Environmental observations in the Gulf of Gdansk and Pomeranian Bay following the summer flood of 1997

Abstract

In July and at the beginning of August 1997 a study was undertaken in the Gulf of Gdansk and Pomeranian Bay to follow the immediate effects of the flood which occurred within the Polish rivers — Wisla and Odra — drainage areas. The study included measurements and observations of meteorological and hydrodynamic parameters, basic physico-chemical variables, certain persistent organic pollutants as well as heavy metals and the level of sanitary pollution. The paper presents an overview of environmental conditions in the bays, based on hydrochemical data, subsequent to the inflow of the flood crests. Results of biological investigations, carried out solely in the Pomeranian Bay, on phytoplankton abundance, biomass, species composition and Zooplankton diversity are also presented in the paper. The results of measurements were evaluated in comparison with long-term (1979–1996) monitoring data and control measurements carried out in the last decade of August. It was found out that the impact of flood water was restricted to internal areas of both bays and the negative environmental effects appeared only locally.