The Department of Environmental Management and the Department of Health (HEALTH) advise people that a recent algae bloom in the Ten Mile River, Central Pond, Turner Reservoir, and Omega Pond may form a naturally occurring algal toxin. People should avoid recreational activities (like swimming, boating, or fishing) in these areas until further notice. In addition, people should not drink water or eat fish from any of these areas.
During a recent sampling event, DEM observed a dense algae bloom turning the waters of Turner Reservoir a bright green color. DEM has confirmed the presence and predominance of the blue-green algae, Microcystis. These algae also referred to as cyanobacteria have the potential to form the naturally occurring algal toxin, Microcystin.
Symptoms of exposure to Microcystin in humans include stomach cramps, vomiting, diarrhea, fever, muscle and joint pain, and irritation of the skin, eyes and throat. People who have been drinking from, swimming, or fishing in these areas and experience those symptoms should contact their healthcare provider. People are advised to avoid contact with water if they see similar conditions (dense algae blooms, bright green colored waters) in other lakes and ponds.
According to Rhode Island State Veterinarian Scott Marshall, DVM, pets can also be affected by exposure to Microcystin. Pet owners should not allow pets to drink this water or swim in the water. Symptoms of exposure to Microcystin in dogs can include rapid onset of lethargy, difficulty breathing, vomiting, diarrhea, muscle rigidity or convulsions.
DEM advises that the algae bloom and the natural production of the toxin will likely resolve itself. This week’s rainfall reduced some of the toxin-producing algae. DEM will re-sample the waters and will inform the public when algae levels are low. At that time, it will be safe to resume recreational activities in these areas.
Microcystis is a type of blue algae that grows naturally in many water bodies. Under certain conditions, such as warm weather and an abundance of nutrients in the water, the algae may undergo an explosive type of growth that is commonly referred to as an algae bloom. Within a few days, a bloom can cause clear water to become cloudy, often forming floating dense mats of algae along the shoreline. As the days get shorter and cooler, the algae are likely to dissipate. Any toxins that are in the water will decline as the algae die off.