ITHACA, N.Y. — Harmful Algal Blooms have been spotted in several locations in Cayuga Lake already this summer. The bacteria’s presence has caused a couple of local swimming spots to close, including Taughannock Falls State Park and the Ithaca Yacht Club.

Despite their name, Harmful Algal Blooms or HABs, are concentrated growths of cyanobacteria, according to the Community Science Institute. They are not all toxic, but if a suspected bloom is spotted in the water, it’s best for people and pets to avoid contact with it and report it. A bloom with toxins present could result in skin rashes and ingestion could result in fatal liver or nervous system toxicity, CSI says.

Three environmental nonprofit groups are actively monitoring Harmful Algal Blooms in the lake — the Community Science Institute, the Cayuga Lake Watershed Network and Discover Cayuga Lake along with more than 80 volunteers or “HABs Harriers.” The Community Science Institute will be regularly updating its Cayuga Lake Cyanobacteria (HABs) Reporting Map here.

Already this summer, there have been about a dozen reports of HABs in Cayuga Lake, including three in Tompkins County — two at Taughannock Falls State Park and one at the Ithaca Yacht Club. The others in Cayuga Lake have been reported farther north.

On Tuesday, July 9, Taughannock Falls State Park issued a notice that swimming is closed due to a harmful algal bloom. The Ithaca Yacht Club also has a “suspicious” bloom, that was spotted at the boat ramp stretching south along a few shoreline properties, according to the CSI map, and the swimming beach is closed. Results of the lab tests for both locations are pending.

CSI’s map has four different colored icons – black, green, yellow and red – that represent the microcystin toxin status of the bloom. As of July 10, all of the icons on the map of Cayuga Lake are black, which means, “Cyanobacteria are present in bloom (HAB) sample. Microscopic examination indicates the presence of cyanobacteria and therefore the potential for the bloom to be harmful. Results of microcystin toxin analysis are pending.”

According to the Cayuga Lake Watershed Network, HABs can look like paint, thick pea soup, and/or parallel streaks, dots, clumps and globs on the water’s surface. Some images of Harmful Algal Blooms are available on the New York State Department of Environmental Conservation here.

Screenshot from DEC website.

If anyone sees a suspected Harmful Algal Bloom, they can report it to the local HABs hotline at Those  who submit a report are asked to include the following information: a picture of the bloom, location of the bloom and date and time the pictures were taken. If possible, send GPS coordinates. Once reported, a trained HABs Harrier will respond and take samples for analysis. You can also call the CSI lab at 607-257-6606 to report a bloom.

For more information, visit the Community Science Institute.

Featured image: HAB on Cayuga Lake in 2017. Photo courtesy of Don Sargent & Shannon Barrett, 2017.

Kelsey O'Connor is the managing editor for the Ithaca Voice. Questions? Story tips? Contact her at and follow her on Twitter @bykelseyoconnor.