Chinese Mitten Crab (Eriocheir sinensis) Aquatic Invasive Species: Risk Screening Summary

On April 22, 2025, a commercial fisherman caught crab of unknown species in the Lower Columbia River east of Tongue Point. The specimen was given to the Oregon Department of Fish and Wildlife (ODFW), who identified the specimen as a Chinese mitten crab (Eriocheir sinensis). This is the first confirmed detection of E. sinensis in Oregon, though a specimen was collected in the Columbia River at the Port of Ilwaco, Washington in 1997. Additional information on the detection can be found at the following website: Chinese mitten crab found in Lower Columbia River.

Classification under Washington Administrative Code (WAC) Chapter 220-640

E. sinensis is listed as a Prohibited Level 1 aquatic invasive species under Washington Administrative Code (WAC) Chapter 220-640-030. Per Revised Code of Washington (RCW) 77.135, Prohibited Level 1 species may not be possessed, introduced on or into a water body or property, or trafficked, without department authorization, a permit, or as otherwise provided by rule.

Distribution in Washington

In 1997, a confirmed specimen of E. sinensis was reported south of Ilwaco in the Columbia River. In 2002, an angler reported catching a mitten crab on their line near Kalama, though no photo or specimen were available for confirmation. Other reports of E. sinensis were ultimately determined to be other species, commonly the native hairy shore crab, Hemigrapsus oregonensis.