Solution Info Hide
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Problem
Bivalve shellfish have historically been a prominent component of benthic, or bottom dwelling, communities of temperate and subtropical estuaries and coastal baysBivalves also have been and continue to be an important food source for people throughout the world, serving as both as a delicacy and a staple. In coastal communities throughout the U.S., shellfish are cultural icons, reflecting traditions and a way of life dating back generations. It is not surprising therefore that until very recently resource management agencies have focused almost exclusively on maximizing short-term returns from commercial and recreational bivalve harvest.
Once considered nearly inexhaustible, many shellfish populations around the world have declined precipitously – some to commercial extinction - over the past two hundred years. These declines are due in large part to over-exploitation as well as from the related overall decline in the condition of estuaries. In recent decades the translocation of shellfish parasites and diseases between coastal areas has contributed to further losses and has exacerbated the effect of habitat loss.
Action
This guide was written to help restoration practitioners design and monitor shellfish restoration projects that restore not only the populations of target shellfish species – primarily clams, oysters, scallops – but also the ‘ecosystem services’ associated with healthy populations of these organisms. As a primer for conservationists, resource managers and others interested in understanding basic approaches to the design and implementation of shellfish restoration projects, this publication provides advice on:
1. Making the case for shellfish restoration
2. Identifying candidate species and an appropriate restoration strategy (or strategies)
3. Choosing sites for restoration projects
4. Monitoring project outcomes
5. Creating effective partnerships for restoration projects
Results
There are three case studies included in the guide:
Hard clam restoration in Great South Bay, New York
Private ownership provides a platform for ecosystem-based conservation, restoration and partnership
Great South Bay, a shallow tidal lagoon inside Long Island’s south shore, was once known as the “clam factory”. In the 1970s, fishermen pulled more than 700,000 bushels of wild hard clams (Mercenaria mercenaria) from the sandy bottom of the Bay, and supplied more than 50 percent of the annual catch in the U.S. However, the fishery was not sustainable and as clam populations declined in the late 20th century, the harvest dwindled to just 1 percent of the peak level seen in the 1970s. In addition to local economic losses, profound changes to the ecosystem have become apparent as well. Without enough clams to filter the bay’s waters, brown tides caused by microscopic algae became prevalent. The blooms killed additional shellfish and prevented sunlight from reaching underwater grasses that provide a refuge for young fish, crabs and other organisms.
Since 2002, The Nature Conservancy has acquired 13,000 acres of submerged lands in Great South Bay from the Bluepoints Oyster Company, representing about 20 percent of the bottom of the Bay. The Conservancy’s Conservation by Design planning process has guided the formation of the Bluepoints Bottomlands Council, a group of stakeholders, local state and federal agencies and scientists, that is committed to creating and implementing a plan “to restore Great South Bay to a thriving, healthy, naturally productive, self-sustaining estuary that supports native shellfish, seagrass, and other essential ecosystem components.”
Eastern oyster restoration in Pamlico Sound, North Carolina
Pamlico Sound oyster reef projects demonstrate strategies for large scale restoration
Like so many coastal embayments from Nova Scotia to the Gulf of Mexico, the Sounds behind North Carolina’s Outer Banks once supported tremendous populations of the eastern oyster, Crassostrea virginica. Extensive areas of
oyster reef habitat were formed by these populations and supported diverse assemblages of fish, crustaceans and other marine life. Tragically, the oyster population and extensive oyster reef structure in North Carolina has declined to only a small fraction of what it once was, and with it the fisheries that shaped coastal communities until well into the 20th century.
In 2001 The Nature Conservancy, in partnership with the NOAA Community-based Restoration Program and the NC Division of Marine Fisheries, began working to develop and refine new approaches for restoring the eastern oyster (Crassostrea virginica) to Sounds of coastal North Carolina
Native oyster restoration in Puget Sound, Washington
A systematic approach leads to development of restoration strategy
At one time, Puget Sound was home to large populations of the Olympia oyster, Ostreola chonchaphila, the only oyster native to the region. Overharvest and pollution led to dramatic declines in Olympia oyster populations between the mid-1800s to the early-1900s, to the point where the commercial shellfish industry now depends on non-native oysters introduced to the region in the early 20th century.
With support from the NOAA Community-based Restoration Program and other funders The Puget Sound Restoration Fund (PSRF) and Washington Department of Fish and Wildlife (WDFW) set out in 2004 to revitalize the native Olympia oyster on a site in Liberty Bay, a small embayment in Puget Sound that once had a robust native oyster population. A systematic approach has been used to determine the best strategies to pursue for restoration.
Here is a list of related shellfish restoration projects:
