Most people think of the shark as the ultimate symbol of dread, giants with cold lifeless eyes who cruise the ocean looking for swimmers they can tear from limb to limb. The very word itself is used to describe people in society who prey on others or who engage in deceptive practices.

There is probably not an animal in the world more despised or feared then sharks, ranking right down there with snakes and spiders.

And whether Islanders care to admit it, much of that disdain can be traced to the shores of the Vineyard, where a movie titled Jaws was made three decades ago that shaped many people's opinions of the much-maligned fish.

Now Oak Bluffs is home to the Monster Shark Tournament sponsored by the Boston Big Game Fishing Club. The 21st annual edition of the tournament, which the club said is the largest offshore sport fishing event in New England, gets under way in earnest today and continues through Sunday.

The tournament draws crowds of spectators to the docks of Oak Bluffs harbor to see the dead sharks landed by competing boats, received the backing of town residents in a non-binding ballot question this past April that asked if the tournament should continue to be held on town-owned land.

But this past Tuesday, a relatively short distance from the harbor docks, a film was screened at the Tabernacle that takes a different point of view on sharks.

In his new film Sharkwater, which screened as part of the Martha's Vineyard Film Society's Summer Film Series, filmmaker Rob Stewart dispels myths and misconceptions about sharks.

He describes them not as our enemy but instead as our protectors, animals that play a vital role in the ocean ecosystem by protecting phytoplankton, the micro-organisms that produce between 70 and 90 percent of the earth's oxygen.

Following the screening, Mr. Stewart was on hand to answer questions and to better explain the role that sharks play in ecosystems.

As highly efficient predators, he said, sharks keep ecosystem populations in check by hunting and killing other animals, particularly those that are weak or diseased. Without sharks, populations of other animals would swell to unsustainable levels, which eliminate the available food in their ecosystems, such as phytoplankton.

"Most people don't realize that most of our oxygen comes from the sea, not from the rain forest," Mr. Stewart said. "Burn the Amazon and there would be a tragic loss of species and beauty. Kill the sharks and there would eventually be very few species left all together."

In his film, Mr. Stewart states that the overall shark population has plummeted 90 per cent over the past 40 years. Sharks are targeted because of their valuable fins, which are considered a delicacy in some Asian nations because shark fin soup is considered a symbol of status and wealth.

Mr. Stewart said he was shocked to learn that the Island plays host to the Monster Shark Tournament.

"I think it's disgusting, really, people standing around and watching a creature being cut open," Mr. Stewart told the Gazette. "Sharks are some of the oldest living creatures on the planet, dating back the last 400 million years. They have survived five major extinctions and now they are pushed to extinction by man's greed and ignorance. And here we have an event which seems to celebrate their slaughter. It's barbaric."

As depicted in the film, Stewart teamed up with renegade conservationist Paul Watson of the Sea Shepherd Conservation Society in order to protect the sharks. Their adventures began with a battle between the Sea Shepherd and shark poachers in Guatemala, which eventually led them to gunboat chases, espionage, corrupt court systems and attempted murder charges.

"What started off as a film intended to showcase the beauty of sharks wound up as a chronicle of people's greed and capacity to destroy their own planet," Mr. Stewart said. "I have been swimming with sharks my whole life, and I have never feared for my safety the way I did at times filming the movie."

Mr. Stewart said that despite mounting evidence of dwindling shark populations, the public continues to be apathetic to the problem, largely because of the Jaws mentality that sharks are the cold killers of the deep. That mind-set is reinforced by the media, he said.

"A dangerous shark makes money and sells papers," he said. "If they tell you a shark is beautiful and perfect and wonderful and won't attack you that's only going to make news once. But if they yell out ‘shark attack, shark attack,' it makes the news every time."

This indifference translates to what he sees as a lack of progress on the conservation front. Only a handful of species like whale sharks and the great white shark have been placed on the World Conservation Union endangered species list.

"People are much more interested in saving Pandas and birds then they are sharks. It's all about perception, and people perceive sharks as killers. But that can change - it wasn't long ago that people thought nothing of killing whales - but all that has changed over the past 50 years," he said.

Mr. Stewart's film often casts sharks in an almost reverent light. He describes them as architects of the world, who unlike other species did not have to evolve to survive from predators because they didn't have any. While man evolved out of the sea and started things like civilization, war and religion, sharks simply stayed the course, perfecting their role at the top of the food chain.

"I can only hope the human race can survive long enough to reach that same level of perfection that sharks have," he said.

But this reverence quickly turns to anger when Mr. Stewart reflects on the mass killing of sharks. As shown in the film, a vast majority of poachers are only interested in shark fins; so they pull the animals out of the water, cut off their fins, and drop them back into the sea where they slowly bleed to death.

While this weekend's Monster Shark Tournament does not approach that level of cruelty, Mr. Stewart said it sends the wrong message that it is okay to kill sharks. Although the event's proponents point to a nearly 99 per cent catch and release rate, Mr. Stewart says that many of the sharks released either die or are traumatized for the rest of their lives.

"How would you feel if someone dragged you around for hours on a giant hook? Anyone who thinks those animals are not damaged are delusional," he said.

Tournament organizer Steve James could not be reached for comment this week, but in an interview earlier this year he said some animal rights groups such as the Humane Society of the United States are propagating a "sport fishing jihad."

He said the tournament organizers are dedicated to promoting ethical and conservative fishing practices while assisting state and federal agencies in scientific research programs.

All of the sharks killed during the event are catalogued and studied by marine biologists and scientists. Last year, the tournament paid for several tracking devices attached to sharks that were released back into the ocean.

Tournament officials also donate meat from the sharks to senior centers and food banks both on and off the Island.

Mr. James said: "Sometimes I think we [the people involved in the tournament] are more concerned with the well-being of the sharks then some of the groups that oppose the event. We make huge strides to learn more about them, while they seem more interested in attaching themselves to a visible event that helps them with fundraising and donations."

Two major changes are in store for the tournament this year. The network ESPN will not be on hand to tape the event as they have done in the past, and organizers have taken blue sharks and tiger sharks off the list of acceptable catches for the tournament. Now, only thresher, mako and porbeagle sharks will count for weigh-in points.

In a published report, Mr. James said the change had nothing to do with the public campaign by the Humane Society. Instead, he said, the sharks were crossed off the list because they are not preferred game fish in the area.

At Tuesday's screening of Sharkwater, however, there were signs that support for the shark tournament may be waning in some quarters. At the end of the question-and-answer period, a visibly moved and uncommonly articulate 12-year-old boy approached Mr. Stewart and lauded him for his film and his dedication.

"You've opened my eyes, and I want to thank you for it," the boy said. "I used to think sharks were these man-eaters, these monsters, but I was wrong. And seeing this [film] makes me want to make a difference. We have to stand up and say this cannot happen anymore."