Algae bloom on Lake Pontoosuc prompts Pittsfield to warn against swimming and other activities | Local News

PITTSFIELD – The presence of a blue-green algal bloom in Lake Pontoosuc that is toxic to people and pets prompted the city on Saturday to advise against swimming, water sports and other activities that may involve contact with the skin or ingestion.

The city has posted warning signs around the lake, said a joint statement from the city’s health department and the mayor’s office.

Recent tests have revealed an overgrowth or “bloom” of algae known as cyanobacteria due to warmer water temperatures and “high nutrient concentrations”.

Normally, cyanobacteria exist in the ecosystem and do not cause harm.

But exposure to flowering causes problems such as skin and eye irritation, vomiting, diarrhea, and muscle cramps. Nerve and liver problems can occur in severe cases.

Exposure is through skin contact, ingestion or inhalation of airborne droplets. In case of exposure, authorities recommend rinsing thoroughly with clear water.







Aerial view of Pontoosuc Lake (copy)

A May view of Lake Pontoosuc from the air in Pittsfield.



Pets are sensitive through the skin and ingest the toxin by licking their damp fur.

“To protect you and your family from the harmful effects of this blue-green algal bloom, residents and visitors are advised to avoid contact with water that has a noxious odor, appears green throughout. . [sometimes referred to as looking like pea soup]or that has mats, films, or scum accumulating on the surface,” the statement read.

Authorities also advise against eating fish caught in the lake, as well as all types of boating.

The city will monitor and sample water for testing until results show algae are at normal levels.


Bacteria levels drop in Lake Pontoosuc despite alarming green tint

This is not the first time that cyanobacteria levels have increased in the lake. Authorities had to close the lake for two days in 2019 due to a bloom.

If you experience any of the symptoms of exposure, contact your healthcare provider or call the poison control center at 1-800-222-1222. If your pet shows symptoms, contact your veterinarian immediately.

For more information or questions, contact the Pittsfield Health Department at 413-499-9411.