Importance of Sharks at the Top of the Food Chain

The Importance of Sharks as a Major Predator at the Top of the Food Pyramid

Catherine Redmond

Averett University

Human Ecology

G446 B104

Lynnette Swanson

April 02, 2011

The Importance of Sharks as a Major Predator at the Top of the Food Pyramid

The Planet Earth is made up of seventy percent ocean and thirty percent land. It only makes sense that what occurs in the ocean impacts human life tremendously. The ocean actually rules what happens on Earth. The climate, floods, disasters and food supplies are all affected by the ocean, as it holds such bio diversity.("Sharks Matter", n.d.)

Phytoplankton is at the first level of the oceanic food pyramid. It is the greatest consumer of carbon dioxide. It uses it for the process of photosynthesis. The product of this process is oxygen. It is estimated that seventy percent of the oxygen in our atmosphere is produced by phytoplankton.

The ocean is a delicately balanced ecosystem that has evolved over millions of years. This system can be seriously upset even if one component is removed or drastically changed. This is why sharks are so important. They act as the controllers and indicators of the population numbers of species beneath them.

Sharks existed before there were dinosaurs. They were in the ocean million of years before humans existed. They are at the top of the food pyramid and are critical to the balance of the ecosystem. They control the fish populations. Some people will say that dolphins and whales also control the fish populations, however, these animals will only eat the healthy, living fish. Sharks eat the dying, sick or dead fish which keep the fish populations healthy and the ocean free of excessive decay. We need sharks in the ocean. The shortage of sharks could be disastrous to the health of the ocean food chains. (Skomal, 2008)

The shark populations are dwindling because of heavy commercial fishing and also the attitudes of uneducated people who think that sharks are just a nuisance. At one time, especially after the movie "Jaws" came out, many people hunted sharks for sport. It takes the shark species ten or more years to become sexually mature. When they finally give birth, it is usually only to a small number of young. Populations of sharks can be destroyed quickly by humans and it takes decades to recover, if they recover at all. ("Shark Reproduction Cannot Overcome Intense Fishing", n.d.)

The rise in shark fishing is mainly because of the growing market for shark fin soup. This soup is considered a delicacy in China and is served in many restaurants. The fins do not add nutritional value to the soup, only a noodle-stringy-like texture to the soup. In fact, the soup may be harmful to human health if eaten a lot over a period of time because shark fins contain high levels of mercury. A bowl of soup can cost one hundred American dollars in Hong Kong, China.

In the process of killing the sharks for this soup, they do not use any of the shark meat to feed hungry people. They just cut the sharks fins off and toss the sharks back into the ocean where they suffer and die a slow, helpless death. By doing this, humans are destroying our natural ecosystem in the ocean. Although it is not visible yet on the surface of the ocean, we are ruining the balance of prey and predator. This affects the natural cycle of life.

As sharks decline, their usual prey populations increase. Great White Sharks, usually hunt smaller predators, including their close relatives, skates, rays and smaller sharks. The population of these animals are surging. This is a component that has upset the balance of the ecosystem.

An example of the increased population of the smaller predators is what occurred in a small, coastal town in North Carolina. The cownose ray is now ten times more common in the Chesapeake Bay area than it was in the 1980's. This is where the domino effect begins. Indirectly, the sharks are actually a form of protection for the animals at the bottom of the food chain. By eating the mid-level predators, such as the cownose rays, they prevented the smaller fish and shellfish from being eaten uncontrollably.

In the 1980's, the cownose rays, in their smaller numbers; made a small dent in the scallop population in the Chesapeake Bay area. This was good for the local seaside towns. At that time, the seafood industry was booming. By 1996, when the cownose rays were numerous, they ate all the scallops and by 2004, many of the local scallop fisheries, scallop boats and markets had to close. They still remain closed today. As you see, the disappearance