{"id":33042,"date":"2025-07-17T15:49:25","date_gmt":"2025-07-17T12:49:25","guid":{"rendered":"https:\/\/www.vesi.fi\/en\/?p=33042"},"modified":"2025-07-17T15:49:25","modified_gmt":"2025-07-17T12:49:25","slug":"warm-weather-has-increased-blue-green-algae-observations-across-the-country","status":"publish","type":"post","link":"https:\/\/www.vesi.fi\/en\/warm-weather-has-increased-blue-green-algae-observations-across-the-country\/","title":{"rendered":"Warm weather has increased blue-green algae observations across the country"},"content":{"rendered":"

Warm and calm weather has increased the occurrence of blue-green algae in inland waters as well as in coastal and offshore areas. Early summer rains and winds have also created favorable conditions for blue-green algae blooms. Observations have been made widely across the country, but the blue-green algae situation still remains fairly typical for mid-summer.<\/p><\/blockquote>\n

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There is an abundance of blue-green algae in the bays and archipelago areas around Raseborg and Hanko. Contains modified Copernicus data, Syke 15 July 2025<\/figcaption><\/figure>\n

Blue-green algae barometers:<\/h2>\n

Barometers for the Gulf of Finland indicate that the blue-green algae season started later this year. Currently, the amount of blue-green algae is rapidly increasing in both the eastern and western parts of the Gulf of Finland and has reached the average level for this time of year.<\/p>\n

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Graph 1: Eastern Gulf of Finland. The observation points represent the average of the blue-green algae observations in the area.\u202f 0=no blue-green algae, 1=possible blue-green algae, 2=probable blue-green algae and 3=definite blue-green algae. Syke dataset, contains modified Copernicus Sentinel & NASA data (2025)<\/figcaption><\/figure>\n
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Graph 2: Western Gulf of Finland. The observation points represent the average of the blue-green algae observations in the area.\u202f 0=no blue-green algae, 1=possible blue-green algae, 2=probable blue-green algae and 3=definite blue-green algae. Syke dataset, contains modified Copernicus Sentinel & NASA data (2025)<\/figcaption><\/figure>\n

Map of the national blue-green algae monitoring observations on week 29<\/a><\/p>\n

Read more in Finnish:<\/p>\n

L\u00e4mmin s\u00e4\u00e4 on lis\u00e4nnyt sinilev\u00e4havaintoja eri puolilla maata (STT Info)<\/a><\/p>\n

Syke observes the cyanobacteria occurrence as part of the monitoring of the state of the environment in Finland<\/h2>\n

The national cyanobacterial monitoring is carried out as part of the monitoring of the state of the environment in cooperation with the Centres for Economic Development, Transport and the Environment, municipal environmental and health authorities, and the Finnish Environment Institute (Syke). Finnish Rotary Clubs are also actively involved in nationwide cyanobacterial monitoring.<\/p>\n

The cyanobacterial monitoring is based on the monitoring of cyanobacterial deposits in surface water. The intention is to provide an overview of the cyanobacterial situation in different water bodies. The monitoring includes about 400 permanent observation sites across the country on inland and coastal waters and in the archipelago.<\/p>\n

Information on the cyanobacterial situation in the open sea areas is mainly obtained from satellite images, but also from the Finnish Border Guard, the marine research vessel Aranda, the optical device located at the Ut\u00f6 Atmospheric and Marine Research Station, as well as cruise and merchant ships (MS Finnmaid and MS Silja Serenade) equipped with Alg@line measuring equipment. The drift forecasts for cyanobacterial rafts in open sea areas are prepared in cooperation with the Finnish Meteorological Institute’s Maritime Services.<\/p>\n

Syke reports on the national cyanobacterial situation on a weekly basis every Thursday from 19 June to 7 August 2024. The weekly algal reporting was launched in 1998.<\/p>\n

Several compounds produced by cyanobacteria can cause health hazards<\/h2>\n

According to the Finnish Institute for Health and Welfare (THL), cyanobacterial occurrences can cause health hazards. Cyanobacteria produce a number of different compounds that can cause symptoms. Some cyanobacteria can produce liver or nerve toxins, but most of the symptoms experienced by swimmers may also be due to other compounds.<\/p>\n

Small children and pets should particularly be kept out of water rich with cyanobacteria. Water with cyanobacteria should not be used in a sauna or as washing or irrigation water.<\/p>\n

If you suspect a poisoning, seek medical advice, or take the pet to a veterinarian. If necessary, the Poison Information Centre will provide additional instructions.<\/p>\n

The municipal health authorities monitor the cyanobacterial situation on beaches.<\/p>\n

More information about blue-green algae and health:<\/strong><\/p>\n