A WARNING HAS been re-issued to all water users in Ireland about the “severe and increasing” threat to the native crayfish species. 

The warning has been issued by the Department of Culture, Heritage and the Gaeltacht’s National Parks and Wildlife Service (NPWS), along with the Marine Institute.

Ireland holds one of the largest populations of the globally endangered white-clawed crayfish. 

This threat comes from the twin impact of disease and invasive alien species.

The warning comes after the confirmation this spring of crayfish plague on the River Maigue, upstream of Adare, Co Limerick.

This is the seventh river affected by the disease.  It is predicted the disease will wipe out the crayfish from the river system, according to the Department. 

The NPWS has also been made aware of a stock of a non-native crayfish being held in an aquarium. The animals which were voluntarily handed over were marbled crayfish.  The keeping, selling and breeding of this species is banned under recent legislation.

The service has confirmed that a population of a non-native crayfish species has been found for the first time in the wild in Ireland.

“There has always been a concern that non-native crayfish species may become established in Ireland and this has now been confirmed by the discovery of a population of an Australian Crayfish, the Yabby, Cherax destructor,” the Department said in a statement.

The site is not being disclosed at this time.

“The discovery of the non-native crayfish species in the wild is of concern as this has never been found before in Ireland. Although the species is one we would not have predicted, it presents us with a greater challenge of eradicating the species,” Brian Nelson, invertebrate ecologist with the NPWS said.

“We would like to emphasise the growing threat that alien invasive species are having on biodiversity in Ireland and globally and we urge everyone to think carefully and help in its prevention,” he said. 

“For the most invasive species, there is now specific legislation in place which bans possession and keeping and gives the NPWS powers to seize specimens and eradicate them from the wild.”