BRIDGTON – Last month, the Lakes Environmental Association installed one of Maine’s first operating remote sensing buoys in Bridgton’s Highland Lake.

Every 15 minutes, the yellow, solar-powered, 500-pound buoy beams data readings to the association, measuring water clarity, oxygen levels, and chlorophyll content, which is an indicator of algae growth. The $30,000 buoy, which was funded through an anonymous grant and has equipment extending to the bottom of the 50-foot lake, features nearly a dozen oxygen and temperature sensors. According to Peter Lowell, the longtime director of the association, the group raised an additional $15,000 from Lakes Region residents to install nine extra sensors on the device.

“We put more sensors on the buoy than it came with, so we kind of souped it up,” Lowell said. “It’s anchored at the deep hole in Highland Lake.”

According to Lowell, Highland Lake is a great candidate for data collection, because it is a relatively small lake that has previously suffered minor algae blooms, which are caused by oxygen depletion, soil erosion, high phosphorous levels, and extreme precipitation events linked to climate change, Lowell said.

Highland Lake is about 3 miles long, and has nearly 400 homes in its watershed. Lowell said the lake is at risk of more significant algae blooms, which could lead, in a worst-case scenario, to a die-off of cold-water fish such as trout and salmon, a decline in water clarity, a green sheen and unpleasant odors.

“Highland Lake seems to be highly stressed, and it’s kind of a quiet lake, so there’s not a lot of big boats or activity that might interfere with the buoy,” Lowell said. “We wanted to do it on a smaller lake and one that we had a lot of previous data and concern about.”

The association has typically employed a labor-intensive data collection process from Highland Lake every two weeks, Lowell said. But the buoy submits roughly 100 readings daily via cellular signal to the group’s website.

Colin Holme, the assistant director of the association, who has been in charge of monitoring the buoy data, said the instantaneous readings have already yielded results. A few days after turning on the buoy, the group found that oxygen levels near the bottom of the lake were declining precipitously.

“Now we’re watching the process as it occurs and how quickly it can go,” Holme said. “It was low oxygen when we got it deployed, but it pretty much went to no oxygen in a couple days.”

“It certainly was depressing, but exciting to see that resolution and the data,” Holme added. “It was phenomenal to watch that process occur.”

According to Whitney King, a Colby College chemistry professor who has provided technical assistance to the association, the Highland Lake remote sensing buoy is the fourth one he is aware of in the state of Maine. King said there are remote sensing buoys installed in Belgrade, Auburn and on Mount Desert Island.

“The buoy provides real-time data to the lake community on the status of the lake,” King wrote, in an email. “The buoy reports lake water quality in much the same way that a weather station reports rain and wind. When the community knows about water quality, they are better position(ed) to advocate for lake health.”

Lowell said his goal is to install remote sensing buoys across the Lakes Region.

“We’re hoping eventually to get a buoy on each one of the major lakes in the area,” he said. “What we’re thinking is the lakes are so sensitive that a lot more research is warranted and the research will kind of guide us in terms of what kind of land-use controls or what kind of voluntary actions are needed to maintain the water quality.”

The Lakes Environmental Association has installed a 500-pound remote sensing buoy in Highland Lake, in order to measure the conditions that lead to fish-killing algae blooms. 


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