Harmful algal blooms return to Chautauqua Lake, pose health risks


Harmful algal blooms are starting to appear in Chautauqua Lake this summer, with one bloom still active and three total cases confirmed so far.

The blooms, produced by algae exposed to nutrients in the water, can create toxins harmful to people in some instances. And their numbers are expected to increase as the summer progresses.

“We have fewer from previous years, although it is early,” said Doug Conroe, executive director of the Chautauqua Lake Association, the primary organization that monitors algae levels in the lake. “Generally, the blooms occur more in August and September.”

As of July 13, a “large localized” harmful algal bloom was present in the south basin of the lake near the Shore Acres area, New York State Department of Environmental Conservation spokeswoman Megan Gollwitzer said. The DEC confirmed two other blooms in the lake in the past month that have since ended, according to its website.

Though not all algal blooms are harmful, residents should avoid contact with any surface scums or heavily discolored water even if a harmful bloom hasn’t been reported in the area, Gollwitzer said. The blooms can cause symptoms such as rashes, abdominal cramps, diarrhea or liver problems depending on the severity of contact, said Jessica Wuerstle, public health sanitarian for the Chautauqua County Department of Health and Human Services.

“We can’t really predict when a bloom is creating toxins,” Wuerstle said.

Rather than predicting toxin levels, the CLA monitors the algae by routinely collecting water samples, Conroe said.

Residents can also call the CLA or the DEC to report an algal bloom that might be harmful.

“That’s how the current bloom that’s posted came to be known,” Conroe said. “A citizen called in, we went to investigate, confirmed it looked like one and the sample confirmed it.”

What causes the blooms? It’s a combination of excess nutrients in the lake – namely phosphorus and nitrogen — with warmer, calmer water, Conroe said.

“When the bloom dies, the bacteria releases toxins,” he said. “Those toxins are harmful to humans and animals.”

Accordingly, residents should also remember their pets when taking precautions against algal blooms, Wuerstle said, especially their canine companions.

“Humans are going to be reluctant to go in gross, slimy water, but dogs don’t care,” she said.

Dogs tend to be more at risk than humans, Wuerstle said, as the animals sometimes swim into bloom-filled areas and can end up ingesting the harmful algae on their fur.

Increases in algae, though, are a part of a global trend associated with climate change, said Jan Bowman, professor of Biology at Jamestown Community College who studies vegetation on Chautauqua Lake. One 2015 study, for example, suggests that climate change pressures are impacting algal blooms globally.

“It’s not just us,” Bowman said. “It’s an environmental change that’s making it worse.”

Chautauquans should be less concerned about encountering algae on Chautauqua Institution’s shoreline than elsewhere on the lake, Conroe said. The CLA performs extra maintenance near the Institution, he said, which reduces the occurrence of blooms because it keeps water flowing instead of stagnating.

“I think Chautauquans can generally be confident that the situation is being monitored well,” he said.

In addition, the Institution has several initiatives that aim to control the level of nutrients by the shoreline. Rain gardens on the grounds, for example, reduced the load of nutrients by about 75 percent after they were implemented, said John Shedd, the Institution’s director of operations and administrator of architectural and land use regulations.

Wuerstle hopes warnings regarding algae don’t scare people from using the lake.

“A bloom may be occurring at Bemus Bay … but that doesn’t mean it’s unsafe to swim in Mayville,” she said. “Chautauqua Lake is a beautiful resource that we should be enjoying.”

Tags : algal bloomsChautauqua LakeCommunityenvironment

The author Alex Meyer

Alex Meyer is a rising senior at Ohio University, majoring in journalism and minoring in history. He enjoys writing about the environment and eating cheese. See what he’s tweeting about @AlxMeyer.