First Recorded Sighting of Climbing Chinese Mitten Crab in Pacific Northwest

In an unprecedented development, a species known for its ability to scale over 13-foot-high barriers has been documented in the Pacific Northwest by environmental authorities.

A recent capture by a commercial fisherman in the Lower Columbia River, near the border of Washington, has revealed the presence of this notorious invader. Identified as a Chinese mitten crab, the Oregon Department of Fish and Wildlife shared photographic evidence of the catch.

Origin and Characteristics of Chinese Mitten Crabs

Hailing originally from regions of East Asia, Chinese mitten crabs are identified by their distinct hairy claws resembling mittens, and come in shades ranging from brownish-orange to greenish-brown. An unusual feature includes four spines flanking a notch above their eyes, setting them apart from native crab species.

These crabs have a well-documented history of causing disruption, having first been noted in San Francisco Bay during the late 1980s. They are now found along the East Coast, even extending into parts of New York.

Remarkably adept at overcoming obstacles, Chinese mitten crabs can navigate over towering structures, utilize river lock systems, and even maneuver land surfaces when the terrain allows. Additionally, these crabs are notorious for damaging fishing gear and infrastructure, and their burrowing can significantly increase flood risks by destabilizing riverbanks.

Impact and Environmental Concerns

Once thriving, populations have previously caused substantial ecological and structural damage, particularly in and around San Francisco Bay during the 1990s at their peak.

The threat they pose extends to potential blockages in power stations' cooling systems, intensifying flooding dangers due to weakened embankments.

Current Measures and Public Engagement

In a collaborative effort to track their presence, Oregon biologists are working alongside agencies in Washington and NOAA to ascertain the extent of any additional mitten crab populations. Strategies include deploying traps and analyzing environmental DNA for indicators specific to these crabs.

Authorities have called upon local citizens to participate by reporting any sightings, crucial to help in constraining their spread. Such reports can be directed to the Oregon Department of Fish and Wildlife with specific location details.