BGA Bloom in South Harris

Environmental Health has been advised by SEPA that there is a BGA bloom on Loch Langabhat, South Harris.

Blue-green algae occur naturally and, especially during warm weather, can multiply sufficiently rapidly to discolour the water so that it appears green, blue-green or greenish-brown. During calm weather, many of these algae can further aggregate by rising to the surface to form a scum which may look like blue-green paint or jelly (but it may equally be black, brown, grey-white, blue or even red on occasions). With changes in the direction and strength of the wind, the scum can be blown around the surface of the water and may thus appear at different places at different times. It may disappear and reappear quickly and accumulate on the shoreline.

These algae may produce toxins, but, because of the fluctuations in concentration and in toxicity at a single site, it is not practicable to assess toxicity on a routine basis. Assessment of risks to human and animal health should take account of the following statements from the Department of Health and the Chief Veterinary Officer; both statements are endorsed by The Scottish Government. The statements differ because animals, in contrast to people, may eat or swallow large quantities of algal scum.

Human Health

‘Illnesses including skin rashes, eye irritation, vomiting, diarrhoea, fever and pains in muscles and joints have occurred in some recreational users of water who swallowed or swam through algal scum. There have been no reports of long-term effects or deaths in humans, but in some cases the illnesses were severe. Although Algal Scum Is Not Always Harmful, It Is A Sensible Precaution To Avoid Contact With The Scum And Water Close To It.

Animal Health

‘The toxins, which may be produced by the algae, are also poisonous to animals and can cause severe illness and death. Crofters And Pet-Owners Should Therefore Ensure That Their Animals Do Not Have Access To Affected Water.

If you suspect a BGA Bloom, it can be reported using the “bloomin’ algae (Opens in a new window or downloads a file)” app