Ryszard Staniszewski, Szymon Jusik
Uniwersytet Przyrodniczy, Poznań
Open cast mines can cause several modification of environment, as like decrease of groundwater level, soil modifications, noise, changes of river discharge and others. The year 2009 was the last year of mine waters discharge from Lubstów mine (Wielkopolska province) to Noteć River, which caused increase of river discharge for approximately 17%. The paper presents results of two years of studies on impact of mine waters from brown coal open-pit mine on lowland river. Most important water quality parameters like pH reaction, conductivity, sulphates and nutrients were analysed in all sites. Biological indication methods (MTR, IBMR, RI and others) based on aquatic plants (macrophytes, algae, mosses, liverworts) were used in studies to evaluate possible water quality changes below mine water discharge. Additionally, indices describing biological diversity (Shannon-Wiener W, Simpson D, uniformity J) were calculated using data from standard Mean Trophic Rank survey. In all three sites domination of several aquatic taxa was observed. Most frequent taxa were Elodea canadensis and Berula erecta. Other taxa often present in Noteć River were Spirodela plyrhiza, Sparganium emersum, Sparganium erectum, Mentha aquatica and Symphytum officinale. Results of studies were used for statistical analyses of Friedman ANOVA. Obtained data showed, that according to analysed water quality parameters as like, pH reaction, conductivity, total phosphorus, nitrates and others, changes of water quality were negligible. Results obtained using macrophyte indices for estimation of water trophy and ecological state confirmed results of chemical measurements. According to ANOVA, statistically significant relations were found for macrophyte biological diversity indices among surveyed river sites (χ2 = 8.40; p = 0.015). It was also confirmed by Kendall coefficient W = 0.84. The highest biological diversity was observed in site 1 situated above mine waters discharge and it was decreasing in sites 2 and 3. For the Shannon-Wiener (H’) index average coefficients were respectively 0.29 and 0.23, thus precise interpretation of these relation is difficult and to some extent could depend on other factors, eg. shading. Results of studies showed, that according to measured water quality parameters mine waters discharge from deep seated drainage did not caused significant changes of Noteć river water quality.
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