Navigating Rising Tides: The Urgent Quest to Save New England's Mudflats

Along the New England coast, the mudflats—often overlooked and underestimated—play a pivotal role in sustaining both the environment and local communities. These expansive tidal flats, stretching from the shore and up to a mile into the ocean, are vital ecosystems, teeming with life and serving as crucial carbon sinks. For generations, shellfish harvesters have relied on these mudflats for their livelihoods, gathering soft-shelled clams and other shellfish from the rich, nutrient-packed sands and mud. But now, these invaluable habitats face an unprecedented threat: rising sea levels.

Understanding how these changes will affect the delicate balance of tidal flat ecosystems has become a priority for a team of researchers at the Northeast Climate Adaptation Science Center (NE CASC). Less than one year into their tenure as a NE CASC research fellow, Ash Oh, a graduate student at UMass Amherst, has already become a critical part of that team.  Working alongside project leader Jon Woodruff, who serves as NE CASC University Codirector, Oh is part of a large-scale effort  to document and measure the ongoing shifts in sediment patterns and their long-term implications for both the shellfish harvesting community and the global climate.

"Sediment is the lifeblood of mudflats," Oh explains, reflecting on the intimate relationship between these dynamic environments and the shellfish that rely on them. "Clams breathe, feed, reproduce, and are hunted within the sand and mud. But with the changing climate and rising seas, everything is in flux. We need to better understand these shifts in sediment deposition and transport if we’re going to protect both the environment and those who depend on it."

Tidal flats are much more than just the muddy land between high and low tides. They are critical carbon stores, locking away carbon in the sediment below ground, preventing it from being released into the atmosphere as greenhouse gases like carbon dioxide. In this way, tidal flats play a hidden yet powerful role in combating climate change. However, with the rapid rise in sea levels, there is growing concern about whether these flats can keep up with the pace of change. Will the mudflats have enough time to deposit new sediment and adapt to shifting conditions before they are overwhelmed by rising tides?

These questions lie at the heart of Oh's research. "Tidal flats are not only home to species like soft-shelled clams, but they also help regulate our climate. The sediment here is a key factor in carbon storage. If we lose that function, it will have far-reaching consequences," says Oh.

To get a clearer picture of how sediment is shifting and whether the flats can maintain their critical functions, Oh is employing innovative methods that combine technology and fieldwork. Using satellite imagery, LiDAR (Light Detection and Ranging) elevation measurements, and on-the-ground field samples, Oh is able to track the complex dynamics of sediment deposition and its impact on the ecosystem.

“By using these advanced tools, we're able to measure and map changes to sediment composition and deposition rates across large areas," Oh explains. "This allows us to collect data on a scale that wasn’t possible before. We can then provide this quantitative information to the shellfish harvesting community to help them better prepare for the future."

This work, however, is driven by more than just a basic desire to collect data. It also seeks to empower local communities in adapting to their changing environment. For New England shellfish harvesters, these mudflats are not only their livelihood but also a cultural touchstone passed down through generations. Understanding how these vital habitats are evolving in real time is essential to ensuring their continued viability.

“Many harvesters have been working these areas for generations, and they have an intimate knowledge of the land. Our goal is to combine their expertise with the data we're gathering to help make informed decisions about how to adapt to these changes," says Oh. "Together, we can create strategies to help these communities survive and thrive in a future where sea level rise is an ongoing concern."

Working in collaboration with shellfish harvesters, Oh harbors a hope that the NE CASC mudflat study will help safeguard a critical natural resource and a way of life–both of which are experiencing an unprecedented threat due to climate change. Even as the tidal flats face an uncertain future, the data and strategies being developed by Oh and the UMass Amherst team will be crucial in helping both the environment and the communities that rely on it navigate the rising tides ahead.

This article was written by Terzah Tippin Poe, a NE CASC Graduate Fellow at the University of Maine. Terzah completed this project while participating in a spring NE CASC skill-building group focused on science communication.