FILE - In this Jan. 5, 2014 file photo, people watch a bluefin tuna laid in front of a sushi restaurant near Tsukiji fish market after the year's celebratory first auction in Tokyo. The researchers at Tokyo University of Marine Science and Technology are fine-tuning a technology to use mackerel surrogates to spawn the bluefin, a process he hopes will enable fisheries to raise the huge, torpedo-shaped fish more quickly and at lower cost than conventional aquaculture. The aim: to relieve pressure on wild fish stocks while preserving vital genetic diversity. (AP Photo/Shizuo Kambayashi, File)