Whale Racket: Sounding out How Loud the Oceans Were from Whale Vocalizing Prior to Industrial Whaling

ScienceDaily (Oct. 23, 2012) — Concern is growing that human-generated noise in the ocean disrupts marine animals that rely on sound for communication and navigation. In the modern ocean, the background noise can be ten times louder than it was just 50 years ago. But new modeling based on recently published data suggests that 200 years ago -- prior to the industrial whaling era -- the ocean was even louder than today due to the various sounds whales make.

California researchers Michael Stocker and Tom Reuterdahl of Ocean Conservation Research in Lagunitas, Calif., present their findings at the 164th meeting of the Acoustical Society of America (ASA), held Oct. 22 -- 26 in Kansas City, Missouri. Using historic population estimates, the researchers assigned "sound generation values" to the species for which they had good vocalization data. "In one example, 350,000 fin whales in the North Atlantic may have contributed 126 decibels -- about as loud as a rock concert -- to the ocean ambient sound level in the early 19th century," Stocker notes. This noise would have been emitted at a frequency from 18 -- 22 hertz.

Read on:  http://www.sciencedaily.com/releases/2012/10/121023123954.htm