Cruise report from R/V Svea week 10-11, 2023

Type: Report
Author: Martin Hansson


During the cruise, which is part of the Swedish pelagic monitoring program, the Skagerrak, Kattegat, the Sound, and the Baltic Proper were visited. In addition to SMHI's regular sampling, during the cruise, a monitoring buoy was deployed at Huvudskär, and Uppsala University's measuring instruments were serviced at Östergarnsholm, east of Gotland.

The nutrient concentration in the surface waters of the Skagerrak and Kattegat had generally started to decrease due to ongoing spring bloom. High winter levels were still found in the Baltic Proper. The beginning of the spring bloom could only be noted in the southern parts of the Baltic Proper. In the deep water of the Baltic Proper, nutrient and hydrogen sulphide levels remained very high. In the deep basins around Gotland, there was no oxygen from 70-80 m. In the Eastern Gotland Basin, hydrogen sulphide levels increased rapidly to record levels below 125 m, and in the Western Gotland Basin, levels of hydrogen sulphide and nutrients were much higher than normal.

The next regular expedition with Svea is planned for April 12-18, starting in Lysekil and ending in Gothenburg.