Cyanobacteria Bloom Seen In Lake Cochituate: DCR

WAYLAND, MA — After a week of warm weather, state parks officials have confirmed a potentially harmful cyanobacteria bloom in Lake Cochituate.

The bloom was seen in the Middle Pond portion of the lake in Natick. The state Department of Conservation and Recreation is advising lake visitors and their pets to stay away from the bloom.

Cyanobacteria blooms are common in lakes and ponds in Massachusetts, and typically happen due to factors like excess nutrients in the water, sunlight and warm temperatures. But not all blooms contain harmful toxins.

"Cyanobacteria (sometimes called blue-green algae) occur naturally in fresh water. Under certain conditions, they can multiply quickly, creating a highly concentrated area known as a cyanobacterial harmful algal bloom, or cyanoHAB. Some HABs produce toxins (known as cyanotoxins)," according to DCR.

When present, those toxins can cause a range of symptoms from skin irritation to gastrointestinal distress and neurological damage. Algae blooms have been confirmed before in Wayland's section of Lake Cochituate, including near the town beach.

Blooms have been confirmed in other water bodies recently, including Lake Waushakum in Framingham and Stokes Pond in Plymouth.