Text of

Sound Theory

Science gets high-tech peek inside whale’s head

Published in the Santa Cruz County Sentinel, April 26, 1998

By Larry O’Hanlon

Sentinel staff writer

In the frigid, black depths of Monterey Bay mysterious monsters are killing fish with murderous death beams.

Or so some scientists suspect.

While it sounds like science fiction, new evidence provided by one scientist’s creative use of military and medical technology on a baby sperm whale – the one that died after beaching at Waddell Creek last July – supports the idea that the predatory whale has the hardware in its nose for generating and focusing lethal blasts of sound at its prey.

"It’s the largest, most complicated nose in the world," said cetacean researcher Ted Cranford, who works for the Space and Naval Warfare Systems Center in San Diego. A full third of a sperm whale’s body is its nose, he said.

In an unprecedented adaptation of military technology, Cranford used the three-dimensional X-ray facility at China Lake Naval Weapons Station to scan the head of the newborn whale. The large China Lake scanning equipment was designed to accommodate huge rocket engines for structural integrity scans, but it’s also great for scanning whale heads, Cranford said.

Cranford processed the massive quantity of data generated from the scan with medical imaging software borrowed from a company called Vital Images, he said. The result is a multicolored, three-dimensional, dissectable computer model of the sperm whale’s head.

"Now we can stand back and look at it on a computer screen and look at it any way we want to," Cranford said.

Not only is the result useful, it’s just plain neat, say marine mammal experts.

"It’s every bit as good as anything you’ve seen on National Geographic," said Dave Casper, a marine mammal veterinarian at UC Santa Cruz Long Marine Lab who helped orchestrate the collection of the whale’s head from the beach.

The inexplicably huge and complex noses of sperm whales have long been the object of speculation by biologists. Some scientists figured the nose serves as a flotation device used by the whale in its deep sea hunting dives. Others, like UC Santa Cruz’s renown cetacean expert Ken Norris, have weighed in with the idea that the nose is a sound generating organ that may focus sound waves to deliver debilitating blasts of sound at its prey.

Scientific ignorance about the sperm whale nose has hinged partially on the fact that no one had a good enough idea how a sperm whale head was put together and how all the mysterious anatomical machinery is arranged. That problem stems from the very practical problem of finding sperm whale specimens to study.

"Sperm whales aren’t uncommon," Casper said, "but sperm whales are deep divers" so when one dies it rarely washes up onto a beach. Being so near the deep waters of the Monterey Bay certainly played a part in why the baby sperm whale – with part of its umbilical cord still attached – came ashore at Waddell Creek beach, he said.

Before Cranford dreamed up the idea of scanning a whale head, researchers had no alternative but to rush to beaches where whales washed ashore and perform hasty dissections before decay ruined it or the tide came in. That was a difficult way to learn about whale anatomy, said James G. Mead, curator of marine mammals for the National Museum of Natural History in Washington, D.C. Not only was it hard work, but it was difficult to visualize how all the parts fit together in an intact whale, Mead said.

Decades ago researchers started learning a lot about sperm whales by dissections done at whaling stations, Mead said. Since then however, getting information about these leviathans has been a matter of luck and timing. As a result, Cranford’s scan is a breakthrough in cetacean study.

"You can see the relationship of structures in the head a lot better," said Mead about Cranford’s scan. "It’s a fantastic tool."

Mead’s only criticism of the scan is that the resolution of the color images is somewhat poor. But that’s because getting color images and a finer resolution would have required an overwhelming amount of data that would have been very difficult for anything but a supercomputer to process.

Despite this, the scan still provides extremely valuable information, he said. Among the most exciting revelations from the scan is the particular alignment of a series of mysterious structures in the sperm whale nose. The alignment supports the idea that they might be acoustical lenses, Cranford said. According to some researchers, such lenses might focus sound created by the whale – much like a glass focuses light – to create a stunning blast of sound.

"Sound can stun prey," Cranford said. And although no one has heard or seen a sperm whale actually zap a school of fish or squid, there is circumstantial evidence they can do it, he said. A nasal stun gun would explain, for example, why full-grown sperm whales that have injured or missing lower jaws have been found with bellies full of fresh fish, he said. With an acoustic paralyzer in your nose, fishing becomes more like grazing: just open your mouth and swim through stunned fish, then swallow, Cranford said.

To figure out if the mysterious nose structures are acoustic lenses, Cranford said he plans to take the information from the scan and create computer models to test whether the structures could physically function in that manner. But that project will take time and money that Cranford doesn’t have right now. He’s still thanking his wife for letting him spend their savings on the China Lake scan after scientific institutions told him his idea wouldn’t work.

"They said it was impossible," Cranford said, referring to the reaction he got to his original proposal, which was to scan a gray whale head, Grant givers at the National Science Foundation and the National Geographic Society acknowledged that it was a great idea, he said, but not feasible.

But now that Cranford has proven that the technique works. Mead hopes someone will try scanning other whale heads or perhaps an entire dolphin or porpoise. There is still so much mystery about the workings of our ocean-going cousins, Mead said, that more scans of any whales at all would be a tremendous scientific windfall.

Back to Features page