Shark.
Reports of shark attacks close entire beaches or small sections of coastline to swimmers. The sight of a large gray dorsal fin in ocean water stirs memories of partying teens being heartlessly gobbled up by the relentless 'Jaws.'
They're vicious movie villains, the antagonists of films such as 'Mako: The Jaws of Death.' Burt Reynolds nearly mussed his hair treasure hunting among them in 'Shark!' And Roy Scheider and his 'Jaws' successors had to electrocute and explode the homicidal great white before it stopped returning for sequels.
But fear of the sharp-toothed sea creatures is based more on hype than the actual danger they pose, says Howard Hall, director of the documentary 'Island of the Sharks.' The film opens Saturday at Carnegie Science Center's Omnimax Theater.
Hall, who spent much of 350 hours underwater filming them around Cocos Island, a remote dot in the Pacific Ocean which author Robert Louis Stevenson called 'Treasure Island,' says sharks aren't even attracted to human blood.
Hall likens sharks attacking humans to a human biting a pine tree - it's a dumb mistake made by a smart creature.
Last year's worldwide statistics for shark attacks on humans stands at about 100, resulting in 10 known deaths. No statistics were available on human attacks on pine trees.
'Infinitesimal' risk
Dr. Samuel Gruber, a highly renowned shark researcher, calls the probability of a shark attack 'infinitesimal.'
Gruber, professor of Marine Biology at the University of Miami's Rosenstiel School of Marine and Atmospheric Science, asks instead, 'When do humans pose a threat⢠And that would be all the time.'
He says that, of the 370 to 420 species of sharks in the world, about six are known for attacks, most often because of human provocation. Gruber prefers not to use the word 'attack,' because he says 70 percent of reported confrontations have nothing to do with the sharks feeding.
One of the more common injuries is from the mild-mannered nurse shark. Humans occasionally grab the nurse shark's tail, and it in turn bites the offender. The only species he says that probably will attack if a human comes too close to its cave is the Australian woddiegong.
The great white - the most fear-inspiring of all sharks - bites humans less often than the nurse shark.
High fear factor
Despite the findings of researchers such as Gruber, the fear of sharks hasn't waned.
Dr. Frank A. Ghinassi, chief of adult services at Western Psychiatric Institute and Clinic in Oakland, says the fear of sharks isn't irrational, but it's excessive when one considers the rarity of actual attacks.
Ghinassi compares the high fear factor caused by rare shark attacks with the fear of plane crashes.
'The number, even though it's a very small one, doesn't relate to the magnitude of the event,' he says.
Shark attacks just appear more likely, he says. 'It's not just a random event or machine going bad, but there is a creature that is imbued with a lot of malevolence. ... They evoke childhood fears.'
Much of the blame for today's fear of sharks Ghinassi places on the media, especially Hollywood. He says the media induces hypervigilance through sensationalistic stories.
He mentions other fears Hollywood has exploited, such as tornadoes in 'Twister' and spiders in 'Arachnophobia.'
Gruber and Hall say some shark documentaries appearing on the Discovery Channel, in which divers swim in cages underwater near exposed raw meat to bait the sharks, exaggerate the behavior of the creatures.
Hall's not saying the cold-blooded hunters are really sensitive souls, but that the typical behavior of sharks 'doesn't make for good commercial television.'
He says 'Island of the Sharks,' which actually focuses on Cocos Island's whole diverse and healthy underwater ecosystem, is about catching life as it is there - untouched by humans. That includes how white-tip, hammerhead, black-tip and silky sharks behave there.
Feeding time
There was a risky encounter with sharks while filming 'Island of the Sharks,' Hall says. Silky sharks had herded together a 'bait ball,' or tightly packed school of fish. They swam through the cloud of smaller fish, loudly crunching whatever they could between their jaws.
If a diver should be so unfortunate to enter that bait ball, Hall says, he or she could be chewed by the sharks, which have poor vision and swim blindly through the swarm as they feed.
Gruber's only advice to avoid shark incidents is to avoid swimming at night, when sharks feed. And if an area of the ocean seems unsafe to swim in, just avoid it.
'It's just common sense,' he says.
Most divers will never have to worry about such a conflict. Gruber's research has found a more likely killer as people go through the course of their daily life - toppling soda machines.
Derek Fuchs can be reached at (412) 320-7987 or dfuchs@tribweb.com .
