Improving water quality on the Afon Eden

Mechanical diggers have been working to help a rare freshwater shellfish in its last remaining stronghold in Wales.

The freshwater pearl mussel, which was once common throughout Europe, has its last remaining “viable” population in Wales on the Afon Eden, near Trawsfynydd.

Now workers for Natural Resources Wales are excavating areas of land close to streams that feed into the Eden to improve water quality – critical for the pearl mussels’ survival.

They will create 11 settlement ponds to act as a natural filter for nutrients, pollutants and sediment before they reach the river.

Elain Gwilym, Project Officer at Natural Resources Wales said:

“After excavating we will be planting 10,000 plants which will act as filters and help the ponds blend in with the surrounding area.

“One of the reasons freshwater pearl mussels have declined so much is because they are very sensitive to changes in water quality.

“This work will help redress the balance on the Eden and improve the habitat of this critically endangered species.

“And the work has other benefits because improved water quality will also help the fish and other wildlife in the river, whilst the ponds will become home to frogs and small mammals like voles.”

Freshwater pearly live to be over 100 years old, making them one of the longest-lived invertebrates, and they can grow as large as your hand.

Pearls in Peril (PIP) is a Life+ Nature project with 22 partners working together to restore river habitats benefiting freshwater pearl mussel and salmonids in 21 Special Areas of Conservation (SAC) rivers across Britain.

In Wales the work is located within the Afon Eden catchment and led by Natural Resources Wales (NRW). Pearls in Peril (PIP) has a total budget of £3.5million.

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