Shetland Islands Council’s environmental health department has issued a warning about algae growth in three lochs in Unst.
The SIC has received notification that there is growth at the Loch of Cliff, Loch of Watlee and Helliers Water. It is probable that the water is contaminated with Blue-green Algae, but samples need to be taken before results can confirm that.
As a precautionary measure, notices have been posted in local shops and will be posted next to the lochs warning that contact with the algal scum should be avoided.
Adjoining landowners and fishing interests have been advised of the situation, as have the Scottish Environmental Protection Agency and Shetland NHS Board.
A council spokesman said at this stage there was no adverse effect on water supplies.
Blue-green Algae exists in fresh waters in Great Britain and throughout the world. They are noticed when their concentrations increase to form “blooms” and when they form scums – looking like blue-green paint – or when they collect on the shore line.
Some Blue-green Algae may give rise to adverse medical effects, but not always. Effects on people coming into contact with toxic scums include skin rashes, eye irritations, vomiting and diarrhoea, fever and pains in muscles and joints. Toxic algae have caused deaths of livestock and dogs.
The treatment of water supplies removes Blue-green Algae and additional treatment may be applied to destroy or remove toxins should they arise. The actions currently taken are precautionary.
The behaviour of algae is erratic and the level of its toxicity can fluctuate; it can appear one day, be dispersed by the wind and mixing and re-accumulate at any time.