We see an exceptionally warm period in the Baltic Sea, says Veera Haapaniemi at the Finnish Meteorological Institute (FMI) to the news agency AFP.
In the Gulf of Finland, the heat wave has lasted for over 50 days and in September, the sea temperature has been between four and five degrees above normal. Veera Haapaniemi adds that they had a 20-day heat wave at the beginning of the summer.
Even in Sweden, unusually high temperatures have been observed in the Baltic Sea.
Generally, it started last spring and then it has gone up and down in different basins, says Ola Kalén, oceanographer at SMHI.
The worst has been in the Bothnian Sea, but we have also had longer periods of heat waves in other Swedish seas.
The reason for the heat waves is largely due to global warming, although there are other factors that play a role.
We have had a number of different heat records and extreme weather events in 2023 and 2024, where El Niño has played a part to some extent. But the underlying cause is climate change.
The Baltic Sea's relatively shallow waters are extremely sensitive to climate changes and warm up faster than other seas. The warmer temperatures will likely affect the marine ecosystem.
Unfortunately, it's a pretty sensitive system, this brackish water. There are few species adapted to live in it, which means the effects can be quite large.
