Suffolk County health officials are warning residents and their pets to stay away from several lakes and ponds on the East End where additional discoveries of the toxic algae, known as cyanobacteria, were found.

Officials said the blue-green algae was found by Stony Brook University biologists in Wolf Pit Lake in Mattituck; Long Pond in Sag Harbor; Poxabogue Pond in Sagaponack; Mill Pond in Water Mill and Agawam Lake in Southampton, according to the Suffolk County Department of Health.

The blooms discovered this week follow previous discoveries last month at Wainscott Pond in Wainscott and in Roth Pond in Stony Brook, health officials reported this week. Officials said cyanobacteria tends to grow during warmer temperatures.

The blue-green algae is naturally found in lake and streams in low numbers, but can grow in larger quantities to form green, yellow, brown or red blooms. They can produce floating pond scums on the surface of pond water. It can also cause the water to appear painted on, according to the Suffolk County Health Department.

Officials are urging anyone who may see the water to avoid contact by touching, bathing or ingesting the contaminated water. Anyone who touches the algae is urged to wash it off their skin immediately with soap and clean water, health officials said. Ingesting it is life-threatening to dogs.

Suffolk County health officials advise anyone who comes in contact with the bacteria to seek medical attention if they develop a sore throat, eye irritation, nausea, vomiting or diarrhea. It can also cause breathing difficulties or allergic reactions.

West Bishop, a North Carolina-based algae scientist with the water quality company EutroPhix, said the algae blooms can be exacerbated by climate change, causing more severe outbreaks.

“The toxins produced by cyanobacteria are particularly concerning,” Bishop said in a statement “They can cause a range of health issues in humans and animals, including liver cancer and neurotoxic effects. These toxins are not only confined to the water; they can become aerosolized and travel significant distances, posing health risks to people who might not even come into direct contact with the contaminated water.”

To report a suspected blue-green algae bloom at Suffolk County beaches open to swimming, residents can contact the Suffolk County Department of Health Services’ Office of Ecology at 631-852-5760 or email

Algae blooms found at bodies of water not open to bathing can be reported to the state DEC at

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