The primary reason that sharks are fished, legally and illegally , is for their fins. This destructive industry could be changed with some creative aquaculture. Aquaculture is the practice of farming fish in the ocean. It should be possible to farm sharks in this manner allowing for a controlled population to be fished instead of the accidental catch that is the primary way that sharks are caught currently. This would also allow regulation on the size of sharks captured as well as provide a research are for studying sharks.
This kind of fishing would probably work best with some of the smaller species of shark. This would allow for more of them to be kept in a similar area and allow for a good ratio of cartilage to fin so that the whole shark is being used.
One thing to keep in mind about shark cartilage is that sharks do get cancer and there has been no proof that shark cartilage has any affect of cancer at all. Most of the uses of shark cartilage could be replaced with the cartilage from a cow, a much more abundant and easy to find creature. Sure, it does not seem as cool to be taking cow cartilage pills, but it sure is better for the environment.
All of the supposed medical uses for shark cartilage need much more research support. There have been no conclusive studies that say that shark cartilage has a benefit to the human body. It seems that just like with the dangerousness of sharks the health benefits have been exaggerated by the media.
From the data it would appear that sharks are as dangerous as their reputation. It is not surprising that people have been hurt by sharks. They are kings of the ocean. If a person goes into the shark's domain they must accept the risk of encountering them and that encounter will go how the shark wants it to. According to Peter Klimley of the University of California at Davis, "We once took a seal and stripped the fat off it and put it all in the water. The shark ate the fat but not the rest of the body. They are actually very discriminating predators" (Benson 2).
Why then, if they are man-eaters, did they swim away? Because of optimal foraging theory, a mathematical explanation of how sharks and other predators weigh the caloric value of prey against the cost to eat it (Martin 3). A shark would not interested in eating something as lean and stringy as a human being. People that eat meat need to think about which they would rather eat, a groundhog or a cow. Personally, I would eat the cow any day. Cows are slower, have a higher fat content which can be converted into energy and I can buy steak at the store making it the easier of the two to get. Sharks are the same way. A shark is not going to eat a person if a seal or tuna fish is available. To a shark a human is like celery; it takes more work to eat it then the energy gained from the eating.
Most people attacked by sharks are attacked because to a shark they looked and acted like a seal in an area where the shark was hunting. A swimming person from below looks like an injured seal. An injured seal is an easy fatty snack for a shark. A surfer looks like a seal resting at the surface of the water. The shark just does what it would do if it saw a tasty morsel floating above it. The shark swam up, grabbed the surfer and pulled him under. The shark would once again be surprised by the lack of sealness once it got the person underwater releasing the surfer and swimming away. As Rob Stewart, director of the documentary on shark finning, Sharkwater, said "The reality is that sharks are not dangerous predators to humans. If people realize that, they'll care about them the same way as they do about pandas and elephants and bears. When an elephant is killed for ivory in Africa, the world goes crazy. But millions of sharks get killed in a year, and no one notices or cares" (Sharkwater).
Looking through more and more cases of shark "attacks" it becomes apparent that most of them were a case of mistaken identity. One rarely reads about a SCUBA diver being attacked. This is because SCUBA equipment is loud and the divers cannot be mistaken for another animal in the sea. Nothing moves like a SCUBA diver in the water or makes as much noise. Since sound travels four times faster underwater then it does in air, sharks hear the racket that people make and typically investigate. They do not attack, they just swim by, maybe bumping into the people but rarely use their mouths to check divers out as they do other creatures.
Not only is there less danger from sharks than there is from lightning but they share the predatory patterns with one of the most beloved of all sea creatures. The orca, or killer whale, is one of the most well known marine mammals. They are famous at Sea World and other marine parks and very few people are afraid of them. Here is an animal that shares the slot of apex predator with the white shark and yet is not feared the same way. One has to think that if an orca took a bite at someone they would basically be eaten. One does not hear about it because whoever was attacked would be gone, completely eaten.
To give an idea of how dangerous orcas are let me tell a story from my days at commercial diving school. I had an instructor for one of my classes named Scott Cassell. Scott is one of those crazy underwater people. He spends his time filming dangerous creatures underwater. He has developed numerous tools to allow him to dive with creatures that very few others will dive with. He told us, "If you are in the water to work and you see a white shark not to worry. If you see a tiger shark you'll be fine, but if you see an orca get the fuck out of the water."
Here is a man who has logged more than five thousand hours underwater, with most of that spent diving in dangerous environments and with dangerous creatures and he will not dive with orcas. And yet these orcas are protected while an animal that has simply gotten a bad reputation from movies and books remains in danger of being fished to extinction.