Assess understanding of processes driving eutrophication in freshwater ecosystems — including external and internal nutrient loading, primary production increases, harmful algal blooms, oxygen depletion and hypoxia, trophic and biodiversity impacts, toxin risks, and socio-ecological consequences — and test ability to interpret common monitoring indicators (chlorophyll-a, Secchi depth, dissolved oxygen), analyze brief case-study data, and evaluate prevention and mitigation strategies (nutrient reduction, restoration, policy measures).