Sharks have a great deal to fear from humans. Compared to the 10-15 people killed by sharks each year; over 100 million sharks perish at the hands of humans annually and many populations may face extinction. Sharks are killed for many reasons, including fear; food, sport, and 'machismo', but the great majority perish due to simple greed. Many shark products have commercial value, including: the flesh; the skin for high-quality leather; teeth and jaws for ornaments; liver oil for cosmetics, medicines, vitamin A, and skin-care products; and cartilage for false cancer 'cures'. However; the product that drives the market are the fins. After drying, collagen fibers are extracted from them, cleaned, and processed to make 'shark fin soup'. In spite of the fact that these fibers have little flavor or nutritional value, the soup is considered a delicacy, and may sell in the Orient for more than $100 ( £65) a bowl.
Over the years, shark fisheries have come and gone. In the early part of the century, sponge fishermen in Florida killed sharks to boil them down for their oil. The oil was then thrown on the ocean to smooth the surface of the water and make it easier to see the sponges from the boat. That ended when a plague killed off the sponges. In the 19405 to .19505 a number of shark fisheries sprang up to supply the market for vitamin A. That ended with the discovery of a method for its synthetic production. However; most shark fisheries, such as the one for dogfish sharks to supply the 'fish and chips' market in the UK, have ended only when the number of sharks dropped too low for the fishery to be sustained.
The explosive growth of the Chinese economy and rapid expansion of trade with the outside world during the 1985 and 1995 created an unprecedented situation. Suddenly there was an insatiable demand for shark fins of almost any size or type. Improvements in shipbuilding and navigational electronics meant that shark fishing boats could now go anywhere in the world, moving from one place to another as local shark populations were destroyed. The fins are now so much more valuable than the rest of the shark that the carcass is often discarded after the fins are removed, to save storage space on the boat. Often the fins are sliced off when the shark is still alive and the mutilated shark is dumped back into the water to die a slow and agonizing death.
Why should we be concerned about this situation? After all, wouldn't the ocean be much safer without sharks? The answer is no. The chance of being attacked by a shark is already less than the chance of being struck by lightning. The real dangers for people in the water are drowning, exposure, and being struck by a boat. In the USA, for example, drowning incidents outnumber shark attacks by 1,000 to I. Without sharks, the whole experience of being in a natural ocean wilderness would be immeasurably reduced. It would be like being on the Serengeti with no lions or cheetahs. In losing the opportunity to view these magnificent and superbly-adapted predators in the wild, we are also losing part of our spiritual connection with nature.
But something else would be changed as well -the whole ecology of the ocean. Predators control the populations of their prey species in a beneficial way. They eliminate diseased and genetically defective individuals, and they stabilize population fluctuations. On land, when we have removed the natural predators of deer; for example, their populations have exploded until they overgrazed their food supply and died of starvation and disease. In the ocean we are not sure what all the consequences of removing the apex predators from the food pyramid might be. We do have one example, though. A shark fishery in Tasmania collapsed after two years of over fishing. Shortly afterwards, the fishery for spiny lobsters also collapsed and fishermen observed a lot of octopus in the area. Octopuses are both major predators of spiny lobster and an important food item for sharks. It seems that once the numbers of octopus were no longer controlled by the sharks, they became too numerous and decimated the lobsters. Economically, for those other than shark fishermen, it doesn't make sense to allow sharks to be fished out, not only because of the possible damage to sustainable fisheries, but also because of the loss of earnings from divers coming to see sharks. Worldwide, shark-watching has become a multi-million dollar business.
Why do shark populations collapse so quickly when people begin fishing them? The answer lies in the life history of these animals. In many aspects, sharks are more similar to mammals such as whales, dolphins, or ourselves, than to other fish. Whereas most fish reach maturity in only a few years and produce thousands or millions of eggs per year; sharks take many years to reach maturity. Some species may not begin to reproduce until they are over 15 years old. Some species produce as few as two pups biannually, averaging only one offspring per year: So when a population is over fished, it may take many years to recover; or it may never recover: Some scientists believe that sharks should never be fished at all, that their biology is too fragile to withstand any exploitation. Perhaps sharks should have the total protection given to marine mammals in many countries. Unfortunately, sharks do not have big 'fan clubs' as dolphins do.
Although both are large predators with slow reproductive rates, sharks are handicapped, from a.: public relations perspective, by the fact that their mouths appear to be frowning, and that they must open their mouths to pass water over their gills, exposing their teeth. Dolphins, on the other hand, always appear to be smiling, because of the shape of their mouths. Since they breathe through the blowholes on top of their heads, they do not have to open their mouths and expose their formidable teeth in order to get oxygen. But even the dolphin's smile may not protect it from the greed inspired by the high prices being offered by international buyers of shark fins. In a number of countries, fishermen are slaughtering dolphins to chop up for shark bait.
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