Chinese Mitten Crabs in the Glaven

A Chinese Mitten Crab has recently been found in the River Glaven, at Glandford.  This is the first record we know of for Norfolk’s rivers, outside of the wash, and a concern for our native species.  The crabs can tolerate fresh water and can reach very high densities.  They feed on native invertebrate species and can undermine river banks and block pipes and culverts.  An identification sheet is available here: Chinese Mitten Crab Identification .  As the young crabs drift in plankton they are impossible to exclude from coastal areas, and it is likely that if they are present in the Glaven they will also be in the Stiffkey and possibly other local rivers.  If you find a mitten crab, or see any crab in fresh water some distance from the sea please contact Norfolk Rivers Trust or inform the Environment Agency directly.