In an ocean full of clicking shrimp and singing whales, fish are often imagined as the silent actors. Fish use motion, color, and chemicals to communicate, but they lack the iconic mewl of a cat or trill of a bird. Yet in reality, many fish chat constantly to mark their territories or find mates. And all of our noise\u2014from seismic surveys to boat motors\u2014is making it much more difficult for fish to hear one another.<\/p>\n
The fact that some fish make noise has been known for a while, says Xavier Mouy, a biologist at the University of Victoria, in British Columbia. But few people have been interested in studying the phenomenon. So this summer, Mouy and his colleagues will gather underwater recordings to determine which fish are making sounds, and why.<\/p>\n
\u201cOf the 400 species in British Columbia\u2019s waters, 22 are known to make sounds,\u201d he says. \u201cBut there are probably a lot more we don\u2019t know about.\u201d<\/p>\n
Fish tend to talk in one of two ways. Some use their bones: catfish make sounds by moving the vertebrae in their spine, while seahorses knock the bones of their skull together. Others, such as rockfish, quickly contract specialized sonic muscles around their swim bladder to make low-frequency grunting noises.<\/p>\n
In primitive fish such as herring, the swim bladder is connected to the digestive system, so a sort of buzzing noise is produced when air is forced out the anus. Lawrence Dill, at Simon Fraser University in Burnaby, British Columbia, and his colleagues won the Ig Nobel prize in 2004<\/a> for discovering these \u201cfast repetitive ticks,\u201d or FRTs. (Yes, Dill knew exactly what he was doing when he named them.)<\/p>\n\n