Fish populations

Aerial view of the Tucannon River

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What we know about fish populations in the Snake River region

Some populations are stable, while others fluctuate

The Snake River region contains 12 demographically-independent populations of salmon, steelhead, and bull trout. Five of these populations have sufficient data to measure, and two, Asotin Creek and Joseph Creek summer steelhead, are exhibiting numbers above the recovery goal. Overall, populations of middle Columbia River steelhead within Washington are showing promising long-term trends towards meeting delisting criteria for adult abundance but distribution (spatial structure) remains a significant challenge for the Walla Walla population because of fish barriers in Mill Creek.

Populations of spring/summer Chinook are stable, and fall Chinook salmon are on the rise and far exceed draft recovery goals (final goals have not been set). The number of adult Snake River steelhead varies but overall is stable – Tucannon River steelhead are below the recovery target, Asotin River and Joseph Creek steelhead are above the target, and insufficient data exist for the Grande Ronde River. The measures below reflect the percent of populations with sufficient data.

Indicator data

Adult Abundance Summary Table

Adult Fish Abundance
Juvenile Fish Abundance

Juvenile populations continue to fluctuate

Results show juvenile spring/summer Chinook salmon and steelhead populations have stabilized while fall Chinook juvenile abundance is increasing.

Peak = [PEAK DENSITY] (juveniles/mile)

Visit How we measure for background about this data, and our Salmon Data Portal for original source data behind the indicator charts and graphs used throughout this site.