210375 Public health consequences of a non-native oyster species introduction in the Chesapeake Bay

Wednesday, November 11, 2009: 11:10 AM

Sharon Nappier , Civil, Architectural and Environmental Engineering Department, Drexel University, Philadelphia, PA
In efforts to ameliorate the economic strain experienced by the Chesapeake Bay's commercial oyster industry, the States of Maryland and Virginia are currently considering the introduction of a non-native oyster species, Crassostrea ariakensis into the Chesapeake Bay. Biosecurity trials of the C. ariakensis have already begun and the official introduction will likely occur without a full understanding of all the public health consequences. Gastroenteritis associated with the consumption of contaminated, raw oysters causes worldwide health concerns, but the ability for C. ariakensis to bioaccumulate, retain, or depurate human pathogens has not been fully evaluated.

We evaluated the ability for the native Crassostrea virginica and non-native C. ariakensis to bioaccumulate, retain, and depurate nine pathogens and indicators over various salinity ranges relevant to the Chesapeake Bay. In all experiments, oysters were allowed to bioaccumulate microorganisms for 24 hours; depurated for 29 days; and sampled at weekly time intervals. The non-native C. ariakensis oysters bioaccumulated and retained human pathogens over broad salinity ranges. C. ariakensis were more likely to harbor viruses, protozoa, and microsporidia as compared to C. virginica oysters. Overall depuration was ineffective in the removal of enteric pathogens from the non-native C. ariakensis and human enteric viruses were detected at day 29 of depuration. If C. ariakensis are introduced into the Chesapeake Bay, they will filter human wastes efficiently. Unfortunately, C. ariakensis oysters will predominately be harvested for human consumption, and thus ecological benefits provided by the oyster's filtration efficiency will likely cause harmful repercussions to the health of consumers.

Learning Objectives:
Describe why there are potential public health implications associated with introducing a nonnative oyster species to the Chesapeake Bay.

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I am an environmental microbiologist and received my PhD from Johns Hopkins School of Public Health, MSPH from UNC School of Public Health. My disseration work focused on the topics to be discussed in this Panel. Additionally I have published the following article in the peer-reviewed journal Applied and Environmental Microbiology, "Bioaccumulation, retention, and depuration of enteric viruses by Crassostrea ariakensis and Crassostrea virginica Oysters."
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.