|Title:||Snake River runs of salmon and steelhead trout: collection and transportation experiments at Little Goose Dam, 1971-74|
|Author/Editor:||Wesley J. Ebel|
|Institution:||Northwest Fisheries Center Processed Report, November 1974. National Marine Fisheries Service. Seattle, Washington|
The National Marine Fisheries Service has been conducting transportation experiments since 1965 to find ways of reducing downstream losses of Snake River populations of juvenile Chinook salmon Oncorhynchus tshawytscha and steelhead trout Salmo gairdneri. Since 1970, we have been concentrating on an experiment where migrating juvenile salmon and steelhead trout are collected at Little Goose Dam and transported to two locations downstream from Bonneville Dam.
The experiment is designed to determine the effect of transportation on homing and survival. Data summaries indicate that survival of both Chinook and steelhead can be increased by collection and transportation. The percentage increase in survival varies from year to year depending on river conditions. During years when survival of natural migrants was very low, we had correspondingly low survival of our control release, and the percentage benefit from transport was greatest. For example, in 1973, when survival estimates indicated an all time low survival rate for both juvenile Chinook and steelhead migrants, transport/control ratios were the highest (22:1 for Chinook; 23:1 for steelhead) recorded to date.