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:

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.

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.
upper image by Linda Shaw, NOAA


Anonymous said...

Is there any commercial use for these critters? What is the control of them?

Star the wonder pup said...

They are kind of tedious to pick, but tasty

freeper said...

We should have strict regulations regarding ballast water dumping but we don't.

Invasive species being spread throughout marine environments is no laughing matter, certainly not just an opportunity for the witless to express inanities.

Speaking as one who has in the past attempted to get the legislature to address our lack of regulation in this regard, I commend phil for raising the issue.

Green crabs are just one example, the threat is very real and it deserves attention if we're to expect the issue to be addressed in a manner in which is called for.

Anonymous said...

Have to say, this is BEYOND scary! I hadn't heard of it before, but they sound like the cockroaches of the sea. Good that you're blowing the whistle! Definitely need to get some attn to ballast water dumping, that seems like an easier task than watching AK's crabs decimated after watching the salmon runs being harmed.

Kath the Scrappy