AN OUTBREAK OF crayfish plague has been confirmed on a stretch of the River Suir after a large numbers of dead freshwater crayfish were reported on the river earlier this month.

The outbreak is at a stretch of the downstream of Clonmel to Carrick-on-Suir.

A total kill of the population is expected as the disease kills all white-clawed crayfish. However, other freshwater animals should not be affected.

Fisheries Ireland said this will have major consequences for the ecology of the river as crayfish are very common in the Suir and are important in maintaining its ecology.

The White-clawed Crayfish is a globally threatened species and Ireland holds one of the largest surviving population. It is the only freshwater crayfish species found in Ireland and is present in lakes, rivers and streams over much of the island.

This is the second confirmed outbreak of the disease in Ireland following one in Cavan in 2015. There is no indication of how the disease reached the Suir although a link to the Cavan outbreak is considered unlikely as the disease there appears to have run its course.

Ireland is still the only European country without any established non-native crayfish species.

Fisheries Ireland said that if Crayfish Plague becomes established there is a high probability that the White-clawed Crayfish, which is currently protected under Irish Law and the EU Habitats Directive, will be eliminated from much of Ireland.

If non-native crayfish are found to be established in Ireland, this could have a severe impact on habitats as they can destabilise canal and river banks by burrowing. It could also impact other freshwater species, such as salmon and trout fisheries.

The National Parks and Wildlife Service, Inland Fisheries Ireland and Tipperary County Council are working to contain the outbreak.

Check, Clean and Dry 

The stretch of river affected is popular with anglers and canoeists. Anyone using the river is being urged to observe the ‘Check, Clean and Dry’ protocol once they leave the river and before using it again.

The crayfish plague organism can be carried on wet equipment to new sites and containment of the outbreak is essential to prevent spread to other unaffected populations in Ireland.

This means that all wet gear such as boats, clothing and equipment should be checked for any silt or mud, plant material or animals before being cleaned and finally dried.

Disinfectant or hot water of over 40 degrees should also be used to clean all equipment and then followed by a 24 hour drying period.

The drying period is especially important in ensuring that all equipment is clear of infectious organism, including the removal of any water inside the boat.

The public are also being asked alert the authorities of any mass mortality of crayfish or sightings of unusual crayfish such as large or red claws.

Read: Investigation launched after 600 dead crayfish are found in Cavan>