White Shark: A Predator in Danger
Overfishing and Biology Lead to the Demise of the Amazing Shark
Apr 7, 2008
The white shark dates back more than 50 million years and is the world's largest predatory fish. It can reach lengths of twenty-two feet and weigh more than two tons. It is an apex predator, which means it is at the top of the animal food chain, and has no predators other than humans. Its diet consists mainly of fish, seals and sea lions.
Shark Fishing Industry
White sharks are sought out for their fins, cartilage, jaws, liver, blood and eyes, though not their meat. A bowl of Shark Fin soup can go for $50 in most Asian restaurants, according to Rachel Cunningham-Day, author of Sharks in Danger. The market for shark fins is so incredible that the number of sharks killed solely for their fins in Hawaii was up 2500% between 1991 and 1998. Fishermen would cut off the fins, then send the live carcasses back into the water. Hawaii now has protective legislation requiring fishermen to bring only whole shark on board, which limits the amount of sharks they can catch, and requires them to use more of the shark than just the fins.
Other sharks are caught as bycatch, or secondary catch that is caught accidentally in large nets or lines. Once the sharks are caught they go into distress and die before they are released. Because bycatch is not monitored, it is hard to get exact data. However, data in Australia showed that the ratio of sharks being caught between 1970 and 1980 jumped from 1:22 to 1:651 of other sharks compared to white sharks.
Some countries, such as the U.S., South Africa, and Australia – where white shark populations are the highest – have protective policies in place, but because the policies do not extend into international waters, the highly migratory sharks are not fully protected.
White Shark Lifespan
It is a shame when the sharks are fished for their fins, or caught for a prize because white sharks have a very slow reproductive rate, and are slow to mature. A white shark will give birth from two to fourteen live pups at a time. The pups immediately swim away and must rely on sheer instinct to survive. This is a tiny number compared to some bony fish which can lay up to hundreds, even thousands of eggs, giving the species a better chance to survive. White sharks reach sexual maturity later in life. Their survival depends on living long enough to find another sexually mature shark and reproduce.
If people continue to catch white sharks at the current rate, they won’t be able to survive much longer. A combination of policy, protection, and eco-tourism may help white sharks survive longer. By bringing positive attention to the sharks, and educating people about them, white shark numbers can remain steady.
For more information:
Pelagic Shark Research Foundations
Cunningham-Day, Rachel. Sharks in Danger: Global Shark Conservation Status with Reference to Management Plans and Legislation. Universal Publishers, 2001.
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