Summary
Oxygen concentrations below 2 ml/l were found in the Baltic at depths exceeding 70 to 80 metres. Hydrogen sulphide was found in the Northern Baltic Proper and West Gotland Basin, at depths exceeding 80 to 90 metres. Surface phosphate and silicate levels in the northern part of the Baltic were above normal values, while inorganic nitrogen showed lower than normal values. Surface DIN was close to zero from the Sound to Hanöbukten, indicating the start of the spring bloom – about a month earlier than normal. There are indications that the initial bloom is subsiding at Anholt E, in the Kattegat, and just beginning in the Skagerrak.