- 1) Institut für Ostseeforschung Warnemünde an der Universität Rostock, Postfach 30 11 61, 18112, Rostock
The temperatures in the western and central Baltic Sea were determined by the relatively mild winter 1993/94 causing positive anomalies of 0.5–1 K in both the surface layer and the intermediate water. The summer 1994 was among the warmest in the past 60 years and produced extremely high temperatures and anomalies of 4–6 K in the surface layer of the whole Baltic Sea. Inflow events in December 1993 and during 1994 did not reach the magnitude of major events but strengthened the effects of the major Baltic inflow in January 1993 and improved especially the oxygen conditions in central Baltic deep waters. The oxygen concentrations measured in the Gotland Deep below 170 m depth in May 1994 were the highest since the 1930s. The deep water was free of hydrogen sulphide in the whole Baltic Sea during this month. Thus, the longest ever stagnation period which began in 1977 terminated in 1994. Large amounts of nitrate were transported into the Baltic Sea by the inflow events in December 1993 and March 1994. The corresponding import of phosphate was of lower significance. Intermediate phosphate and silicate maxima and nitrate minima and maxima developed during the renewal of the deep water in the eastern Gotland Basin. Nitrate accumulation was continuously measured at the permanent station “Darß Sill” over a fairly long period in autumn 1994 by means of anin situ autoanalyzer. This process was characterized by strong fluctuations and correlated with the salinity. Additionally, the distribution patterns of dissolved and particulate organic carbon were studied in the western and central Baltic Sea. Reproduction of the fish species herring, sprat and cod was favoured by the mild winter 1993/94 and by inflow events supplying centrla Baltic deep waters with oxygen and salt.
- 1 - sciences appliquees, technologies et medecines
- 2 - sciences biologiques et medicales
- 3 - sciences biologiques fondamentales et appliquees. psychologie