Summary
Surface water temperatures were lower than normal throughout the study area. Phosphate and silicate values in the surface water of the southern Baltic remain higher than normal. Nitrate concentration of the Arkona Basin was at the limit of detection. This is lower than normal. Phosphate and silicate concentrations in the Kattegat and Sound were also showed higher than normal (for the season). The low nitrate concentration was normal. In the Skagerrak, phosphate and silicate concentrations were higher than normal. In the Baltic Proper, oxygen concentrations below 2 ml/l were found at depths exceeding 70 to 90 metres. Hydrogen sulphide was found in the bottom waters of the Eastern and Western Gotland Basins from 125-145 meters. In the Baltic, plankton activity was low. No real algal bloom could be seen in the Kattegat. In central Skagerrak high chlorophyll fluorescence was measured at a depth of 20 meters.