White-clawed crayfish released into mid Wales site to help save endangered species

Endangered white-clawed crayfish have been released into a specially chosen “Ark Site” in mid Wales.

The release into the River Cledan, led by Natural Resources Wales (NRW) with support from Severn Rivers Trust, Aberystwyth University and local partners, saw juvenile crayfish raised at NRW’s Cynrig Hatchery introduced under strict biosecurity measures this week.

White-clawed crayfish are the UK’s only native freshwater crayfish but their numbers have plummeted in recent decades due to invasive non-native crayfish, crayfish plague, pollution and habitat loss.

Since the 1970s, many populations in Wales have disappeared.

Safe havens

Ark Sites are carefully selected safe havens where new populations can be re-established away from key threats.

Juveniles reared at the Cynrig Hatchery have a survival rate of around 90% compared to less than 10% in the wild, with more than 7,000 crayfish already produced for release.

Oli Brown, NRW’s Aquaculture Officer, said: “This release is an important step in securing the future of white-clawed crayfish in Wales. By creating Ark Sites, we can give new populations the best possible chance to survive and thrive, safeguarding this species for generations to come.”

The project also involved the local community. Landowner Sam Griffiths of Moel Ddolwen Farm and his three daughters helped introduce some of the crayfish after school, symbolising the role of future generations in protecting nature.

Alongside the crayfish release, NRW and Severn Rivers Trust are working with farmers in the Banwy catchment to improve habitats on the River Cledan and nearby River Gam.

New fish habitats

Measures include fencing riverbanks to reduce livestock access, planting trees to cool river corridors, and creating new fish habitats.

Where stock are excluded, solar-powered pumps provide alternative drinking water.

These measures aim to improve water quality and create healthier rivers for fish, crayfish and other wildlife.

Dewi Morris, River Restoration Officer at Severn Rivers Trust, said: “White-clawed crayfish are a vital part of healthy rivers, playing an important role in the freshwater food web. This project shows what can be achieved when communities, landowners and organisations work together. We are delighted to be part of this national effort to give the species a fighting chance.”

The River Cledan Ark Site release follows a wider NRW-led initiative, supported by Montgomeryshire Wildlife Trust, Canal & River Trust, North Wales Wildlife Trust and Aberystwyth University.

The programme is part of national work to conserve white-clawed crayfish through research, monitoring and restoration.