We study ecology, evolution and biodiversity of aquatic organisms, mostly fish, their prey and their predators. We are mostly concernd with evolutionary and ecological diversity dynamics. We wish to understand variation between evolutionary lineages in their rates and mechanisms of evolutionary diversification, in their current diversity, and in the rates of loss of diversity. This includes the origins, maintenance and loss of adaptive divergence between populations, of polymorphisms within populations, and of new species and macroevolutionary diversity.
Ultimately, we like to understand how origin, maintenance and loss of biodiversity are affected by environmental variation, heterogeneity and change. To this end we apply methods from experimental and quantitative ecology, behaviour, morphology, molecular population genetics and phylogenetics. Our main model systems are adaptive radiations of fish, such as the cichlid fish in the great lakes of Africa, the coregonids (whitefish) in the prealpine lake system, and the different ecotypes and geographical varieties of trouts, char and stickleback.
We also study applied fish ecology in the context of management and revitalisation of running waters, effects of hydropower management schemes on habitat connectivity and population dynamics, impacts of hormon-active substances at population level, and methodology for assessing and monitoring river quality.