KETCHIKAN, Alaska (KTUU) - A small but potentially environmentally threatening crab is expanding its area of influence in Alaska. The European Green Crab was first discovered near Alaska's coast in July 2022 by the Metlakatla Indian Community on Annette Island, which is around 50 miles south of Ketchikan.
Now, the species has been discovered in Refuge Cove State Recreation Site, which resides just North of Ketchikan. The evidence of the crabs was discovered while an instructor at the University of Alaska Southeast Ketchikan Campus, Barbara Morgan, was teaching a class on how to identify the crab.
"We went to 10 different beaches, and with the number of people in that group, we did like 48 surveys in four days, and on our last day, the last beach, the last survey," Morgan said. "We found two small, like not quite an inch across, the carcasses of green crabs."
This development was not unexpected, as the European Green Crab is extremely resilient to a multitude of environments and has been slowly moving up the coast from the San Francisco area for many years now.
"The larval stage can stay alive in the water column for three months, so they can get stuck in the kelp... established population there and they have been getting pushed up the coast from the San Francisco Bay through Northern California, Oregon, Washington, British Columbia," Morgan explained.
The species of crab is particularly concerning for other crab species in the region and the potential effect on salmon populations.
"The European Green Crab in particular can beat up and eat Dungeness crab and other crab species that are smaller than them," Morgan said.
"They'll rip up eel grass, which eel grass beds are really important habitat for things like Dungeness crabs, fish species such as the juvenile salmonid species."
The effort now turns to containing the crab while maintaining the surrounding fisheries.
"We're not going to be able to eradicate them, but we can do what's called functional eradication, which is to kind of pinpoint areas that are really good crab habitat, salmon habitat, and try to protect those by trapping out as many as we can in those areas," Morgan said.
If you are out and notice what you believe to be a European Green Crab, Morgan stresses that you should leave them alone and report them to the proper authorities because you might mistake native species for the invasive one.
"We have several different native species, there's Green Shore Crab," Morgan said.
"The identifying feature on the green crab isn't actually the color, they can be green, but they can also be brown or orange or yellowish."
The way to identify a European Green Crab is by looking at the shell.
"There should be 3 little bumps between the eyes, and then on either side of that, there should be 5 big, jagged spines," Morgan explained.
The Alaska Department of Fish and Game (ADF&G) has a guide on how you can identify the species on their website.
It is not legal to harvest, move, or interfere with the invasive crab without a permit, which you can get through ADF&G.
If you believe you have found one of the invasive crustaceans, you are encouraged to report the sighting through the invasive species hotline 1-877-468-2748, by email, or on the website.