Scientists don't know why the minke whales produce the sound, but it is believed to be a form of communication between the mammals. Photo / Thinkstock
It was a bizarre phenomenon that troubled researchers for decades - a mysterious under sea 'quacking' heard every winter and spring in the depths of the Southern Ocean.
But now experts believe they have finally established the origin of the noise. They say that the distinctive duck-like sound is produced
by the undersea chatter of Antarctic minke whales.
According to Biology Letters, researchers attached microphones to two of the marine mammals and heard them making the strange sound.
It was first detected by submarines in the 1960s and since then, the repetitive, low-frequency noise has been recorded many times in deep, uncharted waters around the Antarctic and western Australia.
At first, scientists believed the noise could have come from another submarine. Others posed theories involving ships and fish, but none have provided conclusive evidence until now.
