CASE STUDY #21
Shellfish Reefs United States oyster restoration case study – enhancing fisheries
Shellfish reefs – physical habitats built by the accumulation of masses of mollusk shells – may be the world’s most threatened marine habitats. Once widespread in estuaries and lagoons, a con- servative estimate suggests that 85% have been lost to overfishing, poor river basin management and pollution1 (Beck et al., 2009).
The value of shellfish for food has been recognized for millennia, however it is only in recent decades, as the resources have be- come scarce, that other services provided by shellfish reefs have been realized. Through their complex structure, shellfish reefs greatly enhance commercially important fish and crab stocks. In sufficient quantities they can measurably reduce nitrates and tur- bidity in coastal waters. In so doing they also allow growth and
recovery of other important habitats such as seagrasses. In some locations the large physical structures of shellfish reefs even protect coasts from wave action. Such services are of growing social, eco- nomic and political relevance as pollution and sea level rise are of increasing concern world-wide.
In the US, recognition of these valuable services has led to a surge in interest in the restoration of oyster reefs nation-wide. The fed- eral National Oceanic and Atmospheric Administration, through numerous partnerships, has supported over 128 oyster and shell bottom restoration projects in twenty states since 1998. Many other restoration efforts have been undertaken by state agencies, NGOs and community groups.
Virginia Coast restoration sites
Communities on the east Virginia coast have a long history of oyster harvesting, however the eastern oyster Crassostrea vir- ginica finally became commercially extinct in the region in the early 1990’s. In 2006 a public-private community partnership was formed between the Virginia Marine Resources Commis- sion and The Nature Conservancy which, in collaboration with local businesses and community volunteers, made significant steps to restoring oyster reefs in Smith Island Bay. Local con- tractors dredged over 1188 tonnes of fossil shell, depositing them in shallow areas to form two ~0.8 ha reefs. The rapid colonization and growth of new oysters on the reefs has cata- lyzed further restoration projects. To date the larger Seaside Bays Restoration Project on the Virginia Coast, of which Smith Island Bay is a part, has successfully restored 1.7ha of intertidal oyster reef, with a further 5.5ha planned. An estimated 47 jobs will be maintained or created by oyster restoration work as a result of this project.
Virginia Coast restoration sites are continually monitored, and have been showing significant recruitment since their construc- tion. Research is being undertaken to determine the filtration
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