Plague outbreak affecting threatened white-clawed crayfish in Mayo waterway
RECENT reports from the Marine Institute have confirmed the presence of a plague caused by a water mould (fungal like organism) affecting the native white-clawed crayfish in Annies River at Lough Carra in Mayo.
Efforts are underway to contain the outbreak, which has serious implications.
White-clawed crayfish are a globally threatened species protected under the Wildlife Act and listed on the Annex II and Annex IV of the Habitats Directive. They are found in our rivers, stream and lakes around the country.
Ireland hosts some of the largest surviving populations of the rare, white-clawed crayfish in Europe.
Outbreaks since 2015 has shown that this disease results in the complete elimination of white-clawed crayfish populations in affected waters. It is not a risk to humans, pets or livestock but it difficult to manage and control in affected waters.
All users can protect our waterways and wildlife by following the Clean, Dry and Check method.
Minister for Nature, Heritage and Biodiversity, Christopher O’Sullivan, said: “Ireland hosts some of the largest surviving populations of the rare, white-clawed crayfish in Europe. This vulnerable species plays an important role in keeping our waterways clean and provides food for wildlife around our rivers and freshwater habitats.
“This disease outbreak is a real threat to Ireland’s only native crayfish species as it can spread extremely easily to other waters.
“The National Parks and Wildlife Service is leading efforts and working with stakeholders around Lough Carra to understand the impact of this disease and engage with people using the river. So I’m asking all water users to implement the Check Clean Dry principles to help stop it from spreading. Please check, clean and thoroughly dry all equipment and clothing that comes in contact with the water before entering water again.”
It is not known how the disease has spread to Lough Carra area but it was most likely through contaminated equipment. The disease can be carried on wet equipment.
Furthermore the implications for the white-clawed crayfish population in the entire water catchment of Lough Carra, Lough Mask and Lough Corrib are very serious. The National Parks and Wildlife Service, National Biodiversity Data Centre (NBDC) and other organisations and stakeholders such as the Lough Carra Association, Inland Fisheries Ireland (IFI), the River Basin Management Service, Mayo County Council and the Marine Institute are working hard to contain this outbreak as effectively as possible.
Water users are reminded to:
* Check equipment and clothing for any signs of mud, plant or animal material that has been in contact with the water or river banks. Remove anything you find and dispose of safely.
* Clean everything thoroughly, ideally using hot water. Pay close attention to areas that are damp or hard to access.
* Dry for as long as possible, if you cannot dry your equipment, consider using an appropriate disinfectant. The spores are active for up to three weeks.
* Dogs should be washed if they swim in one river or lake before they enter another system.
* Water users should review guidance on invasives.ie/crayfish for more information.
* Members of the public who see dead crayfish in the area are asked to inform the NPWS by sending reports to info@npws.govie or by logging records directly to the National Biodiversity Centre at invasives.ie.