Volume (Issue #):
Low-powered sound sources were tested for their ability to deter gray whales from potentially harmful areas. An acoustic device (1-s frequency modulated 1-3 kHz warble deterrent signal) was moored to the seafloor in the gray whales migration path off central Oregon. Observers (land based) tracked whales with a theodolite to locate whales as they passed the headland. Tracklines were compared between times when the acoustic deterrent was on and off. Statistical analysis did not show a significant difference between the hypothesized zone of influence (within 500 m of the deterrent) and areas out to 3 km. Poor weather and equipment issues prevented acquiring an adequate sample size, so the results were considered inconclusive.