European Green Crab

The National European Green Crab (EGC) Management and Control Plan was developed by a multi-agency European Green Crab Working Group for implementation by the Aquatic Nuisance Species Task Force following final approval.

The purpose of the 2023 EGC plan is to provide guidance for efforts to prevent future introductions, to rapidly detect and respond to new invasions of EGC before they become established and create ecological and economic damage, and to manage current populations that pose an undue threat to resources of importance for ecosystems and local cultures. The 2023 EGC plan proposes to update the 2002 plan by providing a more focused set of approaches for future management, based on significant changes in the distribution of EGC, new technologies available for identifying sources and mechanisms of spread, better information regarding the tradeoffs for different management efforts, and new methods for data management and sharing. The 2023 EGC plan also describes current strategies for coordinating the activities of scientists, resource agencies, Tribal and First Nation organizations, and other entities.

Public Comment Period -- Written comments must be submitted on or before February 9, 2024. For more information, see the Federal Register notice Draft Revised National European Green Crab Management and Control Plan (Dec 26, 2023)

A new program will enable anyone who walks the shorelines of Puget Sound to identify one of Washington state’s most concerning invasive species: European green crab.

In response to this shore crab’s booming population, Washington State University Extension and Washington Sea Grant outreach specialists are rolling out the Molt Search program in May.

Deployment of emergency measures to control invasive European green crabs on the Washington Coast and at sites within the Salish Sea is well underway, including the implementation of an Incident Command System (ICS) to facilitate statewide coordination between various agencies, tribes, and partners.

The green crab is an invasive marine species spreading throughout the coastal waters of the United States. Efforts between NOAA Fisheries and Metlakatla Indian Community have been leading the way on monitoring to detect this species’ presence in Alaskan waters. The green crab has been found in U.S. waters since the 1800s, but this is the first confirmed presence in Alaska. They are a serious threat for Alaska’s tidal habitats.

If you see an invasive green crab on Annette Islands Reserve, call (907) 886-FISH to make a report. If you encounter a potential green crab elsewhere in Alaska, take photographs from multiple angles and send them to Tammy Davis. Then submit a report to the Alaska Invasive Species Reporter, or call the Invasive Species Hotline: (877) INVASIV.

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.