ohno's bluefin fishery is booked months in advance.jewel-like pieces. the world's most celebrated sushi master warned the most popular item won't be on the item through years ago we're already seeing that come to pass, it's utterly inconceivable we'll be able to kornlt making sushi with the fish we have today. japanese diners aren't the only ones. u.s. consumption has surged almost 30% in recent years with nearly 4,000 sushi restaurants a krois america. >> his son and he are open to it. we'll have to make up for the shortage of wild tuna by using farm fish instead, he says. now most days grilled eel is farm raised. tuna will end up the same wi. for c p s"cbs this morning: saturday," lucy craft, tokyo. >> she focuses on bluefin tuna conservation. on monday she'll be attending a conference in italy where fishing limits in the atlanta good morning to you, shanna. >> good morn to youing to you. >> they say it could be the end. do you believe in it? >> it affects the restaurant as far as what fesh are still available. but there are bee kona