An invasive species of crab that's native to East Asia and is known for its ability to climb vertical structures has been found in U.S. waters.
The Oregon Department of Fish and Wildlife announced a Chinese mitten crab — which has been prohibited in Oregon for over a decade — was caught earlier this month by a person fishing in the Lower Columbia River in the central region of the state. This species of crab was outlawed in the state due to its aggressive and highly adaptive nature, which can damage ecosystems and displace other native species.
Wildlife officials said this marks the first time a Chinese mitten crab has ever been confirmed in the U.S. Pacific Northwest, and suspect this individual crab may have been illegally placed in the river by a human. A single Japanese mitten crab was found in the same area back in 1997.
"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 ODFW said in a statement. "So, it is important to correctly identify this species and report it to your local ODFW office with the location found."
Wildlife officials say Chinese mitten crabs have unique features unlike any other native crab species, including a notch between their eyes and four "spines" on opposite sides of their body. Chinese mitten crabs also get their name from their hairy mitten-like claws and can vary in color from brownish-orange to greenish-brown.
"ODFW biologists are working with the Washington Department of Fish and Wildlife and NOAA to determine if other mitten crabs are in the Columbia River," the agency said. "Methods include setting up trap lines and potentially collecting water and substrate samples to look for environmental genetic markers specific to the mitten crab."
