The report, Non-native Oysters in the Chesapeake Bay was produced by The National Academies at the request of several federal and state agencies. It discusses the proposed plan to introduce reproductive C. ariakensis oysters into the Chesapeake Bay in terms of the current regulatory framework and potential risks and benefits to the ecosystem and economy of the Bay. It also provides a solid background on oyster biology and the history and current status of the oyster fishery in the Chesapeake Bay, as well as case studies of oyster introductions from other areas.

The report assesses whether or not existing research on non-native oysters could support risk assessments for the three possible management options: 1) no introduction, 2) open-water aquaculture of triploid oysters, and 3) introduction of reproductive diploid oysters. The report also recommends research priorities to fill in existing gaps in this knowledge.

A four page fact sheet summarizing this report is available at http://www.nap.edu/html/oysterbrief/oysterbrief.pdf

The NRC identified five myths surrounding the proposed introduction of non-native oysters:

• Myth I:  Declines in the oyster fishery and water quality of the Chesapeake Bay can be quickly reversed.
• Myth II:  Oyster restoration, whether native or non-native, will dramatically improve water quality in the Chesapeake Bay
• Myth III:  Restoration of native oyster populations has been tried and will not work.
• Myth IV:  Crassostrea ariakensis will rapidly populate the Bay, increasing oyster landings and improving water quality.
• Myth V:  Aquaculture of triploid Crassostrea ariakensis will solve the economic problems of a devastated fishery and restore the ecological services once provided by the native oyster.

The NRC found Myth III particularly relevant to the question of native oyster restoration. New approaches for native oyster restoration are showing promise, including:

• Employing watermen to clean areas of diseased oysters, followed by bottom rehabilitation and stocking with disease-free oysters.
• The use of disease-tolerant strains—these strains are the fruit of more than a decade of research, and should be more widely utilized both in government restoration efforts and by private growers.
• Halting the long-standing practice of spreading disease by relaying diseased oysters to lower-salinity waters.
• Encouraging the development of private aquaculture of native oysters, as in Virginia.

There are many challenges to the restoration of native oyster populations in the Chesapeake Bay. Disease is certainly one of them. However, poor water quality and physical habitat degradation are even greater impediments to restoration than disease in many parts of the Chesapeake Bay. Low dissolved oxygen levels, frequent and severe freshets, and excessive sediment loads have rendered previously productive oyster grounds unsuitable for oyster survival today. These water-quality problems must be addressed as part of the oyster restoration effort regardless of the species of oyster being used.