The Plan
tern decoys at the Sheepy Lake site
The Caspian Tern Management to Reduce Predation of Juvenile Salmonids in the Columbia River Estuary was created by the U.S. Army Corps of Engineers (USACE), the U.S. Fish and Wildlife Service and NOAA fisheries in 2005. The aim of the plan is to redistribute a large number of Caspian tern breeding pairs from East Sand Island to alternative nesting sites in the San Francisco Bay Area and inland Oregon by 2015, with the goal of reducing predation by Caspian terns on out-migrating juvenile salmonids in the Columbia River Estuary, in the hope of recovering the stocks [5].
The original plan included three sites in inland Oregon: Fern Ridge Reservoir, Crump Lake, and the Summer Lake Wildlife Area, and three sites in the San Francisco Bay area: the Don Edwards National Wildlife Refuge, Hayward Regional Shoreline and Brooks Island, while simultaneously reducing available nesting space on East Sand Island. The goal ratio was to build two new acres of alternate nesting sites for every one acre taken away from East Sand Island. This would result in an overall 60%-70% reduction in nesting pairs which would reduce the annual consumption of out migrating salmonids by an estimated 3.0 million fish. Because of this, two additional sites, Tule Lake National Wildlife Refuge (NWR) and Lower Klamath NWR, both in California, were added to the plan in 2006. In total the plan called for the creation of 7.3 acres of new or restored nesting habitat on eight new islands [5].
The plan also includes using active attraction methods to encourage the terns to colonize the new islands. This active social attraction method uses audio recordings of Caspian terns and introduces decoys that mimic the Caspian terns visually. Leg bands were attached to East Sand Island terns in order to track the relocation progress [7].
The original plan included three sites in inland Oregon: Fern Ridge Reservoir, Crump Lake, and the Summer Lake Wildlife Area, and three sites in the San Francisco Bay area: the Don Edwards National Wildlife Refuge, Hayward Regional Shoreline and Brooks Island, while simultaneously reducing available nesting space on East Sand Island. The goal ratio was to build two new acres of alternate nesting sites for every one acre taken away from East Sand Island. This would result in an overall 60%-70% reduction in nesting pairs which would reduce the annual consumption of out migrating salmonids by an estimated 3.0 million fish. Because of this, two additional sites, Tule Lake National Wildlife Refuge (NWR) and Lower Klamath NWR, both in California, were added to the plan in 2006. In total the plan called for the creation of 7.3 acres of new or restored nesting habitat on eight new islands [5].
The plan also includes using active attraction methods to encourage the terns to colonize the new islands. This active social attraction method uses audio recordings of Caspian terns and introduces decoys that mimic the Caspian terns visually. Leg bands were attached to East Sand Island terns in order to track the relocation progress [7].
