Researchers have finally been able to unravel the mystery of strange noises emanating from the depths of the deepest point in the world’s oceans. These mysterious sounds, known as “biotwangs,” are reminiscent of noises from science fiction movies and have been linked to the calls of Bryde’s whales (Balaenoptera edeni). Scientists suggest that these sounds help the whales find each other.
LiveScience writes about this.
Unusual noises were first recorded in 2014 during an acoustic survey of the Mariana Trench, the deepest trench on Earth, which reaches a depth of 10,935 meters and is located south of Japan. The biotwang sound is divided into two components: the first is a deep, growling tone, and the second is a high-frequency metallic ringing, reminiscent of the sounds created by spaceships in movies like star wars AND journey to the stars.
At first, researchers were puzzled by the origin of these sounds. In 2016, it was suggested that biotwang might be related to the calls of large baleen whales, such as blue or humpback whales. However, these sounds did not correspond to any previously known whale song.
New study published in the journal Frontiers in marine sciencesallowed us to say with certainty that these noises are made by Bryde’s whales. This was made possible by the use of artificial intelligence (AI), which analysed more than 200,000 hours of audio recordings of underwater sounds.
Researchers already suspected that Bryde’s whales could be the source of the biotwang when they sighted a group of 10 whales in the Mariana Islands and recorded the sounds of nine whales. The study’s lead author, oceanographer Anne Allen, said: “One case can be considered a coincidence. Two cases are an accident. But nine are clearly Bryde’s whales.”
To definitively prove that Bryde’s whales produce biotwangs, the scientists compared the timing of the sounds’ occurrence to the whales’ migratory routes. To analyze years of audio recordings, the researchers used AI to turn the sounds into spectrograms, making them easy to separate from other noises.
The study also found that the biotwang is only found in the northwest Pacific Ocean, despite the wider distribution of Bryde’s whales. This may mean that only a certain population of these whales make such sounds.
Interestingly, there was an increase in biotwang in 2016 which coincided with rising ocean temperatures due to El Niño, with more Bryde’s whales arriving in the area.
While the exact reason for the unusual sound of these calls is still unknown, researchers suggest that the biotwang could serve as a kind of “communication signal,” analogous to the game of Marco Polo in the ocean. “But we need more data to draw definitive conclusions,” Allen added.
