Algae: Problem Or Panacea? Summer Research Flips Approach To Water Quality Improvement

To outdoor recreators, algal blooms may be that annoying blue-green scum on the water’s surface that causes their favorite beach to close. But, to Shannah Weller ’26, algae could be the key to cleaning up polluted waters.

For her summer research project, the Biology major is splitting her time between a canoe on the water and the lab on campus as she grows algae and monitors water quality. The possible pollution solution ramifications aside, Weller hopes to cast algae in a favorable light and utilize its inherent processes – the ability to grow and consume at great rates – for natural water restoration.

The algae conundrum
Algal blooms thrive when there is an abundance of nutrients – particularly nitrogen and phosphorus – in the water. Too much, and the nutrients become pollutants. Humans are major contributors to these nutrients making it into water systems through agricultural runoff, sewage and wastewater, and stormwater causing chemicals to flow into waterways.

The algae, which photosynthesize like plants, flourish in summer when there is more heat and light.

Certain blooms can de-oxygenate the water, affecting aquatic life or even producing toxins that are harmful to humans and pets. Hence, beach closures and smelly, scummy water.

In some cases, bodies of water have been accumulating these nutrients for a hundred years. Meaningful improvement could take many decades without aggressive intervention to speed the process along.

Growing algae to prevent future algae growth
Weller developed a fascination with the behavior of algae and diatoms – single-celled algae which can be used to gauge water quality – through work on algal blooms with Clay Williams, professor of Environmental Science, and her own research over the past year.

“The goal of this study is to look at them [algae] in a different perspective because up until now they’ve been seen as an issue,” she said. “So, what I want to do is see if there’s a potential way to utilize what they are naturally doing – in fact, they metabolize a lot of these nutrients. So is there a way to use that natural process to actually address the issues that they’re causing?”

Weller wanted to test whether she could naturally cleanse water by placing certain types of algae in nutrient-rich samples from Vermont waterways, allowing the algae to consume the excess nutrient pollutants, and then removing the algae mass.

Previously, Weller supported her professor’s research, but for this project, she is following her own scientific curiosities. Williams said he’s basically working for her.

“How humans impact water quality of lakes is within my research area, but this idea of seeing how well they remove nutrients in the lake, and grow, and if they can be used as a solution to their own problem type of thing is definitely all Shannah,” he said.

Getting science-y: Experimentation in familiar waters
In order to test her hypothesis, Weller collected water from five Vermont sources: Colchester Pond, Lake Iroquois, Shelburne Pond, Sunset Lake, and Lake Dunmore. These were chosen based upon their level of nutrient composition – some were highly concentrated, and others were mid- to low-level.

First, she spent hours filtering out the existing algae in the water sources to have an algae-free base from which to start. The bags of water were then spiked with a specific type and amount of algae from one of the other Vermont water sources.

“The technical name would be a microcosm, but really they’re in a fancy Ziploc bag and they’re floating in Gilbrook,” Williams explained, referring to the Gilbrook Natural Area adjacent to campus.

The bags were placed into a floating frame made of PVC pipe and screen door material and left to incubate floating on the surface of the pond in the Gilbrook Natural Area. For the experiment, they wanted to replicate the natural day-night light cycle and temperature differences in an aquatic environment to give the algae the most natural environment in which to grow. After a week, the bags are pulled from the pond so the algae can be measured for growth and the water tested for concentration of nutrient pollutants such as phosphorus, nitrite, and ammonia, using some specialized equipment in the lab.

The ultimate goal is to find out whether algae from one water source can be placed into another to be utilized for pollutant bioremediation, and if it can, what the optimal nutrient-to-algae ratios are for effectiveness.

Small project could have large impacts
If the experiments work, the potential ramifications could be monumental for aquatic ecosystems and human life.

“If there’s a way to harvest the algae and use them as ways to suck out the food,” and afterwards remove the algae, Williams said, “then we can shorten the timespan that a lake might be able to recover from some pollutants it has.”

In theory, applications could include improving drinking water as well. And, after removal, the algae masses that have consumed nutrients Williams speculated could possibly be used as fertilizer or compost for agriculture or lawn care – assuming testing showed the absence of harmful chemicals.

Of course, these are just conjectures of where findings could lead and would require more experimentation built upon Weller’s foundational testing. But, the possibilities are numerous.

St. Mike’s fosters scientific curiosity and exploration
Weller said it’s important for people in the sciences to not look at things in one way – an ethos she’s applied to her own scientific work.

“This is a good example of looking at something in a different light and different perspective to try to problem-solve,” she said. “Doing these types of experiments and keeping an open mind can set us up for biotechnological advancement…I think that’s where we find the solution to a lot of problems that are pressing.”

This type of project and the fact that undergraduate students can participate in and lead scientific research, was a major draw for Weller in choosing Saint Michael’s College.

“I wanted to go into research for a very long time and so that was what helped me make my decision to attend St. Mike’s,” she said. “I knew exactly what I wanted to do, and St. Mike’s provided me the opportunity to do it.”

After St. Mike’s, she hopes to attend graduate school and forge a career in scientific research. In particular, she is interested in marine microbes and their potential for biotechnological applications.

This project – completed over the course of about eight weeks during the summer – sets Weller up to meet her future goals.