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(44-08) Effects of trenbolone on the zooplankton of aquatic model ecosystems. Jaser, Wolfgang*,1, Severin, Gabriele1, Pfister, Gerd1, Schramm, Karl-Werner1, 1 GSF-National Research Center for Environment and Health, Neuherberg, Germany ABSTRACT- Complex microcosms (vol. 230 L) with water, sediment and the plankton biocenosis of a natural lake littoral are suitable tools for the risk assessment of xenobiotica. In the current study the veterinary pharmaceutical trenbolone served as a model substance for an endocrine disruptor with androgenic properties. Effects on the zooplankton were investigated in 12 microcosms using a controlled release method to simulate the continuous release of the substance into surface waters. A regression design was chosen where six different concentrations of trenbolone (Tb 1 − Tb 6) were compared to six untreated controls. Water samples were taken once per week before (4 weeks), during (9 weeks) and for 6 weeks after application of the substance. Physico-chemical parameters as well as the population dynamics of the plankton organisms were analysed. Multivariate statistics were applied to detect the effects of trenbolone on the zooplankton community but food web interactions with the phytoplankton have to be considered as well. Key words: microcosm, zooplankton, endocrine disruptor, trenbolone |
