Anglers have an important ecological-heiferic function, for example in the context of the management of waters and the protection of fish species. Increased attention is, however, also drawn to the possible interference of anglers and the fishing for animals and plants, for example by impact damage or the raising of water-bearing songbirds. Which scientifically reliable findings are there on this topic? And if anglers have a disruptive effect, how strong is it and how does it differ, if at all, from the disruptive effects of other forms of water use? Financed by a new, unique cooperation of three state fishing associations from Lower Saxony, Saxony and Bavaria, since 01.06.2018 in a three-year research and development project called StörBagger the effects of fishing on the biological diversity of waters in comparison to other leisure activities at the Leibniz-Institute of Freshwater Ecology and Inland Fisheries in Berlin. As a result, concrete recommendations for a better harmonization of angling and conservation objectives based on scientific facts should be developed.