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European Green Crab

European Green Crab is an invasive shore crab. Originally from Europe, this crab reached San Francisco from an East Coast population in 1989. By 1998, it had already spread to coastal Washington waters. Like many invasive species, it has traits that make it particularly pesky to our local estuaries. European Green Crab is not picky in its diet—it eats a variety of shoreline food organisms including shellfish, algae, and vegetation. This invasive pest tolerates greater changes in salinity and temperature than native crabs like the Dungeness crab. Limited trapping efforts in the early 2000s revealed that the populations of this crab remained relatively low but have continued to increase their population size with each El Niño event. Increased trapping efforts by local shellfish growers in Willapa Bay and Grays harbor have removed 137,000 adult crabs in one year from March 2022 to April 2023.

wdfw staffer holding two european green crabs

Located at the WSU Long Beach Research Unit, our team is located near two estuaries, Willapa Bay and Grays Harbor, currently at risk of seeing detrimental effects to the ecology and economy from growing European Green Crab populations. Our team focuses on developing an extension program and research to support an Integrated Pest Management framework for European Green Crab.

Integrated Pest Management or IPM refers to a practice of using a variety of pest management strategies, such as biological, cultural, physical, and/or chemical interventions, as part of a science-driven strategy that seeks to minimize risks to human health, the environment, and the local economy.

Our program is focused on understanding the needs of local stakeholders and seeking national and international collaboration and capacity to provide timely and feasible pest management practices that will help protect the ecology and economy of our local estuaries from this invasive pest.


Think you found a European Green Crab? Please, report it to WDFW using their website linked here.Artistic rendering from WDFW of european green crab to show identification features


We’re not the only team at WSU working on this issue. Bob Simmons of WSU Cooperative Extension is collaborating with SeaGrant to train volunteers to identify and report molts of Euorpean Green Crab in an effort to improve early detection of this pest in the Salish Sea.

How to identify crabs using their carapace from molts
Photo: Jeff Adams, Washington Sea Grant