Lough Leane has been signposted by Kerry County Council over the presence of Cyanobacteria that has turned the waters a soupy pea-green colour.
A number of dogs died after exposure to the bacteria during a previous bloom on the lake shore in 2016.
Suspected similar cases have also been reported at Lough Mask as well as waterways further east, including Ballymore Eustace on the River Liffey.
Meanwhile, scientists at the Galway-Mayo Institute of Technology are preparing to use drones to test the water quality of lakes on the West Coast.
GMIT’s Marine and Freshwater Research Centre has secured €132,000 in funding from the EPA for the scheme that will allow for real-time feedback of camera images and data.
Licensed drone pilots will work with lake biologists and water scientists on the two-year project, part of Ireland’s mandate under the EU’s Water Framework Directive.
The Irish Times has more on this story HERE.