SALEM — About 15,000 seagrass pods are being planted along Collins Cove, with the hope that in the decades ahead, a literal hill will grow as well to help protect the area from rising sea levels.

The “living shoreline” being planted by volunteers this week isn’t a totally new idea, but it’s new to the region and being watched throughout New England after four years of planning and permitting, and $439,120 in state and local cash to power the effort.

The actual volunteer-led gardening, so to speak, began Monday morning and will cover 0.75 acres of coir roll-blanketed land, a stretch of earth 800 feet wide, once it wraps up at the end of this week.

But don’t let the earlier word choice fool you. This isn’t a gardening project, nor is it an annual tossing of grass seed to beef up a front yard. What’s happening along the Cove is a horticultural intervention of sorts.

“We took the gravel flat that was protected by this rock fill and found salt marsh plants were trying to grow here but kept getting eroded,” said Barbara Warren, executive director of Salem Sound Coastwatch, on Monday morning. “So it’s the perfect place to try this living shoreline. We’re planting the lower marsh grasses, cordgrass, and that’s our goal — to get 3,280 plants in today.”

Project will plant barrier

Construction kicked off in May with the shutting down of the rocky area immediately beyond Collins Cove’s perimeter bike path along Webb Street. Since then, biodegradable coir roll and a precise network of twine and wooden stakes — also all biodegradable — have been set up to guide volunteers through the planting of the seagrass this week.

“We have this blanket here because we don’t want the tide to come in, or sand to come in and wash away,” Warren said. “The fence will be up all summer and maybe into the fall. The plan is to take it down in the winter and, seeing how well the plants establish, (we’ll see) if it needs to go up again next year.”

There are several partners invested in the work. $326,445 in grants over three years from the state’s Office of Coastal Zone Management joined 25 percent matches from the city worth $112,675. Salem Sound Coastwatch led the project, and bodies are coming in from the Massachusetts Bay’s National Estuary Program, eco-contractor SumCo and more. Webb Street resident and past Historical Commission chairwoman Jessica Herbert is even chipping in water from her tap to help provide irrigation so the young plantings don’t dry up in their earliest days.

As time goes on, twice-daily high tides will wash over the planting area, infusing the seagrass bed with vital salt water, wildlife and more, according to Warren. Small fish will swim among the grass, laying eggs and feeding on amphipods. Horseshoe crabs already known to live in the Cove will have a new place as well.

But as that plays out, the living shoreline will literally grow. Each tide will deposit sand, causing the seagrass to need to reach a little taller and grow a little harder to get sunlight and develop stronger roots. Dead grass and sea life will provide the key biomass to help strengthen the sandy soil as well.

So with each passing year, the seagrass bed will grow in height alongside the rising ocean level.

“The salt marsh is going to keep growing, accreting, rising, as sea levels rise,” Warren said. “Then, it’s a living shoreline. The salt marsh is working to raise itself so it slows down that flooding.”

And that is huge, according to Lisa Engler, director of Coastal Zone Management.

“Coastal communities like Salem face ongoing and growing challenges from climate change as they work to safeguard residents and businesses, and protect developed and natural areas from increasing storm severity and sea level rise impacts,” Engler said. “The Baker-Polito Administration and the Office of Coastal Zone Management is proud to partner with the city of Salem, and Salem Sound Coastwatch, and will continue to work with communities and stakeholders to mitigate and adapt to climate change impacts in an effort to build a more resilient Commonwealth.”

Volunteers come out, but more are needed

Peter Phippen, a coastal coordinator with the Massachusetts Bay’s National Estuary Program, called the project “one of the best and cheapest ways to get salt marsh re-established, especially in urban environments.” He was one of a dozen or so volunteers working on the project on Monday.

“I haven’t done a salt marsh soup to nuts in a while, so I figured I’d come back, help out and do it,” Phippen said. “These are so valuable for the neighborhood, but they also serve a purpose” with rising sea levels.

Eric Roberts, a coastal resiliency specialist with The Nature Conservancy, said he is frequently involved in the recent trend of projects like the Collins Cove restoration.

“In all of New England, this type of approach for shoreline stabilization is a kind of new approach,” Roberts said. “They’ve been seen to show very useful outcomes in stabilizing the shorelines. We anticipate the same here.”

On Tuesday and Wednesday, dozens of new volunteers are expected to flood the project area. That includes Shetland Park-based Excelitas Technology, which is holding a service day Tuesday and paying employees to work on the project, according to Warren.

But one day is looking a little light for hands getting in the dirt: Thursday, by which time Coastwatch hopes to be near the end of the project after doing about a tenth of it on Monday, Warren said.

Volunteers are appreciated for Thursday specifically, she said, and they are encouraged to come with only a pair of gloves beginning at 10:30 a.m., two hours after high tide. Long pants are necessary due to the coarse nature of the coir roll bed, and kneeling pads are also encouraged but not required.

Contact Salem reporter Dustin Luca at 978-338-2523 or DLuca@salemnews.com. Follow him on Facebook at facebook.com/dustinluca or on Twitter @DustinLucaSN.