A great white graduates

The white shark that drew crowds to the Monterey Bay Aquarium for 6 1/2 months set a record for surviving in captivity before being released Thursday. Now officials are starting to reflect on the lessons learned from their ability to keep one of the ocean’s biggest and wildest creatures in a tank.

“The main reason for their success was the planned methodical approach to getting her here,” says Jon Hoech, general curator at the aquarium. “In the past, fishermen caught a shark and tossed it into a tank.”

According to Hoech, the rescue of the white shark was the culmination of three years of planning that allowed researchers to set up camp with a 3-million-gallon holding pen off the Malibu coast. When the shark was accidentally snagged last August in a halibut gill net off Huntington Beach, a white shark breeding ground, researchers were on site in 45 minutes.

They placed the shark in the ocean pen where it was left for 25 days, becoming acclimated to confinement, eating and regaining strength. It was transported to Monterey Bay in a 3,000-gallon life-support system hauled by a semi truck.

The aquarium last had a white shark in its tanks more than 20 years ago, but it wouldn’t eat and survived only 10 days. In 1981, SeaWorld San Diego set a record for holding a white shark on display for 16 days. The SeaWorld shark also failed to eat and died. (Since 1955, only 26 white sharks have been held in captivity.)

According to Hoech, this particular shark’s size also played a role in its survival. “We started with a very young and small animal,” he says. “She was 4 1/2 feet long. And the environment here was a tank whose design is conducive to some sharks.”

The aquarium’s Outer Bay exhibit contains 1.3 million gallons of water and is large enough for sharks to swim and grow. It also doesn’t seem to be affected by electric fields, which in the past have disoriented white sharks, which interpret these impulses as prey and cause them to bump into the walls. In the aquarium environment, researchers were able to monitor how much the shark ate, her food preferences and her swimming patterns.

“We have a set of data that has never ever been possible to get before,” Hoech adds. “We knew exactly how big she was when she got in and how much she weighed when she left and how much she ate -- down to the gram.”

The team developed a diet that included multiple vitamins, whole fish and fish fillets, including wild salmon. Because other species, such as sand tiger sharks, have been known to get fat under similar conditions, adjustments were made to portion size and feeding times to be sure the white shark remained lean and sated.

From its initial measurement of just under 5 feet and 62 pounds, the shark grew to 6 feet 4 inches and weighed, upon its release, 162 pounds.

Officials made the decision early last week to release the white shark two miles offshore south of Monterey Bay after she met certain criteria that biologists had previously set. Not only was she getting too large for her surroundings, but she also was starting to behave aggressively toward other sharks in the tank.

Biologists were also able to observe how the juvenile shark related to other fish that were about five times as large, such as a giant blue-fin tuna and other species of sharks. In addition, research biologists developed new techniques for diving with white sharks.

“We learned that unlike other sharks in that exhibit, she was not fearful of people,” says Hoech. “She wasn’t aggressive; you just had to give her the right of way. So we evolved a technique and tools. We researched the use of chain mail as a protection against a bite.”

The data are significant because so little is known about the species. When Greg Skomal, a shark specialist with the Massachusetts division of Marine Fisheries, sits down with elementary school children to talk about sharks, he is asked questions that neither he nor his colleagues are able to answer.

“We don’t know their relative abundance or their population or status,” he says. “We don’t know their overall distribution. We don’t know the movement patterns of the species in any area -- where are they going and what are they doing. Where do they give birth to their young. How long do they live. What is their growth rate, or their feeding ecology.”

Such a dearth of information puts scientists in a difficult position when they try to make decisions about management of the species. “White sharks are a critical component of the marine ecosystem, and the fact is: We know so little about them that we don’t know how critical they are,” says Skomal.

But according to Hoech, the ultimate success of the project is cultural. “We positively influenced hundreds of thousands of people to care more about sharks,” he says. “Through our mission we inspired people to care for the animal.”

Ken Peterson, a spokesman for Monterey Bay Aquarium, says more than 850,000 people have visited the aquarium since the arrival of the white shark in September 2004, an increase of 30% over the same period the previous year.

According to author and shark expert, Richard Ellis, the aquarium succeeded by being responsible and not turning the shark’s capture into a circus. It was a major accomplishment, says Ellis, in a culture that is still fascinated by the movie “Jaws.”

“They refuted the mythology of ‘Jaws’ because they showed that you could handle one of these creatures and it doesn’t leap out of the water and bite the curator’s head off,” says Ellis, who worked in the 1980s at the California Academy of Sciences in San Francisco. “It really is a beautiful animal, and that is the way they chose to present it.”