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Humans, like all species, consume, yet unlike most other species we also waste—and the greater our population becomes the more we are willing to waste. In the case of 'shark finning', sharks are caught around the world, their fins chopped off, and then the shark itself is thrown back into the water to die. It's a gruesome, barbaric process, but most of all it is startlingly wasteful: sharks are thrown overboard simply because their meat is not worth enough for fishermen to keep. All this death and waste is left unchecked in order to produce vast quantities of the Asian delicacy (barely a 'delicacy' anymore)—'shark-fun soup'—for the wealthy in China and Japan. It is estimated that 26 to 73 million sharks are killed every year for their fins alone.
Not surprisingly, this trade has helped sink shark populations worldwide. In just 15 years sharks have been devastated in the Mediterranean and the Gulf of Mexico: with a 90 percent drop in populations. Some shark species in the Mediterranean have plunged by 97 percents. But the decline also global: shark populations have dropped by 75 percent in the northwestern Atlantic over the same time period. To date 32 percent of open ocean sharks and rays are threatened with extinction.
These dire statistics, pushed sharks to the center of the CITES meeting. However, out of eight species of shark, not one of them received enough votes to garner protection. The porbeagle shark actually won enough votes, but Asian countries were able to force a second vote just before the meeting closed that left the porbeagle, like its cousins, unprotected. As top predators both sharks and Atlantic bluefin tuna play an important role in the ecosystem by controlling prey species populations and thereby also affecting their prey's prey. Without sharks and tuna, the whole marine ecosystem—like Yellowstone was without wolves—will likely go topsy-turvy.
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This, very well may be the same fate for bluefin tuna and sharks: remnants of the population being farmed for humanity's ever-expanding appetite, perhaps crossbred with other tuna or shark species, or simply genetically modified to produce more meat—or in the case of sharks, bigger fins—per fish. So, when it comes to human greed and waste, do not delude yourself: we will knowingly exploit a megafauna species—the Atlantic bluefin tuna, sharks, or the American bison—to extinction (or a fate nearly as bad) today, just as we did yesterday. We have not progressed, but refusing to learn from the past, like the ignorant, we are doomed to repeat it. Of course, unlike the ignorant, we repeat it with the full knowledge of our consequences, yet not even this stops us. Where this cycle will end, I don't know. But it's very likely that one or two hundred years from now the oceans will look as different and lonely as today's western America would appear to Lewis and Clark: little remaining but the absence of what was.
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http://news.mongabay.com/2010/0405-hance_bison_bluefin.html