In the central Kattegat, oxygen concentration near the seabed was not particularly low. An oxygen concentration below 2 ml/l was measured in Skälderviken however. In the Baltic Proper, oxygen concentrations below 2 ml/l were found at depths exceeding 60 to 70 metres. Hydrogen sulphide was found at BY15 (Gotland deep) below 230 metres, in the western Gotland Basin at depths exceeding 70 to 80 metres, and in the Bornholm Basin near the bottom at the stations BY4 and BY5 (~90 metres). A fresh inflow of saline water was observed at BY1. A thin layer near the bottom had relatively high salinity and higher oxygen concentration.