In 2009, the states of Maryland and Virginia and the U.S. Army Corps of Engineers jointly decided against a proposed introduction of a non-native oyster (Crassostrea ariakensis) into the Chesapeake Bay. As the photo to the right illustrates, the ariakensis grows much more quickly than does the native oyster. The Chesapeake Bay Oyster Restoration Programmatic Environmental Impact Statement (PEIS) recommended expanded efforts to restore native oysters. Many considerations went into the PEIS process. Possible risks and benefits that might have resulted from an introduction of Asian oysters were carefully considered.

NOAA supported the PEIS through a five-year non-native oyster research program that provided critical information leading to the final recommendation. This program funded 44 projects, with a total NOAA funding of about $7 million. Topics of this research included:

• understanding C. ariakensis within its native range
• life history and ecology
• susceptibility of C. ariakensis to known disease-causing parasites and pathogens
• human consumption risk
• suitability of C. ariakensis for aquaculture
• economics of growing C. ariakensis

One of the unexpected outcomes of this program was that the triploid native oysters that were used to compare to the triploid non-native oysters as part of the research funded by NOAA grew so well that they are now being used in commercial aquaculture. The research also helped clarify the economics of oyster aquaculture using native oysters.