Status and trends in the Lake Superior fish community, 2025

By: , and 

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Abstract

The U.S. Geological Survey has conducted annual trawl surveys across Lake Superior since 1978 that describe trends in fish species occurrence and relative abundance to support fisheries science and management. In 2025, the Lake Superior fish community was sampled with daytime bottom and surface trawls at 72 nearshore stations in May and June and 36 offshore locations in July. Nearshore bottom trawls collected 63,005 fish represented by 30 species or morphotypes. The number of species collected at each location ranged from 1 to 13, with a median of 7.0 species. Estimated fish biomass density at individual stations ranged from <0.1 to 125.7 kg per ha with a lakewide mean of 7.6 kg per ha. Offshore bottom trawls collected 30,342 fish represented by 13 species or morphotypes. Estimated fish biomass density at individual stations ranged from 1.6 to 34.7 kg per ha with a lakewide mean of 9.1 kg per ha, which was the highest since the offshore survey began in 2011. Lakewide average numerical densities (fish per ha) of age-1 fish were 0.67 per ha for Bloater, 0.01 per ha for Cisco, 1.15 per ha for Kiyi, 0.95 per ha for Lake Whitefish, and 336.33 per ha for Rainbow Smelt. Surface trawling collected 1,562 larval Coregonus individuals which was the fewest Coregonus larvae collected in a whole lake survey since the larval fish survey began in 2014. Nearshore mean larval Coregonus numerical densities were 156 fish per ha in May and June 2025 and 21 fish per ha in July 2025. May mean surface water temperatures (6.1°C) were near the warmest for the period-of-record, while June (6.8°C) and July (10.0°C) were near average or below.  

Suggested Citation

Watson, N.M., Field, I.I., Myers, J.T., and Yule, D., 2026, Status and trends in the Lake Superior fish community, 2025, 24 p.

Study Area

Publication type Report
Publication Subtype Organization Series
Title Status and trends in the Lake Superior fish community, 2025
Publication Date March 31, 2026
Year Published 2026
Language English
Publisher Great Lakes Fishery Commission
Contributing office(s) Great Lakes Science Center
Description 24 p.
Country Canada, United States
Other Geospatial Lake Superior
Additional publication details