A Harmful Algal Bloom, or HAB, is the excessive growth of cyanobacteria, often referred to as blue-green algae, which can produce potentially harmful toxins (cyanotoxins). These cyanobacteria naturally occur in fresh water and can proliferate, or bloom, with the right combination of sunlight, still waters, and excess nutrients like phosphorus. These blooms are usually a bright green, but can also appear as spilled paint, “pea soup,” or as having a thick coating or “mat” on the surface. Exposure to cyanobacteria can cause a range of health effects in people and pets.

The New Jersey Department of Environmental Protection (NJDEP) has developed a color-coded health alert index to provide the public with guidance on suitable recreational activities in water bodies impacted by harmful algal blooms.

If you observe what you think might be a HAB, a suspected Harmful Algal Bloom report can be submitted by smartphone or PC using the DEP HAB Interactive Map Reporting and Communication System. If a smartphone or computer is not available, reports may also be submitted to the DEP Hotline at 1-877-WARNDEP (927-6337).

For more information about HABs visit NJDEP’s HAB resource page. To review HAB testing results by date and location, visit NJDEP’s HAB Dashboard.