The article presents the outcomes of a roundtable discussion sponsored by the US Environmental Protection Agency (EPA) in January 2003, aimed at developing a scientific consensus on the relationship between eutrophication and harmful algal blooms (HABs). The discussion included representatives from academic institutions, federal and state agencies. Seven statements were unanimously adopted based on current and previous data: 1. Degraded water quality from increased nutrient pollution promotes the development and persistence of many HABs, contributing to their expansion in the US and globally. 2. The composition of the nutrient pool, not just the total quantity, impacts HABs, with specific algal species having physiological adaptations to exploit different nutrient regimes. 3. High-biomass blooms require exogenous nutrients to be sustained, and both chronic and episodic nutrient delivery promote HAB development. 4. Recently developed tools and techniques are improving the detection of some HABs, and emerging technologies are advancing towards operational status for prediction and management. 5. Experimental studies are crucial for understanding the role of nutrients in HAB expression and will enhance prediction and mitigation efforts. 6. Management of nutrient inputs to watersheds can lead to significant reductions in HABs, as demonstrated by various case studies. 7. Prevention of large blooms through nutrient control is preferable to attempts to eradicate established HABs, but effective management requires adaptive approaches and timely communication. The article also highlights the complexity of HAB dynamics and the need for continued research and monitoring to address these issues effectively.The article presents the outcomes of a roundtable discussion sponsored by the US Environmental Protection Agency (EPA) in January 2003, aimed at developing a scientific consensus on the relationship between eutrophication and harmful algal blooms (HABs). The discussion included representatives from academic institutions, federal and state agencies. Seven statements were unanimously adopted based on current and previous data: 1. Degraded water quality from increased nutrient pollution promotes the development and persistence of many HABs, contributing to their expansion in the US and globally. 2. The composition of the nutrient pool, not just the total quantity, impacts HABs, with specific algal species having physiological adaptations to exploit different nutrient regimes. 3. High-biomass blooms require exogenous nutrients to be sustained, and both chronic and episodic nutrient delivery promote HAB development. 4. Recently developed tools and techniques are improving the detection of some HABs, and emerging technologies are advancing towards operational status for prediction and management. 5. Experimental studies are crucial for understanding the role of nutrients in HAB expression and will enhance prediction and mitigation efforts. 6. Management of nutrient inputs to watersheds can lead to significant reductions in HABs, as demonstrated by various case studies. 7. Prevention of large blooms through nutrient control is preferable to attempts to eradicate established HABs, but effective management requires adaptive approaches and timely communication. The article also highlights the complexity of HAB dynamics and the need for continued research and monitoring to address these issues effectively.