Water samples take from Lake Peipus on Thursday by the Health Board (Terviseamet) detected a large amount of cyanobacteria. The Agency is warning bathers to be careful when swimming.
Tiia Luhti, Head of the Southern Region of the Health Board, said on Friday samples were taken in three places along the western shore at Mustvee, Kallaste and Kolkja. There were seven species of cyanobacteria potentially secreting toxins.
"The Health Board has also received information about blue-green algae from the part of the lake near Lohusuu, Kauksi and Tammispää, and in fact, there is reason to believe the entire western shore of Lake Peipus has been affected," said Luht.
The Health Board has sent a notification to local governments and G4S for prevention and monitoring.
Cyanobacteria, also known as blue-green algae, is a bacteria that flourishes in warm nutrient-rich water during periods of warm and quiet weather.
In recent days, the weather in Southern Estonia has been very warm, almost 30 degrees. For example, on the beaches managed by G4S, the bathing water temperature in Estonian lakes is currently unusually warm at the beginning of the bathing season, sometimes reaching up to 27 degrees.
In the case of Lake Peipus, the winds blowing from the east, which push algae into our shores, can also be considered an additional factor causing the situation.
Swimming in water with where algae is blooming is not recommended for people with allergies, small children, and the elderly. It is especially dangerous to animals. Swimmers should also be sure to avoid swallowing water. After contacting with bacteria-rich water, swimmers should wash immediately and change their swimwear.
The Health Board explained if the water has turned yellowish-green with visible flakes, and the entire shoreline is covered with a dense green mass with the smell of mildew, it may also be cyanobacteria.
The effects of the toxic substances produced by cyanobacteria can vary ranging from skin rashes and irritated ears and eyes, particularly in children and adults with allergies, to diarrhoea, vomiting and fever in more severe cases.
In addition to Lake Peipus in eastern Estonia, there have also been reports of cyanobacteria at Lake Ähijärv, Värska beach, Arbi and Varstu lakes.
Editor: Katriin Eikin Sein, Helen Wright