Coastal Zone No. 6 • 2003

Gorzysław Poleszczuk

Department of Natural Sciences, Szczecin University

Felczaka St. 3A, 71-412 Szczecin, POLAND

Baltic Coastal Zone No 6, pp. 5-25, ISSN 1643-0115

e-mail: polesz@univ.szczecin.pl

Abstract

TOTAL CONCENTRATIONS OF MAGNESIUM AND CALCIUM IN SELECTED WATER BODIES OF THE ODRA RIVER ESTUARY (NW POLAND)

Basing on results of measurements of total concentrations of magnesium and calcium in surface and near bottom water of the river Odra estuary (at stations located in Roztoka Odrzanska, Great Lagoon and Wicko Lake) between 1991-1993 an attempt was undertaken to quantify the relation between the magnitude of the observed Mg²⁺_tot and Ca²⁺_tot concentrations, monthly mean river flow (Q_s – measured in Gozdowice) and sea level in the Pomeranian Bay (readings from the mareograph in the mouth of the river Swina to the Pomeranian Bay). It was found out that magnesium concentrations are most affected by the mean flow of the river Odra and the strongest relation (the magnitude of correlation coefficients and the highest statistical significance) was obtained between the total concentration of Mg²⁺_tot and the mean Q_s in the month of measurements and the two preceding months. The variations in sea level in the Pomeranian Bay, which can be used as an indicator of saline seawater inflow into the estuary, influenced the studied concentrations only in the southern part of the Great