Swimming with sharks stirs fears - for the fish

The Georgia Aquarium lets divers swim with the giant but gentle whale shark. (John Bazemore/Associated Press)

ATLANTA - Vikas Chinnan stood over a tank at the world's largest aquarium, peering down at the world's largest fish species. He was wondering what it would be like to jump in and frolic beside the whale sharks.

The creature approached, eerily quiet. It was longer than a Ford Expedition, impossibly elegant as it banked into a turn at the tank's edge, flexing its gray, massive, mottled form into a parabola of living flesh.

"Oh man," muttered Chinnan, 32, one of eight divers who had paid $290 for the privilege. "I hope they fill up our [oxygen] tanks, because I'm going to be breathing hard."

Whale sharks are as harmless as they are imposing, preferring plankton to people. But with the Georgia Aquarium launching its "Swim With Gentle Giants" program this month - allowing a dozen swimmers and divers per day to enter the sharks' habitat - marine specialists fear it is the humans who could pose a threat.

Much of the trepidation has to do with the 2 1/2-year-old aquarium's track record with whale sharks. Last year, two died for reasons that baffled staffers. Today, the best hypothesis, according to spokeswoman Meghann Gibbons, is that they reacted poorly to a chemical treatment used to combat parasites.

Jean-Michel Cousteau - son of famed underwater explorer Jacques-Yves Cousteau - was critical of the swim-with-the sharks program, given that the aquarium was not 100 percent sure why the animals died.

"They think maybe those sharks died because of some chemical treatment," said Cousteau, founder of the nonprofit Ocean Futures Society in Santa Barbara, Calif. "I certainly don't think there's something to learn from someone swimming with a whale shark."

George Burgess, director of the Florida Program for Shark Research at the Florida Museum of Natural History in Gainesville, agreed. The whale sharks, which roam hundreds of miles in the wild, are stressed by their confinement, he said. And they probably will be harmed further by close proximity to humans - and by potential exposure to germs exotic to them.

The Georgia Aquarium is not the only one in the United States to offer visitor diving programs. But it is the only one outside of Asia to attempt to keep whale sharks, a little-understood animal that can grow as long as 60 feet. The controversy over the swim program has magnified a tension inherent in many big-ticket aquariums, which have proliferated around the globe in recent decades.

Staffers at the Georgia Aquarium have defended the program. The four whale sharks kept in captivity, they said, are monitored loosely.

Spokesman Dave Santucci said that the fish were used to people swimming among them: Last year, he said, humans made about 5,000 trips into the tank for maintenance.