Monitoring Estuarine Survival of Steelhead Trout Smolts Using Acoustic Telemetry

Steelhead is a species of concern throughout Oregon, with several populations already listed as threatened or endangered. Oregon coastal steelhead are already designated as a species of concern and regulations are in place to completely protect native winter run steelhead from harvest. We developed a method for estimating steelhead smolt survival to the ocean using acoustic telemetry in the Alsea River, Oregon. We collected data during 2009 and 2010, years with very different river flow regimes. Our results are consistent for the 2 years of data: 1) wild steelhead smolts spend little time in the estuary, 2) typically only 50% - 60% of the wild steelhead smolts reaching the estuary actually enter the ocean, 3) most losses occur in the lower estuary. These data can better inform management decisions, benefit steelhead anglers, and assist in guidance for more effective estuarine restoration projects.