Dog-owners are being urged to be vigilant along parts of the Lough Leane shoreline in Killarney where an algal scum was discovered last week.
The main locations are close to Muckross Abbey, and at Bunrower and Castlelough, Fossa.
Samples taken in recent days haven’t shown any worsening of the situation, and it’s being monitored on a daily basis.
Kerry County Council says most of the algae detected is of the harmless variety, but algae can be harmful particularly to dogs, and the council is continuing to urge caution.
People are advised not to swim at or in the immediate vicinity of algal scums, as it can cause skin irritation to swimmers.
The council says the algal scum is confined to the shoreline, and the water quality in Lough Leane is currently very good.