The survey was completed in co-operation with SLU (Swedish University of Agricultural Sciences) and within the international acoustic survey in the Bothnian Sea and Baltic Proper (BIAS) during weeks 38-42. The oxygen situation in the Baltic Proper is severe. Low oxygen concentrations (<2 ml/l) were found at depths exceeding 50 to 80 metres in all basins. Hydrogen sulphide was also found in all areas deeper than 70 to 90 metres. For a more detailed description of the oxygen status in the Baltic, see: Report Oceanography No. 42 Areal Extent and Volume of Anoxia and Hypoxia in the Baltic Sea, 1960-2011.