Weak winds from the north dominated. The surface water temperatures were normal for the season in the whole area i.e. about 6°C in the Skagerak, 6.5°C in the Kattegat and between 5 and 3°C in the Baltic. Water of high nitrate content (20 mM) was found north of Jylland (station HS5). In the Kattegat both inorganic nitrogen and the phosphate concentrations were low in the surface water. The spring bloom in the Baltic had started. The oxygen concentrations in the Baltic were below 2 ml/l from about 80 m depth in the Gotland Basin and about 70 m in the Bornholm Basin. No hydrogen sulphide was detected in the Baltic Sea.