Eutrophication is the process by which a body of water becomes overly enriched with minerals and nutrients that induce excessive growth of algae. This process can be caused by human activities like agricultural runoff containing fertilizers or sewage effluent entering waterways. It leads to negative environmental effects like hypoxia where low oxygen levels harm fish and other wildlife populations. Prevention efforts aim to minimize nonpoint sources of pollution through measures like riparian buffer zones and policies regulating fertilizer and waste management.