Aquarium looks for answers in whale shark death

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How sad,

taken from http://www.cnn.com/2007/TECH/science/01/11/aquarium.death/index.html

ATLANTA, Georgia (CNN) -- Scientists worked Friday to determine what killed Ralph, one of the four giant whale sharks at the Georgia Aquarium.

The 22-foot-long fish stopped swimming Thursday afternoon and divers whisked it from the bottom of its football field-sized tank to an exam area. Teams worked to save him for about eight hours before he died at 9:30 p.m.

"When we found him sitting on the bottom we immediately knew that he was in trouble," said Jeff Swanagan, the aquarium's executive director. (Watch Ralph before he died and how the staff responded )

Swanagan said a necropsy, or animal autopsy, was under way to try to determine the cause of death. Aquarium employees are also monitoring the other animals.

He said whale sharks Norton, Alice and Trixie all seem to be swimming normally.

"We're watching it very carefully, but there's nothing indicating any other problems in the exhibit or anywhere else in the aquarium and no problems with any of the water chemistries," he said.

Ralph was the second popular animal to die at the aquarium in a nine-day period.

On January 2, Gasper the beluga whale was euthanized. He had suffered from a string of chronic illness even before he came to the aquarium.

Swanagan said the deaths were unrelated and that the animals lived in separate tanks with different water supplies.

"To have two big charismatic animals [die] creates a linkage that's probably not there," he said. "I've been doing this since 1979 and I've had cases where I've had two days in a row of births and two days in a row of deaths. Nature just sometimes doesn't give you a schedule of tragedies that's convenient."

Ralph had a physical exam in November with about 50 people taking part -- including veterinarians, biologists, divers and photographers.

Swanagan said the staff was concerned about some unusual swimming behavior a couple of months ago, but that had improved. Ralph's appetite also had been on and off. (Full story)

"There was nothing we could see that would define that this animal was as sick as he turned out to be," he said. Swanagan said there was no indication that stress from the exam could have contributed to Ralph's death but said that was one of the things they would look into.

Saved from the dinner table
Ralph and Norton have been the biggest stars at the aquarium since it opened in November 2005. They were joined by females Alice and Trixie in June.

The aquarium got the whale sharks by negotiating with Taiwan, which catches the animals for food. It is the only aquarium outside of Asia to showcase whale sharks.

The World Conservation Union lists the whale shark as a vulnerable species. Heavy fishing of the whale shark in several areas of Asia is believed to be one reason for its population decline.

Scientists hope to breed the sharks, but Swanagan said that's years down the road.

"The animals are all pre-teenagers and it would be many years before they would be ready to breed," he said. "Our friends in Okinawa, Japan, have had three whale sharks for 10 years in an exhibit that's two-and-a-half times smaller than ours and their animals are not yet breeding."

Mysterious giants
Whale sharks are the world's largest fish and can grow up to 66 feet in length. They are gentle animals that feed on plankton and small fish that they filter into their wide, flat mouths.

Swanagan said the Georgia Aquarium has been working with whale shark researchers for four years, but there are still a lot of things that they don't know.

He said some leading marine scientists worked for years without seeing a whale shark in the wild.

"No one knows, comprehensively, the life cycle of these animals," he said.

Swanagan said he's glad that more than 4 million visitors got to see Ralph.

"People have such an aversion to sharks, so to have these sort of friendly sharks, like whale sharks be ambassadors to get people to want to learn more about sharks is a very important reason to have them," he said.
 
From Georgia Aquariums website http://georgiaaquarium.org/newsroom/pressReleases/011107whaleUpdate.aspx

Press Release


WHALE SHARK DIES AT GEORGIA AQUARIUM

ATLANTA (Jan. 11, 2007) â€"œ Ralph, one of the four whale sharks rescued by the Georgia Aquarium, died unexpectedly Thursday evening, Jan. 11, 2007.

Earlier in the day, Ralph stopped swimming and the Aquarium’s husbandry and veterinary team moved him into an underwater stretcher in the Ocean Voyager gallery and immediately administered emergency care.

“Our staff is grieving from the loss at this time,” said Jeff Swanagan, President and Executive Director. “We are grateful we had the opportunity to give Ralph two extra years of life and bring four million people face to face with whale sharks for the first time.”

Ralph, who had grown to 22 feet in length, had lived at the Georgia Aquarium since June 2005 along with Norton. Alice and Trixie, two female whale sharks, were added to the Aquarium in June 2006. The whale sharks came from Hualien, Taiwan, where an annual quota of whale sharks is harvested for food. Through a partnership between the Georgia Aquarium and the Taiwanese government, the whale sharks were removed from this quota and brought to the Georgia Aquarium. The Georgia Aquarium is the first aquarium outside of Asia to house whale sharks and was the only one in the world to have four on display.

Recently, Ralph’s behavior caused concern among the team due to his unusual behavior, including loss of appetite and abnormal swimming patterns. During the last few weeks, the Aquarium team performed regular medical exams to monitor the whale shark’s health.
Since the Georgia Aquarium opened in November 2005, four million people have viewed the whale sharks, increasing the knowledge base of these animals worldwide. In November 2006, the Georgia Aquarium demonstrated its continued commitment to the understanding of aquatic animals by conducting routine physical exams on the four whale sharks as part of an effort to establish a baseline of normal biology in whale sharks. These exams were the first of their kind, and information learned was shared with researchers throughout the country and added to the database being developed to understand the zoogeography of whale sharks.

A necropsy, or animal autopsy, will be performed to try to determine the cause of death. The results will also allow the Aquarium to advance the knowledge of the species, about which very little is known.

About Whale Sharks
The whale shark is the world’s largest fish, reaching lengths of up to 66 feet. This species of shark, known to the scientific world as Rhincodon typus, is a gentle filter-feeding species. Found worldwide in tropical and subtropical waters, the whale shark is gray to brown in color with light yellow or white markings and a white belly.

Despite its large size, the whale shark is harmless to humans and considered a relatively solitary creature. It has a wide mouth with approximately 3,000 small teeth at the front of its wide, flat head and swims slowly at the surface to feed on plankton and small fish.


Its behavior and basic biology, such as where it travels in the oceans, reproduces and feeds during different life stages, are not well known.

About the Georgia Aquarium
The Georgia Aquarium in Atlanta, Georgia, is the world’s largest with more than eight million gallons of water and more than 100,000 animals of 500 different species. The mission of the Georgia Aquarium is to be an entertaining, educational and scientific institution featuring exhibits and programs of the highest standards, offering engaging and exciting guest experiences and promoting the conservation of aquatic biodiversity throughout the world. For additional information, visit www.georgiaaquarium.org
 
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