The State Wants To Turn Cranberry Bogs Into Wetlands. It's Gritty Work

Alex Hackman picks up a shovel and digs in to what used to be a cranberry bog. Down through an inch or two of tough green cranberry vines, down into the sandy soil beneath. Down, down, down.

"It's tough going," says Hackman, stopping to catch his breath. "This is, you know, a century of effort by the prior farmers to have this beautiful dense layer of cranberry vines."

Hackman is a restoration ecologist with the Massachusetts Division of Ecological Restoration. He runs a state program dedicated to turning cranberry bogs back into wetlands.

The state program partners with the UDSA's Wetland Reserve Easement Program, which has been around for decades. But lately there's been an uptick of interest from local farmers, says Brian Wick, executive director of the Cape Cod Cranberry Growers Association. That's because the cranberry business has been tough in recent years, with prices driven down by competition from Canada and Wisconsin, and the trade war with China. One of the biggest challenges the bog-to-wetland program faces, says Wick, is finding enough money to meet the demand.

"As the price of cranberries has been down, a lot of growers have been turning to that [program] as a possibility," Wick says. "This is a good option for the growers, because short of that it’s selling off house lots that surround the bogs. So you’re left with very limited options of what you can do with that property."

It’s a potential win-win situation. Farmers get much-needed cash. The state gets a wetland, which can absorb water and prevent flooding — an increasing risk with heavier rainstorms and rising sea levels linked to climate change. Wetlands also absorb pollutants, store carbon, and provide homes for fish and wildlife.

But even though many cranberry bogs were built in low-lying, swampy areas, turning a bog back to a wetland can be harder than you might think. That's because cranberry bogs are surprisingly dry. And that's why Hackman is digging a hole in a retired bog. He says that farmers add a layer of sand to their bogs every few years, which helps cranberries grow. After a 100 years, that leaves a lot of sand.

He pries out a block of soil and holds it up. It looks like a layer cake of light sand and darker dirt. He shakes the soil and sand showers out.

"The thing that’s different about this soil than the native wetland soil is that this will not hold water well," says Hackman. "This is sand, and water will move through this and go underground. Wetlands need to hold water to be a wetland."

There's another reason the bogs are dry, says Hackman: the "plumbing" that farmers install on the surface. Cranberry farmers use ditches and dams to steer water where they need it — irrigating crops for the growing season, or flooding them for harvest. The ditches are useful for farming, but — like the sand — disrupt the wetland's natural ability to hold water.

About a foot below the sandy top layers, Hackman hits rich, black peat — the original wetland. Part of getting back to that wetland involves removing, or at least "roughing up" those top feet of soil. The other part is creating more natural waterways on the surface — you “rip out the plumbing,” as Hackman says, and wait for the wetland to return.

The amount of work required, he explains, depends a lot on the cranberry bog itself.

"Some of these sites require very little intervention or even none to become wetlands again," Hackman says. For instance, low-lying bogs with a lot of peat underneath probably need less help; others may need more.

"One of our challenges is determining where we need to do active intervention to restore wetlands," he said, "and where we can just walk away and let these lands self-heal."

Nature's Filter 

There's another pressing question: How much can these restored wetlands improve water quality? This is an important question, given water pollution problems in southeastern Massachusetts and Cape Cod. Many households in these areas use septic systems, which leach nitrogen into groundwater. The excess nutrients pollute ponds and estuaries, causing algae blooms that harm native eel grass, fish and crabs.

The groundwater pollution is so bad in Falmouth, for example, that it affects almost every estuary in town. The town considered installing a municipal sewer system, but balked at the $600 million price tag. Town officials and residents are hoping that restored wetlands can be part of the solution.

Ecologist Chris Neill shares their hope. A senior scientist at the Woods Hole Research Center, he's studying a recently restored wetland on the Coonamessett River, which feeds into Falmouth's Great Pond. By measuring how much nitrogen the wetland absorbs before and after restoration, he hopes to quantify its impact.

"And then hopefully the town could use that removal and calculate that into their overall strategy," Neill says. "So maybe by building 30 or 40 acres of restored wetlands, we can build less sewers and run pipes to fewer houses, and get the same nitrogen removal. That would save the town lots and lots of money — into the millions and even tens of millions of dollars."

Restoring a bog can be pricey. The state's first project, completed in 2010, converted a Plymouth cranberry bog into 40 acres of wetlands at the Eel River Headwaters Reserve. The project took about a year, and included some roadwork, removing a dam, roughing up the surface soil, and planting 20,000 Atlantic white cedars — a tree native to New England swamps. In total, the project cost about $2 million.

"That’s well worth it," Hackman says. "You know, these lands provide important services, like water purification, water storage, fish and wildlife habitat. And so why wouldn’t we pay for that?"

Help For Farmers

The cost also includes payments to farmers for their land. The going rate for the program is $13,600 an acre, which sounds pretty good to cranberry farmer Jeff Kapell.

"We’re kind of in a bad phase right now where there’s a very low price for the fruit, and so people are trying to hang on in any way they can," says Kapell, who has been growing cranberries in Plymouth for 40 years.

Kapell briefly considered selling one of his bogs to a solar farm. But he’s decided to go with the wetland option.

"I would feel very good about being able to put this into conservancy," he says. "All of the land around us is protected forever, and I think that’s what this parcel should be."

Kapell plans to retire the bog next year and reinvest the money into the rest of his farm. He'll keep growing cranberries on the other bogs he owns for as long as he can.