Summary
Western Gotland Basin (southern part): On the Öland side oxygen conditions at the bottom were good. The lowest recorded concentration was 3.0 ml/l at a depth of 72 metres. On the Gotland side, conditions were worse. Levels below 2 ml/l were found at a depth of 60 metres. Bornholm Basin (including Hanö Bight): The 20 km3 of new water, which flowed in through the Sound at the end of October, was detected at station BY4 (in the Bornholm Basin) and at S2 (in the outermost south western part of the Hanö Bight). Oxygen concentration in bottom water at BY4 was between 2 and 3 ml/l. For the remainder of the area, where the halocline was well developed, the oxygen levels were low, with concentrations below 2 ml/l from 60 m depth. Hydrogen sulphide was present at three stations in the north-eastern part of the area.