GROWTH OF EASTERN OYSTER, CRASSOSTREA VIRGINICA, IN CHESAPEAKE BAY

Abstract

I applied modern techniques of modal analysis to track size modes in Eastern oyster, Crassostrea virginica, populations longitudinally through time, from which I inferred age-classes to establish size-at-age relationships for individual oyster bars and across Maryland's Chesapeake Bay. Average shell lengths of putative age-0 through age-5 oysters range from 22.93 (6.67, n=194) mm to 84.46 (8.27, n=4) mm. Growth rates declined with age-class from a mean of 28.97mm/yr to 0.85mm/yr, and the maximum and minimum individual growth rates were 0.78 and 53.0 mm/yr, respectively. I estimated von Bertalanffy growth parameters across all sites as L90.85mm, k=0.55, and to=-0.51. On average, I estimated oysters take 3 years to reach a marketable size within Chesapeake Bay. As an alternative to modal length frequency analysis, annuli in chondrophore sections of known-age oysters in Chesapeake were examined. It was determined that annuli formation was unrelated to chronological age.