ITHACA, N.Y.—The season’s first reported harmful algal bloom (HAB) has been found in Cayuga Lake, though Tompkins County Whole Health (TCWH) stated that the discovered bloom was found “in northern portions of Cayuga Lake.”

The statement from TCWH does not say other HABs have been found closer to the Ithaca- or Tompkins County-adjacent sections of Cayuga Lake. Though at least one has been reported in the lake, places where HABs are not visible are safe for swimming and other such festivities.

“Tompkins County Whole Health urges residents and visitors to be aware of HABs,” the statement reads. “These blooms can occur in any calm body of water and may produce toxins that are harmful to people and animals. Do not drink the water and avoid contact with the water if it appears discolored or has an unpleasant odor. Do not allow pets to swim in water where suspicious cyanobacteria blooms are present.”

The statement continues that high temperatures and runoff from rain can increase the likelihood of HABs forming.

The following is information from Tompkins County Whole Health:

Identifying HABs:

If Contact Occurs With Suspicious HABs:

  • Rinse thoroughly with clean water to remove cyanobacteria.
  • Rinse dogs that may have gone in the water, so they do not lick their coats. Dry the dog thoroughly. If the dog has drank any of the water, contact veterinarian for assistance. Click here for more information on the risks HABs present to dogs:
  • Stop using the water and seek medical attention immediately if symptoms such as vomiting, nausea, diarrhea, skin, eye or throat irritation, allergic reactions or breathing difficulties occur after drinking or having contact with blooms or untreated surface water.

The Community Science Institute (CSI), Cayuga Lake Watershed Network, and Discover Cayuga Lake lead a volunteer program to monitor the Cayuga Lake shoreline for HABs during the summer months. If you’d like to contribute to the HABs monitoring program yourself, please contact Grace Haynes at for more information.

To stay alert to blooms occurring on Cayuga Lake, check the Cayuga Lake HABs Reporting Page on CSI’s website at:

The NYS Department of Environmental Conservation (NYSDEC) has a map of reported HABs across the State: Click here

HABs can also be present in smaller ponds. Residents who have private ponds should monitor their ponds for signs of blooms and avoid contact. Residents may contact Tompkins County Soil and Water Conservation District (SWCD) for guidance on pond management and a possible site visit to view the suspicious bloom.  If a private resident is interested in testing a bloom, please contact the Community Science Institute (607-257-6606) to determine testing options and fees.

Report HAB-Related Sightings And Symptoms:

  • If you see a suspicious bloom in Cayuga Lake, stay out of the water and report the sighting to the Cayuga Lake HABs Monitoring Program by emailing
  • If you see a suspicious bloom in another public body of water, stay out of the water and report the sighting to the NYSDEC by filling out and submitting a Suspicious Algal Bloom Report Form: Click here. Email if you are unable to complete the form.
  • Report any HAB-related health symptoms to the NYS Health Department at and call your healthcare provider.

Learn more about HABs online at:

Matt Butler is the Editor in Chief of The Ithaca Voice. He can be reached by email at