Reef Restoration

Biology of the eastern oyster
Crassostrea virginica

  • Feed on particles (e.g., phytoplankton) suspended in water (filter or suspension feeders)
  • Reef-forming (=biogenic habitat, 3-D structure)
  • Reproduce as males in year 1, mostly females thereafter
  • Broadcast spawners (~2weeks as larvae in water)
  • Larvae settle to bottom (spat), permanent attachment
  • Grow about 2 to 3 cm per year
  • Major predators: crabs, snails, fish, humans
  • Ecosystem services: filter water; form habitat; produce recruits; stabilize sediments; prey item for other species

NH shellfish farmers are providing oysters for oyster reef restoration projects which provide ecosystem services.

Two projects have been established in NH to purchase and deploy farmed oysters “uglies” or surplus oysters that are not suitable for the market but have conservation value by providing ecosystem services (reproducing, filtering water, reef forming and providing habitat for fish and invertebrates.

The two funding agencies involved are:

  • The Nature Conservancy (TNC), SOAR (Supporting Oyster Aquaculture and Restoration) project
  • The Natural Resources Conservation Service (NRCS/USDA), EQIP (Environmental Quality Incentives Program) projects.

Since 2019, approximately 860,000 farmed oysters have been provided from oyster farmers (NH & ME) and deployed on to restoration sites near Nannie Island in Great Bay. Monitoring of these projects show good survival and recruitment.

SOAR – Supporting Oyster Aquaculture and Restoration

In 2019, through conversations with growers, The Nature Conservancy (TNC) started a pilot scale project to purchase and deploy 17,000 adults or surplus oysters that are not suitable for the market, but have conservation value of reproducing, filtering water, and providing habitat for fish. 

Our results from this pilot study yielded good survival rate, good growth, and recruitment (Laferriere & Group, 2020, Grizzle and Ward, 2021).  When the global pandemic hit in March of 2020 it effectively shuttered restaurants and closed the oyster half shell market.

This pilot scale study was the backbone for the National TNC SOAR (Supporting Oyster Aquaculture and Restoration) project that was a collaboration between TNC, PEW and NOAA and NRCS. SOAR was designed to assist oyster farmers impacted by COVID-19 and the resulting economic downturn by purchasing surplus oysters and placing them on nearby oyster restoration projects—a win-win for the shellfish industry and the environment. 

SOAR was implemented in 7 states; in NH we deployed 666,234 adult oysters onto two 1-acre sites on the restoration site at Nannie Island (see map), We  supplemented that with 8000 adults and 40,000 seed (funded by NRCS) in 2020-2021. Preliminary monitoring results show great results from the SOAR program (good survival and excellent recruitment).

NRCS – Natural Resources Conservation Service &
EQIP – Environmental Quality Incentives Program

The Natural Resources Conservation Service (NRCS/USDA) has provided Environmental Quality Incentives Program  (EQIP) funds to oyster farmers for oyster reef restoration (establish permitted areas, add hard substrate for larval settlement from natural reefs) since 2011 in NH.

A few farmers who receive NRCS funds will also purchase clam shell to be put on the estuarine bottom as a reef foundation, then seed with live oysters each year. In 2021 we (Ray Grizzle and Krystin Ward, University of New Hampshire/shellfish farmers) worked with 8 NH oyster farmers to deploy 125,285 “ugly”, large oysters on to a 7-acre restoration site adjacent to the sites used in the SOAR project (see map). NRCS has also made funds available (not just EQIP) for other restoration projects and monitoring of these projects in NH.

In the past few years, the overall aim is to enable the EQIP program to include the oyster growers in marine conservation by establishing a program with a long enough timeline (5-year time horizon) that growers can factor the production of restoration oysters into the business plans (seed, large excess oysters and smaller oysters (2+inches)) to seed permitted oyster reef restoration areas. This mechanism would ensure oyster farms could include the restoration model already in place in their individual business planning with enough time to order seed and grow product for an identified market.


For oyster/shellfish aquaculture and the environment:

For TNC SOAR program:

For oyster reef restoration and monitoring: