Harmful Algal Blooms may not be harmful, algae or, for that matter, blooms.
In fact, a common type of cynobacteria that has been found in Lake George every year since 2020, which the Department of Environmental Conservation labels a harmful algal bloom, does not meet the DEC’s own definition of a HAB, says Dr. Kevin Rose, an aquatic ecologist who teaches at RPI and who now serves as the director of the Darrin Freshwater Institute and the Jefferson Project.
Rose, as well as the Lake George Park Commission’s executive director and the Lake George Waterkeeper, have called for “a Lake George-specific” term for the concentrations of matter that appear on the lake’s surface in late summer and fall.
To mention only the most obvious flaw in the typology, none of the blooms documented in Lake George have been found to be toxic, that is to say, harmful.
According to Rose, the DEC defines a HAB as matter that contains a high proportion of chlorophyll linked to cynobacteria – much higher than the surface streaks observed on Lake George.
“What does it mean to be ‘harmful’ and what does it mean to be ‘a bloom,’ here on Lake George? Let’s come up with a definition that suits Lake George,” said Rose.
“I don’t like the way the DEC defines HABs; it’s not quantitative enough,” Rose told the Lake George Park Commission members on November 28. “Using the DEC’s definitions, the surface streaks we’ve witnessed on Lake George might never have reached the threshold of what constitutes a bloom.”
“When people hear ‘harmful algae blooms,’ they think of a thick, green algae coating the water’s surface and they picture their dogs drinking from the lake and getting sick,” said Dave Wick, the Lake George Park Commission’s executive director. “We don’t do the public any favors by disseminating misinformation.”
“If every event we report is non-toxic, sooner or later, the public will stop paying attention,” Wick continued.
If Lake George’s HABs are defined more carefully, warnings to avoid the water will carry more weight if and when a bloom is ever discovered to be dangerously toxic, said Wick.
From his perspective, inconsistent definitions of HABS impede scientific research, said Rose.
“We need a definition of HABs that will enable us to track them and determine whether they are increasing in frequency and spreading,” said Rose. “An ill-defined bloom makes forecasting an appearance challenging. What, precisely, are we forecasting?”
The Lake George Park Commission endorsed Rose’s proposal to establish a committee composed of Darrin Fresh Water Institute scientists, Waterkeeper Chris Navitsky and representatives of the Park Commission to develop a workable definition of harmful algal blooms appropriate to Lake George.