Assess students' ability to analyze causes, processes, and solutions for eutrophication in freshwater lakes. Topics tested: identification of nutrient sources (point vs nonpoint, nitrogen and phosphorus pathways), algal bloom dynamics (growth drivers, species composition, cyanobacterial toxins), physical and biogeochemical drivers of hypoxia (thermal stratification, organic matter decomposition, oxygen demand), interpretation of empirical data (nutrient loading estimates, chlorophyll‑a, dissolved oxygen profiles), and evaluation/design of remediation strategies (nutrient management, buffer strips, constructed wetlands, aeration, biomanipulation, policy and cost–benefit trade‑offs). Tasks may include diagnosing causal links from datasets and maps, predicting bloom and hypoxia formation, and proposing evidence‑based remediation plans with rationale.