With the weather turning warmer and recreational activities on Rhode Island’s lakes, ponds, and rivers increasing, the Rhode Island Department of Health (RIDOH) and the Rhode Island Department of Environmental Management (DEM) are reminding everyone to be on the lookout for harmful algae blooms on these bodies of water.

Harmful algae blooms caused by blue-green algae, also known as cyanobacteria, are characterized by shades of bright to dark green and may have dense, floating algal mats on the water’s surface. The water may look like green paint, thick pea soup, or green cottage cheese.  Increased temperatures, slow moving water, and excessive amounts of nutrients cause the cyanobacteria to grow quickly and can create colonies of growth called a bloom. Harmful algae blooms are capable of producing toxins, which have the potential to negatively impact humans and animals.

During a harmful algae bloom, all recreation, including swimming, fishing, boating, and kayaking, should be avoided. People should not ingest untreated water or eat fish from affected bodies of water. Pets should not be allowed to drink or swim in this water.

Contact with water containing blue-green algae can cause irritation of the skin, nose, eyes, and/or throat. Common health effects associated with ingesting water containing blue-green algae include stomach ache, diarrhea, vomiting, and nausea. Rarer health effects include dizziness, headache, fever, liver damage, and nervous system damage. If you come into contact with water affected by a harmful algae bloom, rinse your skin with clean water as soon as possible and, when you get home, take a shower and wash your clothes. If your pet comes into contact with the water, immediately wash your pet with clean water. Do not let the animal lick algae off its fur. Call a veterinarian if your animal shows any symptoms of blue-green algae poisoning including loss of energy, loss of appetite, vomiting, diarrhea, or any unexplained sickness that occurs within a day or so after being in contact with water.

People who have had contact with water with algae blooms and who experience the symptoms described above should contact a healthcare provider and call RIDOH at 401-222-7727 to report illness associated with a blue-green algae bloom.

To report suspected blue-green algae blooms, contact DEM’s Office of Water Resources at 401-222-4700 or DEM.OWRCyano@dem.ri.gov and if possible, send a photograph of the reported algae bloom.