Sunday, September 20, 2009

Idaho Salmon overwintering in Snake River

Outmigrating fall Chinook from the Clearwater River are showing a curious migration pattern. Normally most Chinook smolts head straight out and hit the salt water during the spring through the fall, however On the Snake system the overwhelming majority of fall spawning chinook from the clearwater are overwintering in the Lower Mainstem Snake. The pattern was first noticed in the 1990s and scientists with the federal government and the Nez Perce tribe are now hoping to understand whats driving juvenile chinook to spend the entire winter in freshwater. The artificial slack water habitats on the lower Snake typically slow down the passage of fish downstream and there's a chance fish just aren't getting through the system in time to hit their physiological window for smolting. See more coverage in the Oregonian.

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