Tuna: A Love Story
Know Your TunaTuna is the most popular food fish in the world. It is eaten raw, cooked, in sandwiches, in salads, and in catfood.The total worldwide tuna harvest is four million tons.In the past, tuna fishermen in the eastern tropical Pacific set their nets around dolphins, which resulted in the deaths of tens of millions of dolphins.There are many kinds of tuna, but the most popular for the Japanese sashimi market is the bluefin, one of the largest of all fishes.The largest bluefin tuna ever caught weighed 1,496 pounds.The most expensive bluefin tuna was a 440-pounder that sold at the Tsukiji fishmarket in Tokyo for $173,600.Almost all of the bluefin tuna caught by commercial fishermen goes to Japan.The Japanese import 800,000 tons of tuna every year. (That’s right:eight hundred thousand tons.)At the Tsukiji fishmarket in Tokyo, an estimated 1,000 bluefin tunas are auctioned off every day.Is there mercury in tuna? Yes. Is it at levels dangerous to humans? Not unless you eat tuna three meals a day.Many scientists consider the tuna the most highly-evolved fish in the world.Bluefin tunas, along with mako and great white sharks, are the only "warm-blooded" fishes; they can elevate their body temperature as much as 25 degrees above the water they swim in. This makes them particularly effective as predators.Bluefin tuna can swim 55 miles an hour. They can migrate across the Pacific and Atlantic Oceans, then turn around and do it again.MIT scientists built a robot tuna in an attempt to replicate the incredibly efficient swimming performance of the living fish. They failed.The bluefin tuna, and to a lesser extent, the yellowfin, are among the most sought-after of big-game fishes. Celebrated anglers like Zane Grey, Ernest Hemingway, and Phillip Wylie wrote ecstatically about their pursuit of giant tuna.Aquaculture ("fish farming") now accounts for 40% of the world’s fish consumption.Tuna ranching now takes place in every country on and in the Mediterranean, and in Australia and Mexico as well. It is scheduled to begin in Hawaii and Alaska.Because of commercial overfishing, almost exclusively to feed the insatiable Japanese sashimi market, all populations of bluefin tuna are endangered.Overfishing in the Mediterranean has caused such a drop in the bluefin tuna population that the World Wildlife Fund has called for a complete halt to all tuna-fishing there.If we cannot learn to breed bluefin tuna in captivity, the great fish will become extinct, writing finis to commercial and recreational tuna fishing--and to the consumption ofmaguro sashimiin Japan.In March, 2008, an Australian company called "Clean Seas" succeeded in getting captive bluefin tuna to spawn. If they can raise them to market size (200-300 pounds), it may relieve the pressure on wild-caught fish.