Harmful Algal Blooms (HABs)


Harmful algal blooms (HABs) are an overgrowth of algae in a waterbody that can be toxic or fatal to humans, pets and livestock.  HABs are caused by excess nutrients (nitrogen and phosphorus) in water.  Only some species of algae produce dangerous toxins, but these toxins can have serious consequences for the people and animals that swim in or drink from affected water bodies.  To learn more, or if you suspect you have identified a HAB, please click here for additional information.

The MT Department of Environmental Quality has also created a helpful HAB Fact Sheet.

HABs(Harmful Algal Bloom photos from Montana DPHHS website)