In Germany, amateur anglers remove more fish from freshwaters than commercial fisheries. For this reason, an important approach of our transdisciplinary research is to involve these stakeholders in water protection. Our involvement of anglers and river keepers means that research findings are transferred to practice – and vice versa: this close cooperation provides an important impetus for our own research. In this respect, we focus primarily on the complex interactions between humans and the environment (social-ecological research). How do anglers behave at the riverside or lakeside, and how can they be optimally involved in management measures? How does fish stocking by angling associations affect fish communities and the ecological functions of freshwaters? How can stocks be preserved and used in the long term? And which measures are conducive to animal protection? We address questions such as these in cooperation with anglers and angling associations as well as with partners from the areas of species and nature protection.