At Ninigret Pond, on Rhode Island’s south coast, the state’s Coastal Resources Management Council and the U.S. Army Corps of Engineers are restoring vital saltwater eelgrass habitat.  The main problem:  Too much sand had ruined Ninigret Pond’s eelgrass habitat.

Fixing this area ensures the continued survival of the juvenile species that live there, such as bay scallops, cod, winter flounder, blue mussels, blue crabs and lobster, which all rely on eelgrass for food and shelter.

What makes this habitat special?

“It’s a really good juvenile nursery because big fish can’t get in there,” said Janet Freedman, “The small fish can hang out there.”  Freedman is the project coordinator of the South Coast Habitat Restoration Project, of which the Ninigret Pond efforts are an integral part.

“There used to be viable eelgrass in the pond. During the 1950s, jetties were inserted and the inlet widened,” Freedman said, “When this happened, the sedimentation rate within the pond created a tidal delta.”

Freedman clarified, “Sand would be deposited at every high tide onto the inlet where the salt water from the ocean comes in, and so you had all this shoaling that buried the eelgrass beds.”

Chris Hatfield, former project manager from the U.S. Army Corps of Engineers, confirmed this diagnosis, “In some places, there was so much sand that the shore was exposed.”

The restoration’s primary phase involved the removal of nearly 200,000 yards of sand from the flood shoal. “We dredged almost forty acres,” Hatfield said, “When sand moves into the pond and buries the habitat and then you dredge, the natural depth is restored.” Ninigret Pond’s natural depth of 3 to 4 feet was restored between the fall of 2004 and the spring of 2007.

Although the dredging of the flood shoal was major, it wasn’t the only dredging. “We dredged some sedimentation basins in the breach way,” Hatfield said. The breach way is the channel going from the pond to the ocean. Hatfield explains why this dredging was necessary. “The sedimentation basin’s purpose is to fill up with sand, and to catch it before it goes in the pond. That periodically has to be emptied and put back on the ocean side of the beach, the barrier beach.” According to Hatfield, this periodic “emptying” is a maintenance activity that the state of Rhode Island is responsible for. 

Another issue: How to keep the eelgrass thriving?

“The original thinking was that we would harvest eelgrass seeds from other live plants in the pond, and then plant them in order to jumpstart their growth,”  Hatfield said, “We did a two-acre test plot where we did harvest seeds and incubated them in the lab through a contract with University of Rhode Island’s Graduate School of Oceanography.”

Enter the unexpected. “When we planted the seeds in the spring we not only got fantastic growth, we found that restoring the depth of the pond allowed other areas (outside of the two-acre test plot) to naturally seed themselves,” Hatfield explained.

Funding for the Ninigret Pond eelgrass restoration came from federal grants procured from the office of U.S. Senator Jack Reed (D-RI) and from the Rhode Island legislature.  But more funding might be needed, as it’s not quite a done deal.

“Besides additional monitoring from the Army Corps of Engineers, we’re working with the Town of Charlestown and the state trying to get some money to actually do a hydraulic dredging again,” asserted Freedman, “It’s going to take an awful lot of maintenance to keep this sand from filling in again, and suffocating the eelgrass.”