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2I - High-tiered Studies (MO7/6) Effects of trenbolone on the zooplankton of aquatic model ecosystems. Jaser, Wolfgang1, Severin, Gabriele1, Pfister, Gerd1, Kettrup, Antonius1, Schramm, Karl-Werner*,1, 1 Institute of Ecological Chemistry, GSF-National Research Center for Environment and Health, Munich, Bavaria, Germany ABSTRACT- Aquatic model ecosystems are suitable tools to test the effects of substances on organisms in complex systems considering inter− and intraspecific relationships. The synthetic steroid trenbolone was used in a microcosm study to observe the influence of an androgen on the aquatic biocenosis. Trenbolone is the active compound of several implant preparations for cattle with a suggested strong anabolic activity. Incomplete degradation in sewage plants and as a result the entry of the substance into river waters has to be assumed. To design the model ecosystems as close to nature as possible 12 stainless steel cylinders (diameter: 80 cm, height: 60 cm) were filled with a 10 cm layer of sediment and 230 L filtered (mesh size 63 Key words: androgen, trenbolone, microcosm, zooplankton |
m) water from an oligotrophic littoral area of Lake Ammersee (Southern Germany). After a five week pre−application−phase the microcosms were dosed with trenbolone in six different concentrations for nine weeks using a controlled released method to simulate the entry in the aquatic environment close to reality. Six microcosms served as untreated controls. In the following post-application-phase the microcosms were observed for another six weeks. Water temperature, oxygen saturation, pH, conductivity, NO3−N, PO4−P and NH4−N were measured, plankton, water and sediment samples were taken. Referring to these data and also considering interactions in the food web, possible effects of trenbolone on the zooplankton community of aquatic model ecosystems are shown.