What

What

Catherine Griffin
Published: 07/16/2012


Photo: Tom Clifton / CC BY-NC 2.0

There’s been a lot of talk about “Jaws” lately, given a few recent shark incidents. In June, two great whites were detected by an acoustic receiver off of the coast of Cape Cod. Then, after a 14-foot great white shark trailed a kayaker only 150 yards off of Cape Cod on July 7, officials shut down the shore. That same day, an 18-foot great white tried to take a bite out of a kayak in Santa Cruz. None of the incidents resulted in injury (unless you count the bite marks that the boat received), but it was enough to send the media into a Jaws-inspired frenzy, with outlets such as ABC and CBS news mentioning the Hollywood fish legend.

Yet, despite what the horror flick suggests, these sharks aren’t interested in people—they’re interested in seals. The burgeoning population of these mammals near Cape Cod attracted the sharks. Seals have been protected since 1972 when the Marine Mammal Protection Act was passed, which prohibits anyone from harming or harassing any marine mammals. On the west coast, Oregon and Washington are nearing their carrying capacity at 22,380 harbor seals while California is slowly stabilizing with a grand total of 34,233 harbor seals.

These populations pale in comparison to the one in New England, though. It’s estimated to be about 91,000 harbor seals and increasing.

While these mammals have benefited from the MMPA, they’ve also rebounded because of a decline in their natural predators; namely, sharks. With shark finning still occurring—a practice that involves hauling a live shark from the water, cutting off its fins, and throwing it (often still alive and bleeding to death) back into the water—sharks are undergoing a steady decline. This means more seals and more attractive hunting spots for great whites.

Unfortunately, kayakers and surfers look very much like seals floating at the surface, which often prompt great whites to investigate and take an exploratory nibble—which can be sizable when it comes to a creature that can weigh as much as an SUV. Yet this is relatively benign behavior compared to the tactics they use when approaching seals.

“I spent five years in South Africa and observed over 1,000 predatory attacks on sea lions by great whites,” said R. Aiden Martin, director of ReefQuest Centre for Shark Research in Vancouver, Canada, in an interview conducted by National Geographic. “The sharks would rocket to the surface and pulverize their prey with incredible force.” Great whites use this hunting strategy on various species of seals throughout the world. In comparison, great whites usually approach humans cautiously rather than immediately attacking.

On July 6, a great white off of South Africa’s coast conducted its own taste test. It bit the leg of a surfer who was paddling on his board, most likely to investigate whether he was a viable food source. The surfer was able to eventually paddle back to shore where he was rushed to a hospital and treated for his injury.

Such incidents create buzz but in truth, great whites rarely attack people. In the 20th century, there were only 108 authenticated unprovoked shark attacks (and that includes all sharks, not just great whites) along the Pacific Coast—not a huge number considering how many people flock to the beach every year.

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