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 2009-17. Learn More >>

Restoring balance between predators and salmon

Columbia River salmon and steelhead face a serious threat from 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.

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 over a decade, 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 those efforts, alone, have not proven effective in curbing salmon predation by a robust population of 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. While the federal authorization allows wildlife managers to euthanize sea lions that meet specific criteria, the states have worked to place these animals in accredited zoos and aquariums whenever possible.

These efforts have helped to control the portion of the salmon and steelhead runs taken by sea lions below Bonneville Dam, although thousands of fish are still lost to predation every year.

In 2018, the Washington Department of Fish and Wildlife and partnering agencies will continue their effort to manage sea lions preying on protected Columbia River salmon runs.