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Wednesday, November 16, 2005
Aquarium hopes to breed whale sharks
The Atlanta Journal-Constitution
Georgia Aquarium officials say they want to breed whale sharks — the biggest fish on earth — at the Atlanta fish tank, a never-attempted feat that would push the bounds of known aquatic science.
The world’s largest aquarium, which opens its doors to the public next week, has two juvenile male whale sharks now swimming in a 6.2 million-gallon tank. Officials want to get at least one female for a possible breeding program.
John Spink/AJC
Ralph (or is that Norton?) may one day become the proud papa to 300 whale shark pups.“I would love to breed the whale sharks because very little is known about these animals,” said Home Depot co-founder Bernie Marcus, who is funding most of the aquarium’s $280 million construction cost. “The more that we proliferate the species the better. You learn about these animals, and you can save the species by reproducing them.”
Aquarium Executive Director Jeff Swanagan said the Ocean Voyager tank was designed with the capacity to hold four to six whale sharks, which can grow to the size of a school bus. He said there are no immediate plans to bring more whale sharks to Atlanta, but confirmed the facility would like to acquire a female.
“This is a long-term venture, and that’s why we had to design this exhibit so large,” Swanagan said. “This isn’t going to happen quickly. It will happen over years and years of research on these animals.”
Said Marcus: “Whether or not we get another whale shark, I can’t tell you. But if we can, we probably will.”
Shark scientist Robert Hueter, who is studying whale sharks off the Yucatan Peninsula, said he thinks breeding whale sharks in captivity is feasible.
“It’s all doable, but it would take a major effort to sort all of the issues out,” Hueter said.
Hueter, who directs the Center for Shark Research at Mote Marine Laboratory in Sarasota, Fla., said other types of sharks have been bred in captivity. Any breeding program in Atlanta could be years off, he said, because the Georgia Aquarium’s two whale sharks, Ralph and Norton, are still sexually immature.
“I can’t imagine they would be ready for mating any sooner than three years, and it could be longer than that,” Hueter said.
Scientists think male whale sharks do not reach sexual maturity until they are about 27 feet long, Hueter said. Ralph and Norton are growing, but measure less than 20 feet.
Atlanta aquarium officials initially thought they had a male-female pair, which they first dubbed “Ralph and Alice” after the characters in the old TV sitcom, “The Honeymooners.”
Ray Davis, the aquarium’s vice president for zoological operations, said when the big fish were first captured in Taiwan an initial exam confirmed Ralph was a male. The other whale shark appeared to be female — males are identified by so-called “claspers” on their underside, organs that are difficult to detect in immature animals.
“They called me [from Taiwan] and said, ‘Hey, we have Alice,’” Davis recalled. “I said, ‘Are you sure? And they said, ‘Absolutely.’ So I asked them to go back and get me photographic proof.”
A close examination of the photos revealed the truth, Davis recalled.
“It was very hard to discern, but you could see it on the photograph. Alice was really Norton.”
Very little is known about whale sharks in general and almost nothing is known about their courtship and breeding behavior, Hueter said. The gentle plankton-eaters, which can grow to more than 40 feet, are found in most of the world’s warm-water oceans.
They are considered a threatened species because they are killed for food in some countries. But no one knows how many exist or how the populations around the globe are related.
A pregnant female killed by Taiwan fishermen has provided a few hints about the creature’s reproduction, Hueter said. That huge fish had 300 immature “pups” inside, he said. The Georgia Aquarium’s two whale sharks were purchased from a Taiwan fishery where they too were destined for the dinner table.
Many varieties of sharks have been bred in captivity, Hueter said, including sandbar sharks, bonnethead sharks, bamboo sharks, sawfish and rays. Sawfish and rays are closely related to sharks.
Swanagan said scientists have no idea whether a whale shark program would involve natural breeding or artificial insemination.
“All of this would be new ground,” he said. “The body of knowledge [obtained], even if we are not successful, can be shared with field scientists as they try to figure out how to manage this animal in the wild.”
Swanagan said aquarium scientists have already “explored” what they would do if a female whale shark gave birth to a large number of pups in captivity. They would release the young sharks into the wild at some point, he said, but that would require the clearance of numerous government agencies and a complex plan to raise the whale shark pups to release size in offshore pens.
The pups are only about 18 inches at birth, Swanagan said, and scientists would have to create a “head start program” to get them ready for release.
“You want to improve their chances of survival,” he said. “You wouldn’t just want to throw them back in.”
Well-fed fish don’t munch on tank mates
The Atlanta Journal-Constitution
Nobody likes seafood better than, well, seafood — a fact of life in the aquatic food chain that has not been lost on the folks who oversee the soon-to-open Georgia Aquarium.
John Spink/AJC
Is that a look of satisfaction on this grouper’s face? It’s not telling, but chances are it’s not eyeing its neighbors for its next meal.So, gulp, how does the world’s largest aquarium — with 100,000 aquatic creatures representing 500 species — keep its small fry from becoming fast food for the bigger ones?
“We feed ‘em ” says Georgia Aquarium spokesman Dave Santucci.
For decades, in fact, public aquariums throughout the country have been serving up more fish — to their fish — than a sushi bar.
These days the menu for a typical five-star aquarium includes salmon steaks, frozen mackerel, chopped squid, brine shrimp and plankton. And, of course, tons of commercial fish chow — pelletized, gelatinized, flaked, ground and pureed and laced with essential vitamins and minerals.
Unlike gluttonous landlubbers, fish tend to stop eating once they’re full — a trait that aquarium operators have learned to use to their advantage. Good for the smaller fish. And good for the customers.
If the fish are fat and happy, visitors get to see an uncharacteristically peaceable kingdom where the eating of one’s tank mates is the furthest thing from a fish’s mind.
“It takes a tremendous amount of energy for a predator to hunt down its prey and kill it,” says Ken Ramirez, vice president of collections at the Shedd Aquarium in Chicago.
“By keeping everyone well fed, we reduce the incentive for them to chase down and eat other fish in the tank,” he says. “The only time we tend to have problems is when we introduce new fish into the tank that haven’t learned they don’t need to hunt anymore.”
Three squares a day, of course, isn’t the only strategy. Big tanks enable small, fast fish to do what they do best in the wild — flee. And the carefully constructed hidey holes of rock and coral allow small, slow ones to hide.
Occasionally, of course, fish will just be fish. Instinctive behavior that worked in the open ocean is sometimes more compelling than fish chow.
Only last year, for instance, the Monterey Bay Aquarium in California proudly put a rare great white shark — accidentally caught by a halibut fisherman off the coast — on display in its three-story Outer Bay tank. Attendance at the aquarium shot up 30 percent and for a while, things went swimmingly.
Then, in February, the 6-foot great white — despite steady feedings of vitamin-enriched salmon and albacore tuna — attacked and killed a smaller soup fin shark in the tank.
In ensuing weeks, it attacked another and began chasing other sharks — a pattern that prompted aquarium officials to decide that the shark — and its instincts — were better suited for the open sea. They released it back into the Pacific Ocean.
“At some level, you have to accept that most fish are predatory creatures,” says aquarium curator Mark Faulkner. “And most aquariums don’t want to lose the fish in their exhibits.”
“It’s not common, but it happens,” says Jackson Andrews, director of operations for the Tennessee Aquarium in Chattanooga. “Sometimes, after introducing a school of fish into a tank, we’ll see that after awhile there are fewer of them.”
But Andrews says sharks, despite their malevolent popular image, are often the model residents of community tanks.
“We had to pull some angelfish out of a tank once because they were just pecking the dickens out of the sting rays,” he says. “And people who work in our tanks have taken to wearing hoods because the triggerfish have a tendency to swim up and nibble on an earlobe.”
But aquarium managers also recognize that fish sometimes need to dine the old-fashioned way. “We sometimes feed live fish to our dolphins and some other species,” says the Shedd’s Ramirez.
“But we would never do that out in front of the public. We think our guests would just have too much difficulty with it.”
Injured beluga on the mend, rebounding from stress
The Atlanta Journal-Constitution
Visitors to the Georgia Aquarium will soon see more than 100,000 fish and other animals in the world’s largest aquarium.
They will also see one very large patient, who just happens to be a mammal.
Gasper, the beluga whale rescued from abhorrent conditions at a Mexico City amusement park, is now recovering in an 800,000-gallon tank in the Cold Water Quest exhibit.
Gasper and Nico, both males, were brought to the aquarium Oct. 17. Nico was healthy, but Gasper suffered from two large, infected bite marks (courtesy of Nico) and several grapefruit-sized lesions on his white skin.
John Spink/AJC
Gasper the friendly beluga is feeling better these days.Tim Binder, director of husbandry for the Georgia Aquarium, said the Mexico City belugas were stressed from water conditions and the location of their tank. It was situated near a rollercoaster, a tough spot for animals that are sensitive to sound.
“The new owners of the park realized the circumstances, and knew they had to get them out of there,” Binder said.
Aquarium officials say workers at the Mexico City amusement park were doing the best they could for the animals under very bad circumstances. There was considerable stress on the animals, Binder said, and it is very likely Gasper would not have survived had he not been relocated to Atlanta.
Nico and Gasper now share an 800,000-gallon tank at the Georgia Aquarium with three female belugas on a “breeding loan” from the New York Aquarium on Coney Island. Aquarium officials hope baby belugas will be on the way in the next few years.
“The girls have already warmed up to the boys,” said Jeff Swanagan, the aquarium’s executive director. “they’re already forming friendships and maybe a litte more than that.”
Howard Krum, head of veterinary services and conservation medicine at the Georgia Aquarium, said personnel from Atlanta began treating Gasper with antibiotics a month before he left Mexico and have stepped up treatment since his arrival.
“He (Gasper) was unresponsive in his tank in Mexico City,” Krum said. “He didn’t look at people. He was laying like a log at the bottom of his tank.”
Since Gasper’s arrival, Georgia Aquarium officials have done blood work, biopsies and cultures to direct his final phase of treatment.
Both Krum and Binder said the treatment program appears to be working. Gasper has gained about 150 pounds since his arrival, his wounds are healing and he is very active in his tank.
“It’s difficult to speculate on a long-term prognosis,” Binder said. “But so far, we’re encouraged by what we have seen.”
