Invasive Crab Found in Pacific Northwest for First Time

A crab capable of scaling 13-foot concrete walls has been spotted in the Pacific Northwest for the first time, raising serious concerns for local wildlife officials. The Oregon Department of Fish and Wildlife says the Chinese mitten crab, famous for its hairy claws and invasive ways, was caught by a commercial fisherman last week in the Lower Columbia River, just south of the Washington state border, CBS News reports. "Chinese mitten crabs have not been confirmed in the Pacific Northwest until now," the department said.

"While this is a rare event in Oregon, mitten crabs caused significant infrastructure and ecological damage in and around San Francisco Bay when the population was at its height in the late 1990s," the department said a news release. The captured crab was a large male. Officials believe it could have been introduced by people or through ballast water from ships. "Mitten crabs have unique features unlike any native crab species," the department said. "They have a notch between their eyes and four spines on each side of the carapace. They are named for their hairy mitten-like claws and vary in color from brownish-orange to greenish-brown."

Mitten crabs, native to East Asia, can "pass through lock systems and possibly climb fish ladders, or leave the water and walk around barriers where the terrain is suitable," according to the US Bureau of Reclamation. The species is known to steal fishing bait, damage fishing gear, block power plant cooling systems, and increase flooding risk by burrowing into banks, causing erosion. Officials praised the fisherman for doing the right thing and reporting the unusual crab he caught. Oregon officials say they are working with Washington wildlife officials to determine whether there are any more of the crabs in the Columbia River. (This content was created with the help of AI. Read our AI policy.)