Ask A Scientist

Why do people catch Sharks?

Asked by: Justin Yale
School: Maine-Endwell Middle Schools
Grade: 6
Teacher: Mr. Wagstaff
Hobbies/Interests: Hobbies: Playing Playstation 3 and my computer
Career Interest: Aerospace engineer or professional fisherman

Answer from Debbie Dittrich

Research Support Specialist, Binghamton University

Research area:  Teardown analysis of electronic packages
Family: 3 cats and 4 cockatiels
Interests/hobbies: Docent at the Binghamton Zoo, nature photography, gardening

Shark fishing is a sport, just like any other kind of fishing.  Sharks are caught as trophies, and often their meat goes to waste.  Commercial fishermen are interested in sharks as well.  Shark skin is used to make leather, skulls are sold as souvenirs, and some people do eat their meat.  Other parts of the shark, in particular their cartilage, are used to make medicines.  (The skeletons of sharks and rays are not made of bone but of cartilage.  We also have some cartilage, for example in our ears.  Some people believe that shark cartilage can fight cancer since sharks appear to get less cancer than humans.  However, there is much debate as to what if any benefit cancer patients actually get from shark cartilage.)  Also, tuna fishermen accidentally catch sharks. 

Shark fining probably claims the greatest number of sharks.  Shark-fin soup is considered a delicacy in Asia.  One bowl may cost as much as $350!  The fins are provided by fishermen who catch sharks (any kind will do), cut off their fins and drop the fish back into the ocean.  The helpless animals lie on the ocean floor until eventually they die.  A study conducted in 2006 by the Wildlife Conservation Society estimated that 73 million sharks are killed annually for their fins.  Although this practice is outlawed in many countries, including the United States, it still continues.

You may now be wondering if fishing is reducing the number of sharks.  In fact, many shark species are currently listed as threatened or endangered.  The problem is worsened because sharks need to grow for many years before they are able to reproduce, and they create a relatively small number of offspring.  This shouldn’t matter much to an animal at the top of the food chain, but humans have shifted the balance by preying on sharks in great numbers.

Sharks have a bad reputation and many people think it doesn’t matter if they become extinct.  But did you know that sharks keep our oceans clean by eating dead whales?  They also prey on sick animals, preventing disease from spreading.  Perhaps their most important job is to keep populations of other animals under control.  One example of this is the cownose ray, which lives in the Outer Banks of North Carolina.  The rays like to eat scallops, which used to be plentiful in the Outer Banks.  Until recently, there were also lots of sharks inhabiting the area.  The sharks preyed on the rays, but as fishing caused the shark population to decline, the number of cownose rays increased rapidly.  As a result, very few scallops still survive there.

Only a few species of sharks have ever been known to attack humans, and attacks are rare.  Scientists believe that most are accidents, which occur when sharks mistake humans for seals.  In many cases the shark realizes that it has bitten into something that it doesn’t like and swims away.  Lightning kills more people every year than sharks do.  It is beneficial, then, to protect sharks so they can continue to keep our oceans healthy.

Last Updated: 3/1/17