Atlantic bluefin tuna
What to check for
Location
All areas
Production method
Marine net pen, capture-based
Rating summary
Farming or ranching of Bluefin tuna relies on capture of juvenile wild tunas for on-growing and fattening in open net cages until harvest. Therefore this process is completely reliant on wild fish stocks. There is still concern for the biomass of the stock as the stock is still recovering from very low levels and there is a lack of reference points. Farming in this way will not lessen the pressure on the species. In the case of Mediterranean sea ranching operations, the capture of tuna for ongrowing is an increasing part of the catch. The ranching of tuna requires large amounts of fresh fish for feeding, with an average of 20 kg of wild fish required to produce 1 kg of Bluefin. There are currently no known procedures in place to ensure animal welfare and humane slaughter. Tuna resulting in a significant net loss of fish protein. Management and regulation of ranched tuna in the Mediterranean is only partially effective in mitigating the negative environmental impacts from aquaculture. However, it does seem that farming is incorporated in marine spatial planning.Rating last updated January 2025.
Technical consultation summary
Farming or ranching of Bluefin tuna relies on capture of juvenile wild tunas for on-growing and fattening in open net cages until harvest. Therefore this process is completely reliant on wild fish stocks. There is still concern for the biomass of the stock as the stock is still recovering from very low levels and there is a lack of reference points. Farming in this way will not lessen the pressure on the species. In the case of Mediterranean sea ranching operations, the capture of tuna for ongrowing is an increasing part of the catch. The ranching of tuna requires large amounts of fresh fish for feeding, with an average of 20 kg of wild fish required to produce 1 kg of Bluefin. There are currently no known procedures in place to ensure animal welfare and humane slaughter. Tuna resulting in a significant net loss of fish protein. Management and regulation of ranched tuna in the Mediterranean is only partially effective in mitigating the negative environmental impacts from aquaculture. However, it does seem that farming is incorporated in marine spatial planning.
