TOMPKINS COUNTY, N.Y.—The Tompkins County Health Department (TCHD) is warning of suspicious cyanobacteria blooms, or harmful algal blooms (HABs), that have been reported in Cayuga Lake.

Local officials and trained volunteers monitor more than 60% of the Cayuga Lake shoreline within Tompkins County for HABs on a weekly basis during the summer. Blooms are typically small in size and confined to specific areas of shoreline, often lasting only a few hours. Areas where HABs are not observed are still safe for recreational use.

The TCHD is urging residents be aware of blooms that are harmful to people and animals, and recommends avoiding contact with the water if it appears discolored or has an unpleasant odor. Pets should also be kept away from areas where blooms are present.

HABs date in Cayuga Lake suggests that blooms may increase in early September and continue intermittently until subsiding in early October. Late summer blooms often have high levels of microcystin toxin and typically occur in the northern third of the lake.

Ponds are also at risk fro developing blooms, and residents with private ponds should monitor them for signs of HABs. The Tompkins County Soil and Water Conservation District can be contacted for more information.

Cyanobacteria blooms can be identified by strongly colored water with a paint-like appearance with blue-green oily swirls, parallel green streaks and floating mats or scum. Examples can be viewed here, and this video gives more information on identifying HABs.

If contact with HABs occurs, rinse thoroughly with clean water. More information on protecting your pets after exposure can be found here, and blooms can be reported here.

Zoë Freer-Hessler

Zoë Freer-Hessler is the digital editor/reporter for the Ithaca Voice. Joining in November 2021, she has covered a wide range of topics related to local news. She can be reached at,...