By LAURA WEICK For the fifth consecutive year, Warwick Pond is facing blue-green algae blooms, and although levels are not high enough for the Department of Environmental Management (DEM) to issue an advisory, residents are urged to remain cautious
For the fifth consecutive year, Warwick Pond is facing blue-green algae blooms, and although levels are not high enough for the Department of Environmental Management (DEM) to issue an advisory, residents are urged to remain cautious using the pond.
Blue-green algae, also known as cyanobacteria, is caused by high nutrient content in waters, including phosphorus and nitrogen, sunlight, warm temperatures and stagnant water conditions. Despite the name, blue-green algae is not actually algae, but instead, bacteria.
Not all blue-green algae blooms are toxic, but they can cause skin, eye, throat and nose irritation if it contacts skin. If ingested, water containing blue-green algae can cause stomach aches, diarrhea, nausea and vomiting. In the most severe cases, those who ingest blue-green algae may suffer from liver and nervous system damage. Animals can also be harmed by blue-green algae blooms.
The Rhode Island Department of Environmental Management (DEM) tested the water in late July and most recently on Aug. 4, where it found above average amounts of blue-green algae, but not enough to issue an advisory. The DEM still cautioned local residents to avoid contacting the pond water, including recreational activities such as fishing, swimming and canoeing. Warwick Pond is not the only body of water in Warwick to receive this warning, but it is the most high-profile one.
“Cyanobacteria occurs everywhere, they are naturally part of every pond system, but some places have higher prevalence,” Jane Sawyers, supervising environmental scientist for DEM said. “More developed, urban areas have more input of nutrients through human actions, so the development of the watershed can impact the blooms.”
Sawyers explained that depending on weather and the amount of nutrients, cyanobacteria levels may fluctuate.
“It’s very lake and weather-dependent,” Sawyers said in a letter to Phil D’Ercole, president of Friends of Warwick Ponds. “Most lakes after an initial bloom will see worsening conditions, but if weather (wind and rain) dissipate the bloom or conditions leading to the bloom, it may be temporary. In the past, DEM’s experience with algae conditions at Warwick Pond changes very quickly, both increases and decreases.”
According to D’Ercole, problems with cyanobacteria began five years ago. He said that multiple factors led to the growth of the bacteria in the pond. D’Ercole said pollution is one such factor, and suggested that chemicals that come into the pond through drains, particularly from the airport, may be causing the outbreak, but Sawyers said that pollution would not influence cyanobacteria.
D’Ercole also said that obstruction to the Buckeye Brook, in which Warwick Pond drains, elevates the water level by over a foot. Aggressive wetland reeds called phragmites also elevates water. This keeps the water stagnant, and blue-green algae thrives in stagnant water. Ward 3 City Councilman Timothy Howe said that since the phragmites are so aggressive, it is difficult to remove them without creating more growth.
“We need somewhere to put [the phragmites]” Howe said. “You can’t just dump them I guess because they are a very hostile weed, so you have to burn them or put them in plastic or something.”
The City Council received permission from the DEM to remove the phragmites last year, but Howe said that the project would cost about $900,000. Howe explained that this would be expensive in a normal time, but the COVID-19 pandemic has made the City Council hold particularly tight to their wallets.
In addition to the health and safety risks of the cyanobacteria, D’Ercole also voiced concerns regarding how it could affect local property values, which can in turn affect Warwick’s economy and population decline.
“It’s very disappointing to me and my organization,” D’Ercole said regarding the lack of action taken for the pond.