AUBURN — SUNY College of Environmental Science and Forestry professor Dr. Greg Boyer delivered a wide-ranging presentation Thursday evening at Cayuga Community College on the topic of harmful algal blooms with a focus on what caused last year's “explosion” of blooms on Cayuga County's lakes.
Boyer, who has been studying harmful algal blooms in some form for 45 years, started with a brief overview of the biology of cyanobacteria, the organism that actually make up harmful algal blooms, specifically discussing what they need to thrive and create blooms like those seen in 2017.
Cyanobacteria thrive in warm temperatures with calm winds, adequate light, few predators, an established seed population and nutrients.
If humans wish to limit the outbreak of HABs and prevent the threats the toxins produced by same species pose to drinking water supplies, the only one of those conditions that can really be controlled is nutrients, Boyer said.
“It's not the only thing that's important, it's the only thing we can practically control,” Boyer said.
Part of the problem with controlling nutrients is that cyanobacteria are not picky eaters. They will take their preferred nutrients, phosphorous and nitrogen, in whatever form they can get. That could mean it comes from agricultural fertilizer, septic runoff, geese feces from lawns or even absorbed from air-based sources in the absence of anything else.
While 2017 wasn't the first year HABs appeared on the Finger Lakes, it was the first year the blooms “exploded” on all 11 lakes in a single year, according to Boyer. That result puzzled researchers for some time, as many of the lakes, specifically Skaneateles Lake, had levels of phosphorous low enough that they would normally not expect a bloom.
According to Boyer, the significant rainfall of last year's spring flushed significant amounts of phosphorous and nitrogen into the lakes, with the growth of the HABs being further fed by a calm, sunny summer.
The late summer, early fall blooms on Cayuga Lake, specifically, were likely exacerbated by climate change, according to Boyer. Since the lake's temperature stayed warmer longer, the bacteria didn't stop growing until the water became cold much later than normal.
As for what to do to prevent HABs in the future, Boyer addressed the action plans released in June by the state Department of Environmental Conservation, which included recommended projects and actions for 12 priority lakes across the state.
Boyer called the $65 million re-directed from other DEC projects toward HABs a "drop in a bucket" compared to how much would be needed to truly address the issue, but said the plans themselves still contain some sound ideas.
When the presentation moved to the Q&A section, facilitated by a smartphone app allowing for anonymized questions, the discussion moved largely to the topic of nutrient management.
Most of the questions highlighted the amount of nutrients that enter the lakes as a result of agriculture and asked what was being done or what more could be done to limit that.
Discussion moderator and Cornell University nutrient management expert Karl Czymmek, said farms of a large enough size are required by the state to adopt nutrient management practices and are also simply driven by economics to be efficient, Czymmek said.
The agricultural industry locally could do more to manage nutrient loss, Boyer said, pointing to practices like the use of buffer strips on cropland, winter cover crops and more, but said that would not address all the nutrients that enter the lake.
Regardless of if farmers or septic tanks or any other factors were primarily responsible for HABs, Boyer said developing solutions for only one aspect would not solve the problem.
"It shouldn't all go on one group or others, it has to be a community effort," Boyer said.
In addition to nutrient management, Boyer also responded to several other questions, such as those asking if fish from lakes with HABs are safe to eat (yes, though Boyer noted he's no Department of Health official), do unclean boats transmit HABs across lakes (no), and why weren't HABs noticed 30 years ago? (Scientists noticed them, Boyer said.)
The full presentation was streamed and is available on the Facebook page of Partners for Healthy Watersheds, a collection of different agricultural groups which advocates for water quality management practices which organized the discussion.