY JUN JUL RUG SEP OCT NOV DEC
152
-------
NUMBER ENTRflINED/M3
NUMBER ENTRRINED/M3
cn
co
o
(_
3D
Z
m
m
CO
=
ID
3D
"0
31
3D
C
^
C_
^
3D
CD
CO
m
0
o
(
Z
o
a
n
-co
I I I i O O O
it GJ ru i-» o H-- nj
: ' ' ' ' ' ' :
.
; :
; :
-
; :
-
.
-
-
'
'. '_
'
; :
_
; :
:
-
1 1 1 1 1 1 M 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I 1 1 1 1 1 I 1 1 1 1 1 1 1 1 II 1 1 1 1 1 1 1 1
LD
j
CD
3D
CO
"^
CD
3D
^H
<
\
<
rn
n
:r
rn
CD
CD
CO
cn
0
^
^^
~n
m
CO
D
3D
~o
-^
3D
C
(
i
p
3D
CD
cn
m
o
o
i
a
-------
NUMBER ENTRRINED/M3
NUMBER ENTRflINED/M3
o
CO
o
o
o
o
IV)
CO
33
33
33
-o
33
3D
<
01
-pi
3D
CD
cn
m
~
o
n
U)
CD
cn
UD
C
CO
:r
CD
DO
3D
Lfl
m
33
n
CD
CD
cn
m
CD
3D
33
3D
~D
33
3D
CD
cn
m
~o
a
n
o
<
a
m
CO
cn
cn
o
CO
o
1
ru
o
o
o
o
ru
10
c
CD
3D
TJ
m
3
n
CD
CD
CO
-------
NUMBER ENTRRINED/M3
NUMBER ENTRRINED/M3
C
o
z
~n
rn
CO
3
X)
~D
3D
3D
£ fe
cn z
c_
c=
3D
cz
o
cn
m
0
n
i
z
o
n
m
o
CO
CO
en
D O O O " '-' "-
i i i i O O C
4= CO I\J >-* O t-1
. ' ' ' '""1 '"1 ' ' ' '""1 ' ' ' '""1 ' ' ' '""1 ' ' ' ""1
-
:
; :
:
; :
; :
:
-
~
:
; :
, | , , , ,,,! , , , MHll , , , M.ul 1 , , , ,,,,7
- c
3
ru 0
X)
"n
rn
CD
2
X)
3)
$ 3D
CD
' . X)
ui -<
c_
XI z
r~
cn ,
33 t=
C3 £
m r-
cn
n
'~.r
m m
cn
0
n
i
z
o
0
m
n
CO
CD
cn
n o o o ' i i
i i i i O O O
c ui nj H-. o i ru
:
; ;
; :
; :
'
-
:
-n
CO
c
CD
XI
J=
n
XI
CO
m
(
r~
(
m
3D
n
rn
CD
cn
LT>
-------
NUMBER ENTRHINED/M3
o
o
o
o
ru
CO
3D
3D
~D
ID
UD
C
-I
re
cn
00
CD
O
n
O
-------
NUMBER ENTRHINED/M3
NUMBER ENTRRINED/M3
c
o
t_
DD
Z
m
CD
3
D
33
3
X)
C_
d
XI
cr
en
en
m
CD
n
i
Z
o
a
n
CO
CD
en
D O O O O O K
il i ii i C
CO Ul .C: CO r\J ^
:
'-
-
~-
_ -
:
_
-
; -
; :
-
-
1 L_l_l±UlI. 1 1 1 1 1 Illl 1 1 1 1 1 Illl 1 1 1 1 Illll 1 1 1 1 Mill 1 1 7
C
3
^ 0
Z
m
O3
2
Xi
^ 3
CD
X
r~
5 N
5 ^
i
5 en
^ m
m
a
n
i
a
a
o
CO
CO
en
3 O O O O O >-
CO 01 j= tl) r\i .1.
i i i 1 1 1 1 1 i i i 1 1 1 1 1 1 r "ri i MIM 1 i i i mi 1 i i i iii| 1 i i 1 1111
1 -
-
1
_
; :
-
.
; :
-
1
-
D
m
c
-J
n>
X)
IV)
n
o
CD
CD
;*;
<
"D
m
0
XI
33
33
-------
en
00
-n
m
en
3D
3)
3>
-0
3)
3D
<
XI
c
CD
O
n
NUMBER ENTRfllNED/M3
-O
O)
0
ro
a
m
n
CO
CO
on
-o
S
m
33
n
Q
o
n
cu
m
o
NUMBER ENTRfllNED/M3
0
i
01
0
0
0
O
o
O)
on
"D
en
T3
m
3)
n
IE
3D
33
3D
-------
NUMBER ENTRHINED/M3
_
ID
m
CD
ID
-o
ID
u
(71
m
-D
R
D
m
n
O
ui
LD
c
ro
ID
LO
D
m
DO
-a
33
0
n
O
I
on
NUMBER ENTRRINED/M3
o
rvj
LD
-1
a>
n
ID
CD
m
"D
m
ID
o
IT
ID
ID
-------
NUMBER ENTRRINED/M3
o
i
o
o
o
rn
CD
3D
3
ID
3D
O)
CD
CD
O
n
"D
rn
3D
n
:r
3D
<
3D
O
O
CO
CD
CJ1
-------
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
ii
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
-------
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
-------
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
-------
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
-------
United States
Environmental Protection
Agency
Great Lakes National
Program Office
536 South Clark Street
Chicago, Illinois 60605
Official Business
Penalty For Private Use
$300
Postage
Paid
Environmental
Protection
Agency
335
w
l^^All
Design: USEPA Region V, Graphic Arts Section 1981
------- |