Pincher patrol: Over 400K invasive crabs trapped, killed as fight goes on

The European green crab threatens Washington’s shellfish industry and native wildlife. The state is spending millions to keep the pest in check.

By: - June 14, 2023 7:04 pm

European green crabs, a problematic invasive species in Washington. (Washington Department of Fish and Wildlife)

Washington state is clawing back against an invasive crab, which swept into the region’s waters in recent years, threatening native Dungeness crabs, littleneck clams, oysters, and seagrass that fish depend on for habitat.

The state’s battle with the European green crab has significant economic and environmental stakes. If allowed to spread unchecked, the crab could hurt the shellfish sector, which contributes an estimated $270 million a year to the state economy and employs around 3,200 people in rural areas. In addition, the crab could damage coastal ecosystems, making life harder for species ranging from salmon to shorebirds.

As the state’s Department of Fish and Wildlife explains, while green crabs can’t crack mature oysters’ shells, they can prey upon young ones and will dig to depths of six inches to find clams to feast on. One green crab can consume 40 half-inch clams a day, the agency adds, as well as other crabs its own size. The digging is what can damage eelgrass, estuaries, and marshes.

“If you look at its rap sheet worldwide, it’s nasty, and that’s why we’re putting the effort into it,” Allen Pleus, Fish and Wildlife’s European green crab emergency incident commander, said in an interview. 

On Wednesday, Fish and Wildlife announced a new online hub devoted to the species to help coordinate response efforts and share information with the public.

For now, Fish and Wildlife is not asking people to kill suspected green crabs. Mainly because it’s possible to mistake other native crab species for them. People are encouraged to report sightings

European green crabs are somewhat small by crab standards and not known as a culinary delight. They’re typically added to stocks and broths if used in cooking. Drab-colored with tones of green and yellow, the crabs are identifiable by five tooth-like serrations on each side of their shells.

A bucket of captured European green crabs. (Washington Department of Fish and Wildlife)

The state and its partners have captured and euthanized upwards of 400,000 European green crabs since 2021, mostly along the state’s coast and in northern Puget Sound, according to Fish and Wildlife figures. Washington is spending millions in state funding to tackle the problem and officials here say that the feds should be chipping in more.

European green crabs began spreading on the nation’s eastern seaboard in the 1800s after arriving by ship. They were discovered in the late 1980s on the West Coast and began to surge in Washington’s waters about five years ago, with a noticeable population boom in 2021.

The crab is most likely past the point where it will ever be fully eradicated from the region, but Pleus is hopeful its numbers can be held at levels that will prevent severe fallout.

“We haven’t really seen any significant impacts, environmentally, economically, or culturally,” he said, crediting the state’s swift response. “We don’t want to wait around to see those impacts.”

“I think we’re making good headway,” Pleus added. “It could be a stable population, it could be an expanding population.” But, he said, counts in Washington are still short of crab populations on the East Coast, California, or parts of British Columbia’s Vancouver Island.

Hotspots for the crabs so far in Washington have included areas like Willapa Bay, Grays Harbor,  and the northern Pacific coast.

Lawmakers set aside a total of about $12 million over the next two fiscal years for the crab control efforts. That money comes atop $8.5 million in 2022 emergency state funding and $2.3 million the Legislature appropriated before that. 

Pleus said Fish and Wildlife has about 36 staff in his unit working on green crab issues. But he emphasizes that the state’s partnerships with tribes, shellfish farmers, Washington Sea Grant, and other organizations are crucial in the fight. 

“It’s going to take local management and that’s what we’re trying to build up,” he said.

Of the $12 million, Fish and Wildlife will hand off nearly $9 million to others, including $2 million for the Pacific and Grays Harbor conservation districts, $2.9 million to the Lummi Nation, $950,000 to the Makah Tribe, and $1.34 million to Washington Sea Grant.

The agency is pressing for the federal government to do more to fund green crab management, including asking Congress to appropriate $5 million annually for an invasive species mitigation grant program, another $8 million through the Bureau of Indian Affairs, and smaller amounts for other costs. As it stands, some money has actually flowed the other way, with the state giving funding to federal wildlife refuges in Washington to fund green crab control.

A green crab trap deployed in a shallow area of Willapa Bay. (Washington Department of Fish and Wildlife)

Richard Ashley, a natural resource specialist with the Shoalwater Bay Indian Tribe’s Environmental Services department, is one of four people with the tribe who regularly devote some of their work hours to trapping green crabs. The tribe’s lands are near Westport on the north side of Willapa Bay. 

The green crab work it carries out relies on federal dollars from the Bureau of Indian Affairs. Because of tight funding, the tribe doesn’t have a full-time person devoted to the fight.

Still, they net quite a few crabs. So far this year, he said, the tribe has set 1,547 traps and caught 14,890. He said it’s hard to tell at this stage what damage the crabs might be causing to the local ecosystem, or whether the trapping is driving down their numbers. 

He mentioned that it did seem like the catch was younger these days, and noted that some recent trapping efforts in the area have yielded fewer crabs – perhaps a sign of fewer overall.

“I guess we’ve got to stay optimistic to hope to knock them down,” he said. 

Last year, Fish and Wildlife recorded a total of 285,280 green crabs caught. Between Jan. 1 and March 31 this year, 37,152 were trapped. The haul in 2021 was 103,165. Pleus noted that even traps that aren’t catching crabs are useful because they help to identify where the crab is most active.

Fish and Wildlife says it’s been euthanizing the removed green crabs and disposing of them in landfills. The Shoalwater Bay Tribe uses the dead ones for compost in a community garden.

“Not only are we helping out the garden,” Ashley said, “we’re also getting rid of green crab at the same time.”

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Bill Lucia
Bill Lucia

Bill Lucia is the Standard’s editor-in-chief. He’s covered state and local policy and politics for a decade, nationwide for Government Executive’s Route Fifty and in Seattle for Crosscut.