A lone Australian navy Seahawk helicopter swept towards the crew of the Russian fishing boat Lena on a gray February day this year. The rust-speckled trawler and its dozens of workers had been working in one of the loneliest places on Earth, the Southern Ocean around Antarctica, where extreme cold and rough seas discourage all but the heartiest and most determined of seamen. But the Lena certainly had incentive to be in these waters. By the time the Seahawk arrived, the Lena had in its hold an estimated $1.25 million worth of Patagonian toothfish, also known as Chilean sea bass....