Cyanobacteria Monitoring
Cyanobacteria monitoring for the 2025 season is underway. Should a Town waterbody fail to achieve an acceptable result, advisories will be posted below via a Town of Barnstable Water Quality Report as well as shared on the MyBarnstable mobile app, via Town social media, and physcially posted at the waterbody site.
Latest Cyanobacteria Advisories
July 8, 2025 | New Pet Advisories Issued at Hamblin Pond, Parker Pond, and Neck Pond
As of Tuesday, July 8, 2025, at 4:30 PM, the following water quality alerts have been issued: A Pet Advisory has been issued for Hamblin Pond, Marstons Mills due to increased levels of cyanobacteria in samples. A Pet Advisory has been issued for Parker Pond,...
July 1, 2025 | Cyanobacteria Updates – Public Health Advisory Issued at Long Pond, Marstons Mills, and Pet Advisory at Crystal Lake, Osterville and Long Pond, Centerville
As of Tuesday, July 1, 2025, at 2:00 PM, the following water quality alerts have been issued: A Public Health Advisory is posted for Long Pond, Marstons Mills due to a significant increase in cyanobacteria levels in samples. A Pet Advisory is posted for Crystal Lake,...
June 24, 2025 | Cyanobacteria Updates – Public Health Advisory Issued at Schoolhouse Pond, Hyannis and Pet Advisories Issued at Various Locations
As of Tuesday, June 24, 2025, at 2:08 PM, the following water quality alerts have been issued A Public Health Advisory has been issued at Schoolhouse Pond, Hyannis due to a significant increase in cyanobacteria levels in samples. A Pet Advisory has been issued...
June 17, 2025 | Cyanobacteria Updates – Pet Advisories Issued at Hinckley Pond and Schoolhouse Pond
As of Tuesday, June 17, 2025 at 12:30PM, the following water quality alerts have been issued: A Pet Advisory at Hinckley Pond, Barnstable has been issued due to increased levels of cyanobacteria in water samples. A Pet Advisory at Schoolhouse Pond, Hyannis has...
June 10, 2025 | Removal of Pet Advisory at Hamblin Pond, Marstons Mills
As of Tuesday, June 10, 2025, the Pet Advisory will be removed for Hamblin Pond, Marstons Mills due to acceptable water quality samples. As of Tuesday, June 10, 2025, all Barnstable monitoried ponds were found to be acceptable; thus there are no current water quality...
June 3, 2025 | Cyanobacteria Updates – Pet Advisory Removed from Bearses Pond, Centerville
As of Tuesday, June 3, 2025, at 2:46 PM, the following water quality alerts have been updated: A Pet Advisory has been removed at Bearses Pond, Centerville due to acceptable water samples. A Pet Advisory at Hamblin Pond, Marstons Mills remains in place due to...
Cyanobacteria Monitoring Map
Barnstable County has partnered with the Association to Preserve Cape Cod (APCC), a local non-profit environmental organization, to proactively monitor Cape Cod’s ponds for cyanobacteria and, more specifically, the toxins they sometimes produce. For more specifics regarding the particulars of the monitoring program, please visit APCC’s cyanobacteria monitoring web page.
CYANOBACTERIA MONITORING IN THE TOWN OF BARNSTABLE
Understanding the Problem
Cyanobacteria are microscopic bacteria that live in all types of waterbodies. A large growth of these bacteria results in algal blooms. These blooms can pollute the water and may even be toxic to animals and people.
When a dramatic increase in a cyanobacteria population occurs, this is called harmful algal blooms (HABs). This often results in the waterbody turning bright green or blue-green, and forms a surface scum or a discoloration of the water column. CyanoHABs may also form a mat on the bottom sediments, making it more difficult to observe. The surface scums or discolored waters can extend several inches below the water surface, or accumulate near shorelines and in coves as a result of onshore wind activity. They often look like pea soup or spilled, blue or green paint; however, the color can also vary. CyanoHABs can cause dissolved oxygen swings that may result in plant and animal die-off, taste and odor issues, and can cause potential public health issues from the cyanotoxins they may release.
Cyanobacteria on Cape Cod
Typically, cyanobacteria’s potential for overgrowth is kept in check by a balance of several different factors, one of which is nutrient availability. All animals and plants require nutrients to grow and thrive, but if an external force makes nutrients either scarce or overabundant, the balance is disrupted. Here on Cape Cod, human activities – from fertilization to faulty septic systems – have introduced an overabundance of nutrients into the environment, which leads to an ecologically unhealthy condition called eutrophication (the process by which a water body becomes enriched in dissolved nutrients such as phosphates and nitrogen). The greater the nutrient availability, the more fuel for cyanobacteria (and other undesirable plant life) to grow and thrive. Global warming also plays a key role with warmer pond temperatures favoring cyanobacteria. Learn more about cyanobacteria monitoring across Cape Cod through Barnstable County’s efforts.
UNDERSTANDING CYANOBACTERIA ADVISORY ICONS
Protect Yourself and Your Pets
Algae Contact
If you have any contact with water, rinse off immediately.
Do Not Drink
Do not swallow water. Do not use water for cooking. Boiling or filtering will not make it safe.
Children
Keep children away from algae in the water or on the shore.
Stay Out
Stay out of the water until further notice. Do not touch scum in the water or on shore.
Pets
Do not let pets go into or drink the water or eat scum.
Shellfish
Do not consume shellfish harvested from this water.
Swimming
No swimming when blooms are present.
Fishing
Throw away guts, clean fillets with tap or bottled water before cooking.