Rebeka Rand Merson
Rhode Island College
Associate professor; biology
SURF program mentor
Past RI EPSCoR research team leader

Rebeka Rand Merson investigates the molecular impact of environmental chemicals on apex predators, those marine animals at the top level of
the food chain, as part of the Rhode Island NSF EPSCoR effort to understand the resilience and adaptation of marine organisms to environmental change.

Using skates as a model, Merson studies what happens when an organism, say a shark, is exposed to environmental chemicals and tracks the changes wrought at the molecular level.

The lengthy embryonic development — up to eight months from fertilized egg to hatching — sets an intriguing stage for study. Merson says she and Diane Nacci, U.S. Environmental Protection Agency (EPA), hypothesize that the long development creates an embryo more sensitive to the environmental chemicals; that the toxicity is based on time and potency, causing more damage than those embryos that develop in a shorter period of time.

With equipment at the Marine Science Research Facility (MSRF) — an EPSCoR core facility on the University of Rhode Island Narragansett Bay Campus — and the EPA, the research team can decrease the fertilization-to-hatch phase to about five months, allowing the scientists to study the sensitive, early periods of embryonic development.

“There is no way I could do my work without these facilities. It would be impossible to do at RIC; the impact is beyond words.”

When skates are exposed to polychlorinated biphenyls (PCBs), environmental contaminants often found in industrial waste, the chemical travels into the fatty tissue, where it stays and doesn’t break down. Merson’s research looks at the response of one protein, AHR (aryl hydrocarbon receptor), which the chemical binds to and then moves into the cell nucleus, where it alters the protein’s function and disrupts development.

“With exposure to these chemicals, AHR doesn’t function as a normal, every day regulator,” explains Merson. “By the sheer fact that the chemical binds to AHR and moves into the cell nucleus, it changes the gene expression and causes some genes to increase in production of downstream proteins. Changes in gene expression affect the function of cells, and the function of the body.”

The resulting impact, according to preliminary results from Merson’s work, spells developmental trouble for the apex predators, upsetting the delicate process of gene expression and initiating a devastating ripple effect.

“If these apex predators are sick, their disease being caused by chemicals, they will be less able to assert that top down regulation on the food web,” Merson says. “If we lose the apex predator, we’re going to see the impact at the lower levels. And then, we will have a whole myriad of outcomes, from the fisheries to the health of the ecosystem.”

Merson sees a direct connection between climate change and the results turning up in her research. More rain falls in shorter periods of time, increasing the flow of water washing over roads and land, and overwhelming water treatment plants.

The resulting runoff and untreated wastewater load chemicals into Narragansett Bay from industry, agriculture and development that alter the cellular function in marine organisms, which puts at risk the ecosystem that fuels the economy and quality of life in the Ocean State.

Merson says two RI EPSCoR core facilities — the MSRF and the RI Genomics and Sequencing Center — make her work possible: “There is no way I could do my work without these facilities. It would be impossible to do at RIC; the impact is beyond words.”

And, she adds, the RI Science and Technology Advisory Council (STAC) grant, provided by Rhode Island’s match to the EPSCoR funding, offers a new direction for her research and opens up an entirely new set of opportunities.

The Summer Undergraduate Research Fellowship (SURF) program, a 10-week research fellowship for undergraduates, plays an equally pivotal role, with Merson mentoring students through her research. She also provides opportunities for undergraduates and masters students to work on her EPSCoR research during the academic year.

“These students are directly benefitting from EPSCoR,” Merson says. “Many of them are self supporting and have to work in order to go to school. The EPSCoR support allows them to focus on their research and their academics, and not have to work an additional job.”

Story and photos by Amy Dunkle | RI NSF EPSCoR