Field work in the Wadden Sea.

Colonization success and persistence of species depend on their capabilities to disperse and to exploit different resources. We aim at understanding interactions among trophic levels; specifically, how consumers with different dispersal and mobility traits impact distribution, abundance and composition of lower trophic levels and vice versa. We study effects of macrozoobenthic consumers, which exploit different habitats and differ in their dispersal and mobility capabilities. In field and mesocosm studies, we will test how mobility, body size and feeding traits of consumers affect resource composition and abundance. A full field assessment of resource use and community composition of microphytobenthos is complemented by marine mesocosm experiments focusing on five macrozoobenthos species (consumers) and fish (different ecotypes of sticklebacks as top consumers) - all representing different mobility, body size and feeding types.

Threespined Sticklebacks (Gasterosteus aculeatus), female (left), male (right).

We will identify the interactive effects of physiological traits on resource use and quantifiable macrozoobenthos community composition under controlled conditions in marine and freshwater mesocosms. Food resources and trophic levels will be identified by stable isotope and fatty acid analyses. Consequently, we will contribute to understand the dynamic in biodiversity in context of trait dependent differences in resource availability and use.

Genomic differences (FST) between freshwater and marine stickleback populations; arrows indicate specific candidate genes that differ strongly with known (green) and (unknown) function.