Baffling increase in white shark attacks

sharkwhite_260406

After splashing and yelling to his brother that a great white shark was swimming his way, Achmat Hassiem watched as it changed course — toward him.

The 13-foot shark bit his right foot, shook violently and took him under. Seconds later Hassiem was pulled into a nearby boat, alive but missing his right foot.

The Aug. 13 episode in False Bay was the latest in a string of great white incidents around Cape Town that have stirred emotions about a creature often demonized, intensifying a debate about how to balance safety and conservation.

Some surfers say “rogue” sharks that repeatedly turn up near people should be killed. Researchers insist rogue sharks do not exist and that a hunting ban imposed by South Africa in 1991 is key to the endangered species’ long-term survival.

Looking for clues to explain the trend, some people have pointed a finger at the growing cage-diving industry that puts tourists in an underwater cage and lures great whites with bait for a close encounter. So far no research has found any link between cage diving and attacks. Others suggest that overfishing has lured hungry sharks closer to shore. And some say there are simply more people in the water.

What everyone does agree on is that there has been an increase in unprovoked shark bites on people, or small craft, along Cape Town’s nearly 200 miles of shoreline. In the last four years, 13 have been recorded, three of them fatal; in the previous 42 years, there were 17, one fatal.

Nearly all of the attacks are thought to have involved great whites. In two of the recent fatalities — a woman swimmer and a spear fisherman — the bodies were never recovered.

“We’re looking for a balanced approach to this issue without flying off the handle and reacting every time something happens,” said Gregg Oelofse, Cape Town’s environmental policy and research coordinator.

To that end the city is expanding to 11 beaches a shark-spotting program that a group of surfers started at two beaches in 2004. Lookouts on hillsides or in towers sound a siren to warn of a shark and can close a beach until it swims away.

The city plans to put independent observers on cage-diving vessels in False Bay to ensure that operators do not purposely feed sharks — which could condition them to associate boats with food — and do not abuse the animals by enticing them to smack the cage solely to thrill tourists.

Cape Town also is exploring the viability of using exclusion nets to repel sharks from certain beaches. Unlike shark nets used off Durban’s Indian Ocean coast, exclusion nets have fine mesh that does not entangle sharks or other creatures. The nets could be removed whenever whales were present to ensure they were not harmed.

Apart from the shark spotting, none of the measures would enhance safety for surfers, kayakers and surf-ski riders who venture a couple hundred yards from shore. (Nets work only in calmer water between the shore and breakers.)

The relative newness of kayaking and surf-skiing as sports in Cape Town, along with advanced wetsuits enabling surfers to remain in the chilly water for hours, have raised the odds of shark-human encounters, Oelofse said. Most involve great whites, considered the top fish predator of the seas, and might occur when a shark mistakes a person for a seal or is simply curious or aggressive.

In July, Lyle Maasdorp, 19, had a close call off Fish Hoek while riding a surf-ski.

“Lyle said he felt the back of his surf-ski lifting out of the water and he heard a crunching sound,” wrote an official with the National Sea Rescue Institute. “He fell off his surf-ski and realized it was a shark when his hand landed on the shark’s back.”

Unhurt, Maasdorp scrambled onto another person’s surf-ski and found safety on rocks.