Yorkshire Water is working with the Freshwater Biological Association (FBA) and the North York Moors National Park Authority to help release young freshwater pearl mussels to the river Esk, in order to help to further enhance biodiversity and improve the overall health of the river.

Numbers of freshwater pearl mussels, also known as Margaritifera margaritifera, have seen a steep decline in the UK over the last 50 – 70 years and are considered endangered. Population declines have been linked to factors such as habitat loss, river engineering and declining salmonid stocks.

Mussels in the river Esk are over 80 years old and are the last remaining individuals in Yorkshire. Conservationists have collected the adult mussels and temporarily relocated them to a specialist facility to encourage them to release their young. The new born mussels will spend their first few years at the facility before being released back to the river when they are around 7 years old.

The freshwater pearl mussel is important to a functioning ecosystem as their presence significantly enhances biodiversity. They provide critical ecosystem services as the shells often provide or improve habitat for other organisms by providing physical structure, stabilising sediments, improving the food and oxygen availability and filtering and consuming suspended particles, thus improving water clarity. One adult freshwater pearl mussel can filter 50 litres of water per day!

Ben Aston, principal ecologist at Yorkshire Water, said:   “We’re really pleased to be supporting the FBA and funding their pearl mussel project on the River Esk.  “Freshwater pearl mussels are incredible creatures, and their continued presence in British waters is really important. We are delighted to play our part in trying to safeguard at-threat species like the pearl mussel and help the wildlife of Yorkshire to thrive.” Click here to read more