Cultural eutrophication has become a primary water quality issue for most freshwater and coastal marine ecosystems in the world. However, despite extensive research during the past 4-5 decades, numerous questions in eutrophication science remain unanswered. This talk outlines three key questions that deserve extensive future study.
Results/Conclusions Evidence is presented that the trophic state of a lake or reservoir can strongly influence the fate and potential effects of non-nutrient contaminants, both organic and inorganic.  Evidence is also presented that there may be significant potential for interactions between eutrophication status and the biomass and virulence of microbial pathogens that can influence human health. In addition, it will be important to resolve ongoing debates about the nature of the eutrophication models and nutrient loading strategies that can be used to most effectively protect water quality in estuarine and coastal marine ecosystems.