Residents are urged to steer clear of the waters of Sagaponack Pond in Sagaponack because of the confirmed presence of blue-green algae, Suffolk County health officials said Friday.

That means no swimming or wading in the water, and keeping children and pets away, officials said.

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Any water looking “scummy or discolored should be avoided,” health officials said. If contact does occur, rinse off with clean water and see a doctor for symptoms that can include nausea, vomiting or diarrhea; skin, eye or throat irritation; and allergic reactions or breathing difficulties, the health department said.

Blue-green algae, also known as cyanobacteria, is naturally present in low numbers, but can increase, forming blooms of green, blue-green, yellow, brown or red, as well as floating scum, the county health department said in a release.