thank you very much, from mesko city, from down the street. thank you.will be right back. ♪ >> the future of fish food. half of the fish you eat probably comes from a fish farm, but the source of food for those fish farms is in danger. sam takes a look. >> the oceans are magnificent and huge, but certainly not forever. especially the way we are fishing. we are running out of fish. the reason is simple. we have been taking them out of the water faster than nature can put them back. at this pace, the oceans could be out of fish by 2050. in recent decades, we stopped getting many of the fish we eat from the ocean and started raising them in fish farms. there is a problem. to feed our farm fish, we have been going back to the oceans to pull out huge quantities of smaller species. >> sardines and anchovies, they bring them in and grind them up take the oil out and becomes animal feed. but there is limited supply of fish in the world. >> many fish populations are already at dangerously low levels. without their food stores -- source, fish could be off the menu