Summary
In the Skagerrak and Kattegat, the situation was normal for the season. In the Sound, phosphate and silicate concentrations were much higher than normal. In the Baltic Proper the spring bloom was underway, but the concentrations of phosphate and silicate were still much higher than normal. The inflow that occurred in November/December 2011 was still apparent in the southeastern part of the Baltic Proper. Hydrogen sulphide was found in the western and eastern Gotland Basins at depths exceeding 100-150 metres. Oxygen concentrations below 2 ml/l were found at depths exceeding 80-85 metres in the western Gotland Basin and from 70-85 metres in the eastern Gotland Basin. No hydrogen sulphide was detected in the southern part of the western Gotland Basin. Oxygen conditions in the Arkona Basin were very good and in the Hanö Bight it was good.