Salinity trend and variation in the Baltic Sea near the Lithuanian coast and in the Curonian Lagoon in 1984–2005

Abstract

The paper presents the analysis of the interannual water salinity variations in the Baltic Sea near the Lithuanian coast and in the Curonian Lagoon, a shallow and enclosed sub-basin of the Baltic Sea. Time series of some related hydroclimatic factors were also analysed. The data were compiled from measurements taken from 1984 to 2005. The analysis of salinity measurement time series showed that the mean annual salinity in the Klaipėda Strait and in the northern part of the Curonian Lagoon in 1984–2005 was increasing. The average surface salinity in the Baltic Sea near the Lithuania shore and in the Baltic Proper decreased during the same period. The relation between some natural and anthropogenic factors and water salinity in the Curonian Lagoon was investigated. The dredging in the Klaipėda Strait fairway has been intensified since 1994 and the permeability of the strait was increased. The regression analysis showed that the annual mean salinity change in the Curonian Lagoon and in the Baltic Sea near the Lithuanian coast was most influenced by the long-term variations in the Nemunas River runoff and the depth of the Klaipėda port.