Oregon officials have discovered an invasive Chinese mitten crab in the Lower Columbia River, igniting concerns that the invasive species could spread.
The crab was caught by a commercial fisher, who brought it to the Oregon Department of Fish and Wildlife (ODFW) for identification. Chinese mitten crabs have never been seen in the Pacific Northwest, although a Japanese mitten crab was spotted in Oregon 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,” 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.”
Officials say the crab could have been introduced to the area illegally by a person, or have hitchhiked via ballast water as larvae.
ODFW has asked fishers in the state to keep an eye out for any mitten crabs – which have a unique notch between their eyes, four spines on each side of their carapace, and have hairy, mitten-like claws – and report sightings to the Oregon Invasive Species Council.
According to the state, ODFW biologists are working with counterparts in neighboring Washington as well as NOAA Fisheries to detect any other mitten crabs in the Columbia River.
