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Humans, in short, have little to fear from sharks. The reverse, however, isn't close to being true. Fish of all kinds are being hauled from the sea faster than they can reproduce, but until quite recently sharks were exempt from this reckless harvest. Not anymore. Each year between 30 million and 100 million sharks are caught for their meat (boneless and mild-tasting), their fins (a great delicacy in Asia), their hides (source of an exotic, high-quality leather), their jaws (worth thousands of dollars from collectors) and their internal body parts (made into everything from lubricants to cosmetics to "health" products of dubious value).
And at least one shark is accidentally killed, usually by longlines set by shrimp and tuna boats, for every one that is caught deliberately, according to the U.N.'s Food and Agriculture Organization. When you add it all up, each human who dies in the jaws of a shark is avenged roughly 6 million-fold.
Largely as a result of this relentless slaughter, the populations of some shark species have plummeted an estimated 80% over the past decade. "At the current rate," predicts marine biologist Merry Camhi of the National Audubon Society's Living Oceans Program, "some species will reach ecological extinction within 10 years."
That prospect spurred the U.S. government for the first time to slash fishing quotas for certain sharks in Atlantic waters in April. It also moved conservationists to put seven shark species on the IUCN-World Conservation Union's Red List of threatened species and prompted calls for even stricter safeguards for sharks before it's too late.
But why should anyone care? In fact, there are plenty of reasons, starting with the creature's pure elegance of design. Sharks first appeared on earth 400 million years ago, and after about 200 million years of evolutionary trial and error, nature pretty much ran out of ways to improve on its handiwork. Today more than 350 species swim the planet, ranging in size from the less-than-1-ft.-long dwarf shark and pygmy ribbontail catfish shark to the 50-ft. whale shark. Sharks have insinuated themselves into every marine environment from the Arctic to the tropics. One species, the bull shark, even ventures into rivers and lakes as far as 2,000 miles from the nearest salt water.
Beyond that, sharks have immense practical value. While shark cartilage does not, despite the claims, prevent cancer, it has been used to make artificial skin for burn victims. Shark corneas have been used experimentally for human transplants. Shark blood contains anticlotting agents. Shark-liver oil seems to aid white-blood-cell production; it is also an active ingredient in, of all things, Preparation H.
Sharks were the first creatures in evolutionary history to develop an immune system. Biomedical researchers believe that if we can figure out how theirs works we'll gain valuable insights into our own. A shark could someday save your life--if it isn't already extinct.