Invasive European green crab found in Dungeness Bay

SEQUIM — An invasive crab species scientists and locals feared to find on the North Olympic Peninsula was discovered in traps last week in Dungeness Bay.

Staff and volunteers at the Dungeness National Wildlife Refuge found at least 13 European green crabs in Graveyard Spit across from Dungeness Landing and continue to investigate just how prevalent the species might be there.

Emily Grason, program coordinator for Washington Sea Grant’s Crab Team, said these are the first of the crab to be found in inland Washington since the crab was captured in August 2016 in Westcott Bay off San Juan Island in Puget Sound.

Sea Grant officials say the European green crab, a small shore crab measuring up to 4 inches across, is native to the Atlantic Ocean and Baltic Sea and is known for damaging the soft-shell clam industry in Maine.

It will eat clams, oysters, mussels and marine worms, and is potentially harmful to birds and small crustaceans.

The green crab is distinctive for its five spines on the outside of the eye of the shell, but its name can be misleading because its color can be green, brown or reddish, typically with orange joints, Sea Grant staff said.

Lorenz Sollmann, deputy project leader at the Washington Maritime National Wildlife Refuge Complex at the Dungeness refuge, said the green crabs will compete with native species and affect the ecosystem.

“We’re trying to keep the ecosystem healthy and keep the playing fields even,” he said.

Thirteen green crabs have been found so far. Grason said the number isn’t alarming but that staff members know more are out there.

“When you look at pictures of different levels of abundance in other parts of the world, there are piles,” she said. “In our part of the world, we tend to grow larger green crabs that also can have multiple broods per year, so it doesn’t take multiple crabs to have a larger problem.”

Grason said finding the crabs isn’t a complete surprise because they have been spotted before, specifically in Grays Harbor, where there are increases in growth periodically.

The green crab are beginning the mating season now, she said, so they aren’t as attracted to bait in traps after molting.

“That’s why responding swiftly is important before we end up with eggs and larvae,” Grason said.

Staff and volunteers at the wildlife refuge went out four days last week placing traps, Sollmann said, and so far, the green crabs were only found in a channel of the upper part of the lagoon in Graveyard Spit.

“We’re covering as much of the refuge as we can,” he said.

“We’re trapping in new locations this week just to rule out they are there. It’d be great if all three days this week while working with the tides, we come back with nothing. That’s good.”

None of the green crabs trapped so far has molted yet, which means they haven’t begun breeding, Sollmann said.

Depending on progress this week, crews will continue to trap along the Dungeness Spit, Sollmann said, and scale back if they continue to have sessions with no green crab findings.

Staff with the Jamestown S’Klallam Tribe said they plan to check Sequim Bay this week for green crabs.

Efforts to seek out and contain the European green crab continue with the Crab Team monitoring more than 30 sites with volunteers.

Sea Grant staff estimates there are at least 400 sites in Puget Sound, the Strait of Juan de Fuca and the San Juan Islands possessing at least one ideal habitat feature for European green crabs.

To reach the Crab Team to report a European green crab sighting or for information on the organization’s efforts, email crabteam@uw.edu or visit https://wsg.washington.edu and click “Crab Team.”

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Matthew Nash is a reporter with the Olympic Peninsula News Group, which is composed of Sound Publishing newspapers Peninsula Daily News, Sequim Gazette and Forks Forum. Reach him at mnash@sequimgazette.com.