United States
Environmental Protection
Agency
Environmental Research
Laboratory
Duluth MN 55804
Research and Development
EPA-600/S3-84-017 Mar. 1984
&EPA Project Summary
Distribution, Abundance and
Entrainment of Larval Fishes in
the Western and Central Basins
of Lake Erie
C. Lawrence Cooper, John J. Mizera, and Charles E. Herdendorf
As part of a multi-agency effort to
assess the impact of entrainment of lar-
val fishes at steam-generating electrical
power plants, personnel from The Ohio
State University collected samples of
larval fishes from waters of the Western
and Central Basins of Lake Erie.
Samples were collected in the Western
Basin in 1975, 1976 and 1977. Samples
were collected along the southshore of
the Central Basin in 1978.
A total of 19 taxa of larval fish were
collected with metered plankton nets in
Ohio and adjacent Ontario waters of the
Western Basin of Lake Erie in 1975 and
1976. Analysis of yellow perch collec-
tions indicates that shallow inshore
areas serve as important nursery areas
for this species. Collection of larvae pro-
vides evidence of relict breeding popula-
tions of lake whitefish and sculpin in the
Western Basin. Sufficient data were
gathered from 1975 and 1976 collections
to permit calculation of an estimate of
the impact of entrainment on adult
yellow perch and emerald shiner popula-
tions using the equivalent adult
approach.
A total of 17 taxa were collected in the
Maumee River estuary during sampling
periods in 1975,1976 and 1977. A total of
11 taxa were collected from the San-
dusky River estuary in 1976. Gizzard
shad/alewife. white bass/white perch
and freshwater drum constituted 98 per-
cent of the larvae collected in the
Maumee River estuary proper and 91
percent of the larvae collected in the
Sandusky River estuary.
Gizzard shad/alewife, emerald
shiners, white bass/white perch, and
yellow perch, constituted over 97 per-
cent of the larval fish collected in Ohio
and Michigan waters of the Western
Basin of Lake Erie in 1977. Significantly
greater numbers of gizzard shad/alewife
and spottail shiner larvae were captured
immediately adjacent to the shore than
at a depth of five meters offshore while
greater numbers of smelt larvae were
captured at points further offshore at a
depth of five meters than at points im-
mediately adjacent to the shore.
Significantly greater numbers of walleye
larvae were collected along the Ohio
shoreline portion of the study area than
in Maumee Bay or along the Michigan
shoreline. Significantly greater numbers
of freshwater drum larvae were col-
lected in Maumee Bay.
A total of 25 taxa of larval fish were
collected in Ohio waters of the Central
Basin portion of Lake Erie in 1978. Giz-
zard shad/alewives, emerald shiners
and spottail shiners constituted 82.4 per-
cent of the larval fish collected. Larval
gizzard shad, carp/goldfish, spottail
shiners, troutperch and yellow perch
densities were significantly higher in
shallow (1-2 m deep) nearshore areas
than offshore in areas five and ten
meters deep. Significant differences
were found between entrainment
estimates derived from field samples
and in-plant samples from the Central
Basin for gizzard shad, rainbow smelt,
carp and freshwater drum. All estimates
of entrainment from field collections
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were higher than those for in-plant
collections.
This Project Summary was developed
by EPA's Environmental Research
Laboratory, Duluth, MN, to announce
key findings of the research project that
is fully documented in a separate report
of the same title (see Project Report
ordering information at back).
Introduction
The Great Lakes provide a freshwater
supply for 70 to 75 percent of the basin's 29
million residents, attractive recreational
boating and sport fishing areas, and water
for industrial processes and electrical genera-
tion. These conflicting uses have diminished
the prospect of the lakes as an inexhaust-
ible resource. The purpose of this report is
to summarize a series of studies conducted
to assess the abundance, distribution and
entrainment of larval fishes in the Ohio and
Michigan waters of Lake Erie. The imapct of
electrical generating facilities on larval fish
populations is potentially large. Electrical
generation is the largest user of Great Lakes
water. The 89 electrical generating stations
in the coastal areas of the Great Lakes are
responsible for over 70 percent of the total
water use in the Great Lakes Basin. With the
United States relying more heavily on
domestic energy supplies, the role of the
Great Lakes will become even more impor-
tant in energy production; an additional 17
power plants are planned for the basin by the
mid-1980's.
Steam generating plants have three major
types of adverse effects upon the aquatic en-
vironment when they use large amounts of
cooling water: 1. the intake of cooling water
by the facility can cause the entrapment and
impingement of fishes upon the plants' in-
take structures; 2. entrainment can have a
damaging effect upon smaller aquatic
organisms such as plankton, fish eggs, fish
larvae, and shellfish larvae; and 3. the
discharge of heated cooling water into the
aquatic environment can disrupt the func-
tion of complex and highly productive natural
systems. The effect of entrainment on lar-
val fish numbers is the focal point of this
study.
It has been shown that the nearshore zone
of Lake Erie is a valuable fish spawning and
nursery area. The movement of larval fishes
is often controlled more by water movement
than by swimming ability. Thus, larval fishes
and bouyant fish eggs, occurring in high
density in nearshore areas, are highly suscep-
tible to the hazards posed by high-volume
cooling water intakes.
A number of larval fish investigations have
been conducted in Lake Erie. Unfortunately,
these studies tend to report efforts concen-
trated in limited areas and have a very limited
circulation. The most complete study of lar-
val fishes in Lake Erie is the overall program,
of which the present study is a part, de-
signed to assess the impact of cooling water
intakes in Michigan and Ohio. It included
sampling in Ohio, Michigan and Canadian
waters of Lake Erie.
Environmental studies in the vicinity of
Detroit Edison's Monroe, Michigan site
began in 1970. Larval fish studies began in
1973. Larval fish distribution studies were ini-
tiated in 1975. This study makes independent
entrainment estimates for selected power
plants in the Western and Central Basins. In
addition, the distribution and abundance of
selected larval fish species are described for
the study period extending from May, 1975
to August, 1978. An open lake portion of
Lake Erie (1740 km2) was subdivided into six
depth zones. A two-meter contour interval
was used to delineate each depth zone.
Sampling stations were established in a
stratified random pattern with 56 stations
sampled in 1975 and 60 in 1976. Nine cruises
were made between May 12 and September
3 during 1975, and fourteen between April
12 and September 3 in 1976. All collections
were made during daylight hours.
In 1977, numerous transects perpendicular
to the shoreline were made in the nearshore
portions of the Western Basin of Lake Erie,
and samples were taken during the midsum-
mer months. This was done in the Central
Basin in 1978.
Field collections were preserved in buf-
fered 5 percent formaldehyde solution. Lar-
vae from each sample were identified to the
lowest taxon possible, counted, measured
for total length, and transferred to a 70 per-
cent ethanol solution. Data were analysed
with either an IBM 360 or an Amdahl 470
computer. Volume weighted estimates of the
total number of larvae in each depth zone
were calculated.
Open lake samples were used to estimate
the number of larvae entrained at each
power plant along the shoreline. These were
calculated by multiplying the density of lar-
vae at the collecting station closest to the
power plant intake by the average flow rate
for that power plant per day. At power plants
along the shoreline, in-plant ichthyoplankton
samples were collected weekly and used to
estimate the impact of power generation on
fish populations in the lake.
Conclusions
1. Sampling procedures employed were
selective for species inhabiting limnetic
areas and may not adequately represent
species which inhabit littoral regions.
2. Abundance estimates were made. The
resultant standard deviations and stan-
dard errors of the mean were large but
decreased when mean densities ex-
ceeded 100 fish/100 m3.
3. The capture of whitefish larvae on reefs
and along the Michigan and Ohio
shorelines indicated that a remnant
spawning population of whitefish was
inhabiting the Western Basin.
4. The capture of sculpin larvae on reefs
in the island area indicated that a rem-
nant spawning population of sculpins
was inhabiting the Western Basin.
5. The Maumee River estuary contained
higher densities and greater estimated
numbers of larvae than the Sandusky
River estuary. Production estimates of
gizzard shad and freshwater drum in the
two estuaries often approached or
matched the production estimates of
these species in the Western Basin
study areas.
6. Both the Maumee and Sandusky River
estuaries are important spawning and
nursery sites for gizzard shad, white
bass, walleye and freshwater drum.
7. Higher densities of gizzard shad, white
bass and freshwater drum were cap-
tured in Maumee Bay and in Sandusky
Bay than along either the Ohio or
Michigan shorelines. This would in-
dicate that these areas provide valuable
nurseries for these species. The high
densities of larvae in these areas may
result from spawning in the bay as well
as from larvae carried into the bay areas
by river currents.
8. Rainbow smelt and yellow perch larvae
were almost entirely restricted to the
lake proper.
9. In the Western Basin in 1975 and 1976,
larval yellow perch were found
predominantly in nearshore areas
associated with sandy and/or gravel
substrate. Perch larvae were concen-
trated near the bottom. Walleye larvae
were collected in the same areas as
perch larvae in the nearshore zone as
well as offshore on the reefs.
10. Higher densities of rainbow smelt and
emerald shiner were collected at sta-
tions in deeper open water than at sta-
tions located adjacent to the shoreline.
11. In the Western Basin in 1977, larval
yellow perch densities were highest in
the area along the Michigan shoreline
north of Woodtick Peninsula and south
of the River Raisin. The larvae found
here may have been carried into and re-
tained in this area by the eddying effects
of the Maumee and Detroit Rivers, as
suggested by the fact that spawning
habitat in the area is not ideal for yellow
perch.
12. In the Western Basin, yellow perch anc
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walleye larvae densities were generally
highest along the Ohio shoreline, par-
ticularly in the Locus Point area. The
sandy, gravel bottom and offshore
islands and shoals provide the best
spawning habitat for these species re-
maining in Lake Erie.
13. Higher densities of pro-larval smelt cap-
tured along Cedar Point in the Central
Basin indicated that the area probably
is being used as a spawning site for rain-
bow smelt. If so, this would be the first
record of smelt spawning that far west
along the United States shoreline.
14. The capture of larval freshwater drum
was limited to the western half of the
Central Basin study area. Freshwater
drum prefer water less than 12 meters
deep. East of Cleveland, water less than
12 meters deep is limited to a very nar-
row band along the shoreline, limiting
spawning habitat.
15. In 1978, highest densities of larval
yellow perch sampled were found in the
eastern third of the Central Basin study
area. Perch in the area are believed to
be using the harbor breakwalls and sand
collected in the quiet areas of these
structures as spawning habitat.
16. Because fish densities were highest in
the Maumee estuary and Bay, and since
Toledo Edison's Bayshore Plant is
located at the month of the Maumee
River, entrainment is likely to be higher
at the Bayshore Plant than at any other
power plant studied.
17. Significant differences were found be-
tween entrainment estimates derived
from field collections and in-plant col-
lections at Central Basin power plants.
18. In-plant estimates of entrainment, when
samples are collected with submersible
pumps, are believed to give a better
estimate of entrainment than field col-
lections made with metered nets
Avoidance of the gear is not as much
a problem for pump samples as it is for
nets.
19. Based on in-plant collections, entrain-
ment estimates were highest at the
Avon Lake power station. A total of
231,543,500 larvae or 60.1 % of total en-
trainment in the study area of the Cen-
tral Basin occurred there. Cyprinids ac-
counted for 53% of the Avon Lake en-
trainment total.
20. Yellow perch entrainment was
calculated to be highest at the Avon
Lake and Ashtabula A and B plants. An
estimated 1,340,500 yellow perch larvae
were estimated to have been entrained
at Avon Lake and 1,315,417 at the
Ashtabula A and B Plant.
21. Estimates of entrainment at the
Ashtabula A and B Plant and the
Ashtabula C Plant represent a com-
parison of entrainment losses due to in-
shore and offshore intakes. The
Ashtabula C Plant, where the water in-
take is located 1200 meters offshore,
has 78% of the water requirement of
the Ashtabula A and B Plant with an in-
take located 425 meters offshore.
Estimates of entrainment were found to
be much lower for the C Plant in all
cases except rainbow smelt, which was
10 times higher. Yellow perch entrain-
ment at the C Plant was found to be
20% of that at the A and B Plant.
22. Central Basin entrainment estimates
generally represented between 2 and
4% of total estimated nearshore pro-
duction. Yellow perch entrainment
represented 3% of total yellow perch
production. The highest percentage of
any species entrained was carp, as 36%
of the total nearshore carp production
was entrained.
C. Lawrence Cooper, John J. Mizera, and Charles E. Herdendorf are with Ohio
State University, Columbus, OH 43210.
Nelson A. Thomas is the EPA Project Officer (see below).
The complete report, entitled "Distribution, Abundance and Entrainment of Larva/
Fishes in the Western and Central Basins of Lake Erie," (Order No. PB 84-141
522; Cost: $16.00, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Environmental Research Laboratory
U.S. Environmental Protection Agency
6201 Congdon Blvd.
Duluth, MN 55804
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United States
Environmental Protection
Agency
Center for Environmental Research
Information
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Penalty for Private Use $300
ft U S GOVERNMENT PRINTING OFFICE' 1984—759-015/7619
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