Mysterious Call from Mariana Trench Could Have been from Minke Whale: Research

Mysterious Call from Mariana Trench Could Have been from Minke Whale: Research

Mysterious call from the depths of Mariana Trench recorded earlier, has been identified as per a new research paper published by Oregon State University. Researchers have been trying to figure out the source of that mysterious sound recorded from Mariana Trench. The research team claims that the sound could have been a call from minke whale, a type of baleen whale. The call recorded by researchers from Mariana Trench has frequency range from 38 hertz to 8,000 hertz.

Autonomous robots called passive acoustic ocean gliders have been used to record the call from Mariana Trench. Sharon Nieukirk, senior faculty research assistant in marine bioacoustics at Oregon State University informed that the low frequency sound can be associated with baleen whale’s call.

The sounds were collected by Nieukirk and her colleagues during the fall of 2014 and the spring of 2015. The sounds were recorded in the Pacific Ocean in the Mariana Trench, the deepest part of the ocean.

The research team said that baleen whales use specific vocalizations as mating calls and for feeding. These sounds can be recorded all year long and they could be for some other function.

Nieukirk added, "The species is the smallest of the baleen whales, doesn't spend much time at the surface, has an inconspicuous blow, and often lives in areas where high seas make sighting difficult. But they call frequently, making them good candidates for acoustic studies."

"If it's a mating call, why are we getting it year-round? That's a mystery," Nieukirk said. "We need to determine how often the call occurs in summer versus winter, and how widely this call is really distributed."

A story published by Huffington Post informed, “Scientists have been perplexed for years by a hypnotic, symphonic sound emanating from the deepest trench of the world’s oceans. The five-part song, which lasts from 2.8 to 3.5 seconds, was recorded by an underwater robotic glider equipped with a sensor in the fall of 2014 and spring of 2015.”

The research paper further informed...

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.

Minke whales are baleen whales – meaning they feed by using baleen plates in their mouths to filter krill and small fish from seawater – and live in most oceans. They produce a collection of regionally specific calls, which in addition to the Star Wars call include “boings” in the North Pacific and low-frequency pulse trains in the Atlantic.

“We don’t really know that much about minke whale distribution at low latitudes,” said Nieukirk, lead author on the study whose results were recently published in the Journal of the Acoustical Society of America. “The species is the smallest of the baleen whales, doesn’t spend much time at the surface, has an inconspicuous blow, and often lives in areas where high seas make sighting difficult. But they call frequently, making them good candidates for acoustic studies.”

Nieukirk said the Western Pacific Biotwang has enough similarities to the Star Wars call – complex structure, frequency sweep and metallic conclusion – that it’s reasonable to think a minke whale is responsible for it.

But scientists can’t yet be sure, and many other questions remain. For example, baleen whale calls are often related to mating and heard mainly during the winter, yet the Western Pacific Biotwang was recorded throughout the year.