The National Sea Grant Program funded a project to provide relief to aquaculture operations in New Hampshire due to COVID-19 impacts. Ten NH oyster farmers participated in oyster population and ecosystem service enhancement studies using up to 10,000 unmarketable (too large, misshapen) oysters sold to NHSG at market price. The purchased oysters were then moved by the farmers, to pre-selected non-producing areas of their farm license areas to create State permitted experimental oyster reefs. Funds supported the initial condition of the oysters (fall 2020) and ensuing assessments (spring & fall 2021) of ecosystem impacts in terms of recruiting young oysters and the growth and survival of the adult oysters were conducted by NHSG personnel, farmers and UNH researchers. Measurements of average shell growth (% increase), % mortality and recruitment of young oysters showed experimental oysters exhibited growth trends, mortality and evidence of recruitment that varied by site but were in ranges consistent with previous studies of farmed oyster beds in the experimental areas. Growth ranged from 4-46% (average = 19.8%), mortality ranged from 0-25% (average = 9.1%), and evidence of recruitment occurred at 9 of the 10 farms (Table 1) . The study suggests that construction of “restoration areas” on farm or other sites can sustain oysters in the short and long-term because natural recruitment is an important factor affecting restoration success.
Photographs of restoration sites, field observations, and data discussed above indicate that even in the first year at least two important ecosystem services were provided by oysters on the restoration areas: habitat provision and water filtration. Habitat provision for macroalgal communities was evident, dominated by Gracilaria and including Ulva and Ascophyllum that were mostly attached to the oysters. Animals were also observed, including mud crabs (xanthids ), green crabs, hermit crabs, ribbed mussels, blue mussels and hard clams. Thus, as expected, these small, constructed reefs provided important habitat for a wide diversity of organisms. The growth data was evidence of filter feeding associated water filtration of food and other suspended particles, which along with environmental condition data can be used to quantify bioextraction of nitrogen and other dimensions of estuarine health by farmed oysters and oysters in wild and restoration reefs.