European Green Crabs verified in Southeast Alaska

Invasive European green crabs have been verified for the first time in Alaska, in the Annette Islands Reserve in southern Southeast Alaska.

As of Aug. 9, the Metlakatla Indian Community (MIC) Department of Fish and Wildlife had trapped 32 live European green crabs from Tamgas Harbor, according to the Alaska Department of Fish and Game, which is working with the Metlakatla Indian Community and National Marine Fisheries Service to quell the invasion. Surveys in adjacent Smuggler’s Cove have resulted in detection of only dead invasive crabs. European green crabs are classified as a banned invasive species.

European green crabs are considered one of the top 100 worst invasive species globally. As highly competitive, voracious predators, these crabs have decimated shellfish populations, displaced native crabs, and reduced eelgrass and saltmarsh habitats in areas where they have become established outside their native range. Unless controlled, they can significantly reduce biodiversity and abundance of inter- and subtidal species and destroy nearshore ecosystems.

ADF has for nearly two decades supported early detection monitoring for this invasive species by providing technical assistance and traps, and MIC has been conducting its own early detection program around Annette Islands Reserve for the past three years. Since discovery of European green crabs on July 19, MIC has implemented eradication protocols by increasing trapping effort, partnering to collect samples and data for research, and expanding monitoring and outreach. NOAA Fisheries has provided technical and financial assistance for the MIC program. This fall, ADF will survey for presence of European green crabs in vulnerable estuaries and embayments in southern Southeast Alaska.