The European eel stock is in steep decline and consequently the species has been added to the IUCN Red List of Threatened Species as critically endangered. In order to reduce the anthropogenic mortality caused by hydroelectric power plants turbines, it is absolutely necessary to identify the environmental triggers for downstream migration towards their maritime spawning grounds. The aim of this project is to identify and quantitatively describe these triggers and develop predictive models. Therefore, environmental data will be combined with catch data and infrared video data from several trapping sites in three “top-11 rivers” in southern Sweden by means of advanced statistical modelling approaches. This will help to identify environmental windows of optimal migration conditions, described by threshold combinations of triggers. The results will enable an enhanced turbine management for hydroelectric power plants which will consequently contribute to achieve the goals of the Swedish Eel Management Plan.