Between December 13 and 26, a combination of weather systems, which first pushed water out of the Baltic, then pushed 250 km³ of fresh, salty water from the North Sea into the Baltic Sea.
The Baltic Sea is a shallow, brackish sea with areas on the sea floor with so little oxygen that living organisms have a hard time surviving. This oxygen-rich inflow of water will have great impact on the eco-system all the way up to where I live on Kökar. The Baltic brood of small but numerous ESIN islands say thank you to our big, salty Atlantic kin.