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(402) Effects of the endocrine disruptors nonylphenol and ethinylestradiol on phytoplankton in aquatic microcosms. Hense, Burkhard1, Severin, Gabriele2, Jaser, Wolfgang2, Welzl, Gehard1, Jüttner, Ingrid2, Schramm, Karl-Werner2, 1 2 ABSTRACT- Endocrine disruptors increasingly attract attention of environmental protection policy. For a comprehensive protection of aquatic ecosystems all trophic levels, including possible effects on phytoplankton, have to be considered. Investigations on effects on ecosystems often lack positive controls. Therefore microcosm experiments were conducted using the endocrine disruptor nonylphenol (NP) whose estrogenic character has been already shown for vertebrates, and the synthetic hormone 17- Key words: endocrine disruptor, phytoplankton, nonylphenol, ethinylestradiol |
-ethinylestradiol (EE) as a model substance with estrogenic potency. Different concentrations of both chemicals were exposed by using a controlled release system to simulate the conditions in natural systems. The experiments were conducted in cylindrical microcosms filled with littoral water (230 L) and sediment (10 cm) of an oligo-mesotrophic natural lake. For the design of the exposure see Jaser et al. (2001). The phytoplankton was investigated before, and during exposure and for a recovery period after removing the controlled release system. Various parameters, such as cell density of the species, total cell density, biomass, number of different species, and the Shannon-Weaver indices for diversity and evenness of the phytoplankton communities were compared between the different treatments. To detect changes in the community composition, the Principal Response Curve (PRC) method, an ordination method based on Redundancy Analysis (RDA), was applied using the computer software CANOCO 4.0. Jaser W., Severin G.F., Pfister G., Kettrup A., Schramm K.-W., (2001). Effects of 17-