Conversion of Derelict Foster-Lucas Ponds to Semi-Natural Spawning Channels for Upper Columbia River Summer Steelhead Reproductive Success Studies at Winthrop National Fish Hatchery, Winthrop, WA

A complete life history evaluation of Upper Columbia River summer steelhead reared under 1-year and 2-year programs is occurring at Winthrop National Fish Hatchery. To evaluate relative reproductive success of returning adults from both groups, aging Foster-Lucas rearing ponds were converted into semi-natural spawning channels. Repairs were made to two replicate channels, spawning gravels were introduced, habitat units were groomed, air-lift pumps and spray-arms were retrofitted to simulate typical stream conditions, and observation blinds were fitted. To test the efficacy of the spawning channels a 2014 pilot effort was conducted and consisted of introducing eight adult pairs to a single channel. Fish were allowed to naturally compete and spawn. Seven of eight females spawned successfully and fry emerged as predicted by thermal units. Fry were successfully sampled in early August and September. Population estimates in August ranged from 6,676 to 9,076 (95% CI), after some mortality and cannibalism had occurred. Provided sufficient hatchery-origin adults are collected in 2015, the full study will be implemented, consisting of two replicate ponds with 12 pairs stocked in each. Results will help us better understand how different freshwater life histories (1 vs. 2-year rearing) can influence recovery efforts using hatcheries as a conservation tool.