Cruise report from R/V Argos week 20, 2013

Type: Report
Author: Martin Hansson, Lars Andersson


Temperature and salinity in the surface water was normal throughout the investigated area. The phosphorus concentration remains elevated in the south Baltic Proper and the Sound. All inorganic nitrogen (DIN) had been consumed in the surface water at all stations. High silicate concentrations were found in Kattegat, while concentrations in the south-east Baltic Proper, the Bornholm basin and Hanöbukten were lower than normal. Oxygen levels below 2 ml/l were found at depths greater than 70-80 metres throughout the Baltic Proper. The bottom water in the Arkona basin was well oxygenated. Hydrogen sulphide was found in the eastern Gotland basin from 125-145 metres and in the western Gotland basin from 90 metres. High chlorophyll fluorescence was noted at Släggö at 7.5 metres, in intermediate layers in the central Skagerrak at 15 metres and at Anholt E at 12 metres. In co-operation with Göteborg University (FRISBEE-project), water samples were taken for measurements of oxygen- and carbon isotopes. The project will be running for one year.