Há mais de 100 dias, um exemplar de Carcharodon carcharias, fêmea, de aproximadamente oito meses, vem sendo mantido em cativeiro pelos pesquisadores do Monterey Bay Aquarium.

Os cientistas estão aproveitando para estudar os hábitos desta espécies, já que históricamente todas as tentativas de manter exemplares de tubarão-branco em cativeiro fracassaram.

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Posted on Thu, Dec. 23, 2004

Great white learning experience

Scientists have plenty to study as shark spends landmark 100th day in captivity at aquarium
By JULIA REYNOLDS Monterey (Calif.) Herald

While the Monterey Bay Aquarium celebrates a record 100 days of captivity today for its great white shark, researchers are focused on their unique opportunity to study shark habits.

Randy Kochevar, a marine biologist at the aquarium, said researchers are focused on maintaining the health of the 4-foot-4-inch female shark, now estimated to be 8 months old. She was brought to the aquarium on Sept. 14, three weeks after she was inadvertently captured by a Southern California fisherman.

"We don't know a lot about shark growth patterns," Kochevar said. "How does she grow? We don't know what a typical life span is for white sharks. They don't lay down growth rings like other fish, so we don't know if they're living 20, 30 or 50 years."

Researchers began by measuring the shark's food intake, length and weight. Now they hope to update length estimates by using lasers and video cameras, without having to lift her out of the water.

Kochevar said there has been at least one surprise.

"The white shark has a different feeding style. The last couple of feet between them and their meal, they tend to kind of lunge at it," he said. "She bit a pole, so we're using a stouter pole now, with a longer lead between pole and food."

Kochevar said the aquarium won't try to keep her there indefinitely. Eventually, the shark could grow too large to lift out of the tank, so she will be released to the wild before that. The record known weight for a female shark is 7,000 pounds.

She is kept in the aquarium's million-gallon Outer Bay exhibit.

"So far, it's been wildly successful. One hundred is a nice landmark," Kochevar said of the shark's anniversary at the aquarium. "But is 101 any different? I don't think so."

According to an aquarium fact sheet, the previous record for keeping a shark in captivity was 16 days.

"She's doing wonderfully well," Kochevar said. "She had some abrasions from when she was captured that are healing well. If you have an animal that is really stressed, superficial injuries tend not to heal readily."

He dismissed concerns that after a lengthy period of captivity the shark might be unable to fend for herself in the wild, because as soon as sharks are born, they leave their mothers and live on their own.

"She came into this world with everything she needed to know about finding food," Kochevar said. "We have released many, many sharks back to the wild and they've done just fine."

Although he believes that exhibiting the animal is important for raising the public's awareness about conservation issues, Kochevar knows that the popular image of sharks as a deadly enemy to humans is hard to overcome. This week in Australia, authorities are attempting to hunt down and kill a great white after it attacked and killed a teenager, despite pleas from the boy's father to let the animal live.

"I can understand the vengeance mentality," Kochevar said. "But sharks don't prey on human beings. We are not a food item of theirs; it's always a case of mistaken identity.

"The only way to ensure 100 percent safety on beaches is to stay out of the water. You can go out and shoot one shark and 10 sharks will still be out there."

He said shark attacks are very rare occurrences, considering the millions of people who go in the water every year.

"We have shared a really magnificent animal with a great number of people who are learning that sharks are facing threats," he said.

Aquarium staff have no plans to name the shark.

"This is an animal borrowed from nature, and we hope to return her to nature," he said.

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January 22, 2005
Great white shark doing well at aquarium

MONTEREY - As Manny Ezcurra gently dipped a long stick with a mackerel attached to the end of it, the great white shark swam smoothly on its back up to the surface and gobbled the fish with only the slightest splash.

No frenzies. No "Jaws" music. Just the rattle and hum of aquarium machinery.

That's the calm, uneventful way of life for the great white shark housed at Monterey Bay Aquarium.

That serene nature is good news for the animal's health, as well as aquarium visitors, officials said.

The fact that the nameless shark, which has called the aquarium home since mid-September, continues to flourish is a major accomplishment. No other white sharks are known to be on display in the world, and the longest any have been held previously was 16 days.

"I think it's beyond everybody's expectations," said Randy Kochevar, the aquarium's science communications director.

The aquarium's aim is not just to sell tickets - though the shark's presence certainly has accomplished that - but also to foster appreciation of a species much maligned in pop culture.

The approach seems to be working. Stand in front of the exhibit, and it won't be long before a chorus of visitors will say in unison, "There she is!".

Indeed, the shark has been a major factor in the aquarium's attendance surge: About 1.9 million people visited the aquarium in 2004, up from 1.6 million in 2003.

In the gift shops there is no shortage of shark-related items - mugs, DVDs, T-shirts, caps, mugs - just to name a few.

"One thing we know about sharks is that people are fascinated with them," Kochevar said. "Shark merchandise has always been one of the things we know we can move."

School kids, young couples and retirees were gawking at the shark one day this week.

"We've been here before, but my wife said we should come see her before she gets too big," said Stig Davidson of San Mateo. "This is so nice."

The gawking won't last forever, because aquarium scientists are pondering an exit plan when the shark grows too big for its current tank. Eventually, the shark will be returned to the wild. The aquarium wants to ensure the animal doesn't grow too big to be lifted and taken to sea.

Just when that will happen, and how it will be done, is a work in progress. No aquarium has had to deal with that challenge before.

"We're learning ourselves," Kochevar said.

On Wednesday, as the shark swam amid its tankmates - soupfins, hammerheads and tuna - its tailfin barely moved as it glided through the aquarium's Outer Bay exhibit.

"That is a very relaxed swim pattern," said Ezcurra, senior aquarist. "When we see that glide pattern it means she is really relaxed."

The swim pattern and the fact that she is eating have been positive signs during the shark's stay.

She appears to be growing at a healthy rate as well. When brought to the aquarium, the 4-foot-long shark weighed 62 pounds.

Ezcurra estimates her weight now at about 80 to 90 pounds.

Each day around 11 a.m., aquarium staff prepares a special meal for the shark. A salmon filet along with two mackerels with a multivitamin stuffed into them are readied in a small lab one floor above the shark tank.

Ezcurra attaches one piece of food at a time to a stick, then walks out on a catwalk above the water's surface.

A mix of fish blood and salmon oil from the meal is dumped into the water first, to gauge the shark's appetite. Just one mackerel was filling enough Wednesday. After taking it, the shark swam by the salmon offering several times without so much as a nibble.

"I'm not concerned about her not eating all of this," Ezcurra said. "We just want to have enough in case she is hungry."

After the meal, Ezcurra logs how much the shark ate in a notebook documenting daily eating habits.

That data is part of the aquarium's scientific study of great whites.

"We're continuing to learn about growth, feeding and food conversion," Kochevar said. "That's the kind of study you can't do in the wild."

Aquarium scientists, however, have not abandoned researching in the wild. Data is expected within the next few weeks from great white sharks tagged with tracking devices in 2002 and 2003. And researchers plan to return to the sea this summer for more study.

"We're continuing to do field research," Kochevar said.

bseals@santacruzsentinel.com.

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