10 Sep 2010

Mussels collected over five years ago have at last bred in Environment Agency Wales’ fish hatcheries in north Wales. Around 60 mussels, some estimated to be 80 years old, were rescued from the river Dee by a team from Chester Zoo, Environment Agency Wales, Denbighshire County Council, Countryside Council for Wales and North East Wales Wildlife.

With only 21 of the original 60 alive today, hopes among the experts were fading until tiny mussel larvae were spotted in Environment Agency Wales’ fish hatcheries this summer.

Huw Jones, from Environment Agency Wales said:åÊ ‰ÛÏwe think the wild mussels were under a lot of stress in the Dee due to changes in the river and water quality.åÊ It seems that the few years they have had in the hatcheries may have enabled them to recover enough to breed and it is a credit to the dedicated work of the teams at our hatcheries that we now have baby mussels. This means that in conjunction with river improvement actions delivered under the Water Framework Directive, we should eventually be able to return mussels to the places their parents came from to boost the populations of this rare and fascinating creature.‰ÛåÊ It is estimated that the Dee once held a population of hundreds of thousands of pearl mussels.

Jones continues: ‰ÛÏonly the very last remnant of the original population is left now and the remaining mussels seem to be dying of old age without successfully producing any offspring. In the long term the project plans to release young mussels back into safe areas of the river Dee, giving hope to this vulnerable species.‰Û

Sarah Bird, Biodiversity Officer at Chester Zoo, said:åÊ ‰ÛÏthis is a major breakthrough for this fascinating protected species which is classified as ‰Û÷endangered’. These mussels would be lost from the Dee completely without the help of this project; finding larvae this year has given new hope for the survival of the species in the Dee. ‰Û

Pearl mussels are more sensitive to pollution than many other river creatures – they also rely on fish like salmon for a key stage of their lifecycle. They are in serious decline in Wales and their situation is symptomatic of the historic long-term changes that have affected the health of our rivers. The Water Framework Directive places greater emphasis on the ecological status of the water environment and sets new and more challenging standards for improving Wales’ rivers to benefit people and wildlife.

This species of mussel is one of the longest-lived invertebrates; they can live for 150 years, and grow up to 14cm long. They are protected by British and

European law, and are UK Biodiversity Action Plan Priority Species. The Freshwater Pearl Mussel Recovery Group formed to address mussel decline in the Dee and other rivers in north Wales.åÊ As a registered conservation charity, Chester Zoo supports projects such as this through its dedicated Native Species conservation programme.

Photo caption: Freshwater Pearl Mussels ‰ÛÒ courtesy of ANDY HARMER