Those efforts are leading to some surprising findings, including the discovery by a team of researchers of rare right whales swimming in the Gulf of Alaska.
"There has been only one confirmed sighting of a right whale in the Gulf of Alaska since 1980, so discovering them is not only surprising, it is fairly significant," said David K. Mellinger, an assistant professor at Oregon State University's Hatfield Marine Science Center in Newport. "We picked up the sounds of one whale off Kodiak Island, and several others in deep water, which is also something of a surprise, since most right whale sightings have been near-shore."
Results of these and five years of studies have been published in the January 2006 issue of the journal BioScience. Mellinger said scientists have been able to use the hydrophones to distinguish sounds made by different whale species. And some species, he added, have different "dialects" depending on where they are from. Blue whales off the Pacific Northwest sound different than populations of blue whales that live in the western Pacific Ocean, and those sound different from populations of blue whales off Antarctica.
And they all sound different than the blue whales off Chile.
"The whales in the eastern Pacific have a very low-pitched pulsed sound, followed by a tone," Mellinger said. "Other populations use different combinations of pulses, tones and pitches. The difference is really striking, but we don't know if it is tied to genetics, or some other reason.
"There are also some hybrid sounds that are rare," he added. "We don't know if they are part of a common 'language' that different populations of whales use to communicate with each other, or if they come from a confused juvenile who hasn't completely le
Contact: David Mellinger
Oregon State University