Mysterious sounds from the Mariana Trench finally explained

Scientists have been puzzled by strange underwater noises, known as “bio-chirps,” since they were first heard near the Mariana Trench in 2014. These strange sounds have been described as a combination of low rumbles and high-pitched metallic ringings, reminiscent of eerie sounds from science fiction movies. For years, the source of these noises remained unknown, although it was suspected that they were related to marine life. A recent study confirms that Bryde’s whales (Balaenoptera edeni) are responsible for these unique sounds. Researchers believe that whales may use these sounds as a way to communicate across the vast ocean.

Biotwang’s Discovery and Analysis

The calls were originally 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 have struggled to pinpoint the source of these unusual sounds. In 2016, researchers suggested that the calls could come from large baleen whales, such as blue whales or humpback whales, although they couldn’t be sure at the time.

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

Tracking Bryde’s Whales

Ann Allen, an oceanographer at NOAA’s Pacific Islands Fisheries Science Center, led the study. Her team found that the calls matched the migration patterns of Bryde’s whales, confirming their involvement.

The researchers observed Bryde’s whales in the area and recorded several whales making the calls, further confirming the connection. Interestingly, the biophony calls were only detected in the Northwestern Pacific, suggesting that the calls may be unique to a specific whale population.

Although the exact purpose of the chirps is still unclear, scientists think they may be a form of long-distance communication.