In the southern Kattegat and in the Sound, the oxygen concentration below 20 metres was less than 2 ml/l. In the southern and south-western Baltic, oxygen values were low at all stations, except in the Arkona Basin and Hanö Bight. The lowest oxygen value was 0.22 ml/l, observed between BY1 and BY3. In the Baltic Proper and east of Gotland, oxygen concentrations were below 2ml/l. BY5 was the only station where values over 2 ml/l were measured. Hydrogen sulphide was present at BY20 and at both stations in the western Gotland Basin.