Wrentham Algae Bloom Prompts Health Advisory

WRENTHAM, MA—The town of Wrentham issued a public health advisory on Thursday due to a harmful algal bloom at Lake Pearl.

According to the town's website, local and state health officials have declared the lake unsafe for people and pets. Residents and visitors are advised not to swim, swallow the water, or allow pets near the water and should rinse off after any contact. Warning signs have been posted at public access areas to Lake Pearl.

A resident observed the bloom and contacted the town's board of health, which informed the state Department of Public Health, which advised the town to issue a warning. Signs have been posted at the public access areas to the lake.

According to the Massachusetts Department of Public Health, algal blooms are most common in late summer and early fall when cyanobacteria, or bacteria that grow in water, multiply quickly and form "scums" or "mats" on the water's surface.

"The most common types of cyanobacteria that bloom are Microcystis and Anabaena," says the Mass DPH website. "Certain strains of Microcystis and Anabaena manufacture toxins called microcystin and anatoxin, respectively, and these toxins can produce adverse health effects. Toxins are released from intact cyanobacteria cells when they die in the waterbody or when they are ingested by animals or humans. Once ingested, the digestive juices destroy their cell wall (lyse the cell) and the toxin is released into the gastrointestinal tract."

No other algae blooms were reported this year at Lake Pearl or any of the other lakes in Wrentham. However, algae blooms was reported in August at Cabot Pond in Mansfield and Lake Mirimichi in Plainville.