Green crabs top out at about 10 centimeters (4 inches) across. They displace native species with their voracious eating and breeding habits: clams, oyster, mussels, marine worms and other crabs fall prey. Green crabs also devour herring, salmon bones, or canned cat food, which are most commonly used to bait the traps.upper image by Linda Shaw, NOAA
The crabs appear to be moving northward on the currents. Scientists have found them in substantial numbers on the outside coastline of Vancouver Island in British Columbia and speculate that they may have already spread northward to the Queen Charlotte Islands. Vigilant monitors have not yet found any green crabs in Alaska, but the estuaries and sheltered coves of Southeast Alaska are the most likely first sighting points.
Green crabs can also hitch a ride in ballast water of ships.
So in Dutch Harbor, Homer, Kodiak, Tatitlek, Whittier, Valdez, Cordova and Chenega in western and south-central Alaska as well as Glacier Bay, Sitka, Juneau and Ketchikan in southeast Alaska, dedicated individuals are regularly wading into the shallows to check their traps.
Tuesday, May 5, 2009
YIKES! - The Green Crab Invasion of Alaska Coming? Probably
At Wesley Loy's new blog, Deckboss, Loy has posted an article on the probable appearance soon in Alaska waters of the Green Crab. From the article provided by NOAA: