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NOAA Fisheries Northwest Science Center Publication Details

CitationOgden, D. A., A. L. Barenberg, and R. M. Gleason. 2026. Operation of the Adult Trap at Lower Granite Dam, 2025. U.S. Department of Commerce, NOAA Contract Report NMFS-NWFSC-CR-2026-06. (https://doi.org/10.25923/aggw-wk49)
TitleOperation of the Adult Trap at Lower Granite Dam, 2025
Publication Year2026
Date04/14/2026
Keywordsbycatch, coded wire tags, walleye, snake river spring/summer chinook salmon, steelhead, pit tag, lower granite dam, coho salmon, sockeye salmon, spring-run chinook salmon, tissue sample, brood stock collection, adult fish trap, lower granite trap, genetic sampling, scale sampling, bull trout, snake river, fall-run chinook salmon, snake river bycatch, snake river fall chinook, lyons ferry hatchery, nez perce tribal hatchery, summer-run chinoook salmon
Abstract In 2025 the Lower Granite Dam adult trap began operations on Monday, 10 March. We operated the trap 5 d/week from 10 March to 17 August. Sampling started at a respective daily and overall trapping rate of 9 and 6.5%. Sampling was increased to a respective daily and overall trapping rate of 28 and 20% from 14 April to 17 August. The trap operated from 18 August to 9 September at a 70% trapping rate at the planned 24 hours, 7 d/week trapping schedule. Trapping rate was decreased to 16% from 10 September to close of trap on 3 November. Trapping was suspended for 5 days from 16 September to 20 September when water temperatures exceeded 21°C (70°F). A total of 13,488 steelhead Oncorhynchus mykiss were collected and handled at the adult trap in 2025. We injected 3,718 with passive integrated transponder (PIT) tags. All tagged hatchery steelhead had adipose fins intact with coded wire tag. We collected and handled a total of 13,509 wild and hatchery origin, spring, and summer run
Official CitationOgden, D. A., A. L. Barenberg, and R. M. Gleason. 2026. Operation of the Adult Trap at Lower Granite Dam, 2025. U.S. Department of Commerce, NOAA Contract Report NMFS-NWFSC-CR-2026-06.
Links (https://doi.org/10.25923/aggw-wk49)