Scottish Environment Protection Agency confirmed on Thursday that Lunnister Loch in Sullom and Spiggie Loch, Dunrossness, are affected by blue green algae.
SEPA said that the moment there is no adverse effect on water supplies.
Notices will be posted next to the lochs warning against contact with the algal scum.
Adjoining landowners have been notified, as have the anglers association, RSPB and NHS Shetland.
On Friday, Shetland Islands Council also confirmed that blue green algae was found in Tingwall Loch, which also runs into Asta Loch to the south.
This means that a total of five lochs are currently affected, with algae found in Lerwick’s Clickimin Loch and Strand Loch in Tingwall last month.
Contact with the algae may give rise to skin rashes, eye irritations, vomiting, diarrhoea, fever and pains in muscles and joints. It is also known to kill livestock and dogs.
Become a supporter of Shetland News
Shetland News is asking its many readers to consider start paying for their dose of the latest local news delivered straight to their PC, tablet or mobile phone.
Journalism comes at a price and because that price is not being paid in today’s rapidly changing media world, most publishers - national and local - struggle financially despite very healthy audience figures.
Most online publishers have started charging for access to their websites, others have chosen a different route. Shetland News currently has over 430 supporters who are all making small voluntary financial contributions. All funds go towards covering our cost and improving the service further.
Your contribution will ensure Shetland News can: -
- Bring you the headlines as they happen;
- Stay editorially independent;
- Give a voice to the community;
- Grow site traffic further;
- Research and publish more in-depth news, including more Shetland Lives features.
If you appreciate what we do and feel strongly about impartial local journalism, then please become a supporter of Shetland News by either making a single payment or monthly subscription.
Support us from as little as £3 per month – it only takes a minute to sign up. Thank you.Support Shetland News