(Portland, OR) -- The Oregon Department of Fish and Wildlife is concerned about an invasive species of crab found in the Willamette River. On November 17th, a person found a Chinese mitten crab near the shore at the Sellwood Bridge. It was given to ODF-and-W. In April, a mitten crab was found in the Columbia River east of Tongue Point. Mitten crab live their adult life in fresh water and migrate to brackish water to breed. Work is underway to determine if there are more mitten crab in the Columbia and Willamette rivers.