WEST SACRAMENTO — From a boat in the brackish waters of a backwater delta channel, Bernie Krause and his scientific colleagues lower an underwater speaker that emits a staccato symphony of grunts, squeals and squeaks.
They're whale noises, some of which the 68-year-old bio-acoustics expert captured 16 years ago off the Alaska coast as he hovered above a pod of humpback whales in a tiny kayak. Now the gray-haired connoisseur of nature's otherworldly sounds is using this whale language to reach out to an injured mother humpback and her calf circling in the depths below.
Krause is a whale whisperer. And he's spearheading an effort to rescue two wrong-way cetaceans that last week strayed from their seasonal migration on a misguided 100-mile journey up the San Joaquin River Delta.
Now the whales, both injured in an apparent run-in with a boat propeller, have reached a dead end in a murky inland channel not far from the state Capitol dome. Racing against time, a host of governmental agencies for days has tried to coax the leviathans back to sea.
Krause has spent nearly four decades recording natural sounds worldwide -- from pristine underwater soundscapes to jaguars in the Brazilian jungle to corn growing in Iowa.
He earned an international reputation in 1985 when he turned his attention to a whale known as Humphrey, who had ventured many miles into the Sacramento Delta. Using tapes of whales' feeding and social noises, the Detroit native helped coax the wayward humpback out into the open ocean.
On Friday, Krause and a team of scientists tried, for the second straight day, to reprise that success. But the two whales weren't taking the bait.
"The animals are just not responding," Krause said. "It might be from the noise of the boats or aircraft flying overhead or from the effects of their injuries. We just don't know."
Humphrey spent 26 days wandering inland waters, but experts worry that the mother and her calf don't have that much time.
Although the adult humpback's wounds are not life-threatening, officials aren't so sure about the calf, which they believe was nursing when the propeller struck the pair.
The whales' injuries have added pressure and drama to the rescue effort as dozens of reporters wait for updates near the Port of Sacramento and hundreds of onlookers watch from a nearby levee.
On Friday, the news still wasn't good. Scientists varied the sounds. They fiddled with the speaker volume. They changed boats. Nothing worked.
"They call me a whale whisperer," said a frustrated Krause. "Yeah, right. Nature always has the last laugh."
A former musician who plays violin and guitar, Krause became a pioneer of electronic sound in the 1960s and helped introduce the Moog synthesizer to pop music and film.
In 1970, he and a partner produced "In a Wild Sanctuary," an album that incorporated recorded natural sounds into the music.
The record changed his life, launching him on a quest with his microphone and recorder to amass what he says is the world's largest collection of natural sounds: 3,500 hours, featuring countless habitats and 15,000 creatures, many of which are now extinct.
Krause has studied whales and their environment and understands why so many people are captivated by the journey of the humpback and her calf.
"People associate with these wild critters. There's something atavistic in our genes, making us long for a simpler time," he said. "Whales just have a presence, being so gentle and coming back from the brink of extinction."
Twenty-two years ago, when asked to take part in Humphrey's rescue, Krause had not yet made any of his own whale recordings. So he used those collected by a pair of University of Hawaii graduate students who studied humpbacks. Krause took the scratchy tapes into his studio and spent hours working on the sound quality.
He recalled the moment Humphrey reacted to the sounds. He and Diana Reiss, a colleague from Marine World in San Francisco, were aboard a 42-foot boat south of Sacramento. The whale had been wandering for weeks and authorities were losing hope in the rescue.
So the two went to work with their whale sounds.
"I have never seen an animal move so fast. That whale was hydroplaning," Krause said. "He was a quarter-mile away and got to our boat in 15 seconds. He nearly swamped us."
A flotilla of boats behind Humphrey slowly moved the whale toward the ocean. Each time he veered off course, officials played more whale sounds, along with pipe-banging noises from behind to herd him along. Meanwhile, tens of thousands gathered along the delta shores to root the whale on.
"Every time the whale surfaced, an incredible roar arose from the crowd," Krause said. "Every so often, he swam toward shore and did a tail slap. It was an emotional experience."
This time around, Krause has played a prerecorded loop of sounds he described as a "whale dinner call."
"It's a long clear tone, lower than a B flat in pitch, and then it slowly ascends," he said. "It's very powerful, very forceful."