The status and conservation of the freshwater pearl mussel Margaritifera margaritifera Linn. in Great Britain

All available records of the occurrence of the freshwater pearl mussel Margaritifera margaritifera Linn. in Great Britain have been collected. Analysis of these records shows that there has been a recent decline in numbers of the species, which is especially marked in England and Wales. The causes of this decline are thought to be primarily pollution and overfishing in England and Wales, and overfishing in Scotland. Apparently even sparse populations remain fertile, but it is concluded that unless conservation measures can reduce overfishing, pearl mussels will become rare and endangered. It is suggested that the best conservation measures will be to restrict pearl fishing to licensed fishermen, perhaps using non-destructive fishing methods, and to prohibit the use of sub-aqua equipment.