DCR issues advisory for blue green algae in Lake Cochituate

Based on DPH’s recommendation, the Department of Conservation and Recreation (DCR) has issued a cyanobacteria advisory for blue green algae identified in Lake Cochituate.

Signage is being posted at Wayland shore access areas and DCR will be posting signage at access points along its portion of the shore.

DPH will be coordinating with DCR to monitor and evaluate the bloom conditions, including laboratory testing once it starts to dissipate.  The Wayland Health Department will be included on any updates from the state and we will post information on our website: www.wayland.ma.us/health-department.

In the meantime, the state is recommending that we limit all recreational activities where there is a potential for contact with water in Lake Cochituate. DCR will be issuing that recommendation for state-owned access points.

The advisory was based on visual observations and photographs provided by state park officials that indicated cyanobacteria (algae) cells were present at Lake Cochituate at levels that may exceed the MDPH guidelines for recreational waterbodies in Massachusetts.

Accordingly, DPH recommended that a public advisory be issued and signage be posted at each lake access point to notify Lake Cochituate visitors.  MDPH recommends that the advisory be posted at each access point at the water body to warn against water contact.

DPH will coordinate with DCR to conduct follow-up sampling at the waterbody one week from today, provided that the bloom is no longer visibly present.  DPH recommends at least two samples, one week apart, to recommend rescinding the advisory.

DPH updates the listing of algae advisories on the website daily.  This advisory will be included on our list.  DPH is currently aware of 14 other advisories in the state.


Monitoring waterbodies for cyanobacteria (harmful algae) is important because these small cells can multiply quickly, and potentially make people sick.  In some circumstances, MDPH will evaluate monitoring data and recommend people and pets stay out of the water and that an advisory be issued.  Because risks to human health rise with cell counts, the goal is to take action before anyone becomes sick.

MDPH has worked with local health departments and other state agencies and developed guidelines and standard protocols for evaluating potential health concerns related to the presence of algae.  The MDPH guidelines for visual observations and laboratory analyses are consistent with other state and international recreational waterbody guidelines, and MDPH has used them to recommend over 200 waterbody specific advisories since 2008.


What are Algae Blooms?

Algae blooms form in fresh water when cyanobacteria (blue-green algae) grow very quickly and form scums or mats in the water. Some blooms can produce toxins that are harmful to people and animals.  These blooms are most common in Massachusetts during the hotter months of summer and early fall.

How are they identified through visual observations?

Algae blooms can change the water’s appearance from slightly discolored to resembling pea soup or thick paint.  Blooms frequently appear blue or green but could be another color, such as brown or red.  Algae blooms can also give the water a bad odor or taste.


When does MDPH Issue an Advisory?

When a visible scum or mat layer is present or when a water analysis at a laboratory identifies either: (a) a cell count that exceeds 70,000 cells/milliliter of water; or (b) a toxin level that exceeds 8 parts per billion.


What causes them?

Certain environmental conditions, such as warm weather, sunlight, and excess nutrients help blue-green algae grow faster (or “bloom”).  The excess nutrients sometimes come from human-related sources (e.g., phosphorus and nitrogen in fertilizers, or human and animal waste).

What are the primary health concerns?

Health concerns of cyanobacteria and/or the toxins they produce vary depending on the type of exposure and the amount and types of toxin present.  In most circumstances, direct contact with algae causes skin and eye irritation, and ingesting or inhaling small amounts are likely to cause gastrointestinal symptoms. In some circumstances exposure to toxins has been reported to cause serious illness or in rare circumstances, death.  For example, drinking water contaminated with elevated concentrations of several different types of toxin (e.g., microcystin and cylindrospermopsin) could result in significant liver and kidney damage.

What should I do near a waterbody with a Harmful Algae Bloom Advisory present?

Avoid contact with the water and do not ingest the water.  Rinse off immediately if you or your dog comes into contact with the water.

Does MDPH have a website for additional information?

Yes, you may visit:  www.mass.gov/dph/algae


Leave a Reply

Your email address will not be published. Required fields are marked *