Great white sharks are the largest predatory fish in the ocean and are on the endangered list. The sharks have no skeleton. Instead, their structure is made up of cartilage with just partial bones in the spine and teeth. The body temperature is regulated by an internal heat exchange that helps to keep the shark slightly warmer then the ocean waters that surround it. The skin of the shark is made of small scales that are actually micro teeth. These small scales give the skin of the shark a very tough texture and protect it like armor from getting injured.
Dangers to sharks
There are several reasons why sharks are becoming endangered, and the majority of these dangers are caused by man. Every part of the shark is considered valuable in the foreign trade market. Almost all of the parts of the shark are considered in some countries to be good for medicinal purposes or food. The jaws and teeth are powdered or sold as trophies and are worth hundreds of dollars. The meat and skin are used for soups and specialty foods. The liver is considered to be a source of oil for use in some cosmetics. For some, they only catch the shark for it's fins. They cut off the fins and the shark is dumped back into the ocean to die. The fins are then sold for hundreds of dollars a pound to make a soup called fin soup.
Their survival depends also on the ability to reproduce. Sharks reach their sexual maturity between 10 to 12 years of age. They can only produce young four to six times in their lifetime. The number of young pups that are born each time ranges from four to twelve. Over-fishing with no limits or concerns to age or sex could easily damage their existence.
Sharks are caught unintentionally by commercial fishing vessels in their nets and fishing lines. The term used for catching these fish by accident is called bycatch. Trawling nets are nets that are dragged behind ships to catch fish and shrimp, but these nets also catch anything in it's path. Another type of commercial fishing method is the long lines with hooks attached to them. These types of fishing lines can reach miles into the ocean. When the sharks are caught in these nets and on the lines, they are usually dead or badly injured when pulled up. Most fisheries do not throw bycatch back because it provides them with another source of income.
Places that were habitats for sharks such as bays and harbors are now filled with new hotels and resorts. These also bring people wanting to enjoy the waters that are filled with fish and sharks. To protect the swimmers from danger, gill nets are placed in the water to block sharks and any dangerous fish from attacking them. The sharks get entangled and caught in the nets and usually die or become seriously injured before they can be rescued.