European Green Crab

Washington Governor Jay Inslee has issued an emergency order (PDF| 174 KB) to address the exponential increase in the European green crab population within the Lummi Nation’s Sea Pond and outer coast areas. The European green crab is a globally-damaging invasive species that, if they become permanently established, will particularly harm endangered species, impact resources that are part of the cultural identity of the tribes and native peoples, and affect small businesses.

European green crabs are one of the most widespread invasive marine species on the planet, originally reaching Washington in 1996. When green crab populations grow too large, they compete with other shellfish, disturb the sediment, and destroy the eelgrass that is an important habitat for Dungeness crab and salmon. The U.S. Geological Survey (USGS) is working to increase the effectiveness of Washington’s green crab early detection and rapid response program. Research conducted at the USGS' Western Fisheries Research Center aims to improve native shellfish habitat and limit the spread of European green crabs in coastal waters.

The green crab, Carcinus maenas, is a widely distributed invasive species that eventually alters its new environment. It's assumed that such species have high genetic diversity, or a variety of characteristics allowing them to adapt and thrive. But the green crab has low genetic diversity, while still spreading rapidly in a new part of the world. A U.S. National Science Foundation-funded study led by Carolyn Tepolot of the Woods Hole Oceanographic Institution is investigating the adaptive mechanisms of the green crab along the west coast of North America, where it has shown extensive dispersal in the last decade despite minimal genetic diversity. The results are published in Molecular Ecology. The project is a collaboration among scientists at WHOI, Portland State University, the Smithsonian Environmental Research Center and the University of California, Davis.

Natural resource managers in British Columbia discovered several adult male and female European green crabs on Haida Gwaii this past July. Alarm bells immediately went off for biologists in Alaska. The archipelago of Haida Gwaii, off the coast of Prince Rupert in British Columbia, is very close to Alaska. The July discovery is the closest confirmed finding of the invasive crustacean since it was first detected in the San Francisco Bay area in 1989.