A proposed ban of the Altantic Bluefin tuna will be the focus of a two-week United Nations conference.The hundred-seventy-five nation convention is being held in the gulf state of Qatar.There, members will discuss the ban on international trade in the Atlantic Bluefin - a tuna species prized by sushi lovers.The measure pits Europeans and Americans against fishing nations in North Africa and Asia....More prominantly - in Japan - which has already promised to ignore the Bluefin ban.