Cruise report from R/V Aranda week 20, 2016

Type: Report
Author: Karin Wesslander


All nutrients in the surface water were very low in the Skagerrak and the Kattegat. At 15-20 meters, peaks in the fluorescence were observed together with high saturation of oxygen and also higher levels in nutrients. In Baltic Proper, the inorganic nitrogen (nitrite+nitrate) was used up down to 40 meter but phosphate was still present. The silicate levels were still above normal in the entire Baltic Proper.

Acute hypoxia (<2ml/l) was measured from 70-80 meters depth in the Eastern and Western Gotland Basins, and also from 70 meters at the Hanö Bight and from 80 meters in the Bornholm Basin. Hydrogen sulphide was only present intermediary (125-150 meter) at the Fårö Deep and from 90 meters depth in the Western Gotland Basin. The entire water column at the Gotland Deep (BY15) was still oxygenated.