Current attempts to restore the oyster population in the Chesapeake Bay focus on overcoming obstacles that prevent oysters from being able to settle, reproduce, and thrive on their own. These include:

• A lack of clean, hard surfaces for juvenile oysters (spat) to settle on
• Too few breeding adult oysters (broodstock)
• Oyster diseases

Reefs are built of oyster shell and sometimes alternative substrates, to provide substrate upon which spat can settle. Spat-on-shell are produced and added as future broodstock. Two main oyster restoration management strategies are being used in the Chesapeake Bay: sanctuaries and managed reserves.

Sanctuaries are restored oyster bars where harvest is prohibited. The hope is that the oysters in the sanctuary will be able to develop disease tolerance over time, and that they will produce larvae to help supplement oyster populations in nearby areas. The oysters in the sanctuary also provide water quality and habitat benefits.

Managed reserves are a system used in Maryland where watermen are hired to “clean” an oyster bar by dredging up the existing shell to remove diseased oysters. Bar cleaning has been criticized by some, because in addition to removing diseased oysters it removes existing surviving oysters as well—oysters that may be more resistant to disease and could perhaps pass along that disease resistance to the next generation. The University of Maryland Center for Environmental Science has issued a position statement on the use of bar cleaning.

Once the bar has been cleaned, the watermen are hired to plant spat-on-shell. The oysters in the reserve provide water filtration and habitat benefits and produce more oysters for the reserve and for surrounding areas. After a period of time, the reserve is opened to harvest, providing the watermen with oysters that they can sell.

Genetic rehabilitation is a strategy researchers hope will beat the diseases that have plagued oysters in the Chesapeake Bay. In Virginia, the NOAA Chesapeake Bay Office has teamed up with the Army Corps of Engineers, the Virginia Institute of Marine Science, the Virginia Marine Resources Commission, and the Chesapeake Bay Foundation to plant disease-tolerant oysters in the Great Wicomico River. The goal of this effort is to stock the river in a number of select locations with large numbers of spat. The hope is that these disease-tolerant oysters will not only survive, but that they will also reproduce, and in doing so will potentially spread their genes for disease tolerance throughout the existing oyster population in that river.

The states of Maryland and Virginia have proposed to introduce a species of non-native oyster from Asia, Crassostrea ariakensis, into the Chesapeake Bay. C. ariakensis appears to be more resistant to both of the diseases that have devastated the native oyster, and some believe that it is the answer to restoring both the ecological and economic services once provided by the native oyster. Much is being studied about this non-native oyster; however, many questions remain about the consequences of such an introduction. Before the introduction can take place, an Environmental Impact Statement (EIS) must be completed to evaluate the possible consequences and look at alternative solutions. The Draft EIS is currently scheduled for completion in May 2008.