The Gulf of Maine Times: Vol. 7 Num. 3 : How one culvert can create a sea change

Nova Scotia’s first salt marsh restoration project gets cross-border support

Tony Bowron with student interns at Cheverie Creek marsh in Nova Scotia. Bowron is leading a baseline study of the marsh in hopes of restoring tidal flow. If successful, the project will become the first community-based salt marsh restoration in the province.

Photo: Andi Rierden

Tony Bowron is standing on the seaward side of Route 215 over Cheverie Creek peering into a hollow opening called a scouring pool. Beyond us, vast mudflats, the color of sandstone, fan out to the cliffs of Cape Blomidon in an area of Minas Basin known as the Southern Bight. In a few hours, the tide will charge up a river channel, get detained in the pool, then drain slowly landward through a small wooden culvert set deep in the road bed. As the pool rises, Bowron explains, the tidal pressure creates a whirlpool so strong you can hear it swoosh. Throw a stick into the gyrating mass and it spirals to the center then vanishes down a black hole.

Long before road crews filled the opening to this tidal river with rock and inserted a culvert there stood a bridge, which allowed waters to flow unimpeded. Back then, the 30- mile long waterway served as an important habitat for the Atlantic salmon, shad, gaspereau and other sea run fish and wildlife. No longer. Like many streams and rivers along this salty corridor in the Upper Bay of Fundy, Cheverie Creek was “cut out of the marine ecosystem,” Bowron says.

Around half of the rivers in the Bay contain tidal barriers, he adds, while some 80 percent of its salt marshes have been lost or degraded, mostly from the diking of agricultural lands by Acadian farmers more than three centuries ago.

“There’s an entrenched 350-year-old mindset here that says, ‘Hold back the tides,’” Bowron says. “So chances are high that anything swimming up the Bay of Fundy will hit a barrier and stop there.”

For the past four years, Bowron has dedicated his life to educating residents and government agencies in Nova Scotia about the importance salt marshes and free-flowing tidal rivers to the health of the province’s watersheds. At Cheverie Creek, he and a team of student interns are collecting data on the site with the goal of restoring it to a working salt marsh and using it as a model. If carried out, Cheverie Creek will become the first community-based salt marsh restoration in Nova Scotia.

The major work will entail removing the small culvert beneath the roadway and replacing it with a larger opening, an undertaking that will need the support of the provincial department of transportation.

Opening the Cheverie will allow fish to swim upstream, attract birds, plants and other salt marsh inhabitants, and could serve as an interpretive site for the region’s rich natural and cultural history, Bowron says, adding, “There are tremendous ecological, economic and social benefits to doing this. Salt marsh restoration is an activity at which everyone wins.”

Bowron’s project has garnered the financial and technical support of a long list of government and non-government agencies including the Fund for Environmental Cooperation, Fisheries and Oceans Canada and Wildlife Habitat Canada. It is also the first habitat restoration project in Canada to receive funding from the Gulf of Maine Council through a U.S. National Marine Fisheries Service (NMFS) partnership.

Eric Hutchins, a fisheries biologist for the NMFS’s restoration program visited the site in May to lend technical support. Habitat restoration experts from Massachusetts, Maine, New Brunswick and Nova Scotia, along with several local residents joined him. The Cheverie Creek project, he says, gives habitat restoration proponents on both sides of the border the chance to work cooperatively and share information to better the Gulf of Maine ecosystem.

“Many of the fish, marine mammals and bird populations in the Gulf of Maine pass between the two countries’ waters throughout the year or provide forage for the species that do,” Hutchins says. “The ecological food chain in this large marine ecosystem does not recognize political boundaries.”

Walter Regan, a director of the Nova Scotia Salmon Association and president of the Sackville River Association, which has initiated and completed dozens of stream restoration projects in Nova Scotia, is among the project’s most passionate supporters. Cheverie Creek was once an important salmon run, he says, but like the other rivers in the inner Bay, its populations have plummeted.

“One project like this opens up a whole river system—for the salmon, shad, gaspereau and other fish,” Regan says. He adds that returning the Cheverie back to its natural flow, “would just explode the productivity of that watershed. We desperately need this project as a good working example of what we can do for the hundreds and hundreds of other brooks that are blocked throughout the province.”

Bowron too is hopeful that the Cheverie project will begin a new era in the way marshes are perceived in this part of the Gulf of Maine. Raised near the coalfields of Pictou County, he started out as a marine biologist, studying deep-sea corals. But a proclivity to seasickness and an attraction to the field of restoration ecology, which aims to bring entire ecosystems to working health, impelled him to change direction. Restoration ecologists look to rehabilitate ruined ecosystems such as strip-mined land and watersheds wrecked by logging–challenges requiring help from governments and landowners.

Bowron was drawn to the field after seeing how mining pits in his home region were often “restored” to baseball fields or meadows. “It got me thinking about the nature of damaged ecosystems and what it actually means to repair them,” he says.

After learning about the successes of salt marsh restoration work in New England, Bowron redirected his research to the Minas Basin and began stalking fallow dikelands for sites with impaired salt marshes. “We kept coming up against walls,” he says. “There were local people saying ‘here’s this dike, nobody is doing anything with it, but you’ll have to buy it.’ Then even if we were to buy it, there was no way of knowing if the agriculture department would let us pull the dike down.”

At the same time, Bowron says, “I was looking for a way to get the expertise that the folks in the states had, and also wanted to get communities and government people in the Bay of Fundy to start thinking about restoration.”

In 2000 he and his colleagues organized a salt marsh restoration workshop, inviting experts throughout the Gulf of Maine like Michelle Dionne, senior researcher at the Wells National Estuarine Research Reserve and Alan Ammann, of the U.S. Department of Agriculture and a lead engineer for the massive Little River salt marsh restoration in Hampton, New Hampshire.

“The big message from that workshop is that you have to start with smaller projects and get some win-win situations around tidal [road] crossings,” Bowron says. “From there, use those as training grounds to determine how the ecology will respond to restoration efforts and what to do and what not do. If you have some examples of success, you can use them as education and promotion tools, in hopes of changing attitudes.”

After settling on Cheverie Creek, Bowron and his team devised an outreach plan to engage local landowners, educators and residents by explaining why the protection and restoration of tidal rivers and salt marshes makes sense, and what the team aims to accomplish. Unless he gets the community’s blessing, Bowron says, he will not suggest any physical alterations to the site.

Last spring about 150 school children toured the Cheverie Creek with Bowron and his colleagues as part of Ocean Day activities. Hazel Dill, a lifelong resident of the area and principle of the Dr. Arthur Hines Elementary School in nearby Summerville, says the community is supportive of the project. As for younger residents, she adds, a salt marsh restoration “holds all sorts of potential for learning,” from using the site for online education about coastal habitats to “simply, making children aware of their backyard and encouraging them to love and appreciate it.”

Cross over Route 215 to the landward side of Cheverie Creek and it is clear why Bowron chose the site. Here, in the deep green of summer, the watery grassland meanders into a distant stand of hardwoods, the flatness broken by small islands and rolling farmlands. Where we are standing, about 50 yards from the road, saltmeadow cord grass, Spartina patens, undulates in a wavy mat, with natural cowlicks. The more salt tolerant, Spartina alterniflora, or smooth cord grass, grows along the tidal creek with peated blocks of the grass strewed throughout the higher marsh. Bowron and his team of interns pace around looking for signs of salt marsh life. “Periwinkles!” calls out one of the students. Bowron cradles a clump of sea lavender and points out edible marsh grasses. They have recorded mummichogs and American eel, greater and lesser yellowlegs, piping plovers and migratory waterfowl. From all indications so far, the marshland is healthy, Bowron says, but the salt marsh habitat upstream has been reduced due to diminished flow, and salt pannes and ponds on the marsh are not being recharged as frequently. They hope to complete bird and mosquito surveys by early fall.

Ray Konisky, a research associate at the Wells National Estuarine Research Reserve in Maine, has offered to take water elevation data from the site to determine a culvert size that will restore adequate flow. Using a tidal hydrology model to mimic and calibrate tidal fluctuations, Konisky can predict the highest elevation of water on the marsh, then use engineering calculations to fine tune the model “to get the best ecological response,” he says. The dimensions can be adjusted to ensure tidal water does not flood abutting farmlands. Konisky’s recommendations will go to Nova Scotia’s Department of Transportation and Public Works.

Dave Kelly, an engineer with DOTPW has already visited the site and reviewed Bowron’s proposal to remove the Cheverie Creek tidal barrier. He won’t be able to okay a culvert replacement until costs are determined, he says, but adds that, overall, “as more people are pointing these [barriers] out to us, we do the best we can to be sensitive to those things before we proceed” with road construction.

That’s music to Walter Regan’s ears. For years he has espoused the ecological and financial bonuses of removing tidal barriers. He says a recent government study in Nova Scotia determined that “for every dollar you spend on restoration, $29 go back to the local economy.”

Regan adds, “So should you open up a river that’s been blocked 50 or 60 years to allow endangered salmon to come in? To bring the ospreys, otters and other wildlife back? Sounds to me like a no-brainer.”