A Biology Professor’s Research into Corals and Oysters Sheds Light on Climate Change and Infectious Diseases
04/16/2024
By Brooke Coupal
Standing on the side of a boat and donning a wetsuit, fins and an air tank, Sarah Gignoux-Wolfsohn gets ready to jump into the Caribbean Sea.
It’s a plunge that the biological sciences assistant professor has taken roughly 500 times, but the thrill of exploring underwater never gets old.
“It’s like being in another world,” says Gignoux-Wolfsohn, a certified scientific diver who studies corals and oysters. “It’s very quiet and serene underwater.”
Gignoux-Wolfsohn’s fascination with the ocean began at an early age. Growing up in Philadelphia, her family would take trips to beaches in New Jersey and Maine.
“My mom always talks about how I would get excited to look at tide pools and would pick up every rock to see what’s underneath,” she says.
Bleached coral off the coast of Belize.
After getting bachelor’s degrees in biology and French at Wesleyan University, Gignoux-Wolfsohn went on to pursue a Ph.D. in ecology, evolution and marine biology at Northeastern University, where she first got involved in coral research and diving. She briefly switched to researching bats as a postdoctoral associate at Rutgers University, but soon found herself back in the ocean studying oysters as a postdoctoral fellow at the Smithsonian Environmental Research Center in Maryland.
“I realized that I really like working in the ocean,” she says. “I like doing marine fieldwork.”
Gignoux-Wolfsohn brought her coral and oyster research to UMass Lowell when she joined the Kennedy College of Sciences faculty in September 2022. Her projects focus on the persistence of corals and oysters amid climate change and the increasing threat of infectious diseases.
“Oysters and corals have such a big effect on the marine ecosystem,” she says. “It’s important for us to study them and understand their resiliency to climate change and diseases.”
Disease Prevention
From giant sea turtles to baby clownfish, more than a million aquatic species rely on corals for survival.
Corals are invertebrates belonging to the same group of marine creatures as jellyfish and sea anemones. Healthy coral reefs provide a habitat and feeding ground for marine animals, while also protecting coastlines from storms by acting as a buffer.
For the past decade, corals in the Caribbean have been under attack by stony coral tissue loss disease. The disease, which was first reported off the coast of Florida in 2014, causes lesions to develop on coral. The lesions spread across the coral’s surface until no living tissue remains.
While the cause of the disease remains unknown, Gignoux-Wolfsohn and a team of researchers are working to develop a probiotic treatment that will protect corals from the disease. The Coral Research & Development Accelerator Platform awarded the team a grant of roughly $1.5 million for the project, with $323,000 going to UMass Lowell.
“In a lot of places, people have been treating corals with antibiotics once they get the disease, which is not an ideal solution because you’re only treating them once they show disease signs,” Gignoux-Wolfsohn says. “The idea with probiotics is that we could treat corals before they’re exposed to the disease and hopefully make them healthier.”
In the turquoise waters off the coast of San Andrés, a Colombian island, the researchers are searching for healthy corals among those infected by the disease. Caroline DeSouza, a senior and Honors College student majoring in biological sciences and economics, is helping with the search.
“I knew people traveled for work, but I never saw myself doing that,” says DeSouza, who joined Gignoux-Wolfsohn’s lab during her junior year. “It’s incredible getting this opportunity. I’m so excited by the work that we’re doing.”
DeSouza and other researchers are bringing fragments of the healthy corals back to Gignoux-Wolfsohn’s lab on campus, where she is investigating which bacteria are abundant on the corals. Her findings will be provided to her collaborator at the University of North Carolina Wilmington, Asst. Prof. Blake Ushijima, who will develop a probiotic using the bacteria found on the healthy corals.
“Oysters and corals have such a big effect on the marine ecosystem. It’s important for us to study them and understand their resiliency to climate change and diseases.” -Sarah Gignoux-Wolfsohn
In partnership with the Perry Institute of Marine Science, the Blue Indigo Foundation, CORALINA (the Corporation for the Sustainable Development of the Archipelago of San Andres, Providencia and Santa Catalina) and the ECOMARES Foundation, the researchers plan to apply the probiotic to corals to see if it protects them from the disease.
Gignoux-Wolfsohn says preventing stony coral tissue loss disease is crucial, especially as ocean temperatures rise as a result of climate change.
“Climate change is clearly making the corals more stressed, and when the corals are more stressed, they are more susceptible to disease,” she says.
Coral Bleaching
During the summer of 2023, global ocean temperatures hit a record high. Off the coast of Florida, water temperatures climbed above 100 degrees, while the Caribbean Sea recorded temperatures in the high 90s.
The stress induced by the steamy temperatures led to coral bleaching, in which corals expel the algae living in their tissues, causing them to turn white. Bleached corals can recover, but they are more susceptible to disease and death.
Gignoux-Wolfsohn teamed up with Lauren Fuess, an assistant professor at Texas State University, to assess links between coral bleaching and disease. Their research is being funded by a nearly $200,000 grant from the National Science Foundation.
The researchers are focusing their project off the coast of Belize, where they have been monitoring corals since 2019 in collaboration with Leah Harper, a scientist with the Smithsonian’s Marine Global Earth Observatory.
Data sheets dry following a dive off the coast of Panama.
Applied biology Ph.D. student Brooke Sienkiewicz is taking part in the Belize field research after becoming a certified scientific diver with Gignoux-Wolfsohn’s help.
“This is my first diving research experience, which is really exciting,” Sienkiewicz says. “I’ve been wanting to get a scientific diver certificate forever, so having Prof. Gignoux-Wolfsohn organize and fund it was amazing.”
Samples of the bleached coral are being brought back to GignouxWolfsohn’s lab, where Sienkiewicz, scientist Felicia Aronson and others are analyzing the differences between corals that survived and those that died. The team will continue to monitor surviving corals in Belize to see if bleaching makes them more vulnerable to stony coral tissue loss disease, which reached the country in 2021.
Resilient Oysters
Corals have proven to be highly sensitive to climate change, unlike oysters, another marine invertebrate.
“Oysters are like the opposite of corals,” Gignoux-Wolfsohn says. “They are super-resilient.”
Gignoux-Wolfsohn and a team of researchers from UMass Dartmouth and the Chesapeake Biological Laboratory (CBL) in Maryland are studying oysters’ resiliency to climate change while looking at ways to make them more adaptable. The National Science Foundation awarded the researchers a grant of nearly $1.3 million for the project, with more than $500,000 going to UMass Lowell.
Over four years, the researchers plan to expose oysters from the Chesapeake Bay to warmer water temperatures and decreased oxygen, two common climate change stressors. The experiment, which is scheduled to start this summer, will take place in a large-scale quarium system at CBL. Biological sciences sophomore Logan Laurent and master’s student Julia McDonough will be traveling to Maryland to assist with the study.
The researchers’ goal is to expose the oysters to the common climate change stressors multiple times over their lifespan to see if early exposure primes them to be more resilient when exposed to those stressors again.
“If we can help make oysters more resilient, then farmers will experience even fewer losses,” Gignoux-Wolfsohn says. “Oyster aquaculture is beneficial because oysters clean the water (by filtering out algae).”
To further protect the aquaculture industry and coastal communities, Gignoux-Wolfsohn is assisting with a research project that looks to use biosensors to detect bacterial and viral pathogens that can lead to diseases. The project, which received $1 million in funding from the National Science Foundation, is spearheaded by UMass Lowell Electrical Engineering Prof. Yan Luo.
As an extension of the project in the Chesapeake Bay, GignouxWolfsohn is also working with UMass Lowell Biological Sciences Asst. Prof. Teresa Lee to study how early-life stress on oysters affects how their genes function. UML’s Office of Research and Innovation is funding the work with a $15,000 internal seed award.
Gignoux-Wolfsohn says it’s gratifying that her passion for the underwater world has guided her into research that could protect and strengthen two vital marine species.
“It sounds cliché, but I love the ocean,” she says. “The marine ecosystem is extremely important, and being in the water makes me feel more connected to it.”