Cyanobacteria Information

CURRENT STATUS for all Pittsfield waterbodies as of today's date:

GREEN (generally safe)

No cyanobacteria blooms were found along the shoreline areas. City lakes should be safe for recreational use.

IMG_4765What is Cyanobacteria, and Why should I care?
Cyanobacteria, also known as blue-green algae, are naturally found in fresh water in the U.S., and in Pittsfield lakes and other Massachusetts waters. Some types of cyanobacteria can release natural toxins or poisons (called cyanotoxins) into the water, especially when they die and break down.

Cyanobacteria grow well in water that has high amounts of nutrients like phosphorous and nitrogen. Cyanobacteria can multiply quickly to form surface scums and dense populations known as blooms, especially during the warm days of late summer and early fall. In the summer of 2019, cyanobacteria blooms occurred at Pontoosuc Lake.

Blue-green algae blooms can produce toxins that can make pets and people sick. Toxins may be present within the algae cells or in the water.

  • For humans, the primary concern is ingestion of water containing blue-green algae while swimming. Of secondary concern is direct skin contact with the blue-green algae and inhalation of water droplets containing blue-green algae or toxins.
  • For pets, the primary concern is the ingestion of water containing blue-green algae or scum that has washed ashore or gotten onto their skin or fur.

Contact can cause skin and eye irritation, and inhalation can cause respiratory irritation and exacerbate pre-existing respiratory conditions. Toxins are not absorbed through the skin. Ingestion of blue-green algae can cause acute gastrointestinal symptoms, such as vomiting and diarrhea. If the blue-green algae are producing toxin(s), the health effects can be more serious, especially for small pets due to their smaller body weights. Ingestion of the toxins can cause acute gastrointestinal distress and, depending on the specific toxin, can affect the functioning of the liver, kidneys, and/or neurological systems and in severe cases can result in death.

The City regularly monitors the area lakes for signs of  cyanobacteria blooms.  If you see what you think is blue-green algae in a local waterbody, please call 499-9344 to report it. Here's a link to a Vermont video on how to distinguish blue-green algae from other harmless algae found in lakes and waterbodies.  A list of current advisories in MA can be found here.

The City has a response plan in place to keep the public safe from areas where harmful cyanobacteria are present.  This will inlcude well-distributed media advisories and warning posters mounted at public access areas of Onota and Pontoosuc Lake.

Throughout the active recreation season, the City will post on the main page of the Health Department a color-coded lake status for each area lake: Onota, Pontoosuc, and Richmond Pond.   The color codes below correspond to alert levels that the City will make known on a daily basis throughout the summer and fall:

Green – Generally Safe
No cyanobacteria blooms were found along the shoreline areas. These areas should be safe for recreational use.

Yellow – Low Alert
The shoreline areas have cyanobacteria at levels below bloom conditions. These areas are open for recreation, but caution is advised in any areas where dense accumulations or scums are seen.

Red – High Alert
The shorelines have cyanobacteria in dense scums at least in some areas. The water is not safe for recreational use in areas that contain scums.

State of MA