MANAGEMENT PRIORITIES FOR THE RIVER NORE (IRELAND) TO CONSERVE THE PEARL MUSSEL, MARGARITIFERA-DURROVENSIS PHILLIPS, 1928

The River Nore in south-east Ireland is the only location for the fres hwater pearl mussel Margaritifera durrovensis. The Nore also contains all of the freshwater species in Ireland (six species of fsh and one c rustacean) listed as in need of protection in the European Union 'Habi tats' Directive. Since 1991, our studies have assessed the abundance a nd distribution of the pearl mussel and the quality of the river as a mussel habitat. The River Nore suffers from nutrient enrichment, and i n places bank erosion has led to river bed siltation. Mussels are conf ined to the main channel of the River Nore, no juvenile mussels have b een recorded, and the population is considered threatened with extinct ion. In the Nore, mussels are most abundant under the shade of trees b eside the river bank, and least abundant beside eroded banks and where filamentous algae cover the river bed. This suggests that even locali sed river bank management (e.g. fencing, tree planting) may improve ha bitat conditions. There is a variety of authorities, organisations and individuals who must be coordinated to utilise existing resources to improve the river quality. This would have benefits for both nature co nservation of freshwater and riparian species, and for angling and tou rism amenities. It may also benefit land owners through provision of a dvice on land and soil nutrient management. Such an initiative in rive r management would be pioneering in Ireland, and break the ground for similar work on other rivers.