Implementation of the Inland Avian Predation Management Plan in the Columbia River Basin

Based on a multi-year evaluation of piscivorous birds on outmigrating salmonid smolts through the mid-Columbia River, two Caspian tern (Hydroprogne caspia) (tern) colonies in the Columbia River plateau region are known to contribute to predation on ESA-listed salmonids. These colonies, at Goose Island (Potholes Reservoir, Grant County, WA) and Crescent Island (McNary Reservoir, Walla Walla County, WA), are the largest tern colonies within the Columbia River plateau region.  The U.S. Army Corps of Engineers, Walla Walla District and Bureau of Reclamation have developed the Inland Avian Predation Management Plan (IAPMP) to decrease predation on ESA-listed salmonids by terns at these two locations.

Implementation of the IAPMP began in 2014 with initiation of passive and active tern dissuasion efforts at Goose Island. Dissuasion efforts resulted in the reduction of both the number of nesting terns at Goose Island and predation on ESA-listed salmonids.  To help further reduce predation on ESA-listed fish by terns, alternative nesting habitat for Caspian terns was recently completed in southern San Francisco Bay where predation rates by Caspian terns on ESA-listed species is lower.  During the 2015 nesting season, Caspian tern dissuasion efforts will continue at Goose Island and begin to be implemented at Crescent Islands.