FOR THE third year running the largest loch on the Shetland isle of Unst has been hit by a bloom of toxic blue green algae.
Environment watchdog SEPA detected the bloom at Loch of Cliff during a routine inspection on Thursday and Shetland Islands Council immediately started to issue warnings to the public.
Loch of Cliff is a popular fishing loch in northern Unst, and anglers and local landowners have already been contacted.
The council is preparing to put up notices in public places throughout the island, which is currently experiencing one of its busiest weeks as it celebrates UnstFest with a whole series of events.
People are advised to steer clear of water contaminated by blue green algae, which looks like a smear of think paint lying on the surface.
Contact with toxic scum can cause skin rashes, eye irritations, vomiting and diarrhoea, fever and pains in muscles and joints. Blue green algae has also been known to kill cattle and dogs.
No public water supplies have been contaminated by the algae, and environment agencies advise that blooms can come and go depending on weather conditions.