Virginia Institute of Marine Science
Journal Of Shellfish Research
Eastern oysters were ecologically and structurally dominant features of the Chesapeake Bay prior to European colonization. Four centuries of harves pressure, habitat degradation, and more recently, disease activity have affected extant oyster population demographics. We compared population demographics and age-at-shell length relationships for modern mesohaline James River oyster populations with James River oysters collected in the years 1611 to 1612 by Jamestown settlers. Historic oyster collections made by hand included a more complete demographics than modern samples collected with patent longs. Historic oysters had significantly faster growth rates than modern oyster populations. Modern oysters larger than 30-40 mm SL or age 1 grow more slowly than historic oysters of comparable ages. Unlike historic oyster populations, modern james River oyster populations are affected by Dermo and MSX. The downward trend observed in the modern age at length relationships (Fig. 4B see later) between 1 to 1.6 y is probably related to the seasonal onset of disease with increasing temperatures. Observed changes in oyster demographics and growth rates across four centuries reflect changes in the environment as well as changes in oyster biology because of chronic pressure from two oyster diseases.
Eastern Oyster; Crassostrea Virginica; James River; Age-At-Length; Jamestown; Chesapeake Bay
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Harding, Juliana M.; Mann, Roger L.; and Southworth, Melissa, Shell Length-At-Age Relationships In James River, Virginia, Oysters (Crassostrea Virginica) Collected Four Centuries Apart (2008). Journal Of Shellfish Research, 27(5), 1109-1115.