Blue-Green Algae

What is Blue-Green Algae?

Blue-green algae are tiny organisms which occur naturally in loughs, ponds and rivers and commonly occur during periods of prolonged hot weather but can sometimes also appear at other times of the year.

In still waters the algae can multiply to such an extent that they discolour the water which then appears green, blue-green or greenish brown.  Sometimes a scum may form on the surface which is most commonly found at the water’s edge or shore line.

Some, but not all blue-green algae produce toxins which can be  released into the water.  It is not possible to tell which algae do or do not produce toxins simply by their appearance.  Laboratory analysis is needed for this.

What Should I do about Blue-Green Algae?

Avoid all contact with the affected waters and ensure that children and pets are kept away.

If you find areas of water affected with blue-green algae you should inform the local Environmental Health Service.  If the water affected is within the Fermanagh & Omagh District Council area the Environmental Health Service can be contacted by telephone at 0300 303 1777 or by email at eh@fermanaghomagh.com.

Fermanagh & Omagh District Council has erected advisory signs at the following locations which, in the past, have been prone to Blue-Green Algal blooms:

  • Lough Acrussel
  • Muckross Bay
  • Crom Estate

These signs will be present from May to October each year.