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Home / Aquatic Invasives / Aquatic Invertebrates / European Green Crab

European Green Crab

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European green crab
European green crab, adult - Photo by Caleb Siemmons; National Ecological Observatory Network
Scientific Name: 
Carcinus maenas (Linnaeus, 1758) (ITIS)
Common Name: 
European green crab, shore crab, Joe rocker
Native To: 
Date of U.S. Introduction: 
1817 (East Coast); 1980s (West Coast) (Carlton and Cohen 2003)
Means of Introduction: 
Possibly through ballast water, hull fouling, or intentional releases (Carlton and Cohen 2003)
Impact: 
Preys on bivalves and other crustaceans, such as soft-shell clams and scallops (Grosholz and Ruiz 2002)
Current U.S. Distribution: 
North Atlantic coast; Pacific Coast

Spotlights

Office of the Governor (Washington).

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.

National Science Foundation.

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.

DOC. NOAA. Fisheries.

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.

Images

Videos

Google. YouTube; EarthFix Media.

Google. YouTube; Fisheries and Oceans Canada.

Selected Resources

The section below contains highly relevant resources for this species, organized by source. Or, to display all related content view all resources for European Green Crab.

Council or Task Force

Washington State Recreation and Conservation Office. Washington Invasive Species Council.

Aquatic Nuisance Species Task Force.
Partnership

San Francisco Estuary Institute; Center for Research on Aquatic Bioinvasions.

IUCN. Species Survival Commission. Invasive Species Specialist Group.
Northeast Aquatic Nuisance Species Panel.

Texas Commission on Environmental Quality, Galveston Bay Estuary Program; Houston Advanced Research Center (HARC).

Texas State University System. Texas Invasive Species Institute.

Federal Government

DOC. NOAA. Fisheries.

The green crab is considered one of the most invasive species in the marine environment. It has few predators, aggressively hunts and eats its prey, destroys seagrass, and outcompetes local species for food and habitat. Green crab could potentially damage Alaska’s multi-billion dollar fisheries industries, especially for salmon, crab, and mariculture operations. Thankfully, no green crabs have yet been detected in Alaskan waters, but concerned Alaskans have been planning for the arrival of these voracious crustaceans. There are three simple steps you can take to help find, remove and report these crabs on your local beaches. Find it, Keep it, Freeze it!

Smithsonian Institution. Smithsonian Environmental Research Center. Marine Invasions Research Lab.

DOI. USGS. Wetland and Aquatic Research Center.

Provides distribution maps and collection information (State and County).

International Government

New South Wales Department of Primary Industries (Australia).

State and Local Government
Washington Department of Fish and Wildlife.
Alaska Department of Fish and Game.
Academic

University of Delaware. Delaware Sea Grant College Program.

See also: Delaware's Invasive Crabs for more story maps

Washington Sea Grant.
Columbia University. Center for Environmental Research and Conservation.
Professional

Prince William Sound Regional Citizens' Advisory Council.

See also: Marine Invasive Species for more fact sheets

Citations