Sharks And Ocean Ecosystems Worldwide Are In Danger

October 15, 2009

Release from: Sophie Gaze
Honolulu Advertiser

Last year there were 55 unprovoked shark attacks upon humans, 41 of those in the U.S., including four in Hawaii. By contrast, humans killed about 100 million sharks over the same period, according to the International Shark Attack File, a database administered by the American Elasmobranch Society and the Florida Museum of Natural History.

"When we examine the statistics of the number of shark fatalities from humans versus human fatalities from sharks it is very easy to see that the most deadly predator in the ocean does not even live there," said Hawaii Sharks, a Web site containing content from both local and national shark experts and organizations. "It is important to keep these incidents in perspective, and to remember that in Hawaii the chances of being bitten by a shark are less than one in a million."

The statistics can be put in even more surprising terms: "On average there are two to four attacks per year in Hawaii. Think how many people go into the water year round. There are lots and lots of sharks... that's a very low rate of attack! I believe more people are killed by vending machines falling on them than sharks," said Yannis P. Papastamatiou, a PhD student at the University of Hawaii at Manoa and a member of the Hawaii Institute of Marine Biology.

If the chances of being bitten by a shark are so low, then why is this animal one of the most feared? Some experts blame the media. Film productions such as "Jaws" and shark attack survivor documentaries have created some misconceptions about sharks and the true extent of their threat to humans.

"As humans, our imaginations and Hollywood movies have created an ocean dwelling, deadly, ruthless, cold-blooded, voracious killing machine that roams the oceans and terrorizes man," said Hawaii Sharks. "The entertainment industry has turned the word 'shark' into a word that inspires fear and terror."

Tim Tricas, professor of zoology at the University of Hawaii at Manoa and an affiliate faculty at the Hawaii Institute of Marine Biology believes "the media has vastly improved on factual information over the last few decades" in their coverage of sharks. Tricas attributes some of this to the fact that "the younger generation is interested in conservation."

Forty species of sharks roam the waters around Hawaii, according to Hawaii Sharks. These species range from the eight-inch pygmy shark to the 50-foot whale shark. "The most common species are tiger, sandbar, Galapagos, and grey reef sharks, although the species composition varies based on which island you are on," said Papastamatiou. The most dangerous of these is the tiger shark. This species' wide-ranging diet and opportunistic feeding behavior may be the cause for their high number of attacks on humans.

"If you want to understand sharks, then first study dog behavior," said Tricas who simply states that sharks are creatures of habit and opportunistic predators. "We must think of sharks as animals that will investigate whatever comes into their waters."

As much as the public fears sharks, they are also absorbed by them. For example, Shark Week on the Discovery Channel has been aired for 22 years and is cable's longest running event, according to Discovery Press Web.

There are native Hawaiians who consider sharks to be significant ancestor spirits and respect them. On the Hawaii Sharks Web site there is an interview with the late Parley Kanako'ole, a famous cultural figure in Hawaii and a member of the Shark Task Force. "Sharks, the significance of a shark, especially with the niuhi, the tiger and the white shark, they were compared to as chiefs," said Kanako'ole when asked to describe the shark's implication to Hawaiians further than their roles as ancestors.

Regardless of how sharks are viewed by people, there is no doubt that they play a vital role in the ecosystems of the ocean, although the extent to which is not yet known. "It is difficult to know exactly. Sharks are apex predators and feed at the top of the food chain. However, they generally don't consume large amounts of food," Papastamatiou said.

Sara Pelleteri, the director of education at the Waikiki Aquarium said "many studies show that sharks play a major role in maintaining the health of coral reef systems worldwide." Pelleteri also described a situation in the Atlantic Ocean in which declines in shark populations lead to an increase in ray populations that lead to a decrease in scallop populations. This example demonstrates the shark's influence upon the complex food chain in the ocean.

Shark numbers are "crashing precipitously," according to Pelleteri. She believes the solution is through education and awareness. Sharks are killed for many reasons and their populations are in danger. "Humans must exercise as much common sense as possible," said Pelleteri.

Tricas and many scientists believe that the continued large-scale killing of sharks will result in significant changes in the ocean's ecosystem. "Sharks are a major top predator in almost all marine trophic food webs. Anyone who believes that removing sharks will not change the ecology of the ocean is uneducated," said Tricas. "Should we wipe out tigers, lions, wolves, and other top predators as well?"

"Entering the ocean should be considered a 'wilderness experience' where people are visitors in a world that belongs to sharks," said Hawaii Sharks. "By learning more about sharks, using common sense, and observing safety tips, the risk may be greatly reduced." Safety tips for avoiding unwanted shark encounters can be found on the Hawaii Sharks Website: http://hawaii.gov/dlnr/dar/sharks/index.html.