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Chinese Mitten Crab – an invasive alien!


Pen Llŷn a’r Sarnau SAC, the North Wales Wildlife Trust, CCW and the Environment Agency are running a project looking at the Chinese Mitten Crab in North Wales.

Mitten crabs are an invasive non native species which were first found in River Thames in 1935, but since then they have increased dramatically with an established population now in the River Dee, with one individual been found in the River Conwy.  Mitten Crabs can have disastrous consequences for the surrounding area such as the destruction of river banks, out competing local species and consumption of commercial fish larvae.  The project is looking into the river conditions of the Dee and comparing these conditions to the River Clwyd, Conwy and the Mawddach to determine the likelihood of Mitten Crabs invading these rivers. 

A couple of training sessions have been held to enlist volunteers to help survey the river banks for signs of Mitten Crabs and also to help monitor the environmental conditions of the rivers.  If you would like to be involved with this project and help monitor these rivers please get in touch using the contact details below.    

If you have seen a Mitten Crab please report it online

For more information about Pen Llŷn a’r Sarnau SAC and the Chinese Mitten Crab project please contact the Pen Llŷn a’r Sarnau SAC Officer:

Alison Hargrave
SAC Officer
01286 679495

Chinese Mitten Crab

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