BLAB: Fish talk ...

[Colin Allen]

http://www.globeandmail.com/servlet/ArticleNews/TPStory/LAC/20031107/UFISH07GTA/Science/Idx

Tiny bubbles? Fish may be talking
By ANNE McILROY
SCIENCE REPORTER
Friday, November 7, 2003 - Page A6

The sound was unmistakably rude. University of British Columbia  
biologist Ben Wilson was alone in his lab late one night with a tank full  
of herring when he heard what he thought was somebody blowing a  
raspberry.

He worried his equipment was acting up or that his friends were playing  
a joke on him. He had an underwater microphone in the herring tank, part  
of an experiment to see how they reacted to killer whale sounds, and he  
turned up the volume on his speaker. The farting sound came again, and  
then again over the next few nights. It was so loud that his colleagues  
down the hall complained.

"They said I was being rude."

Little did they know that Dr. Wilson was in the midst of discovering  
what may turn out to be a new form of communication between fish, one  
that will have immense appeal to 10-year-old boys.

Careful observation showed the farting noises were coming from the  
herring at a same time as a steady stream of air bubbles was coming out  
of their hind ends. His team dubbed the noise Fast Repetitive Tick, or  
FRT, and found signs the herring may use it to communicate. They make the  
noises more frequently when there are other fish in the tank, and only  
at night, when they can't see each other.

Yesterday, Dr. Wilson headed off for a month at sea off the coast of  
Alaska to monitor the sounds of herring in the wild. Herring are social,  
in that they travel in vast schools with hundreds of thousands of other  
fish.

"I want to know if they are making these sounds in the wild, and what on  
Earth it sounds like," Dr. Wilson says.

What would it smell like? Fish farts probably aren't stinky, Dr. Wilson  
says. The air bubbles come from the swim bladder, which herring use for  
buoyancy. There is, however, some debate about how herring get gas into  
their swim bladders. Some researchers believe it may come from their  
digestive systems.

Most fish can't hear at the frequency the herring use for their FRTs,  
which means they can signal each other without alerting salmon or other  
fish that find herring delicious. But humans can hear it.

"If you put your ear up against the tank, you would have heard it, says  
Dr. Wilson, who has a link to the sound on his Web site,  
http://www.zoology.ubc.ca{tilde}bwilson/herring.html.

He tries to find polite synonyms for fart -- including "digestive system  
venting" and "burst pulse sounds." A paper published by the Royal  
Society in Britain on his discovery avoided the f-word altogether.

If the herring do use the sounds to communicate, the ability must have  
evolved because it helps them to survive. This means that noise pollution  
caused by humans could have an impact on the health of herring  
populations.

Other species of fish have been known to use their swim bladders to  
create grunting or buzzing sounds to attract potential sexual partners.  
But this is the first time scientists have caught fish farting, says  
Dennis Higgs, a biologist at the University of Windsor. "No one thought  
these fish made any noise at all."

Do other fish may also make farting noises? "I just don't know," Dr.  
Wilson says.