In the 1960s, the ocean ‘quacked’. Scientists are close to finding out why

Over four decades after the mysterious 'Bio-Duck' sounds were first recorded in the Southern Ocean, researchers may be close to unraveling the enigma. Ross Chapman, a professor emeritus of ocean acoustics at Canada's University of Victoria, presented his team's work at the virtual 187th Meeting of the Acoustical Society of America, discussing mystery recordings and providing further evidence of a conversation between multiple animals. 

Chapman's research involved analyzing data recorded during an experiment in July 1982, where researchers from Victoria University of Wellington recorded strange, short tones resembling quacking while creating a soundscape of the South Fiji Basin, contributing to the ongoing mystery of the 'Bio-Duck'. 

The regularity of the sounds initially suggested they were not of biological origin. Upon further analysis, Chapman's team determined that the sound had to be coming from an animal. "We discovered that there were usually several speakers in different places in the ocean, and all of them were making those sounds," Chapman stated. "Then the first speaker would stop talking and listen to responses from others," highlighting the possibility of a conversation between the creatures, he added. 

The researchers used an acoustic antenna, a group of hydrophones towed behind a ship, to detect and record ocean sounds from all directions. This allowed them to pinpoint where exactly the unusual sounds were being made.Despite these findings, there was no independent evidence of visual sightings of the whales emitting the sounds in the New Zealand data.

Even if the sound is always made by Antarctic minke whales, there's still a mystery: the purpose of the calls remains unknown. "Maybe they were talking about dinner, perhaps they were parents talking to their children, or maybe they were just commenting on that crazy ship that wouldn't stop going back and forth towing that long cord behind it," Chapman speculated. 

In 2014, scientists were able to link the 'Bio-Duck' sound to Antarctic minke whales (Balaenoptera bonaerensis) using tags that recorded the whales' behavior, providing conclusive evidence that the sound was produced by these whales. 

The findings were reported on by Science Alert, Popular Science, and IFLScience, among other websites.

This article was written in collaboration with generative AI company Alchemiq