AUBURN — More than a hundred people packed the seats at the Auburn Public Theater Saturday morning to hear from a variety of experts on harmful algal blooms in Owasco and the other Finger Lakes.
Hosted by the Owasco Watershed Lake Association, experts at the HABs in Owasco Lake Symposium discussed their latest research and work on HABs including contributions of nitrogen or invasive mussel species to HABs, and what future work will look like.
The event began with a proclamation from Auburn Mayor Mike Quill dedicating the symposium to former OWLA president Bob Brower.
Dr. John Halfman, with the Finger Lakes Institute at Hobart and William Smith Colleges, has been studying Owasco Lake since 2005, and presented the latest results from his work in 2018 that included a review of HAB mitigation technology for the first time.
Most of Halfman's presentation focused on the role phosphorous, the primary nutrient source for the cyanobacteria that forms HABs, plays in Owasco.
Based on his findings, Halfman said it's evident that more than 95 percent of phosphorous loads comes from non-point source pollution sources — meaning it doesn't come from a specific source such as a wastewater treatment plant — that flush into the lake following torrential rain events that have likely become more common due to climate change.
"If you want to start controlling things in the watershed, start by controlling those events," Halfman said.
Measures to protect the lake from dramatic flow events include collecting fluid from drainage tiles, planting riparian buffers — strips of vegetation next to streams or waterbodies that act as a barrier — or cover crops that stop farm soil erosion during off seasons.
Thanks to funding from an OWLS-administered state grant, Halfman was also able to test several HAB mitigation technologies for the first time in 2018.
Somewhat unfortunately, Halfman said, 2018 saw comparatively few blooms. Additionally, data seems to suggest the blooms may be short lived and only farm in calm, sunny conditions, so there were almost never blooms when Halfman went to collect data, making drawing conclusions difficult.
"They're sporadic, maybe neurotic, who knows," Halfman joked.
One aspect of HABs on Owasco Lake that seems at odds with previous research is the role of nitrogen in encouraging HABs, according to Dr. Bob Howarth, professor ecology and environmental biology at Cornell University.
"I'm here to suggest there is a nitrogen issue we should be paying attention to, or at least, perhaps, should be on our minds," Howarth said.
Established research holds that cyanobacteria only thrives in areas where rich in phosphorous but where nitrogen is scarce.
"That is not what's going on in Owasco Lake, that's not what's going on in Skaneateles Lake at all," Howarth said.
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Increasing evidence suggests, Howarth said, that very high levels of nitrogen might allow cyanobacteria to produce more toxins, keeping them safe from predators and encouraging their growth.
That's supported by Howarth's findings that toxin levels in blooms were rising in 2017 and 2018, suggesting an "evolutionary arms race" between cyanobacteria and the zooplankton that preys on it.
To manage the amount of nitrogen entering the lakes, Howarth suggested management practices need to be updated, as nitrogen behaves differently than the phosphorous normally targeted by such techniques.
Another possible factor in what makes the recent HABs different is the presence of invasive zebra and quagga mussels, according to SUNY ESF's Dr. Kim Schulz, who led a dive team in surveying the bottom of Owasco Lake.
"This is not your father's eutrophication," Schulz said, referring to the excess of nutrients in the lake.
According to Schulz, both types of the mussels digest their food in a way that deposits both nitrogen and phosphorous into the sediment. Combined with a deprivation of oxygen the mussels create, this makes the nutrients more readily available for the types of cyanobacteria that can move between the lake bottom and surface.
The mussels aren't only extremely dense on the surface of the lake floor — early analysis showed as many as 30,000 quagga mussels per meters squared at certain depths — but they extend below into the muck as well, Schulz said.
The presence of so many mussels and the potentially large contribution they may offer to HABs makes it unlikely a one-size-fits-all approach to solving the issue will work, Schulz said.
"We maybe need to think we aren't going to have one solution to harmful algal blooms," Schulz said.
Lastly, state Department of Environmental Conservation Research Scientist Tony Prestigiacomo summarized the variety of existing programs conducted throughout the Finger Lakes, as well as next steps for the future.
Prestigiacomo touted in particular the expansion of the DEC's Citizens' Statewide Lake Assessment Program, in which volunteers gather lake samples to provide data to the DEC.
"This is an amazing program, it gives the state kind of a lot more boots on the ground," Prestigiacomo said.
With data gathered from such programs, the state can then make scientifically-informed decisions on how best to address the issues, Prestigiacomo said.
In collaboration with the United States Geological Survey and state Department of Health, the DEC hopes to soon offer a user-friendly website allowing the public easy access to data from its advanced monitoring programs.
OWLA Board of Director Rick Nelson, who emceed the event, said the full presentations from all the experts would be available on the official website at owla.org.