Algae bloom is something that is basically natural for marine organisms plant plankton and cyanobacteria. But due to eutrophication, there has been an increase in the more toxic algal blooms due to cyanobacteria.
- Cyanobacteria blooms start at a certain temperature in the water. Cyanobacteria thrive best when there is still warm weather, which is also the kind of bathing weather we like, says Ann-Turi Skjevik, marine biologist at SMHI.
What does the forecast look like for the weekend?
- It will probably increase. As long as we have the calm and warm weather, they remain in the surface water.
Causes oxygen dead bottoms
Another problem that the cyanobacteria contributes to is the oxygen-dead bottoms in the Baltic Sea.
- When cyanobacteria break down, oxygen is consumed, which in part leads to cyanobacteria blossom being able to increase again. But in addition, hydrogen sulphide is released at the bottom when there is an oxygen deficiency which is also toxic. The animals that can escape leave the area and those that cannot escape, which are trapped, die. It is a huge problem with dead bottoms in the Baltic Sea, which is now as large as Denmark, says Ann-Turi Skjevik.
Flowering has reached Gotland
The poisonous algal bloom, the cyanobacteria bloom, is currently a little more powerful south and east of Gotland and south of the Åland archipelago. In the southern Baltic, flowering is slightly weaker than so far. According to SMHI's forecasts, there is also a beginning flowering from Västervik, along the coast up to the Stockholm archipelago.
- The risks to us humans are that one of the species is toxic. I would be careful if I were to swim and go to the South Baltic Information Center and see what it looks like where I am. You should be careful not to get cold soups so you happen to drink the water.
How Many Cold Soups Are Dangerous?
- I do not recommend taking any cold soup at all, says Ann-Turi Skjevik.