The significant low tides recently introduced many to the wonders of the intertidal zone.
Negative tides for several days led to sea stars and crab delights. Though it may sound counterintuitive, one creature lurks in the shallows that no beachgoer wants to see: the European green crab.
Upfront, none of these crabs have been spotted around Gig Harbor waters. Although none have been found in the Puget Sound south of Admiralty Inlet, they recently were detected in Hood Canal and removed from the Seabeck area.
Early detection and awareness is a great tool against their spread to the South Sound.
European green crabs are easy to confuse with the native hairy helmet crab (Telmessus cheiragonus). Despite its name, the European green crab’s most distinctive feature is not its color – which can vary from reddish to dark mottled green – but the five spines on either side of the shell near its eyes.
These crabs rarely exceed 3.5 to 4 inches across. Helmet crabs, on the other hand, have six spines across, are generally lime green in color, and have a noticeably hairy appearance.
European green crabs have a big impact on the environment around them. They eat clams, oysters and smaller shore crabs. And while they can’t crack the shell of mature oysters, they prey upon young oysters and will dig up to 6 inches into the sand to consume clams.
They have decimated aquaculture globally while damaging eelgrass habitat that is critical for salmon and many other species.
The first detection of green crabs in Washington was in 1998 on the coast in low numbers. According to the Washington Department of Fish and Wildlife (WDFW): “Detection within the Salish Sea occurred at Sooke Basin, British Columbia in 2012, and then in the San Juan Islands and Padilla Bay in 2016.”
By 2018, state and federal agencies, as well as tribes and partners, began to detect significant increases in European green crab populations in Willapa Bay, Grays Harbor, Makah Bay, and Lummi Bay. According to WDFW, these increases are potentially linked to warmer water conditions, especially in 2021.
In 2020, WDFW was provided a one-time provision of $783,000 to control European green crabs, and an additional $2.3 million in ongoing funding in 2021. Then, earlier this year on Jan. 19, Gov. Jay Inslee issued an emergency proclamation to address the exponential increase in populations detected within the Lummi Nation’s Sea Pond and outer coastal areas.
The Washington State Legislature appropriated $8.568 million in funding for European green crab emergency control measures. A formal mission for response was assigned to the Washington State Emergency Management Division on April 18.
This funding supports a collaboration between WDFW, tribes, other state and federal agencies, shellfish growers, and private tidelands owners to establish a “coordinated response, hire and deploy personnel, and purchase and distribute equipment to areas with known infestations.”
More than 64,000 European green crabs have been removed from Washington waters this year alone.
If beachgoers think they have spotted a European green crab, WDFW requests they take a picture of the crab and report it as soon as possible. Identification guides and an online reporting form can be found on WDFW’s website. Do not kill or keep suspected green crabs, as they can easily be mistakenly identified for our native species.
Traps are currently being deployed in areas of infestation, marked by a bright orange buoy and official tag/permit; please do not tamper with them.
While “be crab aware” doesn’t quite roll off the tongue, with any luck, our south Puget Sound waters will remain free of European green crabs.