Reef restoration highlights New Hampshire’s Oyster Week

University leads work to restore native oyster reefs in the Great Bay Estuary

The University of New Hampshire’s College of Life Sciences and Agriculture (COLSA) said native oyster reefs in the state’s expansive Great Bay Estuary now cover about 80 acres, thanks to restoration efforts over the past two decades.

In a news release celebrating “Oyster Week” from Sept. 17–23, the school highlighted the work of COLSA researchers and oyster growers, which includes depositing oyster shells that have been stored and dried for at least six months. UNH has also partnered with organizations like the USDA’s Natural Resources Conservation Service and The Nature Conservancy.

A reef restoration project near Nannie Island, just off the Great Bay National Wildlife Refuge in Newington, N.H., has been ongoing since the 15-acre reef was closed to shellfish harvesting in 2021.

“For the Nannie Island reef, we’re beginning to see more spat settling on the living oysters, indicating that they’re growing the reef naturally,” said Krystin Ward, a laboratory research supervisor at COLSA and owner of Choice Oysters, a farm she started in 2011. “If this trend continues, we’re hopeful that the oyster population may rebound and some of this area will be open to recreational harvest again.”

The bay’s oyster reefs covered as many as 1,000 acres in the 1970s and gradually dwindled, but new oyster farms in Great Bay started over the past decade have aided restoration efforts and increased biodiversity, said Ward.

“If you’re putting shell on the bottom, that’s creating a natural reef and building habitat for fish and other invertebrates — so you’ll see a lot more biodiversity in a reef structure than you would on a mudflat,” she said.

Ailing waterways hail the oyster’s return

Researchers are already seeing that difference — both from large-scale deposits like the one at the Nannie Island reef and from smaller deployments of farmed oysters from farms in Great Bay Estuary’s Little Bay. Using underwater cameras, the researchers are monitoring both the reef growth and the addition of new spat and juvenile oysters. The cameras allow them to know when an area has a solid substrate in place and when the oysters in the area begin reproducing and growing the reef naturally by attaching and settling upon one another.

@GSA_Advocate