Frequent Questions

Where can I find information about nutrient pollution, including red tides or harmful algal blooms?

Harmful algal blooms (HABs) are a major environmental problem in all 50 states. Known as red tides, blue-green algae or cyanobacteria, harmful algal blooms have severe impacts on human health, aquatic ecosystems and the economy. Algal blooms can be toxic. Keep people and pets away from water that is green, scummy, or smells bad.


Harmful algal blooms are caused by nutrient pollution. Nutrient pollution occurs when excess nitrogen and phosphorus are found in air and water. The following EPA Web sites provide information about nutrient pollution in the United States.


The following non-EPA resources also provide information on harmful algal blooms: EXIT


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