The proliferation of sushi and sashimi bars in Shanghai and Beijing is proof of the long-term growth prospects of the premium tuna industry says Beston Global Food chairman Roger Sexton, whose company is funding the acquisition of Mori Seafood based in Port Lincoln, the town that had the most millionaires per capita of any location in Australia in the early 2000s because of tuna fishing.

It's a roller-coaster industry that built the fortunes of Tony Santic – who went on to achieve national fame as the owner of racehorse Makybe Diva, the three-time Melbourne Cup winner – and fellow tuna baron Hagen Stehr, who had net wealth estimated by the BRW Rich 200 of $270 million in the late 2000s. Mr Stehr is still a major shareholder in Clean Seas Tuna, a company that is symbolic of the volatility in the industry, with a share price now languishing at 6¢ after being at $1.30 in early 2008.