Icy Research Drills Down on Summer Algae Blooms

We’ve walked a mile out on the frozen skin of Missisquoi Bay. Clouds, snow and ice blend into an abstract collage of white shapes. To the west, a thin grey line, the New York shore, cuts the world in two… To the south, a pea-size pick-up truck creeps over the lake toward a pinhead-size ice-fishing shack. Trevor Gearhart checks our location on a handheld GPS. “Yep, this is it,” he says. Peter Isles fires up a reassuringly large, safety-yellow drill.

Isles and Gearhart are doctoral students on a large project called RACC—for Research on Adaptation to Climate Change. Involving nearly thirty faculty members from UVM and other Vermont colleges, the project has funding from the National Science Foundation’s EPSCoR program to explore two difficult questions: how will Lake Champlain react to the double whammy of climate change and land use change? And how might different land management and policy choices affect these impacts on the lake?

Booming blooms

As one step toward answering these questions, Isles grips both handles of the drill as the auger disappears into the ice down its full length, almost three feet. Lake water comes surging to the surface. “You could drive a tank out here,” he says, looking down into the black hole.

Unlike most people who schlep a sled full of gear onto this bay in March, Isles is not looking for fish. He’s come with Gearhart and two other researchers to collect water, mud from the bottom — and plankton. He’s especially interested in three types of cyanobacteria — sometimes called blue-green algae — Aphanizomenon, Microcystis, and the benign-sounding Anabaena.

These are microscopic plankton that float around in Lake Champlain. They’re native, but not always benign. Given a diet of phosphorous pollution, they become major culprits in algae blooms that can foul beaches, produce dangerous toxins and suck the oxygen that fish need out of the water.

Cyanobacteria are single-celled organisms that photosynthesize, making their own food from sunlight and carbon dioxide. They’re like plants, but on a different, more ancient, branch of the tree of life. When excess nutrients wash off the land — sometimes from farm fields, roadways, eroding streambanks or wastewater treatment plants — cyanobacteria chow down like a teenager. They can reproduce rapidly, forming a suffocating green scum that drives out other species of plankton and harms critters up the food chain.

Photo caption: Where’s the phosphorous? Historically, there have been few wintertime studies of lakes. Students Peter Isles and Trevor Gearhart are helping to change that as they cut through twenty-seven inches of ice to collect mud from the bottom of Lake Champlain. They’d like to know where algae-enabling nutrient pollution is lurking. (Photo: Joshua Brown)

The University of Vermont

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