Assess students' ability to analyze causes and effects of algal blooms in a freshwater lake: identify and rank nutrient sources (agricultural runoff, sewage, lawn fertilizers, atmospheric deposition), explain eutrophication and resulting toxin production or hypoxia, evaluate ecological impacts on food webs and biodiversity, and propose and justify evidence-based mitigation strategies (source control, land management, wastewater treatment, and in‑lake interventions), including discussion of trade‑offs and practical implementation for a middle‑school advanced scenario.