Chinese Mitten Crabs found in Scotland for the first time

The remains of a Chinese mitten crab has been discovered in the River Clyde causing concern amongst Scottish salmon rivers.  These invasive non-native species where first found in the River Thames in 1935 and since then they have become established in a number of rivers along both the west and east coasts of the UK.  They are normally transported as stowaways in the ballast tanks of boats and ships and were accidently brought over from East Asian by this method.

Adult mitten crabs are found in freshwater but breed in saline conditions, migrating down rivers in the autumn.  The eggs hatch in the spring, after which the juveniles and adults return to freshwater where they burrow into river banks causing considerable damage.  They are able cross dry land in order to find new territory, posing a rise to neighbouring rivers.

Mitten crabs are considered to be one of the 100 worst invasive species in the world and can have detrimental impacts on the ecosystems of the rivers they colonise.

Mitten crabs are easily identified by their hairy claws – see links below on how to identify mitten crabs.  If you find a crab that matches these descriptions, please notify the local Fishery organisation, SEPA or SNH as soon as possible.

For further information follow the links below:

Chinese Mitten Crab – article from The Guardian

Fact sheet – GBNNS

Distribution of Chinese Mitten Crabs

ID_Eriocheir_sinensis_(Chinese_Mitten_Crab)