That question intrigued bioacoustician Whitlow Au, of the Hawaii Institute of Marine Biology, Kailua, and colleagues John Horne and Christopher Jones, of the University of Washington, Seattle. The discriminating taste of the killer whales suggested that the marine mammals were using echolocation to select their dinner, and the scientists wanted to determine why a Chinook sounds different than a Coho or Sockeye. Au's team used simulated killer whale echolocation signals and the measured the structure of the echoes as they bounced back from the three salmon species.
The results indicate that "the echo structure from similar sized but different species of salmon were different and probably recognizable by foraging killer whales." Au said that the radiographic images of the echoes show differences in the "swimbladder shape and volume" in the different species, and the whales can use that to pick the fish they like. The results, Au said, suggest that an echo-sounder could be developed that, when pointed down into the water, could be used to discriminate among salmon species.
The talk, "Backscatter measurements of three species of salmon using simulated killer whale echolocation signals" (2pAB2) by Whitlow W. L. Au, John K. Horne, and Christopher D. Jones will be at 1:50 p.m. on Tuesday, November 11.
2) GIVING A NEW VOICE TO LARYNGECTOMY PATIENTS
Prosthetics for patients with cancer have improved significantly using new technologies, materials, and methods such that their disease and its effects are not apparent to those
|Contact: Jason Bardi|
American Institute of Physics