yellowfin, big eye, albacore, and skipjack. 4 1/2 million tons of tuna are caught each year, and nearly half of the global supply is caught in the western and central pacific. it's a $5 billion a year industry and an economic lifeline for dozens of small island nations, but for how much longer? man: people consider the ocean an endless bounty, but the ocean is far from unlimited. narrator: technology is making it much easier to catch tuna, and that in turn is threatening a whole way of life. man: the pacific if so dependent on these fisheries' resources that a collapse could be devastating. and it might be decades for them to recover from that, if at all. narrator: the fisheries of the western and central pacific cover 40 million square kilometers. it's a vast area pulated by small island countries, which, according to international law, own all of the fish within 200 miles of their coastline. but most countries can't afford navy ships or aircraft to patrol their waters, leaving their prized fishing grounds a target for ocean thieves. 17 of the countries are part of an alliance that hel