How To Talk To Fish
If you have the opportunity to speak with any fish, I suggest you don't choose herring. Herring communicate by shooting a burst of bubbles out of their anus. The sound they make is a fast, repetitive tick that some researchers have compared to "blowing a raspberry."
While herring may specialize in that delightful form of communication, they're far from the only fish that make noise. In fact, the ocean is filled with a rich and varied array of sounds. When Jacques Cousteau named his award-winning 1956 ocean documentary The Silent World, he couldn't have been more wrong about the noise level. (Also, for an environmentalist, he beat a surprising amount of sharks to death with an axe.)
Californians might be familiar with the toadfish, whose mating calls resonate so loudly that they've prompted angry editorials in local papers and houseboaters complaining to elected officials. Until scientists definitively linked the noises to toadfish, most residents couldn't fathom that the loud noises keeping them up at night could possibly be caused by fish. Even now, researchers are only beginning to understand the full spectrum of sounds that fish make and how they use them to communicate.
How Fish Talk
There are three main ways fish produce noise.
Toadfish are drummers. They use muscles attached to or near their swim bladder to beat against it. These muscles can contract extremely quickly, moving more times per second than a hummingbird's wings.
A catfish, on the other hand, uses a method called stridulation to produce their distinctive grunts. Dr. Phil Lobel, an expert on fish noises at Boston University, describes their sound as "a creaky door — cat meowing type of sound." That noise is generated by bones rubbing together at the base of the spine, similar to the way you could play a hair comb by plucking its tines.
Fish can also create sounds underwater by using hydrodynamics, or the water itself. When spawning, parrotfish move so quickly back and forth through the water that they generate a turbulent noise. "That's literally them swishing through the water," according to Dr. Lobel. "they go basically from a standing start to 40 miles an hour, spawn, turn real quick in the water and dart back down."
Why Would Anyone Care About Talking To A Catfish?
We've known that fish make noises for thousands of years. Pull a grouper out of the water and you can hear for yourself. But since sound travels exceptionally large distances underwater, most fish are very strategic and quiet about the noises they emit. It was only with the invention of underwater microphones, called hydrophones, after World War II that science really started listening to fishes, and hearing sounds from many more kinds of species.
Now, scientists are combining those hydrophones with cutting-edge underwater video cameras and near-silent scuba equipment to take the most accurate recordings of fish to date. Billions of dollars are spent managing fisheries internationally, but information about the number of fish and behavior is largely guesswork. For example, spawning is often monitored by catching fish and cutting them open to see if they have eggs inside. With their new measurements, scientists like Dr. Lobel are now able to match specific sounds to behaviors, which gives a more accurate and complete picture. Recordings of specific spawning noises would be a much quicker and less invasive way to monitor the health of a fish population.
The U.S. Navy is also very interested in research on underwater noises. Ever since the invention of the submarine, sailors have struggled to differentiate between natural noises and those of enemy ships.
To learn more about Dr. Phil Lobel and hear samples of some actual fish, listen to the "Fish Noises" episode of You're the Expert here:
Bonus: If you're looking for more, watch this rap video made by Phil Lobel and his colleagues: