Getting to the Core
The hidden past beneath our feet—and lessons for the future
When Jon Woodruff began a new research project in the Cousins River Marsh between Yarmouth and Freeport, Maine, he knew the work wouldn’t be easy. His team would spend long days trudging through the marsh in rubber hip waders, fending off hungry mosquitoes, and getting a serious arm workout when it came time to collect core samples from the ground. As a professor of earth, geographic, and climate sciences at UMass and a veteran of this kind of field work, Woodruff wanted the Cousins River Marsh project to have the strongest start possible.
So he called his mom.
“She grew up in far northern Maine near the Canadian border, and bugs don’t bother her,” says Woodruff, smiling. “She’s made of tough stock, so I asked her to join me at Cousins River when I took the first core sample there. It was good to test the waters and know what we were getting into before I brought the undergrads out.”
A day’s work at the Cousins River Marsh begins at nautical twilight—the moments before sunrise when a clear line of sight to the horizon means you can see what you’re doing while it’s still pitch-black in the woods. The team fans out across the marsh, where native grasses sway and the endangered saltmarsh sparrow chirps to mark its territory. They carry sunscreen, bug nets, GPS units, and a special tool that helps them see into the distant past: a gouge auger. When this hand-powered device—a meter long and 2 inches wide, with sharp edges on each side—is twisted into the earth and then brought back to the surface, it carries with it a tightly packed cylinder of layers with a story to tell. This is a core sample, and it’s why Woodruff and his team are here.
“These salt marshes were like the petroleum fields of their day—they fueled transportation and work,” says Woodruff. “The colonists put in embankments and drainage channels, but all that plumbing has failed now. So instead of draining the marsh, the water is pooling on it.”
With core samples, Woodruff can travel back to a time before satellite photos, weather records, and modern maps and see how the marsh has changed since the precolonial era. His findings have major implications for the future, for as sea levels rise and flooding events become more frequent and severe, coastal marshes have a key protective role to play in the ecosystem—but only if they’re thriving.
People-powered science
Woodruff and his Cousins River Marsh project are in good company at UMass. Brian Yellen ’11MS, ’16PhD, also a professor in earth, geographic, and climate sciences, is the technical lead of MassMarsh, a statewide, UMass-based salt marsh monitoring and restoration program funded by the Massachusetts Department of Environmental Protection. After a childhood spent exploring his neighborhood aqueducts and reservoirs and a stint as a high school science teacher, Yellen earned his master’s degree and PhD at UMass and eventually became the Massachusetts State Geologist—only the sixth person to hold the title in state history. In this role, he oversees the Massachusetts Geological Survey, based at UMass.
What they find is hundreds of years of human impact, compressed into one thin tube.
“The unique thing about a place where sediment is being deposited is that it’s always listening,” he says. “If we can find 10 places where sediment has been accumulating, we can collect cores from all 10 and build not just a temporally continuous record, but a spatial one. That’s the power of sediment cores.”
With Woodruff and Yellen in leadership and liaison roles, many organizations and community groups work together to monitor and restore the region’s marshes and other ecologically sensitive areas. As co-director of the Northeast Climate Adaptation Science Center (NE CASC), Woodruff works with natural and cultural resource managers to translate scientific data into tools to help mitigate the impacts of climate change. He’s also a member of the Leadership Circle for the Center for Braiding Indigenous Knowledges and Science (CBIKS), a National Science Foundation–funded project that connects Indigenous and Western scientific approaches to environmental change, food systems, and cultural heritage.
Less ivory tower, more community engagement—that’s Woodruff’s approach to science in a nutshell. “I was brought up in an era when scientists often joked that it was ‘easier to ask forgiveness than permission,’” he explains, “and when reaching out to people living in the area was seen as an unnecessary burden rather than an opportunity. Through NE CASC and CBIKS, we’re trying to do better, recognizing and showing respect for the fact that local people know their landscape in ways no outside team can.” He goes on to describe their approach, “Starting conversations at the outset of a project helps forge long-term relationships that are worth their weight in gold, improving not only the quality of the science but also its real-world impact.”
In the lab: Where the magic happens
With a Cousins core sample split lengthwise and laid out on a bench, Woodruff and his students begin to understand what they’re dealing with. Starting with peaty, fibrous layers at the top, the core transitions into a denser and darker material as the team peers further back in time. They deploy an array of tools to reveal the details, including microscopes for identifying pollen grains; an X-ray fluorescence scanner to detect elements like titanium, bromine, and lead; and an oven to burn off organic matter and expose the mineral content that remains.
What they find is hundreds of years of human impact, compressed into one thin tube. Starting around 1760, when colonists began raising livestock in the marsh, coprophilous spores (also known as dung-loving fungi) were deposited in the soil. European weeds got a foothold around 1800, having hitchhiked in bales of hay shipped over from England to feed cattle. Industrial-era heavy metals followed around 1850, and a hundred years later, the sudden inclusion of radioactive traces in the sediment marks the advent of widespread nuclear testing.
Along with core samples, Woodruff’s team uses sediment traps—small vials placed discreetly around the marsh across multiple seasons—to better understand how tidal flows and sediment deposits shape the landscape over time. And here’s why that matters: Sediment is what allows a marsh to grow upward, and without a steady supply of it, marshes can’t keep up with rising seas. They drown.
“It’s sort of like if you want to build a sandcastle but you keep taking sand out from the bottom of it—it’s not going to work,” says Yellen. “We’re effectively undermining the base of the system.”
Somewhere between land and water
When scientists study marshes, they ask two simple questions: What kind of marsh did this used to be, and can or should it be that way again?
“Maybe the [Cousins River] system prior to colonization wasn’t a high marsh system,” theorizes Woodruff. “Maybe this was a pretty mucky area, and then the colonists did a pretty good job of engineering things under a rate of very slow sea level rise. But now that the rates of sea level rise are much faster, it needs to convert back.”
Returning marshes to their natural state means intensive restoration work, which involves the use of “runnels”—shallow channels that allow standing water to gradually drain from ponded areas. Runnels can help bring marshes back into ecological balance, allowing the tides to flow naturally in and out. A healthy marsh, as it turns out, also makes a fantastic place to store carbon and supports decarbonization efforts.
In Maine, Woodruff has partnered with the Passamaquoddy Tribe to study their coastal salt marshes. Closer to home, Yellen uses his perch at UMass to bring undergrads into the research process and joins them in the field. And as the state geologist, he takes his findings directly to the elected leaders and agencies who are in a position to change the way coastal marshes and wetlands are managed.
At the end of a day on the Cousins River Marsh, the research team may be tired and their hip waders muddy, but they know the work they’ve done matters—for the marsh, for the people who call this area home, and for the campaign to give “mucky areas” a better reputation.
“There’s a mindset shift happening,” says Woodruff, “from a static landscape to an acceptance of a dynamic one. People are starting to transition back to a mindset we once had before—that nothing is here forever. There will be a lot of challenges, but I don’t get daunted by that. At our root, we are an adaptive species.”
