New Hampshire

Oyster Restoration

Improving the health of New Hampshire's Great Bay Estuary one oyster at a time.

Blue-gloved hands holding oyster shells.
Oyster Spat at Jackson Estuarine Laboratory in Durham. © Jennifer Emerling

The eastern oyster (Crassostrea virginica) has historically played a vital role in the ecology of Great Bay Estuary. As many as 1,000 acres of live oyster reef may have covered the estuary in 1970, but over 90% of oysters were lost due to pollution, harvest, and disease. Without oysters, Great Bay Estuary is lacking the natural filtration capacity to maintain healthy eelgrass beds and fish nurseries as nitrogen and siltation increase. Now with your help, the oysters are making a big comeback.

Two women lean over a mesh cage full of oysters with water in the background.
Oyster Cage Inspection New Hampshire Marine Director Dr. Alix Laferriere (right) inspects oysters pulled from floating oyster rafts in Durham, NH. © Jennifer Emerling

The Nature Conservancy and The University of New Hampshire, together with other partners, are teaming up to rebuild degraded oyster reef habitat in the Piscataqua Region Estuary of New Hampshire and Maine. Thanks to support from dedicated members like you, the program has successfully restored more than 28 acres of reef and 3.5M oysters to the system since 2009. Oysters are an ecological linchpin of the estuary, providing essential fish habitat and water quality regulation services. In recent years the team has scaled-up efforts, with as much as five acres and 1 million oysters restored annually.

A person shoveling bushels of oysters.
New Hampshire, USA Bay Point Oyster Company harvesting oysters on a boat in Little Bay in Durham, New Hampshire. © Jerry and Marcy Monkman/EcoPhotography

Our approach is rooted in science: our restoration strategy includes a review of past restoration efforts  in the estuary and the identification of new sites. We’ll restore oyster reefs, monitor their health over time, and assess these efforts to ensure we’re taking the smartest possible actions together with our partners and communities to improve Great Bay.

From the volunteer oyster conservationists who raise young spat in cages off their docks to the scientists who reconstruct historic reef sites for the juvenile oysters to call home, our approach literally takes a village.

Supporting Oyster Farmers in Seven States (3:39) TNC is working with partners to purchase more than 5 million surplus farmed oysters—unable to go to market because of the restaurant closures caused by the COVID-19 pandemic—and using them in nearby oyster restoration projects, including right here in New Hampshire!

Oyster Program Downloads

  • Cover of Restoration By Design full report.

    Restoration By Design: The Full Report


    Want to know exactly what goes into restoring oysters in the Great Bay Estuary and its tributaries? Here's the plan and how it works.

  • Restoration By Design: The Overview


    Want the Cliff's Notes version? Get to know how and why we restore oysters where we do with this easily digestible overview.

  • Oyster Conservation fact sheet.


    Curious about the process of being an Oyster Conservationist? Take a peek at this all-in-one fact sheet detailing the volunteer "life cycle."

  • Oyster Restoration timeline.


    How are oysters restored to the Great Bay Estuary? It literally takes a village. Here's how it all comes together.

  • 2023 Oyster Conservationist Program Report


    The American oyster is definitely the most valuable creature in the Great Bay Estuary. But due to pollution, harvest and disease we have lost over 90% of our reefs. Our volunteers are helping to turn the tide. Here's how it's going.


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