Population Studies of the Native Eastern Oyster,Crassostrea virginica, (Gmelin, 1791) in the James River, Virginia, USA

Abstract

ABSTRACT We describe oyster population trends in the James River, VA from 1993 through 2006 using quantitative fishery independent survey data collected using a stratified random design. The 23 reefs contained in the study area cover a total of 2.41 × 107 m2 and vary in individual size from 1.26 × 104 m2 to 4.98 × 106 m2. There is a marked pattern in density of oysters among the reefs: during the study period a small group of reefs comprising 5.4% of the total area consistently contained between 25.7 and 55.5% by number and 35.8 and 54.8% by biomass of the total oyster population. The highest density reefs exhibit, with very few exceptions, mean densities well in excess of 200 oysters m-2, typically between 300 and 500 m-2, with a single maximum value of 773 oysters m-2 in 2002 coincident with the highest annual recruitment observed during the study period. Recruitment events were usually followed by very high mortality with very small percentages of the population reaching ages ≥3 y of age. A strong stoc...