When conditions are just right—such as found on warm, sunny days in the summer—small organisms called blue-green algae (or “cyanobacteria”) grow and may multiply rapidly in oceans, lakes, rivers, ponds, and other bodies of water.
As they eat, reproduce, and die, some of these cyanobacteria may produce and release different types of cyanotoxins, which can make people sick if they drink the water. By regularly testing water samples for the presence of these cyanotoxins, water quality specialists can make decisions about treating the water to reduce or remove the toxins, or advise the community when it may not be safe to drink or play in the water.