New, complex call recorded in Mariana Trench believed to be from baleen whale

Date: December 14, 2016

Source: Oregon State University

A sound in the Mariana Trench notable for its complexity and wide frequency range likely represents the discovery of a new baleen whale call, according to the Oregon State University researchers who recorded and analyzed it.

Scientists at OSU's Hatfield Marine Science Center named it the "Western Pacific Biotwang."

Lasting between 2.5 and 3.5 seconds, the five-part call includes deep moans at frequencies as low as 38 hertz and a metallic finale that pushes as high as 8,000 hertz.

"It's very distinct, with all these crazy parts," said Sharon Nieukirk, senior faculty research assistant in marine bioacoustics at Oregon State. "The low-frequency moaning part is typical of baleen whales, and it's that kind of twangy sound that makes it really unique. We don't find many new baleen whale calls."

Recorded via passive acoustic ocean gliders, which are instruments that can travel autonomously for months at a time and dive up to 1,000 meters, the Western Pacific Biotwang most closely resembles the so-called "Star Wars" sound produced by dwarf minke whales on the Great Barrier Reef off the northeast coast of Australia, researchers say.

The Mariana Trench, the deepest known part of the Earth's oceans, lies between Japan to the north and Australia to the south and features depths in excess of 36,000 feet.

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