State officials are advising anglers to be on the lookout for the Chinese mitten crab, an invasive species that can wreak havoc on local crab populations.

Chinese mitten crabs have been caught in New Jersey waters, the most recent being those captured by both commercial and recreational fishermen in Raritan, Barnegat and Delaware Bays. Mitten crabs are native to Asia but have invaded portions of northern Europe and California.

Biologists would like to gather as much information as possible on any mitten crabs that have been caught this year or in recent years to help determine their current distribution. The public can help by providing information on any mitten crabs that are encountered.

The crabs are easy to identify and the online mitten crab poster lists identification characteristics as well as some general information on the species.  If a mitten crab happens to be caught, it is important to document as much information as possible and take a picture of the crab for identification and proof of capture.

Mitten crabs are thought to have come to the United States by way of illegally-dumped bilge water from large, ocean-going container ships that dock at U.S. ports. On the east coast, the Chesapeake Bay was one of the first major waterways where the invasive crabs have been spotted. In addition to competing for food with native crab species, the mitten crab is also known to disrupt ecosystems by burrowing into mud flats and other natural drainage systems.

For more information on the crabs, how to identify them the online poster and how to report them, please visit http://www.njfishandwildlife.com/news/2009/mittencrab09.htm on the division’s website.