Juvenile Chinook Salmon

The Columbia River system in the Pacific Northwest provides critical habitat for thirteen stocks (evolutionarily significant units [ESUs] of threatened or endangered Chinook salmon. There are many factors contributing to the decline of salmon populations in the Columbia River, including habitat degradation, over harvest, hydropower operation, and hatchery production. For outmigrant juvenile salmon, direct mortality may occur from natural causes such as predation, disease, chemical toxicity, water quality, nutrition, injury and physiological stress associated with smoltification.  Elevated fish stress may also result from movement through dams, through juvenile fish-passage and collection facilities, from transportation (barging), and from other strategies designed to facilitate the juvenile salmon outmigration. The goal of research in juvenile salmon outmigration is to evaluate the causes of disease and mortality and to address these problems throughout the system. In partnership with University of California at Davis and NOAA Fisheries, the University of Idaho is participating in a major study to compare Chinook salmon yearlings from Dworshak hatchery with transported and in-river emigration modes through the Snake and Columbia rivers.

Additional juvenile studies conducted by FERL,

·         An evaluation of the dam passage and ultimate survival of juvenile fall Chinook salmon moving past Little Goose Dam in the Lower Snake River, using acoustic telemetry.

·         Study of juvenile salmon transport studies at Bonneville Dam and other hydroelectric sites.

·         A test of the movement of juvenile Chinook from the mouth of Elwha River, Washington using acoustic telemetry: a partnership with the Elwha Klallam Native American Tribe.

·         The development of juvenile life history data for fall Chinook salmon using deterministic and stochastic modeling.