Culture feasibility of eastern oysters (Crassostrea virginica) in zero-water exchange recirculating aquaculture systems using synthetically derived seawater and live feeds

Abstract

The overall objective of this research project was to determine if land-based culture of eastern oysters (Crassostrea virginica) is a feasible option using recirculating aquaculture systems with synthetically derived seawater. A twelve week growout study was conducted in a closed-loop recirculating system with zero discharge using synthetically derived seawater. Two species of marine microalgae (Chaetoceros spp. and Isochrysis spp.) were cultured as oyster feed. Oysters were batch fed daily and amounts of algae cells offered to oysters were monitored. Overall, oyster survival remained greater than 99% and growth was steady and averaged 1.3, 1.1, and 0.33mm per week for length, width, and thickness, respectively. Mean weight increased an average of 0.39g per week. The means to maintaining suitable water quality was nitrification and supplementation of calcium to maintain ambient levels representative of their natural environments. Data collected is also useful for those who wish to study oysters in controlled environments or for genetic and/or breeding programs.