The first time he heard the strange sound coming from the waters around Australia's Great Barrier Reef, Jason Gedamke thought he had somehow slipped into a science fiction movie.
"The first thing I thought of was, wow, it sounds like a laser gun out of Star Wars," Gedamke says.
Listen to the minke whale's Star Wars vocalization.
Gedamke, a doctoral candidate specializing in underwater acoustics at the University of California, Santa Cruz, had gone to the reef to study the minke whale, one of the most curious animals on the planet. He had hoped to record whatever sounds the minkes make, although many experts thought these were relatively quiet creatures, possibly making no distinctive sounds at all.
So Gedamke wasn't sure what the strangely mechanical sound he heard that day was, but he was sure of one thing as he strolled down the deck of the eco-tourism vessel Undersea Explorer. It couldn't possibly have come from a minke. "I told people [aboard the boat] I just heard the craziest sound in the world. But there's no way it came from a whale. I just didn't believe it," he says. "The sound is really synthetic, metallic, like somebody banging on an oil drum, or something like that. It doesn't sound like anything biological." But now, after recording the sounds over three seasons, Gedamke has changed his tune. The sound was, indeed, coming from minke whales that were so curious about humans that they seemed to search for the boat that carried tourists and researchers into their waters.
Skeptical Mission to Australia
Gedamke and his faculty adviser, Daniel Costa, professor of ecology and evolutionary biology at UC Santa Cruz, had gone to Australia at the invitation of Andy Dunstan, a scientist on the Undersea Explorer. The owners of the boat were trying to link eco-tourism with scientific research, and Dunstan had called Costa because of an unusually curious group of minke whales that returned to the reef each year to mate.
Dunstan hoped the California researchers could record any sounds made by the minke whales, despite the fact that many researchers had tried that elsewhere with no definitive results. So with a fair degree of skepticism, and a grant from the Office of Naval Research, which is always curious about underwater sounds, the two headed for the reef. After all, who's going to turn down an invitation like that? They took along a hydro phone array, consisting of five underwater microphones, to drop in the water alongside the boat and record any sounds. The multi-microphone array made it possible to pinpoint the location of any sounds they picked up, thus increasing the odds of finally answering the question of whether the whales have anything interesting to say.
Aka Guitar Fish, Boingfish
They returned in 1997, from the first of three expeditions, with recordings of the strange sounds they had heard in the waters of the reef. Wanting to be sure of what they had, they sent copies of the recordings to whale experts, but the feedback was not always encouraging.
One said there wasn't any way that sound was made by an animal, or anything biological, and urged the researchers to check with the Australian navy. They did, and found that the navy had not produced the sounds, but had recorded them for 15 years.
"But they didn't know what it was," Gedamke says. "Some guys called it the guitar fish, and other people called it the boingfish, but they didn't know what produced it."