- The cyanobacteria like the same weather as us - warm and calm.

The conditions are perfect now, says Markus Lindh, marine biologist at SMHI.

In the video above, you can see what the beaches in S: t Olofsholm on Gotland look like right now.

Not visible on satellite images

SMHI's algal map of the algal situation in the Baltic Sea today shows two large surface accumulations in the southern Baltic Sea and in the eastern Bothnian Sea, but no flowering along the shores of Gotland.

- This is because we do not make any assessment closest to the coast.

There is a lot that in satellite images looks like algal blooms, such as sediment or pollen, says Markus Lindh.

Obstructive haze clouds

It is currently difficult for SMHI to analyze the satellite images over the Baltic Sea due to the haze clouds that lie over the sea.

- But when we try to look down into the gaps between the clouds, there seems to be a risk of surface accumulation in the sea around Gotland.

And when you get to shallow bays and the coast, we see a tendency for heavy surface accumulation.

Toxic?

To find out if it is a toxic algal bloom or not, a detailed water analysis is required.

Only under a microscope do you see what kind of cyanobacteria it is (can often be a mixture).

And a further water analysis to see if they are married or not.

Algae blooms are associated with high summer heat and now the conditions are perfect.