Protectors and Monsters
In many traditional Pacific island cultures, sharks play an important role in human lives and are revered. Fishermen seek their protection and assistance, and reciprocate with gifts of food and song. Fijians have a shark god named Dakuwaqa, who protects the people of Kadavu Island from shark attacks--so they’re not afraid to go into the water. Some native Hawai’ians continue to pay respects to their shark 'aumakua a particular animal whom they can identify and who recognizes them, and who indeed may be a reincarnated family member. Stories are told of men at sea who were rescued and brought home by their 'aumakua.

A California surfer who has spent some years on the beaches of Hawai’i said that Hawai’ian surfers "have a pact with the sharks," so that neither will harm the other. In the rare incidents when a shark attacks a surfer, it’s understood to be a case of mistaken identity: from below, a surfer paddling on a board looks like a sea lion or a sea turtle, favorite foods of great white and tiger sharks, respectively.

Adkison said he’s seen tiger sharks and great whites heading toward him from below more than once. "When you see that, the only thing to do is to dive straight toward him," he said. "He sees he’s made a mistake and turns away."
In much of the Western world, however, sharks are feared more than they are understood, and the vital role they play in the ocean is not widely known. From the 1778 painting Watson and the Shark by John Singleton Copley, to Hemingway’s Old Man and the Sea, to the movie Jaws, popular culture has painted a vivid picture of sharks as bloodthirsty snaggle-toothed horrors. Many of my friends are terrified of sharks--and they don’t even swim in the ocean.

"The fewer sharks the better," is a widely shared view. Yet one result of the North Atlantic shark decline has been the decimation of scallop beds along the East Coast of the United States. In a healthy ecosystem, the big sharks keep populations of smaller sharks and rays, which feed on shellfish, in check; throw that ecosystem out of whack and, well, all hell breaks loose. Andy Nosal suggests that a factor contributing to the recent spread of huge Humboldt squid from Mexico south to Chile and north to Humboldt County, where they are decimating hake, may be the absence of sharks that prey on them.

"Large sharks are at the top of the food chain and directly control the population of species in the food web, including marine mammals," Nosal explained. "When they’re gone, there’s a trophic cascade, a chain reaction down the food web, and entangled in that are things we like to eat."

Tracking Pacific Sharks
Much of what scientists know about sharks they have learned in the last 50 years, said Nosal. With acoustic telemetry--the use of underwater receivers to monitor radio tags--researchers have gathered information about movements of several types of migratory sharks. For most of these wide-ranging species, however, very little is known about mating, or where the sharks give birth.

Sharks range in size from the world’s largest fish, the filter-feeding whale shark, which can reach 50 feet in length, to the six-inch (yes, inch) spined pygmy shark. Most of these animals go about their business quietly, snarfing up crustaceans from reefs and fish out in the open ocean, while a very few--such as the great white--have a taste for marine mammals. (Hence the occasional attack on a human in waters off California and Australia.)