Ij. Killeen et al., THE LOSS OF A FRESH-WATER PEARL MUSSEL (MARGARITIFERA-MARGARITIFERA) POPULATION IN NW WALES, Journal of Conchology, 1998, pp. 245-250
During a recent land drainage scheme, a population of the Freshwater P
earl Mussel Margaritifera margaritifera (L., 1758) was discovered in a
small stream in north-west Wales. The dredging operations effectively
destroyed the population which was estimated to have been as high as
5000 individuals. The presence of juvenile shells under 20 mm in the s
poil tips suggests this was a viable, recruiting population. An attemp
t to translocate the remaining mussels to an unaffected downstream sit
e was unsuccessful. The loss of this nationally important population d
emonstrates the urgent need for comprehensive distributional data upon
which an effective conservation policy can be based.