[Source: EcoRI News]

By ecoRI News staff

The Rhode Island Department of Health (DOH) and the Rhode Island Department of Environmental Management (DEM) recently advised people to avoid contact with St. Mary’s Pond in Portsmouth because of blue-green algae, or cyanobacteria, blooms in the pond. Blue-green algae can produce toxins that can harm humans and animals.

The July 7 advisory noted that people shouldn’t ingest untreated water or eat fish from St. Mary’s Pond. Also, since pets can be affected by exposure to algal toxins, owners shouldn’t allow pets to drink this water or swim in the water. This advisory will remain in effect until further notice.

St. Mary’s Pond is a drinking-water source maintained by Newport Water. The water coming out of customers’ taps is safe to drink, according to state and local officials, but the raw, untreated water coming from the system’s nine reservoirs — North and South Easton ponds, Gardiner Pond, Paradise Pond, St. Mary’s Pond, Sisson Pond, the Lawton Valley Reservoir, Nonquit Pond and the Watson Reservoir — is being stressed by elevated levels of phosphorus and nitrogen.

Sources of phosphorus and nitrogen are varied, but are typically linked to stormwater runoff, pet waste left on the ground, geese waste, and agricultural, lawn and golf course fertilizers.

As the main drinking water supplier for the residents of Newport, Middletown and Portsmouth, Newport Water serves nearly 70,000 people. Even when a cyanobacteria bloom is present in a pond, the treated water that Newport Water distributes to homes is safe, according to officials. Treatment removes harmful bacteria, including cyanobacteria, before the water is delivered to customers.

Contact with water containing cyanobacteria can cause irritation of the skin, nose, eyes, and/or throat. If water containing algal toxins is ingested, health effects can include stomach ache, diarrhea, vomiting and nausea. Young children and pets are at greater risk than adults, due to their size and because they are more likely to drink contaminated water. Other health effects, which are rarer, include dizziness, headache, fever, liver damage, and nervous system damage.

Another DOH/DEM advisory, also released July 7, told people to avoid contact with Elm Lake, Roosevelt Lake and the Japanese Gardens in Roger Williams Park in Providence because of blue-green algae blooms. This advisory will also remain in effect until further notice.

It’s possible that blue-green algae blooms may be affecting other waterbodies in Rhode Island. DEM and DOH advise people to avoid contact with waterbodies that exhibit bright-green coloration and/or dense floating algal mats that form on the water’s surface. The water may look like green paint, thick pea soup, or green cottage cheese. To report suspected blue-green algae blooms, contact DEM’s Office of Water Resources at 401-222-4700, or via e-mail at dem.owrcyano@dem.ri.gov, and if possible, send a photograph of the reported algae bloom.

2015 study found that humans are responsible for increased cyanobacteria growth since the 1800s.