The water temperatures in the surface layer were essentially normal for the season. In the Kattegat as well as in the coastal zone of Skagerrak the spring bloom was in full progress and nutrients showed low concentrations. In the Baltic Proper spring bloom had started in the Arkona while winter conditions prevailed in the rest of the area. High phosphate and silicate concentrations were recorded in the Western Gotland Basin.
The effect of the inflow during December 2014 was clearly seen in many parts of the Baltic Proper. In Western Gotland Basin, however, the oxygen situation remains serious, as acute hypoxia occurred at depths exceeding 70-80 meters and hydrogen sulphide was present from about 100 meters deepth.