If it seems bizarre that serious scientists in Scotland should publish a study of farting in herrings, how improbable is it that they were almost beaten into print by a team of Swedish researchers who had discovered the same phenomenon? But that's great minds for you.

Bob Batty, of the Scottish Association for Marine Science, was certainly surprised when he made the discovery with two Canadian fellow researchers, Ben Wilson, of the University of British Columbia, and Larry Dill, of Simon Fraser University. It won them an Ig Nobel award for improbable biology (they are antidotes to Nobel prizes) and Dr Batty and Dr Wilson are taking part in the Ig Nobel tour of the UK, which starts today.

Dr Batty, who works at the Dunstaffnage marine centre near Oban, and his colleagues were looking at whether herrings could detect sounds made by predators like whales and dolphins. Using infrared lighting with video cameras and underwater microphones, they monitored the herrings behaviour round the clock. "We heard these rasping noises, which sound like high pitched raspberries, only ever at night, whenever we saw tiny gas bubbles coming from the herrings' bottoms," said Dr Batty.

"We also noticed that individual fish release more bubbles the more fish are in the tank with them. In other words, it seems that herring like to fart in company," commented Dr Wilson.

But, as Dr Batty explained, they analysed the bubbles released by herrings through the anus, using gas chromatography, and established that they were air gulped down by the herrings on the surface - there was no hint of flatulence.

He believes that fish like anchovies and sprats, which have similar swim bladders, show this farting behaviour as a means of communicating at night and keeping the shoal together. During the day these fish use visual information, such as the pattern of light reflected off specialised mirror-like scales, to communicate.

Herrings and their fishy relatives release air bubbles in large quantities when attacked, but the low level farting found by Dr Batty and his colleagues appears to serve a different purpose.

To the layperson this may seem a small addition to the sum of scientific knowledge, but it is useful. As Dr Batty points out, it is the air in the herrings' swim bladder that shows up in sonar surveys by marine biologists trying to determine the numbers and size of the fish, so information on how much air is released and when is relevant.

But why were Swedish scientists interested in farting herrings too? The Swedish navy had been picking up strange unidentified sounds and worried they might be from Russian submarines, so they asked scientists to investigate. The upshot was that as the Scots Canadian paper, Pacific and Atlantic herring produce burst pulse sounds, was published in the Proceedings of the Royal Society of London, a second paper established that herrings behave just as badly in Baltic waters too.