.SalmonScape

SalmonScape is an interactive mapping application designed to display and report a wide range of data related to salmon distribution, status, and habitats. The data sources used by Salmonscape include stream specific fish and habitat data, and information about stock status and recovery evaluations
 
 
California sea lion below Bonneville Dam
   
 
Evaluation of sea lion predation
An assessment by the U.S. Army Corps of Engineers of sea lion predation below Bonneville Dam and efforts to address it from 2009-10. Learn More >>
   

Restoring balance between predators and salmon

Columbia River salmon and steelhead face a serious threat from California sea lions that prey on fish waiting to move up the fish ladders at Bonneville Dam in early spring. Each year since 2002, sea lions have consumed thousands of migrating fish, many from threatened and endangered runs protected under the federal Endangered Species Act (ESA).

The federal Marine Mammal Protection Act recognizes that predation by a growing sea lion population can jeopardize salmon and steelhead stocks at risk of extinction.  For the past seven years, wildlife managers from Washington and Oregon have worked with federal and tribal partners to chase sea lions away from the area immediately below Bonneville Dam. But these efforts, alone, have not proven effective in curbing salmon predation by a robust population of California sea lions.

In March 2008, fish and wildlife agencies in Washington, Oregon and Idaho received federal authorization to remove California sea lions that have been observed preying on salmon and steelhead below Bonneville Dam. The federal authorization allows wildlife managers to use lethal measures to remove sea lions that meet specific criteria, although the states’ first priority has been to relocate them to zoos and aquariums.

Through 2013, wildlife managers removed a total of 58 California sea lions – 13 of which were sent to zoos and aquaria – that met the federal criteria. The number of salmon consumed by sea lions below the dam has declined in the past two years, but predation rates are still in the thousands and it is too early to assess the long-term effectiveness of those efforts.

In 2014, the Washington Department of Fish and Wildlife and partnering agencies will mark their ninth straight year in the ongoing effort to manage sea lions preying on protected Columbia River salmon runs.