Mysterious sounds from the Mariana Trench finally explained

Strange underwater sounds known as “biotwang” noises have puzzled scientists since they were first heard near the Mariana Trench in 2014. Described as a combination of a low growl and a high-pitched metallic jingle, the strange sounds are reminiscent of eerie sounds from science fiction films. For years, the source of the sounds remained unknown, although it was suspected that they were related to marine life. Now, a recent study has confirmed that Bryde’s whales (Balaenoptera edeni) are responsible for the unique sounds. Researchers believe the whales use the noises as a way to communicate across the vast ocean.

Discovery and analysis of Biotwang

The biotwang sounds were initially recorded by underwater gliders during an acoustic survey of the Mariana Trench, according to a study published in the journal Frontiers in Marine Science. Scientists struggled to identify the origin of these unusual sounds. In 2016, researchers suggested that the sounds likely came from large baleen whales such as blue whales or humpbacks, although they couldn’t be sure at the time.

It wasn’t until 2023 that the source was definitively traced to Bryde’s whales, thanks to new advances in artificial intelligence (AI). The AI ​​tools sifted through more than 200,000 hours of recordings to help researchers identify the biotwang calls.

In search of Bryde’s whales

Ann Allen, an oceanographer at the National Oceanographic and Atmospheric Administration (NOAA) Pacific Islands Fisheries Science Center, led the study. Her team found that the biotwang sounds matched the migration patterns of Bryde’s whales, confirming their involvement.

The researchers observed Bryde’s whales in the region and recorded several making the sounds, further cementing the connection. Interestingly, the biotwang sounds were only observed in the northwest Pacific, suggesting that these calls may be unique to a specific population of whales.

Although the exact purpose of the biotwang calls remains unclear, scientists believe they are a form of long-distance communication.