Sammanfattning
Surface temperatures in the Skagerrak, the Kattegat and in the Baltic were normal. The nutrients showed, for the season, mostly normal values. The salinity of the surface water in the Skagerrak and the Kattegat was normal. Oxygen concentrations below 2 ml/l were found at depths greater than 80 metres in almost the whole Baltic Proper. Hydrogen sulphide was present at depths greater than 125 metres in the eastern Gotland Basin and in the Norrköping Deep, from 100 metres at the Karlsö Deep and from 90 metres in the Bornholm Basin. An inflow of fresh oxygenated water through Öresund led to elevated oxygen levels in bottom water at the station situated closest to Öresund, BY1. A pronounced bloom of blue-green algae was seen on the sea surface at the northern stations in the Gotland basin.