Sweden Spent Nearly a Decade Chasing Mysterious Underwater Signals — Only to Discover They Were Fish Farts
The World Wars made countries vigilant on all fronts. Espionage was used by many countries during that time with devastating consequences. Therefore, when Swedish authorities picked up mysterious underwater signals, they launched multiple missions to get to the source of these weird sounds, IFL Science reported. Their pursuit bore fruits and the authorities realized that the so-called 'invaders' were herring farts.
In 1982, Swedish authorities picked up underwater signals and sent several submarines, boats, and helicopters on a month-long expedition to reach its source, IFL Science reported. They returned with no results, but the government continued with their efforts for close to a decade.
Magnus Wahlberg, a professor at the University of Southern Denmark, was employed by the Swedish government to investigate the weird signals in 1996, IFL Science reported. He was tasked with figuring out the nature of the bubbles accompanying these 'signals.'
"It sounded like someone frying bacon. Like small air bubbles releasing underwater,” said Wahlberg in a TEDx talk, IFL Science reported. "It turns out herring have a swim bladder... and this swim bladder is connected to the anal duct of the fish. It's a very unique connection, only found in herring. So, a herring can squeeze its swim bladder, and that way it can blurt out a small number of bubbles through the anal opening."
In order to convince authorities beyond a doubt that the 'threat' was herring farts, Wahlberg had to show them footage of the whole phenomenon, IFL Science reported. The man purchased a herring from a store and pressed on its swim bladder, and a small number of bubbles came out of the anal opening. He recorded the sequence of events and submitted it to officials. The authorities were satisfied and the investigation was closed.
In a documentary, a spy herring has been deployed by a network to find out what sounds agitated Sweden for close to a decade, BBC reported. The spy is seen accompanying a school of herrings to get the most authentic sounds. "The clicking is made by the herring," said narrator David Tennant. "As the schools build so do the clicks. They’re from bubbles squeezed from their swim bladder." The footage shows how the 'fart' sounds made by herring attracted sea lions, forcing the school to go into shallower waters.