Can Lake Mattamuskeet Be Saved?

“Here,” says Kelly Davis, handing me a set of binoculars. Without them, it’s clear we’re among a throng of murmuring, honking waterfowl. But they don’t look like much more than distant bumps on the water.

The view through the binoculars is a revelation. Thousands of birds are floating and dabbling among vegetation, taking off for short flights, socializing in a way that’s wholly absorbing to watch. Davis lives nearby and is an appointed member of the N.C. Wildlife Resources Commission, an agency tasked with protecting the state’s wildlife; she explains that among them are Canada geese and ducks that include green-winged teal and northern pintails. And the graceful white birds that look like snow geese?   

“Those are tundra swans,” she kindly corrects me. There are hundreds of them, and every single one flew roughly 3,000 miles from the Arctic to overwinter here. 

This is the Mattamuskeet National Wildlife Refuge, a 50,000-acre preserve on the Albemarle-Pamlico peninsula in Hyde County that’s one of the most important stops along the Atlantic flyway. Every winter it hosts thousands of waterfowl from Canada and other northern locales that overwinter here. 

The refuge is best known for the birds, but they’re just one element. Lake Mattamuskeet itself—at 40,000 acres, it’s North Carolina’s biggest natural lake—is a unique ecosystem. Located 10 miles from the Pamlico Sound and less than three feet deep, it’s mostly freshwater with a little salinity and is filled by rain and runoff from the surrounding land. But its connection to the sea through canals allows fish like alewife, white perch, striped mullet, and American eel to move in and out for reproduction. Hyde County locals talk of years spent crabbing and fishing off the causeway that bisects the lake, and of watching the birds with wonder. 

But the waterfowl we’re watching are not on the lake. They’re in an impoundment, a vegetated area that’s been flooded to provide food for the birds, just past the southern rim of the actual lake.   

That’s because Lake Mattamuskeet itself is in trouble. The wild celery, muskgrass, and other aquatic vegetation that once carpeted the lake bed and fed waterfowl gradually disappeared over the last three decades due to impacts of agriculture, and they are now completely gone. Now, birds no longer visit the lake, and their overall numbers at the refuge have plummeted. In 2022, around 5,000 tundra swans came to the refuge, according to the U.S. Fish and Wildlife Service—an eighth of what the agency counted 20 years earlier. Duck statistics have similarly plunged, from nearly 200,000 in 2016 to 35,000 six years later.

It’s not just the lake’s vegetation. Everything in this ecosystem is struggling. Without plant roots anchoring the lake bottom, sediment is looser. Invasive carp have taken over, and native fish and invertebrate populations have declined. Algae is thriving, and water clarity is diminished, making it impossible for the grasses to regrow. 

It’s an interconnected system, one that is indisputably out of balance. Fixing it, however, is no easy task: The agricultural runoff that is the prime cause can’t be fully stopped, so the solution will have to be as manifold as the lake’s problems. It’s complicated by the fact that some of the forces at play extend far beyond Hyde County.

No one’s close to giving up on Mattamuskeet, which has always served as the county’s centerpiece. But question them enough, and many of the people involved in its restoration admit that it might never get back to its former glory. If they could get it even a little healthier, though, that might be enough. 

A Team Effort

Seated at a long table in the Hyde County courthouse in January, farmer Michael Cahoon is interrogating an engineer about his plans to divert agricultural runoff from the lake and shift it to wetlands.

“What I want to know is, what does this work have to do with moving water out of Lake Mattamuskeet?” says Cahoon, seated in a conference room with 20 people that include farmers, wildlife managers, hydrologists, local officials, and environmentalists, all of whom have an interest in restoring the health of the lake. 

Submerged aquatic vegetation started thinning out on the lake’s western side in the 1990s, but the plants didn’t fully disappear until 2014. In 2016, the state added Mattamuskeet to the EPA’s list of waters significantly threatened by contaminants or sediment. 

In response to the grass’s disappearance, the refuge’s managers created an advisory group of government biologists and water quality experts to determine exactly what was occurring. Testing and data collection showed that surplus nutrients were feeding algae blooms, and too much sediment had turned the formerly clear water murky. Both algae and sediment were blocking sunlight, which was causing the vegetation to die off. 

The excess nutrients were mainly coming from the  farms and commercial waterfowl impoundments that ring Lake Mattamuskeet. In this pancake-flat land that’s almost at sea level, every field has ditches running through it that carry away excess water, and with it comes the nitrogen and phosphorus present in fertilizer. The sediment, meanwhile, is pulled in when farmers and landowners pump water from fields and ditches into the lake. 

The legislation that made Mattamuskeet a national refuge in 1934 gave farmers around the lake the right to do just that–something that’s unlikely to change in this agriculture-dependent region. So, the U.S. Fish and Wildlife Service and the N.C. Wildlife Resources Commission, which co-manage the refuge, got together with Hyde County and the North Carolina Coastal Federation to bring farmers and other property owners to the table to figure out a solution. 

Cahoon remembers the day the Coastal Federation recruited him for the group. “They came here and asked me, ‘What’s wrong with the lake? How’d it get that way? What will it take to fix it?’” Cahoon said. His farm is less than a mile from Mattamuskeet and has been in his family for generations; he was a natural fit for the effort.  

For the past eight years, the group has been trying to answer those questions. Members devised a bare-bones restoration plan in 2018 and have been filling it in ever since. The strategy they’ve hammered out is sprawling, fragmented—and still a work in progress.

Even the parts that are underway haven’t gone as planned. Take, for example, the $1 million carp removal project, funded by the U.S. Fish and Wildlife Service. Carp barriers installed by the agency a few years ago have prevented some fish from entering the lake. But the agency also hired a contractor to remove one million pounds of carp from the lake by late 2025. Since last May, the contractor has caught less than 13,000 pounds. Either there are fewer carp in the lake than biologists originally estimated, or these fish don’t congregate the way the contractor anticipated.

Overall, “it’s been a humbling experience for a lot of folks,” refuge manager Kendall Smith reported to the team at the January meeting.  

Then there’s the Coastal Federation’s ambitious and expensive program to divert agricultural runoff away from the lake by digging new canals and adding pumps. The organization is doing some prep work, and its engineers’ designs are complete, but the $16.8 million in promised funds from the U.S. Department of Agriculture aren’t yet in. And with the  Trump administration’s recent freeze of USDA funding for some conservation programs, there are concerns they might not arrive anytime soon. 

Like many Hyde County residents, Cahoon grew up fishing on Mattamuskeet and is deeply attached to the lake. But its health isn’t his only priority; he’s got to think about his farm. Among farmers’ priorities is lowering the lake’s water level so their land doesn’t flood as often. 

So, there’s something in the plan for them, too. Davis, who is Cahoon’s neighbor, presented an update on it at the meeting. In 2023, the North Carolina General Assembly appropriated $10 million to the N.C. Wildlife Resources Commission to dredge the main canal linking Mattamuskeet to the Pamlico Sound, though it’s not yet clear where the dredged soil will go or when the project will start.

While the Coastal Federation and other environmental groups aren’t big fans of dredging—they say it can damage habitats—just about every longtime resident is, including Davis. She’s certain it’s the best way to get sediment-filled water out of the lake. The “how” is complicated, though. With a cleared-out canal, lake water will flow more easily into the sound; saltwater will be prevented from coming back in by tide gates, which close in one direction, like doors. A lower lake means runoff from fields and impoundments is more likely to flow in through gravity, Davis believes, rather than exclusively by pumping–and that means less sediment coming back in. 

A former biologist at the refuge, Davis came to Hyde County at age 21 and stayed after marrying a local farmer; she’s ideally positioned to mediate between the stakeholders. She’s also probably the lake’s biggest fan. 

The water needs to flow, she says. Without a healthy connection to the sound, “it’s like a toilet that never flushes.” 

A ‘Band-Aid’

Near the end of the meeting, Davis mused to the group, “There’s a lot of arrows in the quiver.” It’s a variation on something people keep repeating about efforts to restore the lake’s water quality: “There’s no silver bullet.”  

The reality of trying to right an out-of-balance ecosystem is that its problems arose from multiple sources over many years. The restoration plan is complicated, unwieldy, and imperfect. As facilitators for the planning process, the Coastal Federation prioritized relationship-building and the community’s practical expertise. Through dozens of meetings over eight years, they’ve crafted a strategy they believe addresses many of the problem’s upstream causes and has the support of various stakeholders.

In 2021, a new actor entered the scene, one that was also aiming to clean up the state’s troubled waters—but apparently without having to go through the time-consuming, expensive, and potentially systems-upending process of addressing root causes: the North Carolina General Assembly.  

This part of the story starts not in Hyde County or even Raleigh, but in Israel, where Florida Gov. Ron DeSantis encountered algaecide producer BlueGreen Water Technologies in 2019.

Several Florida lakes have significant algae blooms, and DeSantis was intrigued. On his recommendation, the Florida legislature appropriated funding for BlueGreen to apply its algaecide, Lake Guard Oxy, at several lakes and waterways in central and south Florida. The product worked as promised, but in several places, newspapers reported, algae blooms were back within a few weeks. 

The company soon took its show on the road, visiting algae-choked lakes in other states and lobbying at statehouses, including the North Carolina legislature. 

The effort was successful; the General Assembly’s 2021 budget included $5 million for the North Carolina Collaboratory, an agency at the University of North Carolina at Chapel Hill  created by the legislature to apply university research on state problems, to run a pilot project addressing algal blooms. The project was designed to take place on a single troubled North Carolina lake in concert with UNC’s own researchers, who would monitor its effectiveness.

The Collaboratory requested proposals later that year seeking a product that sounded identical to the one BlueGreen makes: a pelletized form of hydrogen peroxide that sits on top of the water before breaking down. Perhaps unsurprisingly, BlueGreen won the contract. 

It’s not clear why Lake Mattamuskeet was chosen for the pilot. “Even though I’m not certain exactly how well it will work, I think the treatment represents a low risk but potentially high reward,” wrote UNC researcher Nathan Hall to U.S. Fish and Wildlife Service biologist Wendy Stanton on September 1, 2022, proposing Mattamuskeet for the pilot. Hall is one of the university researchers the Collaboratory has tasked with monitoring the project, and his was one of hundreds of emails the Southern Environmental Law Center accessed in 2023 through a public records request.

U.S. Fish and Wildlife Service leaders were open to experimenting with Lake Guard Oxy, viewing it as another way to address the lake’s water quality problems. But they weren’t the only agency that needed to approve its use. Before even a tablespoon of the algaecide could be applied to the lake, it also had to be cleared with the state’s Division of Water Resources in the Department of Environmental Quality. Leaders from that agency met to discuss it with the government scientists who’d initially assessed Mattamuskeet’s water issues in 2014. 

According to a January 18, 2023, letter from the Division of Water Resources to BlueGreen that was part of the trove of emails gathered by SELC, that group saw something the UNC researchers and administrators had apparently missed: Lake Guard Oxy’s product label, which plainly states, “This pesticide is toxic to birds.” 

SELC began investigating the situation later that month. In May 2024, the organization filed a federal lawsuit on behalf of Defenders of Wildlife and the North Carolina chapter of the Sierra Club to temporarily halt the U.S. Fish and Wildlife Service’s use of Lake Guard Oxy on Lake Mattamuskeet.

The court granted the temporary stay–but it ends April 1. Now SELC is asking the agency to complete a full environmental impact statement for the algaecide rather than the shorter and cursory environmental assessment it issued last March.

“It would be great if the legislature would be funding something that has broad support and is a long-term solution,” said Derb Carter, a senior adviser and attorney with SELC who has been watching the birds at Mattamuskeet for almost 50 years. “The way to address pollution is at the source. This product has a risk of significant impact, and it’s not a long-term solution.” 

Davis and others associated with the restoration plan declined to answer questions about the algaecide and the lawsuit. The Coastal Federation submitted a public comment objecting to its use, however, writing that “implementing proven, non-chemical methods for nutrient control and mitigation of algal blooms should be thoroughly investigated and included before experimental treatments” like Lake Guard Oxy. 

Some scientists worry Lake Guard Oxy imperils not just the birds of Lake Mattamuskeet but the whole ecosystem. “Hydrogen peroxide is an incredibly strong oxidizer, and it can kill most microscopic life—zooplankton, algae, things like that,” said Jim Sullivan, executive director of Florida Atlantic University’s Harbor Branch Oceanographic Institute. “And the entire food chain of the lake is dependent on algae.”

Sullivan, a phytoplankton scientist and member of Florida’s Blue-Green Algae Task Force, accompanied DeSantis on the 2019 trip to Israel. “I don’t think algaecides are the answer,” he said. “With a big natural ecosystem, you’re putting a Band-Aid on a problem. You should be looking at why the algae is there.” 

He added that Lake Guard Oxy is formulated as pellets that lie on top of the water before breaking down. The product works on surface-level algae but is far less powerful against types of blue-green algae that are suspended in the water—the kind that predominates in Mattamuskeet. 

BlueGreen declined to comment for this article, citing the lawsuit (though the company is not a named party in the suit). The judge is expected to issue an opinion by April 1. If he rules in the U.S. Fish and Wildlife Service’s favor, BlueGreen will begin using Lake Guard Oxy on Lake Mattamuskeet this spring. 

An Elusive Balance

Regardless of the decision, the local restoration plan is slowly marching forward. But it is addressing the Mattamuskeet of today, not the lake of the future. 

Climate change is manifesting powerfully on the low-lying peninsula. Few residents of this deeply conservative area use that term, but they can’t ignore it. They agree that the sound is clearly higher. Salt intrusion in the soil has become a major issue for local farmers. Ghost forests line the coast. “The land’s just more wet now,” said Cahoon, echoing other local farmers.  

All of that will likely worsen and continue to throw off the lake’s balance. Wetter soil will necessitate more pumping by farmers, potentially resulting in the lake’s nutrient and sediment levels rising again. And the lake itself won’t continue flowing the way it has in the past. Take the dredging project, for example. It might help for a while. But the Pamlico Sound is already higher than the lake almost half the time, and that’s only going to increase. 

The result is basic physics: No matter how clean the canals are, the lake simply isn’t going to flush well in the future. 

But the timeline is unclear. Those changes could be decades in the future, and Davis—whose house and yard are located on land that was once part of the lake bed centuries ago—still believes in trying to restore the ecosystem. She visits it several times a week, checking whether the tide gates are open and which birds are visiting.  

Ailing or not, Mattamuskeet is still beautiful, especially on clear days when its surface reflects the sky and the far edge is just a thin line on the horizon. 

For now, she says, “You do what you can.”

Amanda Abrams is a freelance journalist in Durham, N.C.