Summary reviews

The cyanobacterial situation in the past summer has varied according to changing weather conditions. Cyanobacterial levels in sea areas and lakes peaked during the hottest periods of the summer in mid-July and mid-August. The cooler weather in late July and early August curbed the growth of cyanobacterial blooms for a while. In lakes, this summer’s cyanobacterial situation remained quite typical compared to previous years.

During the summer, the cyanobacterial situation has varied in both Finnish lakes and sea areas. The amount of cyanobacteria was exceptionally at its peak in the sea areas already in mid-July. Even in inland waters, the sunny and calm weather of early summer, as well as the warm waters, accelerated the growth of cyanobacteria, and as a result cyanobacteria began to bloom earlier than usual at many of the national algal monitoring sites.

The cyanobacterial situation over the past summer has been variable both in inland waters and sea areas. The number of cyanobacterial observations during June–August followed the weather conditions quite closely. In lakes, coastal areas and the archipelago, the cyanobacterial summer began earlier than usual as a result of the warm early summer. In July, the cyanobacterial situation was calmer due to the cooler weather, but in mid-August, warm weather again enriched the cyanobacterial blooms.