Sea Lions

We have worked with the U.S. Army Corps of Engineers to evaluate how California and Steller sea lions that congregate below Bonneville Dam on the Columbia River affect adult Chinook salmon and steelhead. We have estimated stock-specific predation rates for Chinook salmon, evaluated the incidence of sea lion-induced injuries on salmon and steelhead, and examined the effects of sea lion exclusion devices (gates that exclude sea lions from fishway) on the behavior of radio-tagged fish.

Study topics include:

• Population-specific predation estimates
• Effects of sea lions on salmon behavior in the Bonneville tailrace
• Incidence of sea lion injuries and effects on salmon and steelhead migration
• Relationship between sea lion deterrence efforts and fish behavior