Pacific Northwest Research Station

Increasing the population of spring Chinook salmon and summer steelhead in Washington state’s Methow River is a goal of the Upper Columbia Spring Chinook Salmon and Steelhead Recovery Plan. Spring Chinook salmon and summer steelhead are listed as endangered and threatened, respectively, under the Endangered Species Act.

Installing logjams and reconnecting the river to its floodplain are management actions being undertaken to restore salmon habitat. However, researchers with the U.S. Forest Service Pacific Northwest Research Station, the U.S. Geological Survey, and Idaho State University found that focusing solely on physical habitat restoration overlooks the importance of maintaining the food webs supporting all river life.

When comparing prey production and habitat structure in the Methow River system, the research team found that complex floodplain landscapes support an array of food webs. Restoration actions may unintentionally alter these food webs, either to the benefit or detriment of juvenile salmon. Restoration efforts designed to protect the processes that create and maintain habitat complexity and sustain diverse food webs may be more beneficial to fish. As part of this holistic approach, the research team developed a model that allows land managers to explore how proposed river restoration projects influence river food webs and fish populations.