Summary
High surface phosphate concentrations were measured in the southern part of the Baltic Proper. Silicate concentrations were also enhanced there, while levels of nitrogen compounds were normal or somewhat below normal. Nutrient concentrations in the Skagerrak-Kattegat area were normal or almost normal. The spring bloom in the Skagerrak coastal area and in the Kattegat area was almost over, while winter conditions prevailed in the Baltic. In the Baltic Proper, oxygen concentrations below 2 ml/l were found at depths exceeding 70 to 100 metres. Hydrogen sulphide was found in the bottom waters of the Eastern, Northern and Western Gotland Basins.