If you could dive deep beneath the waves and listen closely, the ocean wouldn’t be silent. It would hum, click, whistle, and sing. From the mournful cries of whales to the rhythmic drumming of fish and the gentle crackle of coral reefs, the sea is alive with sound. Beneath its surface, communication happens not through sight or gestures, but through music-like patterns that travel farther than light ever could.
Sound moves differently in water than in air. It travels faster — about four times faster — and can carry across vast distances. For many marine creatures, sound isn’t just background noise; it’s a lifeline. It helps them find food, navigate murky waters, stay together, and even express emotion. Whales, dolphins, seals, fish, and even some shrimps use sound in extraordinary ways, creating an underwater orchestra that humans are only beginning to understand.
The most famous singers of the sea are whales. The humpback whale, for example, produces long, haunting songs that can last for up to half an hour. Each song is made up of repeating phrases — deep moans, high squeaks, and rumbling groans — that change gradually over time. What’s even more fascinating is that all the male humpbacks in a region sing the same song, and when one changes the tune slightly, the others follow. It’s like a vast ocean-wide choir constantly composing new music. Scientists believe these songs may help whales attract mates or communicate across long distances, since their sounds can travel hundreds of kilometres through water.
Dolphins, on the other hand, are known for their clicks and whistles. They use a kind of sonar, called echolocation, to “see” with sound. By sending out quick bursts of clicks and listening to how they bounce back, dolphins can map their surroundings in stunning detail — even detecting the size, shape, and speed of nearby objects. They also have signature whistles, almost like names, that help them identify one another. When a dolphin calls another’s unique whistle, it’s like saying, “Hey, I’m here!”
But whales and dolphins aren’t the only marine musicians. Some fish make grunts, pops, and croaks by vibrating their swim bladders — air-filled organs that help them float. The toadfish, for instance, hums loudly during mating season, creating a chorus that can be heard through boat hulls. Coral reefs, often thought of as quiet, are actually buzzing with sound. Snapping shrimp crack their claws so fast that they create tiny shockwaves, producing a noise so loud that submarines once mistook it for interference. Reef fish listen to these sounds to find their way home after drifting as larvae in the open sea.
Even ice has its melody. In polar oceans, chunks of ice rub, crack, and shift, producing eerie groans and bell-like tones that echo through the water. Scientists studying these “ice songs” say they reveal a lot about melting rates and climate patterns. Each sound beneath the sea tells a story — not just about the creatures that make it, but about the changing world they live in.
Yet, this underwater concert faces growing threats. Ships, sonar systems, and offshore construction fill the oceans with noise that can confuse or harm marine life. Whales have been known to lose their way or stop singing when ship traffic increases. Dolphins may abandon feeding grounds if they can’t hear each other clearly. Scientists call this “noise pollution,” and it’s one of the biggest modern challenges for ocean conservation.
To help, researchers are creating quieter ship engines, designing “acoustic sanctuaries” where marine life can communicate freely, and even using hydrophones (underwater microphones) to monitor how sound affects ecosystems. In some areas, conservationists have started playing recorded reef sounds to help attract young fish and rebuild damaged coral communities — proving that the right kind of noise can actually heal.
For humans, listening to the ocean’s hidden music offers both wonder and wisdom. When scientists first recorded whale songs in the 1960s, the haunting melodies inspired people worldwide to care more about ocean life. Musicians began sampling whale sounds in albums; artists and filmmakers used them to capture the mystery of the deep. Today, marine biologists still use sound to study migration, behaviour, and population health. Each click or song helps them understand what’s happening beneath the waves, far beyond where cameras can see.