Elevation of Sachuest Point Marsh Being Raised to Stave Off Rising Seas

MIDDLETOWN, RI—Work is underway to strengthen and restore critical marsh habitat at the Sachuest Point National Wildlife Refuge as the coastal sanctuary for birds and fish is under increasing climate-based threats.

To do it, it’s a matter of spreading sand.

The U.S. Fish and Wildlife Service and The Nature Conservancy on Tuesday announced a $1.98 million cooperative agreement to begin restoration efforts and deploy a technique known as “thin-layer deposition” to replenish the estuary and actually raise its elevation by strategically spreading sand.

The wildlife refuge in Middletown occupies 242-acres of real estate on a a majestic foot of land that kicks out into the mouth of Narragansett bay, providing the most prime of Rhode Island’s real estate to nature.

The project will concentrate on 11 acres of marsh to raise the elevation through the TLD process, which essentially makes up for what civilization has taken from the marsh: the natural cycle of sand being deposited into the estuary by rivers that have been dammed and drained by Aquidneck Island’s population over hundreds of years.

Unable to keep up with the rising sea, which has measurably increased in just the past few decades, coastal saltmarshes are getting battered and inundated, and Sachuest Point, the section of the marsh behind Third Beach, is too low to drain properly at low tide, leaving it particularly vulnerable to heavy flooding during storm surges.

These prolonged periods of inundation impede the growth of high-marsh vegetation and impact healthy fish and wildlife habitats, said Jennifer White, a service wildlife biologist and coordinator for the restoration project, which will be followed with a similar restoration effort in the Narrow River at the John H. Chafee National Wildlife Refuge in Narragansett.

White said storm surge and wave erosion, combined with the lack of replenishment from estuaries whose rivers have been dammed or choked off by centuries of development, have left once-hardy tidal marsh ecosystems at a point where saltmarsh elevations cannot keep up with sea-level rise.

In balanced ecosystems, the freshly deposited sand gives marsh vegetation new areas to colonize and spread, but Third Beach is cut off by development on one end and the beach on the other.

Raising the elevation will “improve growth of salt marsh plants and reduce overall deterioration of the marsh, benefiting species such as the federally listed Saltmarsh Sparrow, which relies on high marsh as nesting habitat,” White said. “Marshes also play a key role in cleaning and filtering water, and act as a buffer to absorb wind, waves and flood water -- a key factor in storm protection.”

The project is one of 70 projects managed by the service through $167 in federal funding for Hurricane Sandy recovery. The project cost is pegged at $644,000, according to a news release, and the fund were awarded through the cooperative agreement to to The Nature Conservancy, which is working all along Rhode Island’s south coast to promote shoreline resiliency efforts, including salt marsh restoration and oyster reef construction.

It is also part of a larger $4.1 million Sandy-funded effort to restore coastal areas from Rhode Island to Southern Maine.

Lead photo by Tom Mooney, The Nature Conservancy. Used with permission.