Turn’s out the mysterious Mariana Trench sounds were coming from Bryde’s whales (pictured) Photo: NOAA
Scientists have finally solved a long-running mystery of strange “biotwang” sounds coming from the Mariana Trench. The noises, first detected in 2014 and originally incorrectly ascribed to Minke whales, turned out to be calls from Bryde’s whales, as Live Science reported.
The Mariana Trench is a massive undersea trench at the bottom of the western Pacific Ocean, spanning over 1,500 miles and reaching depths of around seven miles. In 2014, scientists sent autonomous gliders down to the trench to collect acoustic data, but were surprised when they picked up a mysterious sound they dubbed a “biotwang.” At first, the sound was ascribed to Minke whales, as it was similar in tone to the whale’s “Star Wars” call (so named for sounding like a science fiction ray gun).
However, in a new study published in the journal Frontiers in Marine Science, researchers have proven that it was actually Bryde’s whales that were making the noises. The discovery came about partially thanks to AI technology, which was used to sort through over 200,000 hours of audio recordings.
The researchers first suspected the Bryde’s whales were causing the biotwang when they recorded nine of them making the noise while swimming near the Mariana Islands. “Once, it’s a coincidence. Twice is happenstance. Nine times, it’s definitely a Bryde’s whale,” study lead author Ann Allen told Scientific American.
To confirm the finding, the researches then used AI to analyze years of audio recordings from monitoring stations in the Mariana Archipelago and compared it to the migration patterns of Bryde’s whales. The occurrence of biotwangs turned out to be consistent with the Bryde’s whale migrations, thus finally solving the decade-long mystery.
One final question remains, though. Scientists still don’t know definitively why the whales make the peculiar sound, although they have a pretty good guess. “It’s possible that they use the biotwang as a contact call, a sort of ‘Marco Polo’ of the ocean,” Allen told Popular Science. “But we need more information before we can say for sure.”
