6 sites covering the Polish part of Zalew Szczecinski - 1 in Roztoka Odrzanska (south of Lagoon), 4 in the open Lagoon and 1 on Wicko Lake (north of Lagoon)

Dissolved oxygen parameters in the water column; Nitrate concentration parameters in the water column; Nitrite concentration parameters in the water column; Phosphate concentration parameters in the water column; Temperature of the water column; Alkalinity, acidity and pH of the water column

PH sensors; titrators; spectrophotometers

The purpose of the investigation was to collect the basic data set concerning conditions of water in the period 1991-1994. The general characteristics of the basin were determined from these measurements and used in a model. In this model the following were fixed: dissolved oxygen concentration as a measure of self-cleaning of water; concentration of nitrate, nitrite and phosphate as a measure of eutrophication; biochemical oxygen demand as a measure of organic loading and concentration of chloride as a measure of general mineralization. Samples were taken when the lagoon was without ice floes i.e. from April to November. At each station the samples were taken using Nansen bottles or Ruttner water samplers. All parameters were determined for the surface and bottom layers of the water. Measurements were made once a month (exceptionally twice). During chemical analysis the following methods were applied: - for determination dissolved oxygen - method described by Winkler; - for determination nitrite, nitrate - method described by Morris and Riley; - for determination phosphate - method described by Atkins (modified by Harvey); - for determination chloride - method described by Mohr.

Sea Fisheries Institute, Research Station in Swinoujscie
pl. Slowianski 11
Swinoujscie
Zachodniopomorskie
72-600
Poland