Nature Conservancy award supports URI research on salt marsh health
By Anna Gray
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| Rhode Island’s salt marshes protect coastlines and provide critical habitat, but many are increasingly threatened by sea level rise and other environmental pressures; shown: Quonochontaug Marsh, Charlestown. (Photos courtesy Madison Geraci) |
Rhode Island’s salt marshes protect coastlines and provide critical habitat, but many are increasingly threatened by sea level rise and other environmental pressures. Madison Geraci, a Ph.D. student in evolution and marine biology at the University of Rhode Island, is studying organisms hidden within marsh sediments to better understand how these ecosystems respond to stress and restoration efforts.
Her work recently received a student award from the Nature
Conservancy that will help expand an innovative approach to monitoring marsh
health across Rhode Island.
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| URI Ph.D. student Madison Geraci (shown at Quonochontaug) recently received a Nature Conservancy award to study how local salt marshes respond to restoration and environmental change. |
At the center of Geraci’s research are foraminifera,
microscopic single-celled organisms that scientists increasingly recognize as
powerful environmental indicators of marsh health.
“They’re like a canary in the coal mine,” she said. “They’re
really sensitive to salinity, sea level rise, coastal acidification, and
pollution, and they can tell us a lot about marshes’ overall health.”
Traditional monitoring often focuses on marsh vegetation,
but microbial communities may reveal ecological stress much earlier.
The Nature Conservancy funding will help pay for the genetic
sequencing needed to identify microbial communities. “Sequencing can be
expensive, so the award allows us to do this work on a broader scale,” she
said.
After collecting sediment samples from marshes across the
state, Geraci and her collaborators use a method called metabarcoding—a type of
DNA sequencing—to identify organisms living in the samples. “We’re using a tool
called metabarcoding to take a sediment sample, extract it, and then tag all
the different forams that might be there and determine their overall
diversity,” she said.
Her research focuses on marsh restoration projects that add thin layers of sediment to help raise marsh elevation and counteract sea level rise. By comparing restored and non-restored marshes, the team hopes to understand how ecosystems respond to these interventions.
“We go out into these either restored or non-restored
marshes locally to assess what their overall ecosystem health is, inform people
where the marsh is going, or how the restoration is affecting the marsh,”
Geraci said.
The project brings together scientists from multiple
organizations, including Kenneth Raposa at the Narragansett Bay National
Estuarine Research Reserve and Decatur Foster, a conservation biologist with
the United States Environmental Protection Agency. By pairing her microbial
analysis with other monitoring efforts, Geraci hopes to create a faster and
more responsive way to evaluate restoration projects.
“Hopefully we can make a more robust long-term tool that an
agency like the Rhode Island Department of Environmental Management could
implement for themselves,” she said.
Some of the most meaningful experiences of her work have
come from time spent in the marsh when community members stop to ask about her
research. “One of the best parts of my research is interacting with the people
and learning how they connect with the marsh throughout their life,” she said.
During one field visit, she spoke with a longtime resident
who had watched the marsh change dramatically over decades. “They remembered
the salt marsh being a lot healthier with a lot more shellfish,” Geraci said.
“They were appreciative that someone was looking into it, but they were also
sad that they no longer could enjoy the same thing that they used to.”
Those conversations reinforce why understanding marsh
ecosystems matters, she said, not only for scientists but for the communities
who depend on them.
“We’re hoping to detect the signals of stress in a marsh before larger changes, such as vegetation loss or erosion really become visible,” Geraci said. “This work helps us guide decisions to keep Rhode Island’s marshes healthy.”