It turns out that fish are very talkative. They communicate about everything from which area of the sea has the best food to where predators hide and of course their desire for a mate.
Now, researchers from universities in Canada, the United States and Brazil have created an online portal called FishSounds that allows people to browse an inventory of the noises of marine creatures. People can listen to the underwater recordings and learn that a black fish makes a harsh sound, while the orange line triggerfish makes a drum sound.
Sarah Vela, senior data manager for a marine environmental research group at Dalhousie University and lead developer of the portal, said FishSounds gives researchers information about whether a fish species makes noise along with its geographic range.
“It’s a dataset that didn’t really exist before. While there are a lot of projects that are working with orca noises…right whale noises,” he said. “Fish is one that is little studied.”
Scientists use a hydrophone, or underwater microphone, to monitor and record these sounds, which are then identified by an expert, Vela said. The project also involves teaching a computer to associate sounds with certain species of fish to develop machine learning.
The portal includes data on some 1,200 fish species compiled from scientific literature and other sources. Of those, 1,061 were shown to make some kind of detectable sound, according to a study published by the portal’s creators last month in Ecological Informatics. So far, the site contains records of more than 260 species of fish.
“Remote sensing of active and passive fish sounds through passive acoustic monitoring presents the opportunity to answer numerous questions related to ecology, evolution, and management in marine, brackish, and freshwater environments,” the study said.
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Co-author Kieran Cox of Simon Fraser University said sound is a means for fish to exchange large amounts of information, just as humans do. He said this exchange of information is crucial because the deeper the ocean, the darker it gets, and visual interaction isn’t always possible.
“The fish have been singing much longer than the birds,” Cox said. “And I’m just saying that from an evolutionary perspective.”
While diving to investigate fish sounds in Belize, he said he could hear fish munching on coral and seagrass near a reef.
It turns out that fish are very talkative. They communicate about everything from which area of the sea has the best food to where predators hide and of course their desire for a mate.
“There’s a certain element of that soundscape that I think we’re all aware of, but then you can fail to appreciate it unless you know what you’re listening to.”
Fish, he said, produce two types of sounds: active and passive. Active sounds are made intentionally using the mouth or other parts of the body and may involve releasing bubbles, maneuvering different muscles to make a certain noise, or moving bones to get a repetitive click. Others make a sound like a drumbeat with their swim bladders, she added.
The common midshipman, a species of fish found in the eastern Pacific Ocean, lives most of its life in the deep, but goes up into the intertidal zone to breed, with males building nests for females to lay eggs. Males produce a distinctive buzz to attract a mate, Cox said.
“Basically, the name of the game with the nest is to build almost an amphitheater for sound. Think of it like a concert hall, if you will. It’s a rock wall nest that they sing from. They use it to attract mates and Las females come to lay eggs in these nests. The number of eggs they give a male will be proportional to the quality of their song, the length of their song, and how well they can hear it outside the nest. It’s really an all facilitated interaction because of the noise,” Cox said.
“If you’re on a beach at night and these fish are around, you can hear them buzzing through the night.”
Passive sounds are those that occur incidentally in your everyday life, such as chewing or digging.
“You can imagine that if a fish is enjoying a good meal, that’s going to create a lot of noise, and that noise provides valuable information to other nearby fish,” he said.
There are 34,000 species of fish in the world, and scientists know that more than 1,000 make some kind of noise and contribute to the soundscape, he said. But the seas hold more secrets of fish sounds that scientists have yet to uncover.
Learning about fish sounds will help scientists understand, preserve and restore habitats drowned out by ship and boat noise, he said. It can also help understand the behavior of fish as the climate changes, with some parts of the ocean warming faster than others, Cox said.
“There is a biological cacophony of sounds in the ocean,” he said. “If we don’t understand that, then we won’t understand how it’s changing as we introduce large amounts of noise pollution. We also won’t understand how we can conserve it.”
This report by The Canadian Press was first published on January 24, 2023.