Evolutionary Ecology of Aquatic Ecosystems

Eawag, Kastanienbaum, Switzerland
Center for Ecology Evolution and Biogeochemistry, Department of Fish Ecology & Evolution

The research in my group focuses on ecological dynamics of natural selection, and the reciprocal interactions among ecological, ecosystem, and evolutionary dynamics. We work in aquatic ecosystems, including Swiss lakes and streams, African Great Lakes, and Southern Greenland ponds.

Feedbacks between phenotypic evolution and ecosystem dynamics - Feedbacks are central to understanding evolving biological systems. In aquatic systems, we study how contemporary trait evolution of predators (e.g. threespine stickleback) can affect community structure (of prey and non-prey) and the functioning of ecosystems (e.g. habitat structure, nutrient cycling, productivity). Such organism-mediated ecosystem effects can feedback to affect selection gradients and evolutionary responses.

Evolution of the organism-environment interaction - All living organisms develop and evolve via reciprocal interaction with their environment. The evolution of phenotypic plasticity is an important component of this interaction. In aquatic organisms, we study both the causes and consequences of plasticity. In isopods, cryptic pigmentation is a developmentally plastic trait, whose evolution is likely mediated by predation, resources, and habitat structure. In stickleback, trait plasticity can have effects on ecosystems that are independent of the genetic background of the population.

Evolution and the resilience of ecosystems - Interactions between ecological and evolutionary processes are fundamental for understanding the balance of feedbacks that govern ecosystem stability and resilience to environmental change. Using pond and mesocosm experiments, we study how species interactions and biodiversity affect the resilience of aquatic systems to perturbations (e.g. nutrient pollution).

The community context of evolution (Greenland) - Contemporary evolution in natural populations is shaped by the interplay of abiotic environments and species interactions. It is the structure and composition of communities that define the ecological dynamics of natural selection. We study the community context of evolution and adaptation in freshwater ecosystems (lakes and streams) on the Southern Peninsula of Greenland. The lakes of Greenland are inhabited by only two fish species (threespine stickleback and arctic char), and so there are a limited number of food web configurations (e.g. only one species, both species, or neither species). We are interested in how this community context (i.e. presence or absence of Char) affects the evolution of interactions between stickleback and their prey. In 2019, we have initiated a long-term whole-ecosystem experiment, involving 6 treatment lakes and 6 control lakes, in which we released stickleback from char predation, and are tracking both the evolution of stickleback over time and concurrent changes in their pond ecosystems. Check out the following blog posts (by Cam Hudson: here and Hanna Rosinger: here) describing some of the work.