Shark Decline Paper
Shark Decline Paper
Every Jaws fan knows the shark gets it in the end. What they do not know is that too many sharks have gotten it; and that has caused a rapid decline in the shark population over the past thirty years. Since the 1970’s, sharks of the Atlantic and Gulf of Mexico shores have declined eighty-five percent. Sharks are vital animal to our world’s ecosystem, and if the decline is not controlled; we could be facing devastating problems in years to come. Information has been obtained from two books: The Shark Almanac by Thomas B. Allen and Sharks, An Introduction for the Amateur Naturalist by Sanford A. Moss. Sources also include a number of online references, among them BBC News, ENS News, The New York Times, and two online scientific journals: Congruent Trends in Long-term Zooplankton Decline in the North-east Atlantic and Basking Shark (Cetorhinus maximus) Fishery Catches off West Ireland and Shitfting baselines and the decline of pelagic sharks in the Gulf of Mexico. Sources conclude with two brief articles: one written for USA Today by Traci Watson, and the second written for Newsweek by Lucy Howard and Paul O’Donnell. The informational taken from these sources include topics such as history of fishing for sharks and what their body parts are used for, the decline in the shark population, and why it is so harmful, and what measures need to be taken to control the shark population. Articles also illustrate how the decline in sharks has been portrayed to the general public and they are reacting.
For centuries, humans have been hunting sharks for sport, food, medicine and leather with little regards for the health of the shark population (Allen, 1999). Sharks are considered one of the most challenging fish to catch, and their flesh is highly prized in certain parts of the world. An ancient Chinese dish, Shark fin soup is in such demand that the fishermen who hunt for shark fin cut off the shark’s fin’s and throw the rest of the shark’s back into the ocean to die. They do this because of the limited amount of space on the ship. Shark liver oil is used as a source of vitamin A, and some people believe that the cartilage and liver of a shark are extremely beneficial to human health. In earlier days the sharks’ teeth-like scales on their skin was used as fine sandpaper, and when the scales were removed from their skin it made fine leather. This leather was used for making shoes, belts and handbags. Each year thousands of sharks are killed unintentionally due to nets used to catch different types of fish, and sometimes humans kill sharks because they fear them (Springer and Gold, 1989). All of these activities have resulted in many shark species being in danger of extinction.
Sharks grow slowly and reproduce at a low rate. Their natural rate of replenishment is low, because they reproduce late in life and produce few offspring (Sims and Reid, 2002). If too many of a certain shark species is killed in a certain area, it is possible that that species may never recover. For example, the number of dusky sharks and sandbar sharks off the eastern United States decreased by more than 80% between 1985 and 1995. The sand tiger shark and the great white shark are threatened world-wide. Despite reproduction, little is known about the status, behavior patterns, and their migration patterns of most sharks. For most sharks species we do not even know their population size.
Scientist and researchers are now beginning to understand the benefits sharks provide. Losing drastic amounts of these vicious predators severally damages our local ecosystems (Baum, 2004). Sharks have remarkable immune systems, and they recover extremely quickly from injuries, and sharks are very resistant to infection, cancers, and circulatory disease (Talbot, 2003). Some people believe that shark cartilage has anticancer properties. Though scientists do not agree on this issue they continue to study the shark immune system in hopes that one day they might apply their findings to aid in the fight against human disease (Encarta, 2004).
There is clear evidence that climatic fluctuations of the atmosphere and ocean affect the distribution and abundance of marine organisms (Aebischer er al., 1990). There have been many new studies out about the declining rates in sharks but none this shocking until now. There are two classifications of sharks; costal sharks, and oceanic sharks. Large coastal sharks, such as hammerheads, tiger sharks, white sharks, and black tip sharks tend to stick close to the shoreline. Oceanic sharks roam the deep oceans, and include thresher sharks and blue sharks (Watson, 2003). The percentage of hammerhead sharks fell 89% from 1986-2000. The thresher sharks population fell 80%, while the number of tiger sharks fell 65%.
Sharks are extremely important to the aquatic ecosystem. Although, they are often thought of as ferocious and scary they, sit at the