Cruise report from R/V Argos week 38-39 and 41-43, 2010

Type: Report
Author: Lars Andersson, Martin Hansson, Philip Axe


The oxygen situation in the deep water of the Baltic Proper continues to be serious. About one sixth (~17%) of the bottom area in the Baltic Proper are affected by anoxia (oxygen free, with toxic hydrogen sulphide present) corresponding to ~10% of the water volume. Acute oxygen deficiency, with concentrations <2ml/l, affected about 28% of the bottom area, about 20% of the volume. This is the largest volume measured since 1960. North of Öland, hydrogen sulphide was present already from depth exceeding 45 meters. Anoxic conditions at these shallow depths have never been observed before in this area. In the south-west, in the Arkona Basin and in parts of the Bornholm Basin, oxygen conditions were good due to some smaller inflows during August and September.