Cruise report from R/V Argos week 31, 2001

Type: Report
Author: Jan Szaron


The surface water temperatures were higher than normal in all areas (although the temperature had dropped 1.5-2.5°C in the Skagerrak and northern Kattegat since the previous expedition) with the exception of the Western Gotland Basin. The temperature was 17.2-20.2°C in Skagerrak-Kattegat and 18.0-19.7°C in the Baltic Proper. Oxygen concentrations below 2 ml/l were found at depths from 80m in almost the whole Baltic Proper. The situation in the Arkona Basin, Hanö Bight, Bornholm Basin and Western Gotland Basin was even worse. Hydrogen sulphide was present at depths from 70m in the Hanö Bight, 85m in Bornholm Basin, 125m in the Eastern Gotland Basin and 80m in theWestern Gotland Basin. The nutrient concentrations in the surface layer were normal for the season in all areas (more or less depleted). Silicate does not deplete in the Baltic Proper but the trend of concentrations lower than normal continued. High fluorescence peaks (chlorophyll) were measured only in the south eastern Kattegat and the Sound. No super saturation of oxygen was found (compared to the previous expedition).