Monaghan County Council has issued a warning notice in relation to algal blooms in Co Monaghan lakes.
During periods of calm and warm weather, algae in lakes may multiply rapidly causing the water to become green, which is known as an algal bloom.
The algae can rise to the surface to form a visible scum.
Members of the public are advised to avoid contact with the affected water as it may cause illness such as skin rashes, eye irritation, vomiting and diarrhoea.
Do not swim or allow children to paddle if there is evidence of discolouration of the water.
Algal blooms and related scums can also be highly toxic to dogs and other animals.
Farmers and dog owners should prevent access of their animals to affected areas and should not allow them to drink, swim or ingest any scum.
