Summary
The water temperature in the surface layer was essentially normal for the season. In the Skagerrak nutrient concentrations in the surface water has risen slightly since the previous survey, while they in the Kattegat showed, for the season, typical concentrations. Phosphate and silicate were generally above normal in most parts of the Baltic proper, while the concentrations of inorganic nitrogen was below the detection limit, in almost the whole area. In the Eastern Gotland Basin, a bloom was ongoing and high fluorescence was registered. In other areas phytoplankton activity was low.
The effects of inflows during December 2014 were now clearly seen in the central part of the Eastern Gotland Basin. In the Western Gotland Basin, the oxygen situation remains serious as acute hypoxia occurred from depths exceeding 70-80 meters and hydrogen sulphide from about 90 meters depth.