The freshwater pearl mussel was once common throughout Europe but it has suffered huge declines as a result of pollution, habitat change and pearl fishing. Habitat change has been caused by conifer plantations exacerbating the effects of river acidification, poor land management in the catchment, drainage schemes, flow regulation and fisheries management.
Wester Ross however is known to support populations of international importance, the River Kerry having a particularly large and healthy population. This has resulted in its designation as a Site of Special Scientific Interest (SSSI) and candidate Special Area of Conservation (cSAC) for its pearl mussels. It is worth noting that it is now illegal to handle pearl mussels without a license.
Pearl mussels live in gravel beds in clean, fast flowing rivers. The adults feed by filtering out small food particles from the water, and can play an important part in maintaining water quality in upland rivers.
They have an interesting lifecycle during which the tiny larvae, called glochidia, are released by adult mussels into the water and subsequently attach onto the gills of young salmon or trout, where they live and grow for over a year before dropping off and settling into the gravel. This relationship does no harm to the fish and is beneficial to the mussels in helping them move upstream. Adult mussels grow slowly and can live for over 100 years.
The species action plan for the freshwater pearl mussel recommends reintroducing the species at suitable sites as well as making every effort to maintain and increase current populations. |
