The feasibility of suspension culture of oysters (Crassostrea virginica) at a petroleum platform off the Texas coast.

The feasibility of experimental off-bottom oyster culture at a petroleum platform offshore from High Island, Texas was established. Offshore and estuarine oysters (120 of each group ranging from 42 to 87 mm length) were suspended at two levels in plastic mesh Vexar bags. The rate of growth of oysters in terms of length was not significantly different for depth or for station. The rate of growth in terms of weight was significantly greater for the estuarine oysters due to a significantly greater rate of growth for oysters at the lower level of that station. The condition index of oysters was higher at the estuarine station than offshore. The chlorophyll a level in the estuary was twice that offshore, indicating a denser phytoplankton standing crop. However, generic composition of the phytoplankton was similar in both stations. Mortality was greater offshore (51 of 120) than at the estuarine station (32 of 120) and was possibly related to the greater incidence of the fungus Labyrinthomyxa marina in the offshore oysters. The problems of adequately containing oysters, obtaining spat and securing disease free oysters must be dealt with before an adequate assessment can be made for using petroleum platforms to culture oysters offshore.