Blue-green algae reported in Great Pond in Southold

County health officials have warned against swimming in Great Pond in Southold. A Stony Brook University analysis confirmed new cyanobacteria blooms — more commonly known as blue-green algae.

The state department of health warns that some blue-green algae can produce toxins and exposure to any blooms can cause health effects in people and animals when touched, swallowed or inhaled. The DOH notes that exposure to high levels of the algae and their toxins can cause symptoms ranging from breathing issues to vomiting or diarrhea. 

Large quantities of the algae can produce floating scums on the surface of the water or cause it to take a paint-like appearance. County officials emphasized that contact with “waters that appear scummy or discolored should be avoided.”

If contact occurs, rinse off immediately. Seek medical attention if any of the following symptoms occur after contact: nausea, vomiting or diarrhea; skin, eye or throat irritation; or allergic reactions or breathing difficulties. 

To report a suspected blue-green algae bloom at bodies of water with Suffolk County-permitted bathing beaches, contact the Suffolk County Department of Health Services’ Office of Ecology at 631-852-5760 between 8:30 a.m. – 4:30 p.m. or by email at any time at [email protected].

Any questions should be emailed to [email protected].