No severe algal blooms – normal season

Despite favorable weather conditions for algal blooms in July, with heat, sun and stagnant water, there was no intense growth of cyanobacteria.

– In its own way, it was a fairly ordinary summer, and it wasn’t exceptionally much or little as far as I can judge now. Now the situation is in a bit of a downturn, says Jürgen Oberg, an oceanographer at SMHI.

stand out

What stands out this summer is that there were no large groups of algae in the middle of the Baltic Sea or, for example, on the coast of Östergötland or Södermanland, as we are used to.

– In normal cases, there is usually a lot around Gotland and the East Coast. However, it was more in the south of the Baltic Sea, down towards the Gulf of Hanno and also towards Poland and Lithuania. In addition, it started early and is still very much in the south of the Bothnian Sea, that is, north of Åland, says Jürgen Oberg.

Changes from year to year

Where and how aggressive an algal bloom occurs varies from year to year, and is influenced by various factors. Weather conditions control how visible and noticeable cyanobacteria are, although they may be similar in total. In a calm summer, algae accumulate on the surface. It also affects the availability of nutrients.

The strongest algae growth occurs between mid-summer to the end of the month from July to August. If the weather changes, the current situation may change with weak surface accumulations south of Öland and outside the Gulf of Finland.

If it gets amazingly sunny and warm, something else could happen, says Jürgen Oberg.