Surface water temperatures as well as surface nutrient concentrations were normal in the whole investigated area. Oxygen concentrations below 2 ml/l were present at depths exceeding 70-80 metres. Hydrogen sulphide was found deeper than 80 metres in the western Gotland Basin and deeper than 100 metres in the eastern Gotland Basin. No surface accumulations of cyanobacteria (blue-green algae) were observed. The next expedition is planned to take place September 12th to September 15th.