No more magnificent fish swims the world's oceans than the giant bluefin tuna, which can grow to 12 feet (3.7 meters) in length, weigh 1,500 pounds (680 kilograms), and live for 30 years. Once, giant bluefin migrated by the millions throughout the Atlantic Basin and the Mediterranean Sea, their flesh so important to the people of the ancient world that they painted the tuna's likeness on cave walls and minted its image on coins.
Doomed by a gill net, a thresher shark in Mexico's Gulf of California is among an estimated 40 million sharks killed yearly for their fins. They add to the devastating global fish catch: nearly 100 million tons.
Photograph by Brian Skerry
The giant, or Atlantic, bluefin possesses another extraordinary attribute, one that may prove to be its undoing: Its buttery belly meat, liberally layered with fat, is considered the finest sushi in the world. Over the past decade, a high-tech armada, often guided by spotter planes, has pursued giant bluefin from one end of the Mediterranean to the other, annually netting tens of thousands of fish, many of them illegally. The bluefin are fattened offshore in sea cages before being shot and butchered for the sushi and steak markets in Japan, America, and Europe. So many giant bluefin have been hauled out of the Mediterranean that the population is in danger of collapse. Meanwhile, European and North African officials have done little to stop the slaughter.
"My big fear is that it may be too late," said Sergi Tudela, a Spanish marine biologist with the World Wildlife Fund, which has led the struggle to rein in the bluefin fishery. "I have a very graphic image in my mind. It is of the migration of so many buffalo in the American West in the early 19th century. It was the same with bluefin tuna in the Mediterranean, a migration of a massive number of animals. And now we are witnessing the same phenomenon happening to giant bluefin tuna that we saw happen with America's buffalo. We are witnessing this, right now, right before our eyes."
The decimation of giant bluefin is emblematic of everything wrong with global fisheries today: the vastly increased killing power of new fishing technology, the shadowy network of international companies making huge profits from the trade, negligent fisheries management and enforcement, and consumers' indifference to the fate of the fish they choose to buy.
The world's oceans are a shadow of what they once were. With a few notable exceptions, such as well-managed fisheries in Alaska, Iceland, and New Zealand, the number of fish swimming the seas is a fraction of what it was a century ago. Marine biologists differ on the extent of the decline. Some argue that stocks of many large oceangoing fish have fallen by 80 to 90 percent, while others say the declines have been less steep. But all agree that, in most places, too many boats are chasing too few fish.
Popular species such as cod have plummeted from the North Sea to Georges Bank off New England. In the Mediterranean, 12 species of shark are commercially extinct, and swordfish there, which should grow as thick as a telephone pole, are now caught as juveniles and eaten when no bigger than a baseball bat. With many Northern Hemisphere waters fished out, commercial fleets have steamed south, overexploiting once teeming fishing grounds. Off West Africa, poorly regulated fleets, both local and foreign, are wiping out fish stocks from the productive waters of the continental shelf, depriving subsistence fishermen in Senegal, Ghana, Angola, and other countries of their families' main source of protein.
In Asia, so many boats have fished the waters of the Gulf of Thailand and the Java Sea that stocks are close to exhaustion. "The oceans are suffering from a lot of things, but the one that overshadows everything else is fishing," said Joshua S. Reichert of the Pew Charitable Trusts. "And unless we get a handle on the extraction of fish and marine resources, we will lose much of the list that remains in the seas.
By Fen Montaigne
Republished from the pages of National Geographic magazine