Tracking Toxic Algae Blooms in the Belgrade Lakes

Hello! My name is Becca Chmiel, and I’ve been working with Peter Countway, a Senior Research Scientist at Bigelow Laboratory for Ocean Science who specializes in the genetic diversity of marine microbes. I spent last summer at Colby College – where I’m now a rising junior – studying the water quality of the Belgrade Lakes. This summer at Bigelow Laboratory, I’m researching Gloeotrichia, a type of algae that is very prevalent in many of the lakes in Maine.

Meet Gloeotrichia: a cyanobacteria, or “blue-green algae” that can be found in many New England lakes. You may have already seen these colonies floating in the water if you’ve visited Lake Sunapee, Lake Auburn, the Belgrade Lakes, Panther Lake, or other clear, low-nutrient lakes throughout Maine and New England. At 1-2 millimeters across, the fuzzy Gloeotrichia echinulate (I’ll just call them “Gloeo”) can be hard to miss. But why is Gloeo in our lakes? Are they increasing? Can they harm us? These are some of the questions scientists need to be able to answer.

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From what scientists can gather from soil records taken from the bottom of Maine lakes, Gloeo is not new to the area; it’s been around since at least the 1400s, although it may have increased or spread to new lakes after European settlement of the area. The reasons why Gloeo show up in one lake but not another are unclear, but it may have something to do with the nutrient availability and amount of sunlight that reaches the bottom of the lake.

Like many other cyanobacteria, Gloeo produces toxins called microcystins, which can be a threat to humans when ingested in high concentrations. Fortunately, the concentration of such toxins in Maine lakes are much lower than the World Health Organization (WHO) recommended level of microcystin that poses a risk for drinking water: 1ppb (parts per million).

To study the amount of Gloeo in the water, scientists have been counting visible colonies on a microscope, which can be a long and tedious process. We can only count what we see, and we don’t know that the Gloeo cells that make up a visible colony are the only ones in the water. What if there are cells present that we can’t see?

My goal for this summer has been to create a new way of measuring the abundance of Gloeo in a water sample using DNA detection technology. To do this, I am studying one gene from the Gloeo genome, the 16S gene that codes for the protein rRNA in bacteria. This gene is found in all bacteria because rRNA is necessary for the function of all cells, but the Gloeo 16S gene should be different enough from other bacteria sequences to allow us to “tag” it with a fluorescent dye. The “tag,” a DNA probe that latches on to the Gloeo 16S gene, would allow us to measure how fast Gloeo DNA amplifies in a qPCR (quantitative polymerase chain reaction), which would tell us how much of the DNA was present in the sample. In this way, we can measure the abundance of Gloeo in a water sample by detecting how many Gloeo 16S genes are present.

With this method, scientists can more accurately measure the amount of Gloeo DNA that is in our lakes, and can better understand when, where, and why it appears. But that’s not all Bigelow Laboratory has planned for Gloeo; we also want to take a closer look at the toxins it produces and the genetic diversity of the colonies in Maine. Ultimately, we want to better understand Gloeo and other potentially harmful algae so we can protect the water quality of our lakes.


Tracking Toxic Algae Blooms in the Belgrade Lakes