Fishes are the most diverse group of vertebrates, are key players in aquatic ecosystems, provide a diverse set of ecosystem services, and are sensitive to environmental change. We study their ecology, evolution and conservation. We work with fish diversity from traits and genes in populations to the diversity of species assemblages, their change through time and the ecosystem consequences. We are particularly interested in understanding the evolution of endemic diversity within individual ecosystems, such as the radiations of cichlid fish in African lakes and the radiation of whitefish in the lakes around the European Alps. We are a single research group led by Ole Seehausen at the University of Bern but Ole also leads the Department Fish Ecology and Evolution at the Eawag Center for Ecology, Evolution and Biogeochemistry, Kastanienbaum, where we currently host three other research groups that are all associated with the IEE too. The work of the Eawag department is motivated by the aim to contribute to the emerging synthesis between evolutionary biology and ecosystems ecology. There we also host the Swiss Fisheries Advisory Service.
Ecol&Evol - Rapid buildup of sympatric species diversity in Alpine whitefish
Carmela and colleagues studied the whitefish diversity of Lakes Thun and Brienz. Using genetic, morphological and ecological data, they discovered that there are not five but six species of whitefish in Lake Thun. The newly discovered species also occurs in Lake Brienz, making it four instead three species in this lake. Another species of Lake Thun turned out to be introduced from Lake Constance in the 1930ies and was able to persist in sympatry with the other five native whitefish species of Lake Thun despite all these species having evolved in less than 15'000 years. Furthermore, consistent with speciation theory, they found stronger correlations between genetic and ecological differentiation for sympatrically than for allopatrically evolved species.