New tech buoys Sebago Lake research


STANDISH — One hundred and forty-five pounds of high-tech equipment is currently submerged in Sebago Lake’s lower bay, sending out real-time data that researchers can use to study the massive water body that provides drinking water to the greater Portland area.

The new monitoring buoy, a joint project between the Portland Water District and Saint Joseph’s College, has an array of sensors that transmit data on the lake’s temperature, dissolved oxygen, chlorophyll, pH and water clarity. That information is updated every 15 minutes and available online.

The water district has been taking monthly sampling for decades in order to better understand the health of Sebago, which supplies drinking water to about 15 percent of Maine’s population. Researches say the new, near-constant stream of data will make a big difference in understanding Maine’s second-biggest lake.

“We’re going from once a month to every 15 minutes,” said Brie Holme, a water resources specialist with the water district.

“More data is almost always better,” said Dr. Emily Lesher, and assistant professor in Saint Joseph’s Science Department.

Lesher said that being able to monitor the lake in shorter intervals will allow researcher to better understand how changes affect the lake over time, including weather events.

While the buoy was officially launched in May, it was deployed for a test last fall, which coincided with a late October wind storm that caused massive power outages and damages.

The buoy data showed how the storm caused the various layers of water within the lake to mix – a seasonal process known as lake turnover that redistributes nutrients.

“We could see that flipping happening,” Lesher said, explaining that the storm “induced the lake to turn over, which was really cool.” Such day-to-day changes weren’t detectable before, she said.

She also noted that atmospheric impact is a less understood area of lake science, and that the abilty to better understand those impacts is “a real innovative area of research.”

The new research opportunities enabled by the buoy have a myriad of applications, Lesher said, noting that she’ll use the data in her environmental chemistry course and that Windham High School teacher Jeff Riddle will be incorporating it into high school learning.

“The cool thing about this project is there’s so many different uses,” Lesher said. For example, information about lake temperature could also be helpful to anglers looking to locate fish in the lake, she said.

The approximately $45,000 buoy was made by Fondriest Environmental and paid for in part by a grant through the U.S. Geological Survey. It’s powered almost entirely by a small solar panel array, with the exception of some-battery powered parts to keep sensors clean under water.

According to Lesher and Holme, the deepest sensor on the buoy measures dissolved oxygen in the lake at a depth of 145 feet.

The sensors can last several years, and the buoy will be calibrated each month on the lake and taken out every three years for factory calibration.

This type of buoy technology is already being used by the Lakes Environmental Association to monitor Long Lake and Highland Lake in Bridgton. Holme said the LEA’s buoys were the inspiration for the Sebago Lake buoy project.

Sebago Lake monitoring buoy data is available on the Portland Water District Website and via a mobile app

Matt Junker can be reached at 781-3661 ext. 123 or Follow him on Twitter: @MattJunker.

Saint Joseph’s College professor Dr. Emily Lesher, left, and Portland Water District water resources specialist Brie Holme survey the new research buoy that provides data on Sebago Lake every 15 minutes.

Saint Joseph’s College professor Dr. Emily Lesher, right, and Portland Water District water resources specialists Brie Holme, left, and Laurel Jackson calibrated the new research buoy that provides data on Sebago Lake every 15 minutes.