Trait-based approaches are being increasingly used in ecology. They consider simultaneously multiple morphological and functional traits to explain community distributions along various environmental gradients and predict ecosystem functioning. Traditional taxon-based approaches become unwieldy as the number of species increases; trait-based approaches provide a way to simplify this complexity, by focusing attention on the functional traits that determine how organisms interact with each other and their environment. Although much of the work on trait-based approaches come from terrestrial plant ecology, we have recently begun to apply them to phytoplankton communities. While we have made good progress at applying trait-based approaches to phytoplankton, a significant challenge will be to extend these approaches to higher trophic levels in the aquatic ecosystem. The goal of this International Incoming Fellowship at DTU-Aqua is to work with researchers there to lay the foundation for applying trait-based approaches to understanding the entire aquatic food web, from phytoplankton to zooplankton and fish. In particular, we will: 1) identify and characterize key functional traits of zooplankton and fish, 2) develop a mechanistic basis for scaling zooplankton foraging traits to the population and community level, 3) investigate basic theoretical issues relating to the interaction of multiple traits, and 4) construct end-to-end adaptive food web models for aquatic ecosystems. The novelty of the project is that it brings together ideas from evolutionary game theory with detailed models of aquatic ecosystems. The project is a natural extension of fellow’s work that will benefit greatly from collaboration with the DTU-Aqua scientists, who are experts in mechanistic approaches to modeling zooplankton and fish. It should result in significant synergy and innovation, with tangible outcomes in both fundamental and applied aspects of aquatic ecosystem research.