Smithsonian Environmental Research Center

The Smithsonian Environmental Research Center needs the help of local citizens to track and monitor the appearance of the Chinese Mitten Crab, a potentially harmful invasive species along the eastern United States.

The crab is distinctive because its claws are covered with setae which looks like fur and gives them the appearance of wearing mittens. They have established themselves in California, and in England where they’ve been shown to clog power plant intake valves and other industrial equipment and to cause severe shoreline erosion.

Mitten crabs began showing up in the Mid-Atlantic region of the United States in 2005. In total, thirteen Mitten Crabs have now been confirmed in the Chesapeake Bay, the Delaware Bay and the Hudson River. All of the crabs were found between 2005-2008. Additional Mitten Crabs were reportedly captured in Chesapeake Bay and Delaware Bay in 2007, although species identification has not been confirmed.

The Mitten Crab Task Force monitored freshwater tributaries of the Chesapeake Bay this spring. With special traps used to collect mitten crabs in China, the task force surveyed areas near previous sightings where conditions are thought to be favorable for over-wintering mitten crabs. No mitten crabs were found during these surveys, but if they are established in the region, the scientists expect them to be moving into salt water throughout the summer months.

SERC asks the public to be on alert for Mitten Crabs in bays and estuaries of the Atlantic coast. Mitten crabs have been found crab pots and washed up on the shore. Identifying photos and materials can be found on the following website: www.serc.si.edu/labs/marine_invasions/.

For anyone finding a Mitten Crab, please:
- do not throw it back alive!
- note the location and date of capture;
- take a photograph and/or retain the crab; and
- contact the Mitten Crab hotline at SERCMittenCrab@si.edu or 443-482-2222.