Institution: | 1. Zoological Institute, University of Cologne, Ecological Research Station Grietherbusch, Cologne, Germany and Landesfischereiverband Westfalen und Lippe e.V., Münster, Germany;2. Department of Physics, University of Oslo, Blindern, Oslo, Norway;3. Landesfischereiverband Westfalen und Lippe e.V., Münster, Germany;4. Zoological Institute, University of Cologne, Ecological Research Station Grietherbusch, Cologne, Germany |