Jan. 25, 2005 — The whale that won world attention by swimming through central London died from severe dehydration while trying to head westward back to its North Atlantic feeding grounds, experts said Wednesday.

The young northern bottlenose whale had not been able to feed for three days after swimming up the shallow River Thames and was also suffering from muscle damage and reduced kidney function, preliminary postmortem results showed.

The whale was a juvenile female, sexually immature and probably less than 11 years old, experts revealed. It measured 5.85 meters (19 feet) in length and weighed several tons.

Its unlikely journey and failed rescue generated round-the-clock live television coverage and drew popular wonder and sympathy.

Paul Jepson, the veterinary pathologist of the Zoological Society of London (ZSL), insisted the Thames whale did not die in vain as it had aroused interest and its remains would enhance scientific understanding of the creatures.

The whale was probably lost in the North Sea and trying to head back to the deep waters of the northeast Atlantic to find squid, experts said.

Jepson explained: "Whales and dolphins obtain water from their food and northern bottlenose whales normally feed on deep-water squid in the Atlantic Ocean.

"This animal would not have been able to feed while in the North Sea and so would have become dehydrated."

Jepson and his team of scientists examined the rare whale's body for up to eight hours at the dockside in Gravesend, downstream from London, and samples were sent back to the ZSL for further analysis.

The whale amazed onlookers by swimming past several London landmarks on Friday. Such a creature had not been seen in the Thames since records began in 1913.

As news of the bizarre sight spread, people flocked to the river to see the animal, which swam more than 40 miles (60 kilometers) from the open sea.

Jepson dismissed speculation that sonar from navy warships exercising in the North Sea could have disorientated the whale.

"Some scientists have speculated that northern bottlenose whales sometimes get into the North Sea by taking a wrong turn at Scotland," he said, outlining the most likely explanation for the whale's extraordinary journey.

"They use their innate sense of navigation to try and get back west to where they actually belong in the northeast Atlantic, often by perhaps trying to swim up rivers, despite shallow water and human presence."

Rescuers tried Saturday to return the whale to the North Sea, lifting it by crane onto a barge. However, it suffered convulsions and died halfway along the journey near Gravesend.

ZSL veterinary scientist Becki Lawson said the whale's condition deteriorated rapidly on the barge.

"Her main body systems were collapsing at that stage," she said.

Jepson was ready to put down the whale humanely. "While I was drawing the lethal injection, she died," he said, adding there was nothing more they could have done.

Laboratory tests for infections and pollutants were continuing.

The whale's bones are to be donated to Britain's Natural History Museum and the entire skeleton will be kept for scientific research.

Jepson said: "The last few days have been an unforgettable and ultimately sad experience for us all, and we are now determined that the whale did not die in vain."

He said the mammal's extraordinary plight had evoked popular passion for conserving whales and that all the knowledge gained from the experience should be shared as widely as possible.

The British Divers Marine Life Rescue charity, which tried to save the whale, is auctioning online a watering can used to keep the whale moist to raise money for future rescues.

The price had reached 125,300 pounds (182,800 euros, $224,000) after 186 bids, with seven days remaining until the auction closes, while a slew of other whale memorabilia, some highly dubious, are also up for grabs.