(Nova Scotia, Canada, Farmed in Tank Systems)
Atlantic halibut farmed in Canada in closed, recirculating systems is a "Good Alternative."
The term flatfish includes many bottom-dwelling fish, including flounder, sole, plaice and halibut. Flatfishes are known as hirame when prepared for sushi.
Aquaculture of Atlantic halibut is a relatively new practice, particularly in Canada where exploratory research did not commence until the mid-1990s.
These types of land-based farms are "closed" from the surrounding environment, and therefore limit the impact the farming operation can have on local ecosystems. Risk of disease spreading, or escape of fish from the farm is minimized. Water and effluent can be treated, and with minimum use of chemicals, and water that is recirculated, the outputs from the farm can be minimized.
Atlantic halibut is a carnivorous fish, and there is a high level of fishmeal and fish oil included in the farmed diet. In fact, the net result is that more fish by weight is fed to the farmed fish than is produced by the farm. This factor limits this ranking to a "Good Alternative."