Temporary closure of the Wash Mussel Fisheries

Having received a report of Chinese Mitten Crabs (CMC) in The Wash, the Authority is investigating the potential biosecurity risks associated with both the harvestable and re-laying mussel fisheries. A temporary closure is being put in place to provide time to develop biosecurity protocols and advice in support of the fishing industry and to mitigate associated biosecurity risks in the meantime.

Therefore, The Wash harvestable mussel fishery is closed temporarily with effect from 0400hrson 26 April 2025. The mussel relaying fishery will also not open until consideration of the matter is complete.

CMC are one of the world’s most impactful invasive species, more information about CMC can be found on the GB non-native species secretariat website here. In particular, they are known to damage riverbanks and predate on native species in the UK.

CMC are thought to release their eggs during January and February, which settle in estuaries and develop into juveniles in early spring.  The eggs, larvae and juvenile CMC are very likely to be present in The Wash mussel beds until September as they grow before travelling back upriver. CMC are therefore also likely to be found within mussel seed catch from re-laying fisheries and could be transported to new parts of the coast if re-laid.  It is an offence under the Wildlife and Countryside Act 1981 to return CMC, including their eggs, larvae and juveniles, to the wild after being caught.

The temporary closure and delay to the opening of the re-laying fishery is intended to provide time to support industry by developing protocols to manage the risk associated with CMC. It is intended that the fishery will re-open at the earliest opportunity.

Please contact us if you have any questions or for further information.