GREENWICH, Conn. — A Chinese mitten crab capable of wreaking environmental havoc has been found in Greenwich's Mianus River.
The crabs can drive native species out of their habitats, cause riverbank erosion, clog pipes and damage fishing gear, said Susan Frechette, deputy commissioner of Connecticut's Department of Energy and Environmental Protection.
"This discovery is of some concern," Frechette said on the agency's website. "However, these crabs are relatively new to the Atlantic Coast, and, at this time, it is unclear as to what their effects actually will be."
A Chinese mitten crab also may have been spotted in Fairfield's Mill River in 2010, but biologists called to investigate could not find it, said Nancy Balcom, associate director of Connecticut Sea Grant at the University of Connecticut.
"It's important that people keep an eye out for these crabs and report them," Balcom said. "Early detection of new species in our marine or fresh waters can help lead to more options for control and spread prevention.
Here's how you can identify the crabs, according to the Department of Energy and Environmental Protection:
• Claws are of equal size. "Furry" claws with whitish tips.
• Brown to green carapace, four spines (the fourth can be small) on each side.
• Notch between the eyes.
• Only crab that would be found in freshwater in the Northeast.
• They can be up to 12 inches.
It is illegal to transport these crabs. If you find one, the agency said, keep the crab on ice or freeze it, note the exact location it was found, and contact DEEP Marine Fisheries at 860-434-6043, DEEP Inland Fisheries at 860-424-3474 or Nancy Balcom of CT Sea Grant at 860-407-9107.
All crabs found in freshwater should be investigated because there are no native freshwater crabs in New England, the agency said.