Updated 2026-09-17 18:14:53
Lake Erie-2021-2025 -> 4.0 Prey Fish -> Prey Fish
Reporting Interval
2021 - 2025
Area
Lake Erie
Meeting Target?
Does Not Meet
Indicator Trend
Downward trend
Confidence?
High
Prey fish populations support predator condition and growth rates near the long-term average
Dominant prey fish species vary between basins with young-of-year spiny-rayed prey fishes (white perch and yellow perch) and young-of-year gizzard shad being more prevalent in the west basin and rainbow smelt, round goby, and emerald shiners being dominant in the central and east basins. Determination of critical levels of prey fish is based on growth and condition of walleye and lake trout with the goal of keeping predator growth and condition at or near the long-term average.
During the 2021–2025 reporting period, the lakewide prey fish index in Lake Erie was 3,307 fish/ha, which was higher than the prior reporting period (2,961 fish/ha; Figure 1). However, the index was highly variable with a sharp increase in 2021 and decline in 2023. Prey fish indices in 2023 and 2025 were the lowest values in the 34-year time series. While historically abundant, emerald shiner and adult rainbow smelt catches have been particularly low in recent years. Lake trout exhibited a declining trend in condition during the reporting period, while walleye condition appears to have stabilized relative to the prior reporting period (Figure 2). The average condition indices for both species fall below the average for the prior reporting period as well as the long-term average.
Figure 1. Annual mean lakewide prey fish abundance (fish/ha) in Lake Erie, 1992–2025.
Figure 2. Annual mean condition (relative weight; Wege and Anderson 1978) and time-series average of lake trout (age-5) and walleye (ages 3–6) in Lake Erie, 1983–2025.
Methodology
The prey fish community is assessed through long-term trawl surveys that occur in each of the basins. Four bottom trawl surveys are conducted annually by three agencies in late summer through fall across the three lake basins: west (Ontario Ministry of Natural Resources (OMNR) and Ohio Department of Natural Resources (ODNR); combined into the Interagency Trawl), central (ODNR), and east (New York State Department of Environmental Conservation and OMNR). The lakewide index is an average of basin-specific abundance indices. Generally, all small fishes that can be eaten by an average-size, age-1+ walleye are considered prey fish; the most important prey fishes in Lake Erie include rainbow smelt, emerald shiner, gizzard shad, and round goby (Knight et al. 1984).
Condition metrics (i.e., how heavy a fish is at a given length) are obtained from length and weights of individual fish taken in assessment surveys. Lake trout condition data for age-5 fish are collected during August by a multi-jurisdictional cold-water assessment survey conducted in the east basin. Walleye condition data for ages 3–6 are collected during October and November from ODNR gillnet surveys in the west and central basins. Relative weight (Wr; Wege and Anderson 1978) is calculated by comparing the weight of each fish at a given length to the weight of a standard “good condition” fish at that length (Wr = 100 indicates “good” condition; Neumann et al. 2012). Relative weight means are calculated by year and species.
Other Resources
- Forage Task Group. 2026. Report of the Lake Erie Forage Task Group, March 2026. Presented to the Standing Technical Committee, Lake Erie Committee of the Great Lakes Fishery Commission, Ann Arbor, Michigan. Available at: https://www.glfc.org/pubs/lake_committees/erie/FTG_docs/annual_reports/FTG_report_2026.pdf
- Francis, J., T. Hartman, K. Kuhn, B. Locke, and J. Robinson. 2020. Fish community objectives for the Lake Erie basin [online]. Available at: www.glfc.org/pubs/FisheryMgmtDocs/Fmd20-01.pdf
- Knight, R. L., F. J. Margraf, and R. F. Carline. 1984. Piscivory by Walleyes and Yellow Perch in Western Lake Erie. Transactions of the American Fisheries Society 113(6):677–693.
- Neumann, R. M., C. S. Guy, and D. W. Willis. 2012. Length, weight, and associated indices. Pages 637–676 in Fisheries Techniques, third edition. American Fisheries Society, Bethesda, Maryland.
- Wege, G. W. and R. O. Anderson. 1978. Relative weight (Wr): A new index of condition for largemouth bass. In G. D. Novinger and J. G. Dillard (editors), New Approaches to the Management of Small Impoundments, Special Publication, volume 5, pp. 79–91, American Fisheries Society.
Contributing Author(s)
- Arthur Bonsall - OMNR
- Zak Slagle - ODNR