journal:sharks

1. base on what I understanding about sharks:
Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago, before the time of the dinosaurs.
Since that time, sharks have diversified into 440 species, ranging in size from the small dwarf lanternshark, Etmopterus perryi, a deep sea species of only 17 centimetres (7 in) in length, to the whale shark, Rhincodon typus, the largest fish, which reaches approximately 12 metres (39 ft).

2.what is the purpose for people killing sharks?

"Shark fin soup" is a Chinese soup that has been a popular item of Chinese cuisine since the Ming Dynasty, usually served at special occasions such as weddings and banquets, or as a luxury item in Chinese culture.

There is controversy over the practice of shark finning which is used to source the signature ingredient for the soup. Consumption of shark fin soup has risen dramatically with the middle class becoming more affluent. Animal rights activists and environmentalists have called the practice brutal[3], and it is also named as a primary contributing factor in the global decline of many shark species.

China's growing economy has resulted in a large increase in demand for shark fins; combined with the importance of this top predator in oceanic ecosystems, has exacerbated problems the practice perpetuates.

3. Sustainability
See also: Shark finning
Over 100 million sharks are killed every year, a portion of which due to the demand for shark fin soup. Major declines in shark populations have been recorded in recent years—some species have been depleted by over 90% over the past 20–30 years with a population decline of 70% not being unusual. Only a small amount of the shark is actually kept. This is done is a process called finning where the fins of the shark is cut from living sharks. After the fins have been cut off, the remainder of the fish which is often still-living, is thrown back into the sea.[28] When returned to the ocean, the finless shark is unable to swim and sinks to the ocean bottom and dies a slow death.

The 2007 documentary Sharkwater exposes the abuse in shark-finning industry and the damage it is causing to the ocean's ecosystems. It also uncovers government corruption supporting the industry.


(parts of information come from Wikipedia)