It was about the time of the Jaws movies that a number of factors increased demand for sharks.
One was the dubious notion that shark cartilage, when eaten dried or as a supplement, reduces the risk of cancer. Another was the diminishing stocks of tuna and swordfish, which drew attention to shark as a cuisine alternative. And then there was the demand for shark teeth (thank you, Jaws), skin and liver oil, which added to the pilfering of sharks from world waters.Fishermen simply remove fins from live sharks and then throw the mutilated animals back into the water to die
But the most influential factor has been the surge in demand for a Chinese soup that calls for dried shark fin. In powdered form, the fins can sell for as much as $200 a pound. Some fishermen simply remove fins from live sharks and then throw the mutilated animals back into the water to die.
Though the data are sketchy, yet another factor is at work. Sharks are getting caught in nets used by fishermen looking to catch other species. In 1947 the amount of shark and related species brought to shore was about 220,000 tons. In 1997 the reported catch was about 800,000 tons--a figure that represents probably only half the real amount, since it doesn't include the sharks dragged in unintentionally.
Add to this the fact that sharks come to sexual maturity relatively late in life and have small litters when they do give birth. Generally, the catch rate for sharks has been twice the birth rate in recent years. Not a good combination.
Perhaps because many governments lack data on shark populations, the depletion of sharks continues at a dangerous pace. Without proof of diminishing numbers, it is hard to ask fishermen to cut back. Still, many would agree that protecting sharks from the ravages of overfishing is a global imperative.
Despite the image of sharks as man-eating beasts, most of the world's 400 species are fairly harmless to humans. Unquestionably, a shark has a much better chance of survival if he opts to swim quickly in the other direction when a human comes near.
Recently, the United States courageously enacted rules to cut shark fishing in half as well as to ban the fishing of five species of shark altogether. Hopefully, this will set an example for the rest of the world. But the ultimate solution is for people to just stop eating sharks.