Rearing Density: A Tool To Shape Eastern Oysters (Crassostrea Virginica)?

The cultivated Eastern oyster (Crassostrea virginica) is sold in a niche market seeking rounder and thicker oysters. While most of the research conducted on optimal rearing densities focuses on survival and length growth, the present study looks at the oyster's shape. Three initial length classes were used for this study and reared in floating bags at different densities. The effects of the tested rearing densities were more pronounced on oyster shape than on length growth. In the smaller oysters, the three lower densities produced the rounder shape while thicker ones were obtained with the 500 densities. For the medium oysters, rounder and thicker shape was obtained with the two lower densities. The shape of the larger oysters was not influenced by the tested densities. This study showed that there was significant impact of rearing densities on smaller and medium oysters' growth and shape, while only length growth of larger ones was impacted by this factor. Based on these findings, oyster farmers should target rearing density of 500 oysters per bag for the 20-35 mm stage, 250 oysters for the 35-50 mm oysters and 200 oysters for the larger ones (50-65 mm). The latest recommendations are based on technical considerations.