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IPSWICH — It sustains the local shellfish industry and assists in coastal carbon sequestration. But the Great Marsh — and all that relies upon it — is in serious trouble.
“What we are facing is a collapse of the ecosystem,” said David Moon, community science and coastal resilience manager at Mass Audubon.
For hundreds of years, the culture of the North Shore has been dependent on one major factor: the 20,000-acre Great Marsh.
Local art galleries are filled to the brim with salt marsh paintings and images, dating all the way back to the late 1800s with images from Arthur Wesley Dow and George Dexter.
Summer sunbathing and swimming at Crane Beach are sheltered by the marsh, which brings endangered shorebirds to the property each year.
Almost every Ipswich kid — or dog — has experienced the thrill of jumping off the Labor In Vain Bridge into the marsh.
Whether you’re enjoying an Ipswich clam at the Clam Box, Ipswich Shellfish, Woodman’s, or Farnham’s, it is almost entirely dependent upon that same ecosystem.
But as unprecedented climate change hits the shore, the character of this community is at immense risk.
A wave of consequence hits the coast
Rising global temperatures have led to sea level rise. These levels disproportionately impact coastal communities, including those found within the North Shore.
Helping to mitigate this change, the marshes sequester up to ten times more carbon from the atmosphere than one acre of forest at their full potential.
Not only that, but the marshes act as a coastal buffer for storm surge and flooding, absorbing excess water. They provide a barrier for local houses, roads, beaches, and the river.
But this protection is threatened.
A long legacy of agriculture
Ever since the first European colonists arrived on Ipswich shores, the salt marshes have been used for agricultural purposes.
As a result, the hydrology (movement of water across and throughout the ecosystem) of the marsh system has been “completely altered,” said Russell Hopping, lead coastal ecologist at the Trustees of Reservations.
“What farmers did is profound,” Moon said. “For hundreds of years, the work that was done to increase yields of salt marsh hay and other crops was done through controlling water.
Evidence showing the extensive use of raised berms to hold back water would then be controlled by ditches and varying the levels of the marsh.”
These berms have since eroded away, but they have left behind a denser microtopography (marsh surface) and man-made ditches.
“As it decayed, it made a lot more ditches than would have been comparable to natural creaks,” Hopping said. “That allows air to get into the peat and causes oxidation — decomposition — that allows the marsh to sink and subside.”
A sinking system
This sinking has led to clogged ditches that retain water in far greater quantities than the ecosystem can naturally handle.
This results in flooding, which brings water right up to the wetland plant species. The two most common species of marsh — high marsh and low marsh of the spartina genus — are adapted to different levels of high tide.
The high marsh grasses grow taller and look more like hay, but the low marsh is adapted to the inundation of water every day, with only a “breath of air at low tide,” Moon said.
While the marshes were being used for agriculture, the growth of high marsh was encouraged to produce more hay — and economic yield. Approximately 80% of the current ecosystem now consists of high marsh, with only 20% low marsh.
With only low marsh adapted to flooding, most species found within the ecosystem are non-aquatic and cannot sustain continuous saturation.
The roots of these plants die, bringing the absorption levels even lower than before. Puddles begin to appear on the marsh, and it subsides even further into the ground.
Now that sea-level rise has been added into the equation, what was once a temporary concern might now be irreversible.
Accretion levels (the accumulation of sediment on the marsh surface) haven’t built up the marsh at the same rate as sea-level rise.
The marshes are sinking, and the tide is rising.
Supporting species far and wide
Mummichogs are a keynote species (a dominant predator in the ecosystem that other species are dependent upon) within the marsh habitat. But their abundant population has dwindled in recent years.
They are found within the “low marsh grasses, hiding and eating crustaceans,” Moon said.
From there, they find their way out to the Plum Island Sound, where they are eaten by larger fish and predators.
But now, as the tide rises, they are dragged into taller grasses that have less adequate food for both the fish and other consumers higher in the food chain.
In the ecosystem, “everybody is eating mummichogs,” Moon said. “If we have reduction in mummichogs, we have a reduction in [the ecosystem’s] health.”
Fisheries are dependent upon the species, and so are shellfish within the same food web.
“Imagine a world without the Ipswich clam,” said Hopping, adding, “I don’t want to.”
Not the end of their story
As sea levels rise and temperatures increase across the globe, mitigation efforts on the marshes are underway — and they involve all generations that have grown up upon them.
Mass Audubon, the Trustees of Reservations, Essex County Greenbelt, Massachusetts Wildlife, and the U.S. Fish and Wildlife Service have all joined together to help — agencies and organizations that “realize the tremendous value and importance of the marsh to our communities,” Hopping said.
“We realized we need to do something quick, and we need to do it on a big scale. Otherwise, we are going to start to lose them,” he added.
The main goal of the partnership’s efforts is to restore the hydrology of the ecosystem — turning the straight, man-made ditches back into the naturally flowing, wiggly streams.
This will lead to proper sediment distribution and drainage — both of which the marsh currently lacks.
By filling ditches and encouraging natural water flow, “We can utilize that existing agriculture that is out there and essentially replicate the natural marsh hydrology,” Hopping said.
“We need to be thinking at the ecosystem level, and the Great Marsh is the largest ecosystem in all of New England,” he added.
The end goal is to help the marsh will keep up with sea level rise. “What we are projecting are thousands of acres of hydrological restoration,” Moon said.
Not only have these five organizations been leading these efforts. Students all over the North Shore have been doing part, too.
The Salt Marsh Science Project
For the past 20 years, the Salt Marsh Science Project has been bringing high school students out into local marshes to collect data on salinity in the peat and vegetation, the species that are present, and accretion levels.
Liz Duff of Mass Audubon had been leading the project. After her death in 2020, it was passed off to Moon. But Duff’s impact on the program helped to drive research forward for hundreds of students.
Lori LaFrance has also been bringing students out since the fall of 2006, following in the footsteps of other IHS educators who helped kickstart the project ten years earlier.
In recent years, Ipswich students have been conducting tests in the Cedar Point Marshes alongside the Crane Estate.
“Bringing kids there can activate their curiosity and get them thinking about why the marsh is so important to protect,” LaFrance said.
“I hope that by the end of the course, students are able to make connections between their way of life and the health of the marsh, and that this stays with them as they become decision-makers in town,” she added.
Kayden Flather is one of the students who worked with LaFrance. She recently graduated from IHS and will be attending Colby College this fall.
“Living in Ipswich, really every natural science class I have taken focused on these marshes. It has given me a greater appreciation for the conservation efforts,” Flather said.
“And when we went to collect data, I went off by myself and was just traipsing through — it was my favorite memory. I became a little kid again,” she added.
The project awakens interest in students of all ages and allows them to appreciate this resource right on their doorstep. Future generations will soon take the reins in these mitigation efforts.
It all comes down to the locals
But there is only so far that these organizations and projects can reach.
According to Moon’s stats, 5.69% of the marsh parcel ownership is government-owned, and 3.78% is non-governmental organization owned.
This leaves a whopping 87.72% of the marsh that is privately-owned — meaning the future of the marsh truly comes down to “personal education and awareness” of these individuals, said Hopping.
“It is really important for people to understand what sea level rise and storm surge might mean — not only for their community, but individual properties. Be aware, then apply it to your property to bring [the restoration] to a whole other level,” he added.
He says this is not just an issue that these four agencies can solve. “It is being aware and understanding what this work is going to do for that community, but also what others need to be thinking about for their own needs,” Hopping said.
“There is a whole other effort that has grown up around the Great Marsh.”
Moon said, “There is so much that we can do when people just buy in and help.”
A small town with a big message
Although the scale of the issue may seem discouraging at first, involvement and awareness are seen as crucial efforts to help these organizations’ progress.
“These marshes set the context, the identity, the culture of these communities,” Hopping said. “I don’t think any of us can imagine a world without the Great Marsh.”
The organizations hope that their efforts will act as a call to action and raise awareness, even if it is just by reading an article.
“For one person, what is happening in the Great Marsh may seem extremely complex and daunting,” Moon said. “But it is not hopeless. We can reverse this.”
He added, “Our footprint may be small, but our capacity to help is big.”
