Geneva lakefront HABs

Blue-green algae toxic blooms found in north end of Seneca Lake

GENEVA — The number of Harmful Algal Blooms in Seneca Lake is growing.

In August, testing discovered two HAB blooms with cyanobacteria near Dresden on the west side of the lake.

The most recent testing of samples collected by monitors with the Seneca Lake Pure Waters Association (SLPWA) found six blooms above the threshold of 25 micrograms per liter of blue-green chlorophyl in the north and northwest end of the lake near Geneva.

Blooms were also located in the southwest and northeast areas of the lake.

The Finger Lakes Institute at Hobart and William Smith Colleges tested six of 16 bloom samples taken from the lake on Thursday. The lab reported all six samples were above the threshold, with additional samples being tested Friday.

“This is the first widespread bloom day for Seneca Lake and follows the same pattern of the last few years, with major bloom occurances in mid-September,’’ said Frank D’Orio, HABs director for SLPWA.

“This is the fifth year in a row that cyanobacteria has been confirmed in Seneca Lake. HABs tend to occur in calm, nutrient-rich, warm waters,’’ he said.

“Blooms can produce toxins that may have harmful effects, from skin irritation to lung, liver and nervous system problems, depending on the exposure. People and animals should stay clear of waters that have HABs characteristics,’’ D’Orio said.

Those characteristics are water that looks like pea soup, blue-green or white spilled paint, green dots or green globs in the water and parallel streaks, usually green.

SLPWA, in collaboration with the Finger Lake Institute and the state Department of Environmental Conservation, has been monitoring the shoreline of Seneca Lake since early August on a weekly basis. There are more than 120 trained volunteers involved, with monitoring to continue through October.

Bloom locations are posted to an interactive bloom map available to the public via the website at

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