Economic Damages of Impingement and Entrainment of Fish, 

Fish Eggs, and Fish Larvae at the Bay Shore Power Plant

Gentner Consulting Group 

9007 Eton Road 

Silver Spring, MD 20901 

May, 2010 
Table of Contents 

Executive summary......................................................................................................................... 3 

Introduction..................................................................................................................................... 5 

Economic Impacts of Lake Erie Fisheries ...................................................................................... 7 

Biological Assessment of Impingement/Entrainment .................................................................. 10 

Economic Damages of Impingement and Entrainment ................................................................ 17 

Estimating Values per Fish ....................................................................................................... 20 

Findings..................................................................................................................................... 21 

Conclusion .................................................................................................................................... 23 

References..................................................................................................................................... 25 

Appendix 1: Commercial Fisheries Detail.................................................................................... 28 

Acknowledgements 

This report was prepared by Brad Gentner with the assistance of Mike Bur. 

Brad Gentner is president and Chief Economist for Gentner Consulting Group an Economics and Public Opinion 

consulting firm specializing in fisheries policy and damage assessment. Before starting Gentner Consulting Group, 

Brad Gentner was a Senior Research Economist for the National Marine Fisheries Service for eight years. For more 

information on Gentner Consulting Group and Brad Gentner please visit www.GentnerGroup.com. 

Mike Bur is recently retired after 32 years with the Great lakes Science Center, USGS as both the Lake Erie 

Biological Station's supervisor and research fisheries biologist. His career started with the National Marine 

Fisheries Service in San Diego in 1977, and after one year he transferred to the Lake Erie Biological Station in 

Sandusky, Ohio. 

Gentner Consulting Group thanks Frank Lupi, Ph.D., for his input on the fish valuations. Frank Lupi is a professor 

of natural resource and environmental economics at Michigan State University and has a PhD in Applied Economics 

from the University of Minnesota. His research and teaching addresses the valuation of ecosystem goods and 

services, and he has over 15 years of applied research experience in the Great Lakes. 
Executive summary 

First Energy’s Bay Shore power plant is located in Oregon, Ohio (east of Toledo), near the 

outfall of the Maumee River in Maumee Bay. The 130 mile long Maumee River is at the heart 

of the Great Lakes’ largest watershed and is also known as the Great Lakes’ most biologically 

productive river. The Maumee River flows into Maumee Bay and then the Western Basin of 

Lake Erie. Lake Erie has more consumable fish than all the other Great Lakes combined, and 

over half of these fish are in the Western Basin. Studies by the Ohio Department of Natural 

Resources show that walleye populations in Lake Erie have declined from an estimated 80 

million in 2004 to an estimated 20 million in 2010. Yellow perch populations in the Western 

Basin are also low enough that the commercial fishery for them in the Western Basin has been 

closed for the last three years. 

The Bay Shore power plant (BSPP) draws 650 million gallons of water from a narrow intake 

channel that connects to Maumee Bay every day. The intake waters travel through a cooling 

process, which discharges to Maumee Bay at 5-12 degrees Fahrenheit warmer than intake 

temperatures. To compound this thermal pollution, the BSPP kills a large quantity of fish 

through impingement and entrainment in its cooling system. 

The BSPP impinges 46-52 million fish annually, representing 270.3 metric tons of biomass. In 

addition, it entrains 208.6 million eggs, 2.2 billion larval fish and 13.8 billion juvenile fish. This 

report explores the economic importance of Lake Erie commercial and recreational fisheries, 

estimates the adult equivalents of impinged and entrained fish and uses those estimates to derive 

the economic damages accruing only to fishery users resulting from the intake of cooling water 

at the BSPP. 

The Maumee River and Maumee Bay are economically and ecologically important for fisheries 

production in Lake Erie. Lake Erie-wide commercial fisheries generate $25.8 million in 

landings revenue annually, with Ohio responsible for $4.0 million of those landings revenue in 

2009. Commercial fishing in Lake Erie generates $22.0 million in total sales, $12.3 million in 

income and supports 524 jobs from the harvester through to the consumer. 

Recreational fishing in Lake Erie has an even larger economic footprint. Anglers fishing in Lake 

Erie spent $518.9 million pursuing their sport in 2009. That level of recreational expenditures 

supports $1.2 billion in total sales, $632.7 million in personal income and 10,708 jobs. Walleye 

and yellow perch are the most popular target species. All together, commercial and recreational 

fishing generate $1.4 billion in total sales, $711.1 million in personal income and support 14,052 

jobs. 

The biological assessment utilized published studies on fish mortality from egg to adult to 

estimate adult equivalents. Across both impinged and entrained fish, the BSPP prevents 54.5 

million predator and prey species from reaching adulthood. Of that total, 8.5 million fish are 

predators targeted by commercial and recreational fishermen. A separate prey analysis indicates 

that the 46 million prey fish would support an additional 407,645 walleye. 
Economic damages stemming from both predator and prey impingement and entrainment were 

estimated based on the biological assessment using benefit transfer techniques. Recreational 

values were taken from studies conducted in the Great Lakes where possible. Commercial value 

proxies were taken from economic impact models of the US fisheries industry and include values 

from the harvester through to the consumer. 

Applying the commercial and recreational benefits transfer estimates per fish results in annual 

economic damages of $21.4 million per year, for just the predator species impinged and 

entrained at BSPP. The BSPP also impinges and entrains a large quantity of prey fish. If the 

value of the walleye that could be supported by the lost prey fish are valued using those same 

benefit transfer estimates, the losses climb by $8.3 million annually for a total annual loss of 

$29.7 million. The net present value of a 20 year stream of the losses discounted at the 

government-recommended 7% discount rate yields $315.0 million or $22.1 million more than the 

cost of implementing cooling towers at the Bay Shore Power Plant. 

Mid-range values per fish were used for the recreational calculations and upper bound estimates 

were used for the commercial values per fish. Damages resulting from other uses, like bird 

watching or hunting were not included in this analysis. Additionally, non-use damages from fish 

impingement and entrainment were not estimated nor were health or non-use damages from 

increased algal blooms and other damages from the thermal plume. Finally, there is evidence 

that the actual impingement and entrainment estimates from the plant are higher than those 

estimated by the plant. Had any of these other use and non-use values and higher impingement 

and entrainment estimates been included, the economic damage estimates would be higher than 

those presented here, all else being equal.
Introduction

The Maumee River and the Western Basin of Lake Erie (WBLE) are ecologically and 

economically important to the state of Ohio and the Great Lakes region. The Maumee River 

flows into the Maumee Bay and the Western Basin of Lake Erie in Toledo and Oregon, Ohio. 

Please see Figure 1 for details on its location. The Maumee River is an important spawning river 

for yellow perch, walleye, white perch, white bass and many other economically important fish 

species and forage species. 

The US EPA has determined that a portion of the Maumee River and its watershed constitute an 

area of concern (AOC). This designation was applied due to the high and increasing levels of 

phosphorous pollution, other nutrient pollution, sources of thermal pollution and sedimentation. 

All of these factors contribute to increasing algal blooms, some of them harmful such as 

Microcystis and Lyngbya. In addition to the problems of thermal pollution, impingement and 

entrainment of fish, fish larva and other benthic organisms threaten economically important fish 

species that depend on the Maumee for reproduction. 

Figure 1. Environmental Protection Agency Maumee Area of Concern.1

FirstEnergy operates the Bay Shore Power Plant (BSPP) in the city of Oregon, Ohio. The BSPP 

utilizes a conventional steam boiler with a 631 megawatt rated generating capacity (Tetra Tech 

2009). The BSPP burns coal and petroleum coke for fuel and draws water primarily from the 

Maumee River for cooling and discharges warmed water into Maumee Bay and the WBLE. 

 

1

 Personal communication from Ohio Environmental Protection Agency. 2009. 
In 1978, the Ohio Environmental Protection Agency (OEPA) listed the BSPP as a high risk 

facility (OEPA 1978, p. 38). On average, the BSPP draws 650 million gallons of water from the 

Maumee River, daily releasing the cooling water 5-12 degrees Fahrenheit hotter into the WBLE. 

This heated water is discharged into a shallow, low-oxygen environment only 2’ to 3’ deep, 

compounding the impact of thermal pollution (Tetra Tech 2009). At the highest flows, this 

represents 30% of the instream flow of the Maumee River. At the lowest flows, this represents 

100% of the instream flow. At the lowest flows, this level of withdrawal has its highest impact, 

particularly with regard to thermal pollution. 

Figure 2 displays the intake and outflow configuration of BSPP. The intakes of the BSPP are at 

the entrance to an important upstream spawning area for many fish species, and the 

impingement/entrainment rates for this facility are high. The BSPP intakes impinge 46-52 

million fish (270.3 metric tons) and entrain 208.6 million fish eggs, 2.2 billion larval fish and 

13.8 billion juvenile fish. The BSPP does very little to mitigate impingement and entrainment. 

From the Tetra Tech report: “BSPP does not employ any technologies that are typically 

considered effective for reducing impingement mortality, although FirstEnergy contends that the 

cooling water intake structure, as currently configured, partially reduces impingement and does 

not result in 100 percent mortality for all impinged fish as had long been assumed” (Tetra Tech 

2009, p. 11). 

Figure 2. Bay Shore Power Plant (BSPP) Location (Tetra Tech 2009). 

The purpose of this report is to detail the economic importance of both the commercial and 

recreational fisheries in Lake Erie and assess the economic damages associated with the high 

rates of impingement and entrainment from the BSPP. The report will begin by detailing the 

economic impacts of the commercial and recreational fisheries as a matter of context on the 

importance of these fisheries to the state of Ohio and the local community. Next, impingement 

and entrainment estimates will be used to model the number of equivalent adults that could 
generate economic value had they not been impinged or entrained. Along with those estimates, 

the counts of prey species impinged and entrained will be used to estimate the potential 

additional fisheries production that could have been supported had those species not been 

impinged or entrained. To determine economic damages, a benefit transfer methodology will be 

used to determine the economic value of each adult fish that has been removed from the 

ecosystem by the BSPP and the net present value of those losses will be calculated based on a 20 

year time horizon. Finally, this report focuses only on the damages associated with fisheries use. 

The economic use damages accruing to other activities, such as bird watching and wildlife 

watching, are not included, nor are non-use values for ecosystem services foregone because of 

the BSPP’s water intake.

Economic Impacts of Lake Erie Fisheries 

While the focus of this report is estimating economic damages, economic impacts provide 

important context regarding the economic activity supported through the use of natural resources 

in local communities. Economic impact models are a representation of all the transactions in an 

economy and allow analysts to outline the relationships between the production of goods and 

their final consumers. 

Economic impacts begin with an angler’s purchase of fishing tackle or a consumer’s purchase of 

a yellow perch fillet. Those initial expenditures constitute the direct impact. From that initial 

purchase, the store purchases its inventory and labor, as do the suppliers of those goods and 

services required by the store. When businesses and suppliers import goods from outside the 

economy, that money, called a leakage, leaves the economy and is not considered in further 

calculations. Tracking purchases of supplies and labor by business continues until all the 

original purchase amount is exhausted by leakages. The sum of all this activity is called the 

indirect impact. The portion of laborer’s income and business owner’s profits from the indirect 

phase that is then re-spent on goods and services in the normal course of that consumer’s life is 

considered the induced impact. The sum of direct, indirect and induced impacts describes the 

total impact of consumer expenditures in an economy. These impacts can be denominated by the 

number of jobs supported, income or the total output in an economy. For this study, IMPLAN 

software and modified IMPLAN models were used to calculate impacts (MIG 2008). 

Lake Erie supports a vibrant commercial and recreational fishery. Lake Erie has more 

consumable fish than all the other Great Lakes combined.2

 The Western Basin and the Maumee 

River play an important role in both fisheries as a major spawning river for many species. Lakewide commercial fisheries generate $25.8 million in revenues with the majority of that harvest 

being landed by Canadian commercial fishermen ($21.3 million)3, followed by Ohio fishermen 

with $4.0 million in 2009.4

 Due to low abundance, the Western Basin has been closed to yellow 

perch harvest the previous two years. 

Total Ohio landed value by species over the last 10 years is captured in Table 1. In 2009, the 

most valuable species landed commercially was yellow perch, even with the Western Basin 

closure. While walleye cannot be landed commercially in Ohio, it is a commercially important 

 

2

 Personal communication, Jeff Reuter, Ohio Sea Grant 

3

 Personal communication, John Johnson, Ontario Ministry of Natural Resource 4

 Personal communication , Travis Hartman, Ohio Department of Natural Resources 
species to Ontario. As stated, economic impact models are formulated to utilize final consumer 

purchases to track industry in the supply chain backwards from the consumer. Unfortunately, 

retail data on consumer purchases of fish is impossible to obtain, particularly from restaurants. 

Instead, this analysis only has access to purchases made at various places in the supply chain 

before the product reaches the consumer. As a result, a special economic impact model has to be 

constructed to examine the typical economic linkages down the supply chain from the fisherman 

as well as the linkages forward in the supply chain to the consumers. Additional detail regarding 

landings in pounds and fish prices per pound can be found in Appendix 1. 

Table 1. Landed Value for Ohio Commercial Fishes Harvested in Lake Erie, 2000-2009 (2009 

dollars). 

Year Carp Channel 

Catfish 

Freshwater 

Drum 

White 

Bass 

White 

Perch 

Yellow 

Perchab Others Total 

Value 

2000 $100,868 $196,947 $64,813 $322,667 $131,652 $3,159,363 $165,887 $4,142,197 

2001 $104,638 $236,061 $34,755 $174,125 $67,384 $3,142,824 $160,292 $3,920,080 

2002 $84,157 $224,513 $37,027 $97,490 $80,584 $3,008,543 $175,561 $3,707,875 

2003 $92,872 $62,180 $38,338 $214,705 $136,938 $2,669,126 $164,085 $3,378,243 

2004 $80,913 $124,949 $41,944 $251,935 $178,423 $2,973,794 $174,821 $3,826,778 

2005 $56,677 $137,691 $65,568 $280,969 $189,513 $3,731,801 $164,421 $4,626,639 

2006 $41,538 $135,315 $60,803 $356,462 $274,040 $2,570,129 $209,463 $3,647,750 

2007 $40,361 $107,673 $58,948 $254,601 $220,416 $4,675,235 $210,029 $5,567,264 

2008 $40,120 $148,377 $72,506 $231,708 $221,528 $2,494,234 $244,056 $3,452,530 

2009 $51,925 $134,987 $102,210 $510,092 $287,516 $2,427,503 $535,327 $4,049,560 

Mean $69,407 $150,869 $57,691 $269,475 $178,799 $3,085,255 $220,394 $4,031,892 

a A spring (March - April) closure on commercial yellow perch harvest was enacted in 1993. 

b Management unit 1 (the western basin) was closed to commercial yellow perch harvest in 2008 and 2009. 

 

The yellow perch task group (YPTG) three years ago found that the stock of yellow perch in the 

Western Basin was lower than desired, primarily due to excessive mortality. The YPTG was 

faced with reducing commercial and/or recreational harvest. Because ODNR had recently 

reduced yellow perch bag limits from 50/day to 25/day, ODNR felt that reducing recreational 

limits again would be unfair. Additionally, ODNR felt that it would be easier to achieve a 

reduction in mortality by targeting the commercial fleet because monitoring and enforcement 

would be easier (YPTG 2007). While walleye cannot be harvested by commercial fishermen in 

Ohio, studies by the Ohio Department of Natural Resources show that walleye populations in 

Lake Erie have declined from an estimated 80 million in 2004 to an estimated 20 million in 

2010.5

 Clearly, ODNR would prefer to see more yellow perch and walleye in the Western 

Basin. 

To examine economic impact forward of the landed value from Table 1 above, margins or price 

mark-ups for the sectors forward in the supply chain are used to determine the value entering the 

next industry link forward. For instance, the nationwide average processor mark-up is used to 

increase the landed price to the value the wholesale sector would pay the processor. This 

procedure is repeated until the value paid by the consumer is estimated. 

 

5

 Personal communication, Jeff Tyson Ohio Department of Natural Resources 
Commercial fisheries sectors are not well described in the standard IMPLAN industry 

classifications due to the relative small size of the fishing industry and the lack of standardized 

cost and earnings data on fisheries sectors. Therefore the analysis here uses a mixture of models 

and data sources, where necessary, to calculate the economic impacts. The model developed by 

Kirkley, Duberg, and Gentner (2004) was adapted for use across the fisheries wholesale sector 

backwards. Data regarding the consumption of fish in restaurants versus other retail outlets as 

well as margins for the retail sectors were taken from the value added model in Fisheries of the 

United States (FUS 2009) and from Fisheries Economics of the United States (FEUS) (NMFS 

2006). Economic impacts of the retail trade sectors were calculated in IMPLAN using the 

margined expenditures. 

Table 2. Economic Impacts of the Commercial Fisheries Sector in Lake Erie. 

Industry Sector Total 

Harvesters 

Employment impacts (FTE jobs) 48

Income Impacts (1000s of dollars) $1,159

Output Impacts (1000s of dollars) $3,034

Primary dealers/processors 

Employment impacts (FTE jobs) 34

Income Impacts (1000s of dollars) $1,213

Output Impacts (1000s of dollars) $1,749

Secondary wholesalers/distributors 

Employment impacts (FTE jobs) 29

Income Impacts (1000s of dollars) $1,508

Output Impacts (1000s of dollars) $3,014

Grocers 

Employment impacts (FTE jobs) 18

Income Impacts (1000s of dollars) $671

Output Impacts (1000s of dollars) $1,136

Restaurants 

Employment impacts (FTE jobs) 395

Income Impacts (1000s of dollars) $7,747

Output Impacts (1000s of dollars) $13,102

Harvesters and seafood industry 

Employment impacts (FTE jobs) 524

Income Impacts (1000s of dollars) $12,298

Output Impacts (1000s of dollars) $22,035

Table 2 contains the economic impact estimates for commercial fishing in all of Lake Erie. The 

Western Basin accounts for about 46.7% of the total Lake Erie commercial harvest by volume 

and 20.1% by value in 2009.6

 Lake Erie-wide, commercial harvest generates $22.0 million in 

total sales, $12.3 million in income and supports 524 jobs. 

 

6

 With the closure of yellow perch fishing in the Western Basin in 2008, the percentage of value landed in the 

Western Basin has dropped significantly as commercial fishermen have shifted their harvest to higher volumes of 

less valuable species to make up the difference. 
Recreational fishing in all of Lake Erie is big business. Using data from the United States Fish 

and Wildlife Service 2006 survey (USFWS 2006) and data from the Ontario Ministry of Natural 

Resources (OMNR 2009), recreational anglers take 5.2 million fishing trips on Lake Erie each 

year. This level of activity generates $708.8 million in recreational trip expenditures annually.7

 

Table 3 contains the expenditures and economic impacts of recreational anglers from Ohio only. 

Ohio Lake Erie recreational expenditures were taken from the USFWS (USFWS 2006) and 

inflated to 2009 dollars using the consumer price index. Economic impacts were calculated 

using US level multipliers from Gentner and Steinback (2008). These multipliers were estimated 

at the US level for all recreational angling and, while based on the IMPLAN model, were 

modified specifically for recreational fishing based on survey data. All Ohio trips generated 

$518.9 million in expenditures, including equipment purchased in Ohio, which supports $1.2 

billion in total sales, $632.7 million in personal income and 10,708 jobs. By far, the most 

popular target species are walleye and yellow perch (ODW 2009). Using Table 2 and 3, total 

commercial revenue and recreational expenditures in the Ohio portion of Lake Erie generate $1.4 

billion in total sales, $711.1 million in personal income and support 14,052 jobs. 

Table 3. Recreation Expenditure and Economic Impacts Resulting from Ohio Recreational 

Fishing Trips (2009 dollars). 

Impact Recreational 

(1000s of US$) 

Ohio Lake Erie Total $518,920

Total Sales $1,218,378

Personal Income $632,732

Jobs 10,708

Biological Assessment of Impingement/Entrainment 

Estimating damages from entrainment and impingement first involves the evaluation of the loss 

of eggs, larvae, juvenile fish, adult fish, and benthic organisms. It is beyond the scope of this 

project to estimate those losses directly at the BSPP, and therefore estimates from previous 

studies of BSPP impingement and entrainment will be used to establish fish and benthic species 

loss. These studies will be summarized and used to generate separate estimates of catchable and 

juvenile fish. Catchable sized fish will be used in the evaluation of use values, while juveniles, 

eggs, larvae and benthic species will be used for the assessment of the loss of ecosystem 

services. Additionally, recruitment models (survival and/or mortality) will be used to estimate 

the adult equivalent for eggs, larvae, and juvenile fish to be used in the use value assessment. 

Finally, the quality of these industry sponsored studies will be evaluated. 

Data for this effort was taken from the Kinetrics report written by Ager et al (2008). Tetra Tech 

deemed these data insufficient to fully estimate impingement and entrainment for a number of 

reasons (Tetra Tech 2009). Kinetrics performed 104 impingement sampling events between 

 

7

 Total Great Lakes expenditures from USFWS 2006 were multiplied by the percentage of total Great Lakes effort 

(26%) attributable to Lake Erie. Canadian Lake Erie expenditures were calculated by taking the per trip 

expenditures from OMNR (2009) and multiplying those by total Canadian Lake Erie effort and converted to 2009 

US dollars using current exchange rates. 
May of 2005 and December 2006. They then averaged the numbers of impinged fish by month 

and summed those numbers into an annual estimate. Tetra Tech found that the more typical 

average of the sums technique yields impingement estimates 13% higher than those published by 

Kinetrics. While Kinetrics classified impinged fish as alive and healthy, alive but stressed, 

recently dead and long dead, all impinged fish used for this analysis are assumed to be dead or 

die shortly after impingement. Standard BSPP practices involve the use of high pressure water to 

remove fish from the intake screens, likely killing or stressing all impinged fish. Fish were also 

sampled before transiting the debris sluiceway. Additionally, the return conduit is rough 

textured, contains many sharp turns and involves a long drop into the discharge sluiceway. 

Finally, fish are released into the thermal plume and end up in the shallow, warm and often lowoxygen portion of Maumee Bay. Table 4 contains the total number of fish impinged at BSPP 

from the Kinetrics study. Overall, 45.8 million fish are impinged at the BSPP facility annually. 

Both common and scientific names are given in Table 4, but only common names with be used 

hereafter. 

Table 4. Total Impingement Estimates from Ager et al (2008). 

Species Type Scientific Name Common Name 

Total Fish 

Impinged 

Osmerus mordax Rainbow smelt 12,923

Dorosoma cepedianum Gizzard shad 5,992,629

Notropis atherinoides Emerald shiner 32,688,994

Notropis hudsonius Spottail shiner 341,718

Prey 

Neogobius melanostomus Round goby 106,890

Cyprinus carpio Carp 6,837

Catostomidae spp. Sucker spp. 9,041

Ictalurus punctatus Channel catfish 73,040

Morone chrysops White bass 1,577,083

Morone americana White perch 4,669,894

Micropterus salmoides Largemouth bass 4,251

Micropterus dolomieu Smallmouth bass 2,760

Sander vitreus Walleye 25,454

Perca flavescens Yellow perch 71,348

Predator 

Aplodinotus grunniens Freshwater drum 227,504

Total 45,810,366

To ascertain the full extent of fish losses by entrainment and impingement at the BSPP, the 

number of adults and adult-equivalents (AE) were determined. A direct count of adults was 

achieved by using impingement data from the Kinetrics report (Ager et al. 2008). To calculate 

AE, survival rates for different species and life stages of fish (i.e. egg, larvae, juvenile, and adult) 

were used in conjunction with data from the Kinetrics report (Ager et al. 2008). Survival rates 

were taken from literature for Lake Erie or bodies of water in similar latitudes. When survival or 

mortality rates were not available in the literature or reports, rates from similar species were 

substituted (e.g., white bass survival rates for white perch) or, if not available, an average of 

published rates for a particular life stage for known species was substituted. 
Prey fish are important for the growth and survival of predator species. Many of the species in 

Lake Erie are piscivorus, at least during some portion of their life cycle. Increasing the prey base 

typically has the effect of increasing growth and fecundity while decreasing mortality. As a 

result fishing quality and fish quantity would increase. Typically, models of predator/prey 

interaction and bio-energetic models are used to quantify the ecosystem benefits of prey fish. 

Unfortunately, estimating these complex models were beyond the scope of this analysis. Instead, 

published walleye stomach content analysis was used to estimate the number of adult walleye the 

prey fish could technically support. Walleye was chosen because stomach content data were 

available, it is a piscivorus fish and it is the most popular recreational target species in Lake Erie. 

Estimation of fish population abundance is indispensable for understanding changes in 

population numbers and composition for estimating yield and as a basis for good management 

(Everhart 1975). Occasionally there is an opportunity for direct counting when a population is 

concentrated and is available during some life history stage. More often, indirect methods must 

be employed individually or in combinations to minimize errors in estimation. Although direct 

enumeration is the most accurate method, the expense may exceed natural resource budgets, 

which is one reason for indirect methods. Indirect methods usually employ a combination of 

direct (e.g., use of trawls) and indirect (e.g., computer generated population models). Some 

common methods to assess fish populations are: trawling (a cone-shape net towed behind a boat 

to collect fish), gill netting (a net used to entangle fish, usually by their gills), fyke netting 

(passive cages with openings for fish to swim inside), echo sounding (a technique of using sound 

pulses directed from the surface toward the bottom to measure fish abundance and spatial 

distributions vertically), and electro-shocking (the use of electricity to stun fish before they are 

caught with dip nets). 

The most effective scenario for determining how many adults will survive from an egg for each 

fish species would entail raising them (starting from a known number of eggs) in a pond with 

similar conditions to those existing in western Lake Erie (e.g., similar water temperature and fish 

community composition). At the end of this experiment (when the egg has finally 

metamorphosed into an adult), counting all adults of each species ascertains what the actual 

survival from egg to adult life stage will be. The next best scenario is to calculate adult 

equivalents (AE) from fish population models, similar to walleye and yellow perch task group 

models (Walleye Task Group. 2007, Yellow Perch Task Group 2007). But due to constraints of 

time and money this analysis employed a review of the literature (including published scientific 

papers, theses/dissertations, and state or federal reports) to find suitable survival/mortality rates 

for each species to calculate an estimate of AE. The survival rate (e.g., S=0.67) is the proportion 

of the population that survives after a set amount of time (i.e., one year). Mortality rate is 

calculated similarly (e.g., 1.0 - 0.67=0.33=M). As an example, estimates of AE from eggs of a 

fish species, which were entrained through the intake screens, was determined primarily with 

survival rates of eggs to larvae, larvae to juveniles, and juveniles to adults [(Seggs x # eggs) + 

(Slarvae x # larvae) + (Sjuvenile x # juvenile) = # adults]. Table 5 contains the results of the analysis 

of entrained eggs. 

Similarly, estimates of AE from larvae entrained were calculated using survival rates for life 

stages: larvae to juveniles and then juveniles to adults. For estimates of juveniles entrained or 
impinged, survival rates for juveniles to adults were employed. When survival or mortality rates 

were not available in the literature or reports, rates from similar species were substituted or, if 

not available, an average of published rates at a particular life stage for known species was 

substituted. Table 6 contains the estimates of adult equivalents from entrained larvae. 

Table 5. Estimates of Adult Equivalents from Entrained Eggs. 

Eggs to Age 1 Age 1 to Adult 

Species 

Total eggs Survival 

rate Age 1 equivalents Survival rate Age 2+ equivalents

Freshwater drum 21,576,285 x 0.00004 = 863 x 0.73 = 630

Catostomidae 25,319 x 0.057 = 1443 x 0.634 = 915

Morone spp 8,404 x 0.057 = 479 x 0.634 = 304

Total 22,434,637 2,785 1,849

 

A review of the literature was completed and survival or mortality rates were identified for most 

of the fish species and life stages of those fish that were entrained or impinged at BSPP’s intake 

structure. When a species and life stage’s survival/mortality rate were not available in the 

literature, a similar species survival/mortality was substituted. If a species did not have a 

survival/mortality rate available for similar taxa, then an average survival/mortality rate of all 

species at a particular life stage was substituted. Appendix 10 in the Kinetrics report (Ager et al. 

2008) listed live-healthy, live-stressed, recently dead, long dead, and total of eggs. All eggs 

other than ‘long dead’ were considered dead for the estimation of AE. Studies indicate that 

capture and handling of fish induces some level of mortality. Due to these studies and the typical 

poor handling of impinged species documented by Tetra Tech (2009), it is assumed here that all 

impinged and entrained fish are killed. 

Walleye AE were based on survival rates from both larvae (entrained) and juveniles (impinged) 

in published literature (Forney 1976 and Walleye Task Group 2007), as well as direct counts of 

impinged adults from Ager et al. (2008). Forney (1976) studied survival of both larvae (13.2%) 

and juveniles (33.3%) in Oneida Lake, N.Y., which has a similar latitude and comparable fish 

community to western Lake Erie. The survival from age 1 to adult walleye was taken from a 

report by the Lake Erie Committee’s Walleye Task Group (2007). The survival rate for age 1 

(63.7%) was not found in the literature, so the rate for age 2 and older (Walleye Task Group 

2007) was used as a substitute. The calculation of AE from entrained larvae are shown in Table 

6. The AE results from impinged juveniles and adults are in Table 4, and the total number of AE 

is in Table 7. 

The AE for yellow perch was derived from entrained larvae and impinged juveniles and adults. 

Indirect counts were derived from calculating AE from both larvae and juveniles from survival 

rates from bodies of water of similar latitude (Clady 1976 [10.5%] and Patterson 1976 [26%]). 

The survival rate for larvae for age 1 equivalents is 45.7%, taken from the Lake Erie Yellow 

Perch Task Group report (2007). The AE results from larvae entrained are in Table 6. Yellow 

perch AE were also calculated from impingement, which included both juveniles and adults. 

Survival rate for juveniles is 26% (Patterson 1976) and for age 1 is 45.7% (Yellow Perch Task 
Group 2007). The AE results from impinged juveniles are in Table 4, while the total AE for 

yellow perch is listed in Table 7. 

Freshwater drum AE were derived from estimates of entrained eggs (Table 5) and larvae (Table 

6), and impinged juveniles and adults (Table 4). Adult equivalents were estimated from 

entrained eggs to age 1 with a survival rate of 0.004% (Ager et al. 2008), and entrained larvae 

with survival rate to age 1 of 0.04% (USEPA 2004). The survival rate for age 1 equivalents to 

adult is 73% (USEPA 2004). Freshwater drum were also impinged on the intake screens and AE 

were estimated from both juveniles and adults. Survival rates are the same for juvenile and age 1 

for the impinged fish. The total AE for freshwater drum is listed in Table 7. 

The AE for rainbow smelt were derived from entrained larvae (Table 6) and from impinged 

juveniles and adults (Table 4). All survival rates came from a report by the USEPA (2004), with 

survival rates of 8% for larvae, 57.2% for juveniles, and 79.5% for age 1 to adults. 

Gizzard shad survival rates were from three sources: survival from larvae (6.8%) from 

Michaeletz (1997), survival from juveniles (16%) in Michaeletz (2010), and survival to adults 

(63.4%) is from a mean of survival rates. The AE from entrainment is listed in Table 6, the AE 

from impingement is in Table 4, and total AE is in Table 7. 

Emerald shiner AE from entrainment is based on survival rates for larvae (10.2%) and juveniles 

(30.3%), derived from the mean of survival rates. The survival rate for age 1 is from a mean of 

survival rates (63.4%), since one was not listed in the literature. A direct count of adults was 

taken from impinged emerald shiners. Again, AE for entrained fish are in Table 6, adults from 

impingement are contained in Table 4, and total AE from all sources are in Table 7. 

The AE for entrained and impinged spottail shiners were calculated from survival rates for larvae 

(10.2%), for juveniles (30.3%), and age 1 to adults (63.4%). There were no available survival 

rates for spottail shiners, hence all survival rates were derived from a mean of available species 

in this report. The AE for entrained fish are listed in Table 6, AE for impinged fish in Table 4, 

and total AE in Table 7. 

The AE for carp and goldfish are based on a mean survival rates for all species and life stages 

listed in this report (larvae=10.2%, juveniles=30.3%, age 1=63.4%). The AEs are listed in Tables 

4, 6 and 7. 

Catostomidae AE were based on entrainment survival rates from eggs to age 1 (5.7%, which is a 

mean of all species in this report); larvae (10.2%, a mean of all species in this report); juveniles 

(30.3%, a mean of all species in this report); and age 1 (63.4%, a mean of all species in this 

report). A direct count was made of all Catostomidae from impingement, since all were adults. 

The AEs are listed in Tables 4, 6 and 7. 

The AE for channel catfish, white bass, and white perch are based on mean survival rates for all 

species at each life stage listed in this report (10.2% for larvae, 30.3% for juveniles, and 63.4% 

for age 1). The AEs are listed in Tables 4, 6 and 7. 
Table 6. Estimates of Adult Equivalents from Entrained Larvae. 

Larval to Juvenile Juvenile to Age 1 Age 1 to Adult 

Species Survival 

Rate Larvae Juvenile Equivalents Survival Rate Juvenile Equivalents Age 1 Equivalents Survival Rate Age 1 Equivalents Adult Equivalents 

Gizzard shad 0.068 x 590,567,582 = 40,158,596 0.160 x 40,158,596 = 6,425,375 0.634 x 6,425,375 = 4,073,688 Rainbow smelt 0.080 x 65,618,620 = 5,249,490 0.572 x 5,249,490 = 3,002,708 0.795 x 3,002,708 = 2,387,153 Emerald shiner 0.102 x 19,001,574 = 1,938,161 0.303 x 1,938,161 = 587,263 0.634 x 587,263 = 372,325 Spottail shiner 0.102 x 79,825 = 8,142 0.303 x 8,142 = 2,467 0.634 x 2,467 = 1,564 Common carp 0.102 x 2,180,081 = 222,368 0.303 x 222,368 = 67,378 0.634 x 67,378 = 42,717 Catostomidae 0.102 x 1,277,487 = 130,304 0.303 x 130,304 = 39,482 0.634 x 39,482 = 25,032 Channel catfish 0.102 x 70,390 = 7,180 0.303 x 7,180 = 2,175 0.634 x 2,175 = 1,379 Yellow perch 0.105 x 4,323,595 = 453,977 0.260 x 453,977 = 118,034 0.457 x 118,034 = 53,942 Walleye 0.132 x 14,371,888 = 1,897,089 0.333 x 1,897,089 = 631,731 0.637 x 631,731 = 402,412 White bass 0.102 x 132,478,763 = 13,512,834 0.303 x 13,512,834 = 4,094,389 0.230 x 4,094,389 = 941,709 White perch 0.102 x 3,800,385 = 387,639 0.303 x 387,639 = 117,455 0.535 x 117,455 = 62,838 Freshwater drum 0.0004* x 977,426,912 = 390,971 0.730 x = 285,409 *Survival rate from larval to age 1 
Table 7. Adult Equivalents of Fish Impinged and Entrained at the BSPP by Species. 

Adult Equivalent Estimates 

Type Common Name 

Egg 

Entrainment 

Larval 

Entrainment Impingement Total 

Rainbow smelt 2,387,153 12,923 2,400,076

Gizzard shad 4,073,688 5,992,629 10,066,317

Emerald shiner 372,325 32,688,994 33,061,318

Spottail shiner 1,564 341,718 343,282

Prey 

Round goby 106,890 106,890

Carp 42,717 6,837 49,554

Sucker spp. 915 25,032 9,041 34,988

Channel catfish 1,379 73,040 74,419

White bass 941,709 1,577,083 2,518,792

White perch 62,838 4,669,894 4,732,732

Morone spp. 304 304

Largemouth bass 4,251 4,251

Smallmouth bass 2,760 2,760

Walleye 402,412 25,454 427,866

Yellow perch 53,942 71,348 125,290

Predator 

Freshwater drum 630 285,409 227,504 513,543

Prey fish constitute an invaluable source of food for many piscivorus (predator) fish, such as 

walleye, which account for the majority of prey fish consumed. Hartman and Margraf (1992) 

estimated that walleye consumed from 83,700 tonnes in 1987 to 94,300 tonnes in 1986. 

Prey fish are not a limiting factor in the survival or growth of walleye, nor is the walleye 

population reaching a carrying capacity. The visceral fat content in fall-caught walleyes is 

indicative that prey fish are not limiting growth.8

 During the warmer months of the year when 

the water temperature approaches 25Co,most walleyes move east into the cooler waters of central 

Lake Erie. 

As a means to express the loss of prey fish through entrainment and impingement, the number of 

potential walleyes that could consume those lost prey fish in one year was calculated. An 

examination of the fall walleye diet in 2008-09 from a gill net survey (unpublished data from 

Ohio DNR, Sandusky, OH) allowed for the determination of the mean number of prey fish, by 

species, for both years combined. The number by suitably sized prey fish (Knight et al. 1984) 

for each species was taken from Tables 4 and 5. For this activity we considered all ages of smelt 

and emerald shiners, and only young-of the-year for gizzard shad, white perch, and yellow perch 

as potential prey fish for walleye. To estimate how many potential walleye could feed on the 

available prey fish in one feeding season (175 days, Hartman and Margraf 1992), the number of 

prey fish (by species) was divided by the mean number of prey per stomach and that number was 

 

8

 Personal communication with Chris Vandergoot, Ohio DNR. 
divided by 175 (days) to equal the potential number of walleyes that could feed on each prey 

species. 

In order to express the loss of potential prey fish, a mean was calculated for the potential walleye 

that could consume all prey species combined. Using these techniques, the mean number of 

walleye that could be supported by the impinged/entrained prey species is 407,645 additional 

walleye. Since prey fish at this time are not a limiting factor in either the survival or growth of 

walleye, this section presents a way to indicate how many potential walleyes could be fed by the 

prey that died as a result of entrainment or impingement. If at some point the prey fish do 

become a limiting factor, the loss of up to one million prey fish could negatively impact the 

population size or growth of walleye and other predaceous fish (e.g., smallmouth bass, yellow 

perch, and white bass). 

Economic Damages of Impingement and Entrainment 

Economic value is based on people’s willingness to give something up in order to obtain 

something else; economic value has nothing to do with money, per se. Value could be translated 

into any standardized units, but placing values on a dollar scale makes them comparable with 

other market activities (e.g., the costs of a program or the cost of a changing technology at a 

power plant). To infer economic value, economists rely on the choices made by individuals. 

Since many goods are traded in markets, the “market” is a convenient mechanism for revealing 

economic values. However, the fact that something does not have a market price does not mean 

that it does not have economic value. Economists have developed a suite of valuation techniques 

for non-market goods or services. In the case of recreation activities such as fishing, economists 

can use observations of individuals’ willingness to spend time and money to get to a recreation 

site to estimate willingness to pay for the recreation trips. This technique is referred to as the 

travel cost method (TCM). 

The essence of the travel cost method is to determine statistically the relationship between price 

(travel costs) and quantity (the number of visits to some site); this relationship is referred to as 

the “demand curve.” Figure 1 presents a graph of two hypothetical recreational demand curves 

for trips to a recreation site. The two demand curves are linked to two different levels of 

environmental quality at the site (Q0

<Q1). The price (travel cost) per trip is on the vertical axis, 

and the number of trips is on the horizontal axis. As the price decreases, we expect anglers to 

take more trips to the site. 

The travel cost demand curve reveals two key pieces of information. First, it shows the number 

of trips an individual will make at any given price. In the figure, when the price of a trip to the 

site is P, the number of trips taken by anglers is T0

 and T1, respectively. Second, the demand 

curve shows the maximum amount individuals would be willing to pay to take each trip. For the 

initial trips taken by anglers, the amount they would be willing to pay exceeds the price. Anglers 

will take trips until their benefit (willingness to pay) for an additional trip just equals their cost -- 

see points A and D for the two demand curves in Figure 3. Note from Figure 3 that the benefit 

for each trip is higher under level of quality, Q1

, than under Q0. That is, the demand curves show 

that willingness to pay for each trip is larger when the level of quality at the site is higher. The 

total amount the anglers actually pay to take T trips is equal to P×T which is less than total 

willingness to pay. The total difference between what individuals would pay and actually pay is 
referred to as consumer surplus (the areas PAB and PDC in Figure 3). If access to the recreation 

site were eliminated, the anglers would lose the consumer surplus associated with the site. 

Consumer surplus is the appropriate measure of economic value associated with the use of any 

good such as a recreation site (Freeman 1993). Note that while the amount expressed by P×T is 

a measure of the expenditures at the site, it is not a measure of economic value. This money may 

be important to a local economy surrounding the recreation site, but the money (and the other 

opportunities it can provide) is not lost to the individual should the site close. 

We note that the travel cost method is used to estimate the use value of fishing. The method 

cannot measure all the general values associated with fishing. Moreover, since the method is 

based on relationships between recreational use and price and quality of a fishing site, factors 

that are not revealed through anglers’ fishing behavior cannot be measured. For this reason, the 

values are referred to as use-values. The fact that TCM can only measure use values does not 

preclude other non-use values from being held by individuals. 

Figure 3. Hypothetical Recreational Demand Curves. 

We have illustrated how TCM can be used for estimating the value associated with access to 

some recreation site, but in the case at hand we are interested in how value is related to the 

number of fish that can be caught. Establishing this change in value is more difficult than simply 

establishing the value of access to a site (given by the consumer surplus). When catch rates 

change, the benefits or losses are given by the change in the consumer surplus. To measure 

changes in value associated with changes in quality, one needs to know how the demand curve 

shifts when quality changes. The value is then given by the change in consumer surplus. The 

two demand curves shown in Figure 3 illustrate the idea. Consider two levels of quality (Q0

<Q1) 

at the site. The lower demand curve in Figure 3 represents the demand under the baseline level 

of quality, Q0

, and the upper demand curve reflects the upward shift in demand under some 
increased level of quality, Q1

. The value of the change in quality (Q0 to Q1) is given by the 

change in the consumer surplus, the area ABCD. 

On the commercial fisheries side, the supply curve traces the locus of all profit maximizing 

production points for a given set of production costs. While a production decision is always the 

result of a market transaction, calculating producer surplus requires detailed data on the costs and 

earnings structure of individual firms in the fishery. Figure 4 contains a representation of a 

producer surplus under the typical upward sloping supply function. Under perfect competition, 

the output supply function is equal to the marginal cost function of the firm. In most cases, 

perfectly competitive firms face increasing marginal industry costs and therefore have upward 

sloping supply functions. 

To illustrate producer surplus in a competitive market, in Figure 4, the price of a good such as 

fish flesh is a function of its supply and demand in the market where producers supply their 

products. In Figure 4, the quantity of good demanded is shown to decrease as price increases, as 

is typical under diminishing marginal utility as described above. The supply of the good relates 

to the costs of its production (e.g., fuel to catch fish). At low prices only the most efficient 

producers are able to operate, but as the price increases, less efficient producers enter the 

industry, resulting in increased supply. As a result, the supply of the good increases with 

increasing price and marginal cost is an increasing function of quantity supplied. In perfectly 

competitive markets, market price is set at the intersection of supply and demand at price P and 

quantity demanded Q. Consumer surplus is the darker shaded triangle PCB. 

Figure 4. Commercial Fisheries Producer and Consumer Surplus. 

C

Price

B

P

A

O Q Quantity 

Demand 

Supply 

Consumer 

surplus 

Producer 

surplus 
Total revenue in Figure 4 is the rectangle OPCQ. The total cost of producing the good by all 

producers is given by the area under the supply curve, OACQ. The difference between the total 

revenue generated from sales and the total costs of production, given by the area APC, is a 

surplus accruing to the production industry. This producer surplus (PS) represents benefits 

accruing to the producers from being able to sell the good at market price P. In essence, it is the 

return earned by the firm selling fish products. Total surplus or the total value of fish in this 

illustrative market is the sum of both the producer and consumer surplus or the area ABC. 

Estimating Values per Fish 

On the recreational side, it was beyond the scope of this study to establish recreational fishing 

values using original angler surveys or observation of actual fishing trips. Instead, to establish 

values for fish, a literature review was conducted and the benefits transfer approach was applied. 

Benefits transfer refers to the process of identifying value estimates from existing literature and 

applying them in a new context. That is, benefit estimates are “transferred” from one site to 

another. 

In the present analysis, we have reviewed literature on changes in consumer surplus as a result of 

changes in the number of fish so that we can derive values per fish. In all the literature 

examined, the conceptual notion of value is, as described above, the change in consumer surplus 

associated with catching an additional fish. 

To begin the benefits transfer, the economic literature on valuation of sport fish was reviewed. 

In particular, I have reviewed dozens of studies on fish valuations. Most of the studies are based 

on the travel cost method for estimating the value of non-market goods and services associated 

with recreation. About half those studies were specific to the Great Lakes. Although all of the 

studies provided valuation information related to fishing, not all studies provided sufficient 

information to obtain estimates expressed as “values per fish. “ 

Several studies are of note here because they were conducted in the Great Lakes and involve 

similar species to those at issue in the present case: Breffle et al, 1999; Lupi et al, 2001; 

Murdock, 2001; and Besedin et al, 2004. Furthermore, all of these studies use contemporary 

valuation methods based in random utility theory, making the results readily comparable. 

Although Breffle et al (1999) is based on a stated preference method, the others are based on 

travel cost models that include a broad range of substitute fishing sites. Further, the values 

derived from these studies are well within the ranges reported in the literature and consistent 

with the general species-specific patterns in values reported by the analysis of Johnston et al 

(which includes many studies outside the Great Lakes area). 

After review of these studies, the values reported by Besedin et al (2004) are suggested for use in 

benefit transfers to value fish lost due to entrainment and impingement. The reasons for this 

suggestion include: the Besedin et al (2004) estimates were developed with this use in mind; the 

estimates cover a range of species that reasonably matches those considered in the present 

analysis; the results fall roughly in the middle of the range of values reported by other studies 

(that is, they are not the lowest or the highest values found in the literature); and the preference 
rankings of species implied by the values are generally consistent with other findings reported in 

the literature. 

Estimating the producer surplus, or value per fish, that accrues to commercial fishermen in the 

study area requires detailed cost and earnings data for individual fishing vessels, processors, 

distributors, grocers and restaurants. Estimating consumer surplus of Lake Erie seafood 

consumers requires detailed data on seafood consumption. Unfortunately neither type of data is 

available. Instead income impacts can be used as a proxy measure of both producer surplus and 

consumer surplus in the total commercial fisheries supply chain. 

 

While total output impacts are clearly inappropriate for estimating the economic value in the 

commercial fishery, income impacts have been used as a proxy for consumer and producer 

surplus (Kirkley et al 2000). It is widely acknowledged, however, that income impacts overstate 

estimates of consumer and producer value (Edwards 1990). Because of the lack of data, income 

impact multipliers, from the commercial fisheries model above, were used as proxies for 

producer surplus from the consumer back to the retailer (Kirkley et al. 2004). As a result, the 

estimates presented in Table 8 for the commercial fishery are assumed to be upper bounds on the 

true economic damages facing the commercial fisheries in Lake Erie. 

Findings 

Table 8 reproduces the Besedin et al (2004) values, updated to 2010 dollars using the Bureau of 

Labor Statistics inflation calculator and the commercial values described above.9

 In addition to 

adjusting for inflation, the values in Table 8 have been transformed from the Besedin et al (2004) 

numbers to take the average values across all modes of fishing (boat, shore, and ice) where the 

averages are computed using the reported distribution of trips by each of these modes. Note that 

the white bass, white perch and yellow perch share the same value, as the Besedin et al (2004) 

study grouped those species together. Freshwater drum and channel catfish were taken from the 

“General” category. The Lake Erie commercial fisheries do not land largemouth bass, 

smallmouth bass or walleye so there is no commercial value for these species. Catostomidae, or 

suckers, are only landed by commercial fishermen for sale mostly in the bait market and 

therefore do not have a recreational value. Carp is currently only landed by the commercial fleet 

and therefore only has a commercial value. There is anecdotal evidence of a nascent and 

growing recreational carp fishery in the Western Basin, but carp landings by recreational 

fishermen do not appear in the Ohio Department of Wildlife Data. 

To calculate total damages, total commercial and total recreational harvests from 2008 were used 

to calculate the proportion of annual total harvest taken by each sector (ODW 2009). Adult 

equivalents estimated above were distributed to each sector based on these proportions and the 

WTP values from Table 8 were applied to the sector totals. Overall, the economic value of the 

damages caused to predator species from the BSPP are $21.4 million dollars annually. This 

technique assumes that any increase in production of predator fish will be distributed to the 

sectors following the current harvest distributions. The largest damages are from losses of 

walleye, $8.7 million, and losses of white perch, $8.3 million, each year. It is assumed that Lake 

 

9

 http://data.bls.gov/cgi-bin/cpicalc.pl 
Erie’s current ecosystem is currently not prey limited and these additional predator species 

would be able to find enough prey to consume in the current ecosystem.10

Table 8. Recreational and Commercial Values per Fish for use in Benefits Transfer of Great 

Lakes Fish Values (adapted from table 6 of Besedin et al 2004, adjusted to 2010 dollars). 

Species Commercial Recreational 

Catostomidae $0.49 n/a 

Carp $0.24 n/a 

Channel catfish $0.71 $2.41 

White bass $1.13 $2.86 

White perch $1.73 $2.86 

Largemouth bass n/a $16.77 

Smallmouth bass n/a $16.77 

Walleye na/ $20.38 

Yellow perch $3.45 $2.86 

Freshwater drum $0.24 $2.41 

Table 9. Economic Damage Estimates For Commercial and Recreational Target Species. 

Species Adult Equivalents Total 

Catostomidae 34,988 $17,021 

Carp 49,554 $11,972 

Channel catfish 74,419 $54,865 

White bass 2,518,792 $3,621,561 

White perch 4,733,036 $8,327,796 

Largemouth bass 4,251 $71,289 

Smallmouth bass 2,760 $46,285 

Walleye 427,866 $8,719,918 

Yellow perch 125,290 $394,847 

Freshwater drum 513,543 $160,048 

Total 8,484,500 $21,425,603 

While the authors readily acknowledge that the prey fish analysis presented above likely presents 

an upper bound on the number of walleye that could be supported by the prey species killed by 

the BSPP, these estimates remain as the only available technique to assess the economic 

damages due to the loss of prey species. Walleye were selected because they are the most 

popular target species, they are piscivorus and stomach content data was available. They are also 

the highest valued species and the values calculated here would be less if other species were used 

such as largemouth bass, smallmouth bass or white bass. 

It is more likely that the effect of increased prey availability would be to increase walleye growth 

and fecundity while reducing mortality, thereby increasing both the numbers and the value of 

each fish caught (larger fish are preferred to smaller fish), but estimating those biological 

relationships were beyond the scope of this project. The current carrying capacity for walleye in 

Lake Erie is far from its maximum, so the ecosystem could support additional walleye.8

 From the 

 

10 Personal communication with Chris Vandergoot, Ohio DNR. 
discussion above, 407,645 additional walleye could be supported by the impinged/entrained prey 

species. Applying the values per fish from Table 8, the value of prey species in the production of 

walleye increases the damage estimate $8.3 million in additional damages each year. Because 

Lake Erie is neither prey limited nor near its carrying capacity for walleye it is believed that this 

additional fish production could be supported. If prey species are included, total damages equal 

$29.7 million annually. 

These damage estimates were used to estimate the net present value (NPV) of the stream of 

damages identical to the length of time used in the Tetra Tech report to model the life cycle of 

cooling tower installation (Tetra Tech 2009). For this analysis, it was assumed the damages 

presented here would be exactly the same, year in and year out for 20 years into the future. The 

same discount rate, 7%, was used for this analysis as was used in the Tetra Tech report. This is 

also the discount rate recommended by the Office of Management and Budget (2007). Using 

this methodology the NPV of just the predator losses would be $227.0 million in 2010 dollars. 

Taking the prey losses into consideration increases the NPV of the stream of fish damages $88.0 

million over twenty years. Taking both streams of losses represents an NPF of $315.0 million 

over 20 years. The Tetra Tech estimate places the NPV of cooling tower installation at $292.9 

million over twenty years. 

Conclusion 

The estimates of adult equivalents killed by the impingement and entrainment of predators and 

prey by the BSPP are large and significant. Each year, the BSPP impinges at least 46 million 

fish and entrains 208.6 million eggs, 2.2 billion larval fish and 13.8 billion juvenile fish. These 

impinged and entrained fish equate to 54.5 million adult fish removed from the ecosystem each 

year with 8.5 million fish being adult predator fish targeted by commercial and recreational 

fishermen. The per year economic damages of this level of mortality equal $29.7 million per 

year with prey losses included and the NPV of a twenty year stream of these losses equals 

$315.0 million, or $22.1 million more than the cost of the cooling towers. This level of damages 

clearly supports the installation of cooling towers from the fisheries use damages alone. Some 

caveats apply to these estimates. 

Mid-range Values: The values per fish used above are suggested for use for this benefit transfer. 

As in any scientific study, there are sources of error within any benefits transfer. One source of 

error is the possibility that the context surrounding the study site (BSPP and the Western Basin) 

is very different than the context of the study sites used in the research studies that have been 

suggested here for benefit transfer. For that reason, only Great Lakes fishing studies were 

considered for transfer. However, the economic literature review did not identify a large number 

of studies with values from the Great Lakes that had suitable information to derive values in perfish units. The sample size of studies adds another element of uncertainty to the values. For that 

reason, values were selected that reasonably fell in the middle of the range of values and that 

were consistent with other values found in studies conducted outside the Great Lakes. Thus, the 

values in Table 8 are suitable for benefits transfer and reveal values that are in the middle of the 

range of values found in the literature. 

Other Economic Values: The benefits transfer approach taken here relies on studies of 

recreational fishing values to determine values for catching fish that can be applied to the losses 
in fish. The values that are estimated are only for fish and are only for the use of these fish via 

recreational and commercial harvests. There are likely other values that are affected by the lost 

fish that were not quantified here. For example, there would be losses in use values associated 

with wildlife viewing such as bird-watching to the extent that populations of migratory and 

resident birds that prey on Lake Erie fish are affected by the impinged and entrained fish. 

Similarly, if the impinged and entrained fish affect the quality of waterfowl hunting, there would 

be lost values for hunting. 

In addition to possible other lost recreational use values, there may be lost non-use value 

associated with the foregone fish and their ecological consequences. Non-use values refer to the 

values for the losses that are not in any way tied to one’s own use of the resource. For example, 

if a person who does not engage in any outdoor recreation, does not eat fish, and does not in any 

way use the resource, were nonetheless willing to pay higher energy bills to reduce the fish 

losses, then we would refer to that willingness to pay as a non-use value. There is nothing in 

economic theory that precludes the existence of such non-use values, though the measurement of 

non-use values can be challenging and was not addressed within this analysis. 

In addition, there are damages that are caused by the thermal pollution from the BSPP that are 

not accounted for here. Thermal pollution may induce additional fish mortality during the warm 

summer months. Thermal pollution may also increase the incidence and severity of algal 

blooms. Algal blooms have the potential to have negative health impacts and local residents 

certainly have a positive willingness-to-pay to avoid health problems from algal blooms. 

Additionally, local residents and visitors may have a willingness-to-pay to avoid algal blooms for 

reasons beyond adverse health consequences. None of these damages have been examined in 

this analysis. 

Also, the Tetra Tech report (2009) found that using a more typical estimation routine would have 

yielded 13% more impinged fish than the Ager et al (2008) study reported. The Tetra Tech 

report also suggested that seasonality may not have been adequately accounted for during the 

Ager et al (2008) study, meaning actual impingement and entrainment rates may be higher. If 

the impingement and entrainment estimates used are lower than the actual number of impinged 

and entrained fish, the economic damages would be higher than those presented here. 

As with losses in non-fishing uses, any loss of non-use value has not been quantified here due to 

limited information on the necessary ecological linkages as well as few economic valuation 

studies to apply to such losses. Had these other use and non-use values been included, the 

damage estimates would have been higher than those presented here, all else being equal. 
References 

Ager, D.D., I. Cord, S. Rkman-Filipovic, and P.H. Patrick. 2007. Bay Shore Power Plant Fish 

Entrainment and Impingement Study Report. Kinetrics report 112026-005-RA-0001-R00. 

163pp. 

Ager, D., D. Marttila, and P. Patrick. 2008. Bay Shore Power Plant cooling water intake 

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Appendix 1: Commercial Fisheries Detail 

Table A1. Annual commercial harvest (pounds) from the Ohio waters of Lake Erie, by species, 

2000-2009. 

Year Carp Channel 

Catfish 

Freshwater 

Drum 

White 

Bass 

White 

Perch 

Yellow 

Perchab Other Total 

2000 956,218 260,512 428,660 317,336 182,254 962,841 438,382 3,107,821 

2001 857,694 322,488 284,883 226,664 155,555 1,089,247 540,809 2,936,531 

2002 523,539 311,824 248,567 161,664 269,512 1,438,215 1,070,475 2,953,321 

2003 582,035 319,378 261,068 318,327 312,240 1,505,840 587,910 3,298,888 

2004 469,059 271,627 298,336 358,810 386,800 1,577,113 593,205 3,361,745 

2005 340,399 310,115 438,589 347,657 428,822 1,563,200 813,191 3,428,782 

2006 271,190 385,134 411,840 483,314 655,551 1,050,614 660,906 3,257,643 

2007 322,323 341,843 320,747 334,721 573,996 1,950,661 649,055 3,844,291 

2008 198,616 447,232 423,705 424,225 545,138 1,515,666 628,935 3,554,582 

2009 249,417 407,386 543,409 671,151 680,125 1,450,646 1,012,225 4,002,134 

Mean 477,049 337,754 365,980 364,387 418,999 1,410,404 3,374,574 

a A spring (March - April) closure on commercial yellow perch harvest was enacted in 1993. 

b Management unit 1 (the western basin) was closed to commercial yellow perch harvest in 2008 and 2009. 

Table A2. Ohio Dockside Prices, 2000-2009 (2009 dollars). 

Year Carp Channel 

Catfish 

Freshwater 

Drum 

White 

Bass 

White 

Perch 

Yellow 

Perch Others 

2000 $0.11 $0.76 $0.15 $1.02 $1.26 $3.28 $0.38 

2001 $0.12 $0.73 $0.12 $0.77 $1.22 $2.89 $0.30 

2002 $0.16 $0.72 $0.15 $0.60 $1.20 $2.09 $0.16 

2003 $0.16 $0.19 $0.15 $0.67 $1.18 $1.77 $0.28 

2004 $0.17 $0.46 $0.14 $0.70 $1.15 $1.89 $0.29 

2005 $0.17 $0.44 $0.15 $0.81 $1.11 $2.39 $0.20 

2006 $0.15 $0.35 $0.15 $0.74 $1.08 $2.45 $0.32 

2007 $0.13 $0.31 $0.18 $0.76 $1.05 $2.40 $0.32 

2008 $0.20 $0.33 $0.17 $0.55 $1.01 $1.65 $0.39 

2009 $0.21 $0.33 $0.19 $0.76 $1.01 $1.67 $0.53 

Mean $0.16 $0.46 $0.15 $0.74 $1.13 $2.25 $0.32