Growth of Eastern oyster (Crassostrea virginica) using two oyster - bag float configurations

ABSTRACT Two bag float configurations (on-side; on-top) for the culture of four length classes of Eastern oyster (Crassostrea virginica) were tested at two sites in Tracadie Bay, Canada. An interaction between the site and the float configurations was observed at the northern site for the 21–30, 31–45 and 46–65 mm oyster classes for their length, and in the 46–65 mm for width as well. The observed differences give a potential increase of 32.5% in growth on a 4-year cycle when on-top configuration is used. About 12.7% more market size oysters were produced in this configuration representing an increase of $9.24 (CAN) per bag. This study shows the potential benefit of the on-top configuration, but also the interaction between the site and the float configurations. Since the on-top configuration needs more maintenance time, it is suggested that the float configurations be chosen based on biofouling, growth variation, effect on oyster shape, and cost/advantage.