It ’s dead feasible that in the eighties a major diplomatic incident between atomic superpowers could have been triggered by fish farts . In fact , Russia and Sweden nearly came to blows over this very thing . They just did n’t know it at the time .

Before we move on to wind , first , some background . In 1981 , a Soviet submarineran agroundon the south sea-coast of Sweden , just 10 kilometers ( 6.2 mile ) from   a Swedish naval base . The Soviets claimed that they were forced into Swedish territory by wicked distress , and later navigation errors , while Sweden pick up it as trial impression that the then Soviet Union was infiltrating Swedish water . It did n’t avail that when Swedish officials secretly evaluate for radioactive stuff using   gamma - shaft of light spectroscopy , they   detected   what they were 90 percent sure was uranium-23 ( used for cladding in nuclear weapon ) inside the sub , point that it may be nuclear armed .

The bomber was returned to international waters , but the Swedish government stay alert , convert that Russian submarine could still be operating near their territory . Which is when they start to find fault up problematic subaqueous signal and sounds . In 1982 , several of Sweden ’s subs , boats , and helicopters pursue one of these unidentified sourcesfor a whole calendar month , only to come up empty - handed .

This continued for over a ten . Every time they picked up an acoustic signal they would search and detect nothing but for a few bubble on the ocean ’s surface . Sweden was , of course , worried about the intrusions , and could n’t think why , with the Cold War now over , Russia would continue to chevy them in this manner .

But it was farting .

In 1996 ,   Magnus Wahlberg , a professor at the University of Southern Denmark , became involved in the investigating of the strange signals .

" We were brought into this very secret elbow room under the naval bag of Bergen in Stockholm , " he excuse in aTEDx Talkin 2012 . " We were ride there with all these officers and they were actually play these sound for us . It was the first time any civilian hear the sound . "

He had been imagining it to go like the ping you hear in films when a submarine is detected or even the disturbance of a propellor .

" It was nothing at all like that , "   Wahlberg pronounce . " It sound like someone fry bacon . Like modest line bubbles releasing underwater . "

He and a colleague began the task of enter out what could be make bubbles on a musical scale that would make Sweden conceive it was dealing with a nuclear submarine .

" It turns out Clupea harangus have a swim vesica … and this swim bladder is link to the anal duct of the fish , "   Wahlberg said . " It ’s a very unparalleled connection , only found in herring . So a herring can squeeze its swim bladder , and that way it can blurt out a minuscule turn of bubbles through the anal retentive opening . "

In layperson ’s terms , they let one snag . herring swim in gigantic schools that can pass several square kilometers and up to 20 metre ( 65 feet ) deep . When something near them fright them   – say , a hungry schoolhouse of mackerel or a submarine on the lookout for Russian spy – they can engender a lot of gas .

To test his theory , Wahlberg bought a Clupea harangus from a store and applied insistency , and sure enough , it made a phone . He took the footage to the navy personnel and recreate it back to them . It was a perfect match for the haphazardness they had been hear .

The estimable word was that Sweden was n’t under terror from Russia , the spoiled news was it had spent 10 years deploying its armed services in following of fish farts . Since it figured out what was and was n’t Pisces the Fishes flatus , there have been zero report of hostile intruders in Swedish piss .