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."
With additional funding from the National Geographic Society, Gedamke and Costa returned to the reef in 1998 and 1999, recording a total of 92 hours of whale sounds during 49 encounters.
By carefully matching the sounds they recorded with their logs of whale sightings, the researchers were finally able to nail it down. The bizarre sounds were, indeed, coming from the minke whales. They published their findings in the current issue of the Journal of the Acoustic Society of America.
Gedamke speculates they succeeded because they made their recordings at a different time, and in a different location, than other researchers who had also tried to catch the minke yapping. The whales at the Great Barrier Reef, called dwarf minkes because they are a little smaller than the two other minke populations in the Northern and Southern hemispheres, just seemed to love all the attention.
"Minkes in general have been known to be curious," Gedamke says, "but this particular population is really unlike anything else that's out there." Sometimes, the Undersea Explorer would just stop and drift, without a whale in sight, and within a few minutes whales would suddenly appear and start circling the boat. "We had one encounter that lasted almost 11 hours," he says. "Probably eight to 10 whales just circled the boat. It was amazing." The researchers, along with tourists who were along for the ride, repeatedly slipped into the water to socialize with the whales. "It's an absolutely incredible, surreal experience to be in the water, holding on to a line that's being towed behind the Undersea Explorer, and looking around and seeing whales everywhere you look."
Dwarfs at 14 Tons
Gedamke admits it can be a bit intimidating. These animals may be called dwarfs, but that doesn't mean they are small. Adults are about 30 feet long, and weigh up to 14 tons. "Here's this huge creature that's swimming around, coming within a few feet of you, and very clearly eying you up and down. So the first time you get in the water you might be a little intimidated by the size of these animals, but once you are in there for just a few minutes you realize they are completely passive. "They will just circle for hours on end, looking at us, looking at the boat and going about their lives," Gedamke says. "It's just an incredible experience." Gedamke could even hear the Star Wars sounds as he swam with the whales. If the animals were close enough, he could feel the acoustic waves pushing through the water, announcing that the whales were yakking it up. But it's not real clear just what they were trying to say. Gedamke theorizes it may be a mating sound, which would explain why it was heard so clearly in the courting area and not in the high seas, but he admits no one knows for sure. Maybe the whales were just saying that when nature talks, you better listen.
Lee Dye’s column appears weekly on ABCNEWS.com. A former science writer for the Los Angeles Times, he now lives in Juneau, Alaska.