A Biology Professor鈥檚 Research into Corals and Oysters Sheds Light on Climate Change and Infectious Diseases

Ph.D. student Brooke Sienkiewicz in scuba gear examining corals in the ocean.
Ph.D. student Brooke Sienkiewicz, a member of Asst. Prof. Sarah Gignoux-Wolfsohn鈥檚 research team, examines corals off the coast of Belize.

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.聽

It鈥檚 a plunge that the biological sciences assistant professor has taken roughly 500 times, but the thrill of exploring underwater never gets old.

鈥淚t鈥檚 like being in another world,鈥 says Gignoux-Wolfsohn, a certified scientific diver who studies corals and oysters. 鈥淚t鈥檚 very quiet and serene underwater.鈥

Gignoux-Wolfsohn鈥檚 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.

鈥淢y mom always talks about how I would get excited to look at tide pools and would pick up every rock to see what鈥檚 underneath,鈥 she says.

Coral and other marine life at the bottom of the ocean.

Bleached coral off the coast of Belize.

After getting bachelor鈥檚 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.

鈥淚 realized that I really like working in the ocean,鈥 she says. 鈥淚 like doing marine fieldwork.鈥

Gignoux-Wolfsohn brought her coral and oyster research to 51视频 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.

鈥淥ysters and corals have such a big effect on the marine ecosystem,鈥 she says. 鈥淚t鈥檚 important for us to study them and understand their resiliency to climate change and diseases.鈥

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鈥檚 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 51视频.

Person in scuba diving gear examining corals in the ocean.
Asst. Prof. Sarah Gignoux-Wolfsohn surveys healthy corals off the coast of the Cayman Islands.

鈥淚n a lot of places, people have been treating corals with antibiotics once they get the disease, which is not an ideal solution because you鈥檙e only treating them once they show disease signs,鈥 Gignoux-Wolfsohn says. 鈥淭he idea with probiotics is that we could treat corals before they鈥檙e exposed to the disease and hopefully make them healthier.鈥澛

In the turquoise waters off the coast of San Andr茅s, 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.

鈥淚 knew people traveled for work, but I never saw myself doing that,鈥 says DeSouza, who joined Gignoux-Wolfsohn鈥檚 lab during her junior year. 鈥淚t鈥檚 incredible getting this opportunity. I鈥檓 so excited by the work that we鈥檙e doing.鈥澛

DeSouza and other researchers are bringing fragments of the healthy corals back to Gignoux-Wolfsohn鈥檚 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.

鈥淥ysters and corals have such a big effect on the marine ecosystem. It鈥檚 important for us to study them and understand their resiliency to climate change and diseases.鈥 -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.聽

Gignoux-Wolfsohn says preventing stony coral tissue loss disease is crucial, especially as ocean temperatures rise as a result of climate change.

鈥淐limate change is clearly making the corals more stressed, and when the corals are more stressed, they are more susceptible to disease,鈥 she says.聽

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鈥檚 Marine Global Earth Observatory.

Data sheets drying off following a dive.

Data sheets dry following a dive off the coast of Panama.聽

鈥淲e have all this historical data about these corals,鈥 Gignoux-Wolfsohn says. 鈥淲e are continuing to go down once a month to check on the corals to see which ones are recovering from bleaching and which ones have died.鈥

Applied biology Ph.D. student Brooke Sienkiewicz is taking part in the Belize field research after becoming a certified scientific diver with Gignoux-Wolfsohn鈥檚 help.

鈥淭his is my first diving research experience, which is really exciting,鈥 Sienkiewicz says. 鈥淚鈥檝e been wanting to get a scientific diver certificate forever, so having Prof. Gignoux-Wolfsohn organize and fund it was amazing.鈥澛

Samples of the bleached coral are being brought back to GignouxWolfsohn鈥檚 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.

鈥淥ysters are like the opposite of corals,鈥 Gignoux-Wolfsohn says. 鈥淭hey are super-resilient.鈥澛

Gignoux-Wolfsohn and a team of researchers from UMass Dartmouth and the Chesapeake Biological Laboratory (CBL) in Maryland are studying oysters鈥 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 51视频.

Asst. Prof. Sarah Gignoux Wolfsohn and two others survey healthy corals off the coast of Cayman Islands.
Gignoux-Wolfsohn, center, collects oysters from the Chesapeake Bay in Maryland.

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鈥檚 student Julia McDonough will be traveling to Maryland to assist with the study.

The researchers鈥 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.

鈥淚f we can help make oysters more resilient, then farmers will experience even fewer losses,鈥 Gignoux-Wolfsohn says. 鈥淥yster aquaculture is beneficial because oysters clean the water (by filtering out algae).鈥

A hand holding an open oyster.
The inside of an oyster.
Oysters also build reefs, similar to corals, that protect the coastline and provide homes for other aquatic species.

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 51视频 Electrical Engineering Prof. Yan Luo.

As an extension of the project in the Chesapeake Bay, GignouxWolfsohn is also working with 51视频 Biological Sciences Asst. Prof. Teresa Lee to study how early-life stress on oysters affects how their genes function. UML鈥檚 Office of Research and Innovation is funding the work with a $15,000 internal seed award.

Gignoux-Wolfsohn says it鈥檚 gratifying that her passion for the underwater world has guided her into research that could protect and strengthen two vital marine species.

鈥淚t sounds clich茅, but I love the ocean,鈥 she says. 鈥淭he marine ecosystem is extremely important, and being in the water makes me feel more connected to it.鈥