Wrong-Way Whale Taught the Experts a Thing or Two

Humphrey, the humpback whale rescued from the Sacramento River and lured back out to sea, taught researchers volumes about the behavior of its species--and a good deal about the behavior of human beings too, scientists said Tuesday.

The unprecedented opportunity to study the whale so closely offered new clues to how humpbacks may navigate by using sonar and the currents, how they respond to noise and electromagnetic forces, and how well they can survive in fresh water.

At the same time, the operation to free Humphrey demonstrated the depth of public concern for whales and taught whale lovers and government agencies how they can work together.

Scientists and leaders of the rescue effort gathered here Tuesday to discuss their successful mission and dismantle their command post in an old California Department of Transportation building overlooking the strait separating the Sacramento River and San Francisco Bay.

“I think the main thing we learned was about people and the love and generosity they poured forth,” said Debbie Ferrari, half of a husband-and-wife team of marine biologists who helped inspire the rescue effort.

Humphrey, one of an estimated 10,000 humpback whales left in the world, was escorted two miles past the Golden Gate Bridge at dusk Monday and by Tuesday had disappeared into the Pacific.

For the first time since the celebrated whale entered San Francisco Bay on Oct. 10, there was not a single reported sighting of the 40-ton mammal.

“You hear the slogan a lot: ‘Save the Whale. Save the Whale,’ ” said Mark Ferrari, who with his wife has studied humpbacks in Hawaii for years. “All these people got together and actually saved one. If we saved one, maybe we can save the whole species. And if we can save the species, there’s hope for mankind.”

Because rescuers were unable to implant a satellite transmitter into the whale’s blubber, they have no way to track the animal. The Ferraris hope that when they return to Hawaii this winter, they will be able to identify the whale from photographs taken of its tail, which in whales are as individual as human fingerprints. The Ferraris have catalogued photographs of about half of the 1,200 humpbacks living in the Pacific.

For 3 1/2 weeks, scientists watched the whale closely as they drove it down the Sacramento River toward the Golden Gate.

One discovery about the humpback’s navigational system came Monday as the whale swam through San Francisco Bay.

Instead of moving with the tide, as rescuers had expected, the giant mammal repeatedly swam against the current.

“Maybe he feels he has more control,” said Charles Fullerton, regional director of the National Marine Fisheries Service, who headed the rescue operation in the final days. “It’s something we’re going to look at.”

During their observations, the researchers gathered evidence that humpback whales may use echolocation, a sonar method of navigating used by other whales but never before observed in humpbacks.

When the whale was trapped behind a small bridge several weeks ago, marine biologist Diana Riess recorded the animal’s groans and whistling sounds, which she will analyze to see if Humphrey was indeed echolocating.

Rescuers also discovered that each time the whale passed under power lines and the electromagnetic force they cast, it seemed to lose its sense of direction and began swimming in circles. At least once, rescuers arranged to turn off power lines to lessen the whale’s confusion.

Originally, researchers predicted Humphrey could not survive more than two weeks in fresh water. They were particularly concerned that the fresh water would break down the skin’s ability to repel salt in the ocean.

But the only harm marine biologists observered were large blisters on the whale’s skin, which quickly disappeared once the animal returned to salt water.

Humphrey’s response to man-made noise was another significant discovery. The whale reacted much more positively to the tape-recorded sounds of other humpbacks feeding than it did to the unpleasant banging of pipes in the water or loud explosions. But both helped in herding the animal back toward the sea.