Warm weather increases blue-green algae in lakes, sea

The blue-green algae situation has deteriorated significantly in inland waters and coastal areas, also abundant blue-green algae in sea areas, said Finnish Environment Institute (SYKE) in a press release on Thursday.

Sentinel satellites’ images revealed blue-green algae in the Gulf of Finland, both in subsurface layers and in places also on the surface.

Blue-green algae observations from lakes and coastal areas have doubled since last week, as a result of warm weather.

Observations have even been made in the northern parts of the country. Abundant amounts of subsurface blue-green algae have also been observed in Finland's open sea areas, and some of the blooms have already surfaced in the Gulf of Finland.

SYKE observes the cyanobacteria occurrence as part of the monitoring of the state of the environment in Finland.

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 SYKE. Finnish Rotary Clubs are also actively involved in nationwide cyanobacterial monitoring.

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.

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 Utö Atmospheric and Marine Research Station, as well as cruise and merchant ships (MS Finnmaid and MS Silja Serenade).

The drift forecasts for cyanobacterial rafts in open sea areas are prepared in cooperation with the Finnish Meteorological Institute's Maritime Services.

SYKE reports on the national cyanobacterial situation on a weekly basis every Thursday from the beginning of June until the end of August. The weekly algal reporting was launched in 1998.