Water column leases (WCL) use production practices where oysters are containerized in cages, bags or baskets and held within the water column. Single oysters (also referred to as seed or cultchless oysters) are used on these leases. The final product is generally targeted towards the half-shell industry, where shape, consistency and general appearance are highly prized. Oysters grown in WCL require significant inputs of labor and maintenance during growout.
Common gear types used in Maryland WCL include bottom and floating gears. In bottom cages, oysters are contained within sturdy wire cages, or bags within cages, and held off of the substrate below by feet on the underside of the cage, holding the oysters ~6 inches off of the underlying substrate. Floating gear types consist of cages, baskets or bags affixed with floats to provide adequate flotation, allowing the oysters to remain submerged at the water’s surface during growout. These may facilitate aerial exposure or desiccation which can help with biofouling control, one challenge faced by water column oyster growers.