by Shi En Kim/Smithsonianmag.com
In the vast depths of the ocean, pygmy blue whales are hard to spot despite their immense size—the length of two buses. Luckily, they’re loud enough to eavesdrop on.
With the help of a network of deep sea, nuclear bomb-detecting microphones, researchers have now found an entirely new population of these whales lurking in the Indian Ocean, simply by listening in on their distinct song patterns, reports Angela Heathcote for Australian Geographic. This group is the fifth known pygmy blue whale population residing in the Indian Ocean, which makes the area a thriving locale for the species.
Scientists identified the new population of pygmy blue whales while analyzing almost two decades’ worth of acoustic data from underwater nuclear bomb detectors in the bottom of the Indian Ocean, according to a study published April 22 in Scientific Reports.
Run by the international Comprehensive Nuclear-Test-Ban Treaty Organization, the deep-sea mics are meant to listen for illegal nuclear bomb tests in the ocean. The organization’s long-term data collection incidentally came in handy for monitoring whale populations when the recordings inadvertently picked up their songs.