Cruise report from KBV001 Poseidon week 9, 2012

Type: Report
Author: Martin Hansson


In Skagerrak and the north Kattegat the spring bloom was ongoing and the amount of nutrients was low. The southern parts of the Kattegat and the Sound were influenced by outflowing winter water from the Baltic with high concentrations of nutrients. In the Baltic Proper winter conditions prevailed. The concentrations of nitrite+nitrate were normal while the amount of phosphate were elevated at all stations and much over normal in the southwest parts. Silicate was also elevated in these areas. The inflow that occurred in November/December 2011 had reached the southeast parts of the Baltic Proper and had started to enter the eastern Gotland Basin. Hydrogen sulphide was found in the western Gotland basin from depth exceeding 125 meters and in the north Gotland Basin from 100 meters depth. In the central parts of the eastern Gotland Basin from 80-90 meters depth. The oxygen concentrations below 2 ml/l (hypoxia) was found from depth exceeding 65-75 meters in the eastern Gotland Basin and from 85 meters in the northern and western Gotland Basin.