Wetlands in Oregon

Wetlands have special significance for Oregon's biodiversity. Although limited in their distribution, they are among the most biologically productive and species-rich habitats in Oregon. Wetlands also play key roles in major ecological processes and provide a number of important ecosystem services, regulating water flows, reducing flooding, and improving water quality, among other functions.

Thirty percent of Oregon's terrestrial vertebrates (164 species) regularly use freshwater marshes, and Oregon's estuaries alone are used by more than 100 bird species and 35 species of fish and shellfish. Oregon's wetlands also support dozens of rare plant communities and sensitive, threatened and endangered species ranging from coho salmon and spotted frogs to the western pond turtle, upland sandpiper and sandhill crane.

Wetlands have particular significance because of their importance for migratory species that depend on these habitats as critical links in a chain that may extend far beyond the state's borders. Oregon's wetlands provide critical habitat for millions of birds traveling the Pacific Flyway, and all of Oregon's native salmon stocks depend on wetland habitats at one or more critical stages in their life history.

Estimates of wetland losses in Oregon vary widely. One widely quoted 1990 U.S. Fish and Wildlife Service study estimated 38 percent of the state's historic wetlands have been converted to agricultural, commercial and other uses. These losses are compounded by the fact that most remaining wetlands have been significantly degraded. These habitat losses have magnified the importance of remaining wetlands and spurred development of a variety of strategies to protect and restore estuarine and freshwater wetlands.

For a brief regional overview of some of Oregon's most important wetlands, click on one of the ecoregions listed below:

Coast Range
Willamette Valley
East Cascades
Basin and Range
Blue Mountains
Columbia Basin

Updated September 22, 2004