SELECTED CHEMICAL INDICATORS OF WATER QUALITY IN THE NEAR BOTTOM LAYER OF THE POMERANIAN BAY CLOSE TO THE MOUTH OF THE CHANNEL SWINA BETWEEN 1991-1994

Abstract

Between 1991-1994 a study was conducted on the chemical composition of near bottom water of the Pomeranian Bay liable to back flow in the water-way to the Szczecin Lagoon. The aim of this study was to investigate the quality of water in the vicinity of the river Świna mouth (water depth ³10 m) in respect to the following parameters: chlorinity, concentrations of sulphate, bicarbonate as well as calcium and magnesium ions, temperature, pH, redox conditions indicators – Eh, O_2diss., COD-Mn and BOD₅, and indicators of the trophic status, i.e. the concentrations of nitrate, nitrite, total nitrogen, dissolved phosphate, total phosphorus and dissolved silicate. The collected results of measurements, if compared with data on riverine outflow form the Odra river, can be used in mass balance calculations of substances inflowing into the Szczecin Lagoon. Further on, the balance calculations can indicate the biogeochemical processes influencing the chemical composition of water in the estuary of the river Odra.

Key words: water composition, near bottom water, Swina mouth, Pomeranian Bay, Baltic Sea