The effect of aquaculture gear and tidal zone on the growth and shape of the oyster Crassostrea virginica during a “finishing period” in Chesapeake Bay.

Abstract

This study investigated how aquaculture gear type and increased wave action influenced growth and shape of eastern oysters Crassostrea virginica during a “finishing” period in Chesapeake Bay. Oysters were deployed in three different gear treatments in the intertidal or upper water column: bottom cages, OysterGro™ floats, and rack and bag, and a bottom cage was also deployed in the subtidal zone as an industry control. Shell length(L), width(W), height(H), total weight and wet meat weight were measured each month from August to December 2015 and an index of shell shape (deviation of L-W-H from idealized 3-2-1 ratio) calculated. OysterGro™ floats produced the greatest increase in wet and total weight and the most ideal shaped oysters (lowest 3-2-1 ratio deviation). Overall, these results demonstrate the benefit of deploying oysters in higher wave action gear types such as the OysterGro™ and will increase the available data on gear performance in Chesapeake Bay.