Abstract:After presentation of the characteristics of a water reservoir in CaCO3 excavation pit, called the Turkusowe Lake, situated in the Wolin National Park on the Wolin Island, available results of the analyses referring to the quality of surface water of this water reservoir and being carried out since 1986 as well as those of own studies being carried out from 1999 to 2010 were gathered, collecting this way a research material covering the quarter-century 1986-2010. It was shown that the Turkusowe Lake is a water reservoir being resistant by nature to eutrophication (lake basin development and depth, surrounding by the heights adhering to it, and presence of CaCO3 building the lake basin), whereas an increase in the trophic level and development of eutrophication phenomena in the form of weak phytoplankton blooms being observed, particularly in 2005-2010, is connected with increased anthropogenic pressure in the form of direct discharge of municipal sewage to the lake and waste-water to the soil in the alimentation zone of underground waters feeding this lake. The extent of anthropogenic pressure was so big that it started to prevail over the natural processes limiting an increase in the trophic level in this lake.

No abstract

During spring 2008 and 2013, the concentrations of nitrogen substances (NO 3-, NO 2 and NH 4 +) were investigated against the background of changes in other selected physical and chemical water quality indices in the surface waters of Lake Warnowo located in Wolin National Park on Volin Island. It was found that the investigated waters were additionally contaminated by nitrogen compounds. This is illustrated by increased values of NO 3-, NO 2 and NH 4 + concentrations of the investigated waters in 2013 to max. values 0,28 (N-NO 3 /dm 3), 0,103 (N-NO 2 /dm 3) and 0,34 (N-NH 4 /dm 3), causing water quality deterioration in the lake by one class of quality compared to 2008 (where the max. values amounted to 0,39 (N-NO 3 /dm 3), 0,016 (N-NO 2 /dm 3) and 0,13 (N-NH 4 /dm 3), which led to accelerated water eutrophication in the lake in 2008-2013. This paper performs one of the chemometric techniques-principal component analysis (PCA)-used to classify water quality indices.