Original scientific paper
Published in: Holistic Approach Environ. 1(2011) 4, pp. 125 – 136
Paper reference number: HAE-21
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EUTROPHICATION IMPACT ON ZOOPLANKTON COMMUNITY: A SHALLOW LAKE APPROACH

Maria Špoljar^*, Tea Tomljanović^**, Ivana Lalić^***

^* Faculty of Science, University of Zagreb, Croatia

^** Faculty of Agriculture, University of Zagreb, Croatia

^*** Ministry of Environmental Protection, Physical Planning and Construction, Zagreb, Croatia

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ABSTRACT

Zooplankton communities were investigated in a turbid shallow lake with an aim to analyse (i) relationships between ecological  conditions  and  the  communities  and  (ii)  trophic  state  inferred  from  abiotic  and  biotic  indicators. According to results emerged littoral vegetated zone increased diversity (30 taxa) in comparison to the pelagial (17 taxa). Rotifers dominated in terms of diversity and abundance in littoral and pelagial, 15 and 27 taxa, 58 and 71 %, respectively.  Thus, they were chosen for approximation of the system trophic level according to their feeding preferences exhibited as guild ratio. Mean guild ratios in littoral (– 0.36) and pelagial (– 0.31) suggested the prevalence of microfagous rotifers. They fed mostly on bacteria and detritus suspension, thus together with environmental parameters indicated high trophic level of the lake.  It is supposed that turbidity resulted from anthropogenic eutrophication has affected biocoenosis assemblage, not only zooplankton but also the primary producers and the fishes.

Keywords: transparency/turbidity, vegetation, trophic state, zooplankton
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