| Title | Improvement of disease resistance and understanding of summer mortality in Pacific oyster Crassostrea gigas |
| Publication Type | Magazine Article |
| Year of Publication | 2004 |
| Authors | Cheney, D., L. Burnett, A. Christy, J. Davis, R. Elston, C. Friedman, F. Griffin, C. Langdon, and A. Suhrbier |
| Secondary Title | Journal of Shellfish Research |
| Volume | 23 |
| Number | 1 |
| Pagination | 284-285 |
| Date Published | 2004 |
| Call Number | OSU Libraries: Valley SH370.A1 J61, Guin SH370.A1 J61, Electronic Subscription |
| Keywords | bivalves, genetics, human use and impacts, molluscs, mortality, Netarts Bay, Pacific oyster = Crassostrea gigas, shellfish |
| Abstract | Pacific oyster (Crassostrea gigas) summer mortalities are a recurring problem in the United States, Japan, France, and Mexico. During the 2002 to 2003 growing season, for example, farmers in Carlsbad, CA, Netarts Bay, OR, and Willapa Bay and south Puget Sound, Washington reported up to a 50% loss of market-ready oysters occurring over a brief 2 to 3 week span. Research findings indicate genetic pedigree, ploidy, culture practice, and prior exposure to environmental stress have varying influences on the expression of the summer mortality disease in Pacific oysters. Key facets of research to date include (1) the ability of oysters to survive episodes of summer mortality is in part genetically determined and perhaps can be enhanced through selective breeding of families showing high survival traits. Pedigreed lines of oysters with different genetic histories, produced by the Oregon State University Molluscan Broodstock Program (MBP), displayed markedly differential survival, yields, and growth rates during episodes of summer mortality at project study locations in California and Washington. There is a strong and consistent genetic response of families to environmental stress that is independent of when the families were produced and planted. In addition, prior inconsistent mortalities occurring across large culture plots can, at least in part, be explained by differential genetic backgrounds of the oyster crops. (2) Triploid and diploid oysters appear to have different optimal environments and definition of their respective requirements and response is essential for maximizing their survival and productivity. Field experiments and grower observations have demonstrated sporadic high triploid mortalities and wide variation in survival compared with diploid oysters planted at the same locations. Overall, triploid oysters grown at Puget Sound test sites in 2000 to 2002 experienced a cumulative mortality of 8%-28% above the mortality rates of diploid oysters planted in comparable plots. |
| Notes | Abstract only. Discusses summer mortalities of Pacific oysters and points to genetics as a major factor. "During the 2002 to 2003 growing season, . . . farmers in Carlsbad, CA, Netarts Bay, OR, and Willapa Bay and south Puget Sound, Washington reported up to a 50% loss of market-ready oysters occurring over a brief 2 to 3 week span." |
| DOI | 10.2983/035.030.0310 |
| Label | 720 |
