But today the most profitable crop is southern bluefin tuna.

FORBES: The Future Is Fish

The key to the success of the quota system, which is overseen by the Commission for the Conservation of Southern Bluefin Tuna in Canberra, is that the permits in Australia, New Zealand and elsewhere are treated as private property and can be bought and sold or handed down to the next generation.

FORBES: The Future Is Fish

Finally, in 1993, Japan, Australia and New Zealand devised a quota system that allows the trawlers to catch a set amount of southern bluefin in the wild and not one tuna more.

FORBES: The Future Is Fish