Crayfish population in Cavan's Bruskey river threatened by disease
A plague is feared to have hit Irish waters killing h undreds of globally important crayfish in one short stretch of river.
A water borne disease is believed to be responsible for wiping out huge numbers of the native crustacean that resembles a small lobster in the Bruskey River at Killydoon, near Ballinagh, Co Cavan.
The National Parks and Wildlife Service (NPWS) and Inland Fisheries Ireland described the outbreak as a concern and warned it could have a potentially irreversible ecological impact.
"If the disease outbreak was accidentally introduced on contaminated equipment, then containment may be possible, but if non-native crayfish have been introduced then the disease is likely to become established with severe and probably irreversible ecological impact on freshwater fauna and flora," it said.
Ireland is a world sanctuary for the white-clawed crayfish austropotamobius pallipes.
But it is at huge risk from invasive, aggressive signal crayfish which devour the small native species and which also carries a virulent infection called crayfish plague which DNA tests have found in the creatures in the Bruskey.
Until now, Ireland has been considered free of the disease and is the only European country without any established non-native crayfish.
Environment authorities are investigating how the disease got into the Bruskey/Erne system and whether it has spread.
Fish and other freshwater animals are not affected, the NPWS said.
Officials said i t appears the disease was accidentally introduced on contaminated equipment such as wet fishing gear, boots or boats or that non-native species have been illegally introduced to the area and have now passed the disease on.
Anglers and the public are being urged to take precautions such as thoroughly disinfecting fishing gear to stop the plague spreading and to report mass mortalities, sightings of large red clawed crayfish.
Across Europe, the rare white-clawed Crayfish species is being wiped out by the invasive American signal crayfish - originally imported to be farmed.