River boost for endangered pearl mussel.
A healthy population of endangered freshwater pearl mussels is important for water quality – each mussel filters 50 to 70 litres of water.
The Environment Agency’s Kielder Salmon Centre staff Richard Bond and Jess Anson have developed a technique to enable pearl mussel larvae to attach to the fish gills, replicating their natural life cycle in the wild.
The larvae will drop off the sea trout gills towards the end of May where they will settle on to the river bed.
Kielder Salmon Centre breeds 360,000 salmon and between 10,000 and 20,000 sea trout every year to stock rivers.
“This work at the hatchery is to try to increase the numbers of juveniles in the river, boost future numbers, natural reproduction and survival rates in efforts to halt the population decline.” After considerable investment, water quality has improved dramatically across the UK and rivers in England are the healthiest they have been for 20 years.
The improvements in water quality of the River Tyne and its tributaries has been excellent, and along with the continued work of the Environment Agency and partners, has resulted in improved conditions for natural breeding in the rivers, and a flourishing ecology.
Richard added: “In 2010 we first managed to successfully get freshwater pearl mussel larvae to attach to the gills of sea trout.
Since then we have released sea trout every spring to the River Tyne tributaries.
In another 7 to 10 years they should be old enough to breed.”