Researchers have found that the unusual "biotwang" sounds come from Bryde's whales. The photo shows a Bryde's whale swimming through a school of fish. Getty Images
Researchers have finally uncovered the source of unusual sounds emanating from the Mariana Trench, the deepest part of the world's oceans. These intriguing noises, known as "biotwang," bear a resemblance to the sound effects of sci-fi starships. In reality, they are the calls of Bryde's whales, which may be using these vocalizations to locate one another, much like a game of Marco Polo.
The strange sounds were first detected in 2014 during an acoustic survey conducted with underwater gliders in the Mariana Trench, located over 1,500 miles south of Japan and reaching depths of nearly 36,000 feet. The biotwang consists of two distinct components: a deep, rumbling sound and a higher-pitched, metallic tone, reminiscent of the futuristic sounds from popular space movies like Star Trek and Star Wars.
Initially, scientists were puzzled by these sounds. In 2016, it was suggested that they originated from large baleen whales, such as blue or humpback whales, although they didn’t match any known calls. Recent research, published on September 18, has now confirmed that Bryde's whales are responsible for the biotwang, thanks to advances in artificial intelligence.
Using AI tools, researchers analyzed over 200,000 hours of ocean audio recordings. This extensive data review led them to observe ten Bryde's whales near the Mariana Islands, with nine of them producing the distinctive biotwang sound. "Once, it's a coincidence. Twice is happenstance. Nine times, it's definitely a Bryde's whale," remarked Ann Allen, the study’s lead author and an oceanographer with the National Oceanographic and Atmospheric Administration’s Pacific Islands Fisheries Science Center.
To conclusively link the whales to the sounds, the researchers matched the noise patterns with the migration habits of the Bryde's whales. They sifted through years of audio captured by monitoring stations around the Mariana Archipelago. By converting the biotwang into visual representations called spectrograms, the team employed machine learning algorithms to differentiate these sounds from others in the recordings.
The strange noise from the Mariana Trench has been explained at last. Live Science
Interestingly, the study revealed that biotwang was only heard in the northwest Pacific, suggesting that a specific group of Bryde's whales is responsible for these calls, despite the species roaming over a broader area. The research also indicated a noticeable increase in biotwang sounds during 2016, coinciding with an El Niño event that raised ocean temperatures and attracted more Bryde's whales to the region.
While the exact purpose of these unusual calls remains a mystery, researchers speculate that they serve as a form of contact communication among the whales. "It's possible that they use the biotwang as a contact call, a sort of 'Marco Polo' of the ocean," Allen explained. However, more research is needed to draw definitive conclusions about the reasons behind these fascinating sounds.
