A bucket containing seagrass and oysters involved in a Bowdoin College experiment. C. Thacher Carter / The Times Record

An experiment being conducted by Bowdoin College students and faculty will test if there is a positive relationship between oyster growth and seagrass meadows – a finding that, if true, could potentially aid the state’s booming aquaculture industry.

The month-long experiment is taking place at Bowdoin College’s Schiller Coastal Studies Center on Orr’s Island and uses seven-gallon buckets containing oysters that are filled with water varying in temperature, acidity and seagrass quantity. The project also has a field component, where oysters were placed in a nearby cove in different locations relative to seagrass meadows.

Bowdoin College junior Fiona Ralph inspects an oyster tray involved in an experiment that tests the relationship between sea grass and oysters. C. Thacher Carter / The Times Record

The Quahag Bay Conservancy, the organization that runs Snow Island Oyster, is also collaborating with Bowdoin on the project. Snow Island Oyster grows between 600,000 and 1 million oysters a year through a nearby aquaculture operation.

Ultimately, those working on the experiment think the project will show that seagrass helps oysters grow.

“We expect that the oysters are going to grow faster in the presence of seagrass and that the seagrass is going to grow faster in the presence of oysters,” said Bowdoin College Biology Professor and Schiller Coastal Studies Center Director David Carlon. “It’s a result that could be used to design essentially permits or design a layout for an aquaculture system.”

Carlon said that when seagrass is photosynthesizing, it acts as a sink for carbon dioxide — a greenhouse gas —  and buffers the acidity of the seawater in a way that could be favorable for oysters. In turn, the oysters nitrogen byproduct could act as a fertilizer for and promote the growth of the seagrass.

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Seagrass is a form of underwater plant life distinct from seaweed that provides habitat for different marine species.

The aquaculture industry is on the rise in Maine, and there are currently 172 licensed operations in the state, which translates to just over 1,663 acres. Of that, over 615 acres or 102 operations are cultivating the American oyster – the same species in the experiment.

Bowdoin College students Fiona Ralph and Eban Charles. C. Thacher Carter / The Times Record

According to Carlon, some of the bucket’s temperature and acidity are also adjusted for where the Gulf of Maine is expected to be in the year 2100 due to climate change.

“What’s the most important issue of our time? I mean I think you could say it’s climate change,” Carlon said. “Another important issue of our time is sustainable food … we have to think more carefully about what kind of aquaculture systems will support local economies.”

The two Bowdoin College students who are working on the experiment for the summer are Eban Charles, a rising junior who grew up in Waterville, and Fiona Ralph, a rising second-semester junior who is from New Jersey.

Charles said other components that the experiment will attempt to measure include shell size and strength, seagrass length and water chemistry conditions.

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“There’s a lot to decipher.” Charles said. “Say the shells grow a lot but the meat doesn’t. That’s something that’s relevant because that’s not exactly what the world of aquaculture cares about – they want the meat.”

“Honestly, every week I would say has been very different,” Ralph said, detailing the work it took to build the plumbing system, organizing the field component and finally launching the experiment with the oysters.

Ralph added that the hands-on project has been particularly enjoyable after months of remote learning due to the COVID-19 pandemic. “As a science major, having to do labs online and science classes online, just as it is with everyone, is just so challenging,” Ralph added.

Once the experiment is complete, the group plans to submit the findings to a peer-reviewed scientific journal.

Two rows of buckets in the Bowdoin College experiment that are filled with seawater, oysters and seagrass. C. Thacher Carter / The Times Record


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