ORONO — Last summer, Sofia Diaz Flint spent her days working on a Maine oyster farm, hauling cages and tending shellfish that would not reach the market for another year.
Seeing firsthand how much farmers depend on their crop surviving the winter shaped the direction of her senior capstone project at the University of Maine.
“I worked on an oyster farm and wanted to base my project on oysters,” she said.
Now, Diaz Flint, a marine science major with a concentration in aquaculture, is developing a tool to help Maine oyster farmers monitor oyster health and better predict overwintering survival.
The work comes as oyster farming continues to grow across the state, even as farms remain vulnerable to diseases such as Sudden Unusual Mortality Syndrome, or SUMS, and to seasonal stress during the winter months.
Her project focuses on near-infrared spectroscopy, an analytical method that uses infrared light to measure the chemical composition of organic materials. Aquaculturists, including researchers and farmers, can use the technology to measure lipid reserves in oysters by scanning the tissues of shellfish, allowing them to assess nutritional health of the animal.
“I turned to spectrometry, which involves passing infrared light through tissue samples and analyzing what reflects back to determine chemical concentration,” she said. “From there, I can build a model and use samples from farmed oysters to see whether they are susceptible to dying over the winter or how prepared they are for winter and other environmental stressors.”
Lipids are concentrated energy reserves stored within an oyster’s tissue. They can serve as fuel during winter and early spring if oysters are active but food supplies are short. They may also help oysters resist stress associated with SUMS, which refers to unpredictable die-offs triggered when an oyster’s energy is depleted.
Oysters typically require a two-year culture cycle to reach market size. They must accumulate enough lipids to survive the winter, when cold water temperatures reduce feeding activity.
Paul Rawson, a professor of marine science in the University of Maine’s School of Marine Sciences and Diaz Flint’s project adviser, said the industry has long sought better ways to understand overwintering success.
“It has long been an interest in the oyster industry to understand what limits overwintering success,” Rawson said. “In Maine, there has always been a need to understand ways to sustain oysters from their first season in the water through the winter to the second season, when they reach market size.”
Although near-infrared spectroscopy has existed for years, Diaz Flint’s project aims to refine the technology to address modern challenges in a changing coastal environment.
“Just by providing a model, it allows scientists, researchers and farmers to base their research on it and learn from it,” Diaz Flint said. “Ultimately, I want to contribute to more resilient and sustainable aquaculture in Maine’s changing coastal environment.”
