The expedition was part of the Swedish regular marine monitoring programme and covered the western and eastern parts of the Baltic Proper. Data presented in this report have been subject to preliminary quality control procedures only. Surface water temperatures were normal in the whole area and surface nutrient concentrations were normal for this season at most of the visited stations. Oxygen concentrations below 2 ml/l were found at depths exceeding 70-80 metres. Hydrogen sulphide was found deeper than 90 metres in the western Gotland Basin and deeper than 100 metres in the eastern Gotland Basin. Surface accumulations of cyanobacteria (blue-green algae) were observed in the northern part of the western Gotland Basin. A more detailed report describing observed algae can be found here: http://www.smhi.se/oceanografi/oce_info_data/reports/havmiljoarkiv/oce_reportarchive13.html The next expedition is planned to take place July 30th to August 3rd.