Over 98% of the Australian Southern Bluefin Tuna harvest comes from tuna ranching operations in South Australia. The SBT are captured live in the wild at around 17kg average, and then grown out in the sea off Port Lincoln (see www.pir.sa.gov.au).
￼As soon as the Southern Bluefin Tuna are transferred from the tow pontoons to ranching pontoons, they pass from Commonwealth to SA Government management under the SA Aquaculture Act. This Act and regulations prescribe sustainability criteria that aquaculture operations must meet.
In the case of SBT:
- Ranching is in the special wild tuna Zone. This Zone was declared after a detailed scientific assessment by government scientists, and extensive public consultation.
- The ranching is under annual government licences, with strict conditions on stocking rates in the Zone, in each ranching area, and in each ranching pontoon. There are also provisions on any interaction with other species, fallowing, and research.
- Each operation has a full environmental assessment annually, with benchmarks measuring any impact on the ocean bottom and water column