May 27, 2020, 01:12:23 AM
Welcome, Guest. Please login or register.
Did you miss your activation email?
Total time logged in: 0 minutes.
   Home   Help Login Register  



Pages: [1]   Go Down
Author Topic: Crab attack: Chinese mitten crabs are invading Columbia County, NY State  (Read 2540 times)
0 Members and 1 Guest are viewing this topic.
Registered User

Offline Offline

Gender: Female
Posts: 30
Location: Long Island, NY

« on: October 06, 2008, 12:31:26 AM »

Hi from Long Island, NY. This story has me very worried! anxious

Crab attack: Chinese mitten crabs are invading Columbia County
By TADD GERO 09/30/2008
[ps: Columbia county is half way up the Hudson River to Lake George.]

FISHERMEN NEAR THE MOUTH of the Hudson River found the first Chinese mitten crabs in the Hudson in 2007. Robert Schmidt of Hillsdale, Professor of Biology at Bard College at Simon's Rock and assistant director of Hudsonia, says he had discovered Chinese mitten crabs at the mouth of the Roeliff Jansen Kill [Kill is old Dutch for creek or stream] by this past spring. In a couple of years, he says, "They'll be coming to a neighborhood near you."

      The crabs originate in a region stretching from the Korean Peninsula to the Fujian province in southern China. They have a black shell that can get upwards of 100 millimeters, nearly 4 inches wide; and once they mature, their claws develop a thick hairy coating that resembles a mitten, explaining their name.

      According to Schmidt, Chinese mitten crabs were first recorded as an invasive species in Europe, where they have become a significant problem, during the 1920's.

      An invasive species is a non-indigenous organism that negatively impacts the habitat it invades economically, ecologically or environmentally.

      Schmidt says as recently as September 23 he found four mitten crabs in the Kline Kill under a bridge on Wire Road in Germantown, and with the help of interns Erin Swift and Ira Shadis he consistently found mitten crabs in other waterways of Columbia Dutchess counties this past summer. Near Hudsonia, the environmental research institute on the campus of Bard College in Annandale, Schmidt says he has found more than 150 exoskeletons shed by mitten crabs in a small stream, indicating a sizable population there. He has also found crabs in the Cheviot Brook in northern Germantown.

      When Nyack Fisherman Bob Gabrielson discovered the first crabs in the Hudson River, he was struck by their appearance.

      "When we caught the first one in 2007 the crab was pretty darn ugly," says Gabrielson. "It looked like a spider crab, looked like it had a muff of hair on its claws. I guess that's 'cause it looked like a mitten."

      Gabrielson said he's heard more have been spotted, but he doesn't want them around. "There would be no market for them, they'd be a real problem if they generate, and we don't want anything to interact with blue crabs," he says. "In the west coast they're detrimental to crabbing business, apparently infringing on the food sources...A real pain in the [arse] and they ain't good for nothing."

      They're actually downright destructive, according to the state Department of Environmental Conservation. "They have the potential to destroy commercial catches and nets by pinching the fish and nets--this was a big issue in San Francisco Bay," Lori O'Connell of DEC said in an email.

      Mitten crabs were first discovered in the United States during the 1990s in San Francisco Bay, where Schmidt says they have interfered significantly with commercial fisheries. On the east coast, they've been found in the Chesapeake Bay and the St. Lawrence River.

      A potential problem for the Hudson River ecosystem is that the crabs reproduce at a rapid rate and are known to lay upwards of a million eggs at a time, causing them to push native species of all kinds out of the environment and clog water systems by their sheer numbers. Mitten crabs also make their homes by burrowing into riverbanks, causing significant erosion and habitat destruction.

      Another issue is that there are no indigenous fresh water crabs of any kind in North America: blue crabs native to the Hudson are saltwater crabs that exist primarily in the southern part of the river, where the water has a high salt content. Schmidt says the mitten crabs' rapid reproductive rate will force a sudden high density of crabs into an environment that never has had crabs, and that this will disrupt the ecosystem.

      Mitten crabs mate in salt water, but they migrate into freshwater as they mature. The fact that they have moved into Columbia County only two years after they were first discovered at the mouth of the Hudson is the result of the crabs' ability to travel through waterways rapidly. Another problematic factor is that mitten crabs have the capacity to travel long distances on land.
     "There was an example in Europe where they traveled over 1,000 kilometers from Germany to Prague in the Czech Republic," says Schmidt. "People have watched thousands of mitten crabs moving around a barrier at a fishery. They're incredible."

      Schmidt says there was also one occasion in Germany where the crabs were running down the street and into people's houses. "But don't worry if you're swimming," he says. "They're so skittish they'd be gone before you ever saw them, which unfortunately for me, makes them very hard to catch and monitor."

      No one has come up with any sort of method to control their population yet, according to Schmidt, so they're continuing to spread at alarming rates. "They're frightening," he says. "They could spread all over Columbia County and the United States."

      Schmidt says one of the ways mitten crabs could have been able to travel from East Asia to United was through international shipping. Ships take in seawater before departure--ballast water used to maintain a ship's balance--then release it upon arrival. He says it is likely that mitten crab larvae got sucked up in East Asia and released into American waters.

      Mitten crabs are also a delicacy in Chinese Szechwan cuisine, and Schmidt says it's possible that live crabs were brought by ship to a Chinese market, from where a few escaped the kitchen and into American waters. He says it is now illegal in New York to be in possession of a live Chinese mitten crab, but with a price of $25 a crab, a black market has developed. New York Fish and Wildlife recently confiscated a shipment of 2,500 mitten crabs in New York harbor.

      Anyone who comes into possession of a mitten crab has been instructed by the New York State Department of Environmental Conservation to kill it immediately, by freezing it, and reporting the crab and the location where it was found to the New York State Fish and Wildlife Department.


Pages: [1]   Go Up
Jump to:  

Powered by SMF 1.1.21 | SMF © 2015, Simple Machines
Simple Audio Video Embedder

Google visited last this page March 26, 2020, 08:31:07 AM