The Environmental Administration says that algae on Finland’s south coast has thickened and in places clustered on the surface. Widespread algal rafts have not, however, been detected. Algae has been most abundant in marinas and sheltered bays.

Algae have been detected in moderate or abundant amounts in the Gulf of Finland and the Archipelago Sea. Although some of the algae are non-toxic, some is the toxic Nodularia blue-green algae, which swimmers should avoid.

The water temperature in the Gulf of Finland and the Archipelago Sea has risen to twenty degrees Celsius, helping the growth of the algae.

More algae than usual in lakes

Blue-green algae have also been spotted in 260 inland lakes. Abundant algae were found in ten locations, and especially abundant algae were found in four. Altogether algae were found at 70 different observation points.

This is more than usual for this stage of the summer. The average water temperature at the observation points was between two and five degrees higher than usual.