Bluefin tuna are threatened by extinction as the global appetite for the fish soars. A fishing ban is unlikely, so one solution is to breed the fish in underwater cages. But they're not easy to rear in captivity.
In Australia, German-born Hagen Stehr is working to mimic natural living conditions of the fish in his onshore farm. The idea is to create an artificial model of the journey to their spawning grounds in order to trick the fish into reproducing.
For more go to: www.dw.de/dw/episode/0,,15878760,00.html