Harmful Seneca Lake algal blooms expand with warm days
Publisher's note: Many of the area lakes have experienced harmful algal blooms recently. This story is about the high number of blooms on Seneca Lake.
SENECA LAKE--The warm, calm days of September have triggered an unprecedented outbreak of harmful algal blooms, or HABs, along the shorelines of Seneca Lake.
HABs are cyanobacteria, commonly referred to as blue-green algae, which often produce toxins that are harmful to people and their pets, particularly dogs.
The blooms were first reported in Seneca in 2015. Last year, several more were reported, including a few that produced laboratory-confirmed high toxins.
The lake appeared to have escaped this summer until the recent sunny, calm weather created a near-perfect incubator, and blooms popped up in virtually every section of the lake.
"I can only blame it on the weather," said Edwin Przybylowicz of Seneca Lake Pure Waters Association, who coordinates 80 volunteers charged with patrolling sections of Seneca shoreline for possible blooms. "I thought we were home free this year. Nothing at all through July and August, and then the roof caved in."
About two weeks ago, more than a dozen suspicious algae patches appeared along the lake's eastern shore. When several were tested at the Finger Lakes Institute at Hobart and William Smith Colleges in Geneva, virtually all exceeded by 30-40 times the threshold the state has set for a cyanobacteria indicator.
But in the past week, the western side of the lake got hit as well. And many of the HABs-indicator readings for its blooms -- in Dresden, Reed Point and Kashong Point, for example -- were significantly higher than any earlier readings from the other side of the lake.
Meanwhile last week, more than a dozen new blooms were spotted on both sides of the southern half of the lake, where SLPWA has fewer shoreline monitors. Samples from many of those latest sightings have been sent to FLI for tests to confirm that they are HABs.
The chemical marker the state Department of Environmental Conservation uses to classify a bloom as a HAB is alpha chlorophyll. Any sample that tests above the threshold of 25 micrograms of "AC" per liter is presumed to be cyanobacteria.
Not all cyanobacteria blooms are toxic, but many are, especially ones that show exceptionally high readings of alpha chlorophyll. Confirmed HABs must undergo a separate test to determine whether they are producing the dangerous liver and neurotoxins that threaten people and their pets.
Przybylowicz said those tests for toxins, conducted at a lab at SUNY-ESF in Syracuse, are pending for a series of confirmed HABs samples from Seneca. Results are due later this week, he said, adding, "I'd be very surprised if it didn't come out (showing) high toxins."
On its website, the DEC warns: "Direct contact or breathing airborne droplets containing high levels of blue-green algal toxins during swimming or showering can cause irritation of the skin, eyes, nose and throat and inflammation in the respiratory tract."
Pets, in particular, are at risk, the agency says: "Because of their behavior, dogs are much more susceptible than humans to cyanobacterial poisoning. When toxins are present, dogs can be exposed to toxins by drinking the water, by eating washed up mats or scum of toxic cyanobacteria and by having skin contact with water. Dogs are often attracted to algal scum odors. After leaving the water, dogs can also be poisoned by grooming their fur and paws."
For people, scientific studies have shown, exposure to toxins produced by cyanobacteria has been associated with irreversible neurological diseases, including dementia, Alzheimer's, Parkinson's and ALS (Lou Gehrig's disease).
Seneca is far from the only lake that has been blitzed by HABs this year. Even before the recent warm front, eight of the 11 Finger Lakes had reported HABs -- more than any year since the DEC began keeping careful track in 2012.
Now all 11 Finger Lakes have been hit, including three lakes that had never had an HABs report before 2017: Skaneateles, Hemlock and Canadice.
Hemlock and Canadice, which provide drinking water to the city of Rochester, experienced their HABs outbreaks earlier in the summer after heavy rains added nutrient-rich runoff, which fuels blooms. But those blooms have dissipated and those lakes have had a clean September.
The opposite is true of Skaneateles, which provides unfiltered drinking water to the city of Syracuse. It had never had a HABs outbreak before Sept. 15. Now they are widespread along both eastern and western shorelines and even mid-lake.
More concerning, trace levels of the cyanobacteria toxin microcystin have been confirmed in the water at the gatehouse to the Syracuse water system in the town of Skaneateles. No toxins have been reported in Syracuse tap water, officials reported, in part because the raw lake water is treated with extra chlorine.
But Syracuse officials have confirmed that they may need to consider investing in sophisticated carbon filtering.
Meanwhile, high toxins have been confirmed in HABs samples from both Keuka and Canandaigua lakes.
Peter Mantius is a Watkins Glen journalist who publishes a blog at https://waterfrontonline.blog.