BY Jason Emerson
Editor
While 2016 was notable as a year with a high volume of invasive weeds choking Cazenovia Lake, 2017 was equally as notable for the lake of weeds. And while the use of the chemical herbicide Renovate had a huge impact on the amount of invasive aquatic plant life in the lake this year, that is only one part of the overall lake health treatment plan currently ongoing.
This was the message nearly 100 local residents heard at the Cazenovia Lake Summit on Nov. 18, the annual event in which the latest news on the ecological health and maintenance of Cazenovia Lake is discussed by numerous municipalities, organizations and experts.
“The lake looked very good this year,” said Sam Woods, of the Cazenovia Lake Association, but added that chemical treatments alone cannot be the only tool used to fight invasive species, and the purpose of the lake summit is to discuss and create strategies for continued lake health.
In 2017, Cazenovia Lake was treated with the chemical herbicide Renovate — after no treatment was done in 2016 — and the weed harvester was used at the north and south ends of the lake. The chemical treatments worked so well, however, that there was not a lot of weeds removed by the harvester, said Tim Hunt, town highway superintendent and director of the town weed harvester program.
Hunt said that 309 tons of weeds, or 41 boatloads, were removed from the lake this year, compared to 2,656 tons removed in 2016. “We found the chemical treatment was very effective,” Hunt said.
The town also started taking aerial photos of the lake every month to compare and contrast weed growth by month and, eventually, by year, to help the town understand where and how lake treatment is working.
Bob Johnson, of Racine-Johnson Aquatic Ecologists, said the annual rake toss survey of aquatic plants in Caz Lake this year, done by his company, also showed that the 2017 Renovate had a major impact on the presence of invasive weeds in the lake.
“The lake looked fantastic this year,” Johnson said. “It looked as good as ever for as long as we have been here.”
Johnson said the presence of Eurasian watermilfoil was reduced from 95 percent to 55 percent in the 304 sampling points throughout the lake, while the amount of medium-dense milfoil areas in the lake likewise reduced from 163 to five locations, he said.
According to Johnson’s research numbers, as shown during the summit, the amount of medium-dense milfoil growth in Cazenovia Lake has not been this low since 2010.
“The herbicide really worked well this year on Eurasian watermilfoil,” he said. “The treatment was very successful.”
Scott Kishbaugh, chief of the lake monitoring and assessment section of the state Department of Environmental Conservation, also discussed milfoil in the lake, but talked mainly about the presence of harmful blue-green algae blooms on Cazenovia Lake and lakes around the state, and how and why they occur.
“There’s been a tremendous amount of attention to harmful algae blooms (HAB) in the past 5 to 10 years, and there will continue to be for the next 5 to 10 years,” he said. “They’re here, they’re problematic and we still don’t know a lot about them.”
Kishbaugh said the amount of HABs being reported increases every year, although the percentage of lakes throughout the state in which they occur has not changed. Scientists still do not understand how and why HABs occur, and some theories include high levels of phosphorous or nitrogen in the water, increasing global temperatures or the presence of zebra mussels in the water (which eat the “good” algae in the water and leave the “bad” algae), he said.
There were no HABs in Cazenovia Lake in 2017 even though there were multiple blooms in 2016; while in water bodies such as DeRuyter Reservoir and Skaneateles Lake, which have never had algae blooms, both had occurrences this year — both of which were “unprecedented.”
This only adds to the mystery of HABs, he said. “The fact that Cazenovia Lake had no blooms this year was surprising,” he said. “The fact that Cazenovia had none and Skaneateles Lake had a bloom is shocking.”
The state DEC continues to monitor the HAB problem, and multiple studies are currently ongoing to better understand the phenomenon, not only by the DEC but also by the state health department, SUNY ESF, Cornell University and multiple other colleges and universities, he said.
New to this year’s Lake Summit were the results of an economic impact study of the lake, which was funded by the Cazenovia Lake Foundation. The purpose of the study was to quantify the social, cultural and economic impact of the lake on the community.
The results of the 25-page study showed that the economic impact from lake-dependent activities and services yields a yearly benefit stream of $10.5 million to the community; that lakefront properties comprise 7 percent of the taxable properties in the town and provide 20 percent of the tax base; and that Cazenovia properties have a higher average value and sale price than of communities without a lake.
An online survey taken earlier this year by 316 people, as part of the economic impact study, showed that a majority of respondents did not feel the lake was healthy; that their most frequent lake activity uses were walking, being near the lake, wildlife viewing, and seeking solitude followed by swimming and walking the dog; and that there was a need to maintain lake water quality, the lake’s contribution to quality of life and the lake’s economic benefit to the community. The results also showed “significant differences” in lakefront residents and non-lakefront residents in response to the positive recognition of lake qualities and access.
“There’s a whole lot of ways the community is impacted by the lake,” said Scott Shannon, SUNY ESF associate provost for instruction and dean of the graduate school, who presented the study results at the lake summit. “There is a significant economic benefit attributed to have a lake.”
All the Cazenovia Lake Summit presentations will be posted on the Town of Cazenovia website for public viewing at townofcazenovia.org.
