Harmful Algal Bloom (HAB) Event Information
Bloom Code 25-3423-B1
Where
Water Body Cayuga Lake
Latitude and Longitude 42.47878, -76.50816
Segment Lakeshore Segment Southeast 5: Myers Park to East Shore Park
County Tompkins
Extent Widespread
When
Bloom Reported September 24, 2025 04:35 PM
Bloom Sampled September 24, 2025 04:40 PM
Microscopic Examination September 25, 2025
What
Bloom Genera [1]
Microscopy Present Dominant
Dolichospermum
Microcystis

Bloom Chemistry
Total Chlorophyll a 2430.0 ug/L
Total Microcystin and Nodularins (EPA 546) [2] 1511.0 ug/L
[1] Genera - plural of genus, a category of classification in biology that ranks between the family level and the species level. Because there are many different species of bacteria that are difficult to distinguish, it is more useful to classify bacteria by genus rather than species.
[2] Microcystin
Map of HAB event
Bloom Description

Adjacent to priority site #3424, 1 continuous HAB. Volunteer Reports: It is in much of zone 3423 where the sample was taken and extends South into zone 3424 including East Shore Park and Cornell sailing club, did not observe it at S. end of sailing club. The lake was virtually still and flat, no wind. Smelled fishy in places, moderate rain today and yesterday, warm in the low 70's. I paddled the entire zone 3424 and 3423 North to Twin Glenns -- the bloom I photographed and sampled continued from Cornell sailing club, included East Shore Park to several properties South of Twin Glenns-the density varied across the stretch, and the extent to which it stretched into the lake, sometimes only 10-20 feet and in some places several hundred feet. At East Shore Park it was dense on the south side, though barely visible where people mainly swim, close to shore -- more visible further out into the lake at that point.

Weather
Weather
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