UNH Researcher: NH Commercial Oyster Farming Gains Ground

Monday, August 19, 2019

Ray Grizzle/Oyster farming

DURHAM, N.H.—New Hampshire’s commercial oyster farming industry is strong and growing, with substantial growth potential to increase production, according to a researcher with the New Hampshire Agricultural Experiment Station at the University of New Hampshire.

“The growth of oyster farming in the state is strong, and likely to continue for quite some time,” said Ray Grizzle, research professor of biological sciences. “Overall oyster production is only a small fraction, perhaps 10 percent, of what it could be. The total number of farms and their areal coverage is probably nearing maximum for the Little Bay area, but production is not,” Grizzle said.

According to new data released by the USDA in the 2017 Census of Agriculture, New Hampshire has 32 commercial mollusk operations in Strafford and Rockingham counties representing $419,000 in sales. Most of them are oyster farming. New Hampshire only had two licensed oyster farms when Grizzle began conducting research about 10 years ago. On average, it takes about three years to go from small “seed” oysters provided by hatcheries to market size, which creates a lag for oyster farmers beginning commercial production.

“Most farms are still small with respect to production, some with just the owner doing all or most of the work,” he said. “The ones that have been in existence for more than five years, however, have evolved substantially to include employees, improved farming methods, and marketing networks that involve wholesalers as well as directly selling to local chefs. New Hampshire oysters are regularly featured at local raw bars and are shipped to other states in the region and elsewhere.”

Grizzle sees several opportunities to grow the state’s oyster farming industry, which will require farmers, regulatory agencies and those involved in marketing to work together. He said average annual production per farm is still quite low when compared to the more mature industries in Massachusetts and Maine. Thus, most growth in the near-term likely will come from individual farmers increasing their production.

“There may also be opportunities for expanding from bottom gear such as the commonly used ‘racks-and-bags’ to surface gear or perhaps raft culture. This would allow farmers to move into deeper waters. Overall, the industry will hopefully evolve in a positive manner along with changes in farming methods, marketing opportunities, and regulatory management,” Grizzle said.

Grizzle’s oyster research began 20 years ago with efforts to restore wild oysters. That early work, in partnership with the NH Department of Environmental Services and the NH Fish and Game Department, was experimental and small-scale. While it still is experimental, it has expanded in scale, now with each project typically involving a few acres. Recently, the restoration effort expanded to involve more oyster farmers.

According to The Nature Conservancy in New Hampshire, the eastern oyster 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 more than 90 percent 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.

UNH and The Nature Conservancy, together with other partners, have successfully restored more than 18 acres of reef and 3.5 million oysters to the system since 2009. In recent years, the team has scaled-up efforts, with as much as five acres and 1 million oysters restored annually.

“The oyster is, in many, ways a remarkable species. What other creature in our estuaries filters the water, builds large reefs that provide habitat for many other species, supports recreational and commercial fisheries, is now grown on farms throughout its range, and tastes good?” Grizzle said. “Oyster farming is a rapidly growing industry in New Hampshire, and it is occurring in one of the state’s most treasured waterways: the Great Bay estuarine system.”

This material is based upon work supported by the NH Agricultural Experiment Station, through joint funding of the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 1013469, and the state of New Hampshire. This research also has been supported by USDA’s Natural Resources Conservation Service, U.S. Environmental Protection Agency, National Oceanic and Atmospheric Administration, NH Department of Environmental Services, NH Fish and Game Department, The Nature Conservancy, and the Piscataqua Region Estuaries Partnership.

Founded in 1887, the NH Agricultural Experiment Station at the UNH College of Life Sciences and Agriculture is UNH’s original research center and an elemental component of New Hampshire's land-grant university heritage and mission.

The University of New Hampshire inspires innovation and transforms lives in our state, nation and world. More than 16,000 students from all 50 states and 71 countries engage with an award-winning faculty in top-ranked programs in business, engineering, law, health and human services, liberal arts and the sciences across more than 200 programs of study. As one of the nation’s highest-performing research universities, UNH partners with NASA, NOAA, NSF and NIH, and receives more than $110 million in competitive external funding every year to further explore and define the frontiers of land, sea and space.


Working with existing and prospective farms as well as regulatory agencies, New Hampshire Agricultural Experiment Station researcher Ray Grizzle began conducting research to expand the state’s oyster farming industry about 10 years ago. According to new data released by the USDA in the 2017 Census of Agriculture, New Hampshire has 32 commercial mollusk operations representing $419,000 in sales.