Effects of eutrophication on vendace, Coregonus albula (L.). I. Limnological characteristics of selected lakes in Wielkopolska
Małgorzata Fiszer, Antoni Przybył, Wojciech Andrzejewski, Jan Mazurkiewicz, Janusz Golski, Katarzyna Przybylska, Sławomir Runowski
ABSTRACT. The aim of the study was to characterize the abiotic environmental factors influencing the occurrence and biology of vendace, Coregonus albula (L.). The analyses covered four lakes in the Wielkopolska region – lakes Dominickie, Gorzyńskie, Lubikowskie, and Strzeszyńskie. The most important natural characteristics of the lakes were analyzed, and their current trophic states were determined. Moreover, two trophic state indicators were also used – the HB index and the Carlson index. Parameters differentiating the lakes most strongly included area, depth, area-depth index, shoreline development, and fish yield index. In terms of morphometry, lakes Gorzyńskie and Lubikowskie are most suitable for optimal vendace fishery management. The least developed stratification was observed in Lake Dominickie, while the most marked stratification was noted in Lake Gorzyńskie, which had the shallowest epilimnion depth, the highest thermocline temperature gradient, and a deep, cool hypolimnion. Considerable deoxygenation was observed in the summer in the hypolimnions in all the lakes; however, oxygen deficits were also detected in the metalimnion of Lake Strzeszyńskie. Based of the analysis of physicochemical factors and trophic state indexes, good water quality was noted in all the analyzed lakes. The trophic state of Lake Gorzyńskie was designated as on the border between the mesoeutrophic and eutrophic states, while lakes Dominickie, Lubikowskie, and Strzeszyńskie were designated as eutrophic.
Keywords: environmental factors, habitat, lakes, stratification
CORRESPONDING AUTHOR:
M. Fiszer, A. Przybył, W. Andrzejewski [+], J. Mazurkiewicz,
J. Golski, K. Przybylska, S. Runowski
Department of Fisheries and Aquaculture, Institute of Zoology Poznań University of Life Sciences
Wojska Polskiego 71c, 60-125 Poznań, Poland
Tel./fax: +48 618487706; e-mail: wojtek@up.poznan.pl