The NC Department of Environmental Quality’s Division of Marine Fisheries is reminding people to please report any sightings of Blue Land Crabs, Cardisoma guanhumi.
Blue Land Crabs are a non-native species to the Carolinas that look like enormous fiddler crabs. There have been an uptick in sightings in North Carolina, South Carolina and Georga in recent years.
They are native to the southern Atlantic coasts from Brazil to South Florida, but sightings were first reported in South Carolina in 2008. The first confirmed blue land crab sighting in North Carolina occurred in summer 2023. Since then, there have been 23 confirmed sightings in North Carolina and another 34 unconfirmed reports. Two of the 23 confirmed cases were this year, both in Emerald Isle.
Researchers do not yet know the extent of the crab’s range throughout the Carolinas or its impact on the environment and other wildlife. Whether the species arrived through natural expansion or human intervention is also not clear. Reporting sightings can help biologists learn more about where these crabs are spreading.
Despite their name, the crabs vary widely in color. Adult males tend to have the characteristic blue-gray coloring, but females can also be white or ash-gray. Juveniles can range from orangish to dark brown to purple. They're unusually long-lived and slow-growing among crab species, reaching maturity at four years of age and surviving up to 11 years. For more information and images please visit the Blue Land Crab Species Profile Page.
Blue land crabs are difficult to catch. In addition to their speed at retreating into burrows deep below ground, the crabs possess a large claw they can use to dexterously defend themselves. If you see one of these crabs, biologists encourage you to snap a photo and report the date and the location of your sighting using the link below. Biologists suspect the crabs may be more visible following heavy rains, which can drive them out of their burrows.
Click here to report sightings. For more information, please contact Scott Scripter with the NC Division of Marine Fisheries or Bronwyn Williams with the N.C. Museum of Natural Sciences.