MPI Observer Programme
Toothfish do not have a swimbladder, which makes it possible to mark and recapture tagged fish even at the great depths of the Ross Sea. This ongoing tagging programme is unique in the world and has been mandatory since 2004. Toothfish are tagged and released at a rate of 1 fish per ton of fish caught, averaging 1 in 30 fish captured. There is also a tag reward program.