Which marine animals are most sensitive to noise?

In one line

The rule

Many marine animals use sound to communicate, find food, and navigate. Loud or unnatural noises can disturb, harm, or even kill them.

Let's understand it simply

Imagine you are in a crowded market in Diwali season. People are shouting, crackers are bursting, and you cannot hear your friend calling you. Now, think about living like this every day, all the time. For many marine animals, the ocean is their world of sound. They use their ears more than their eyes. Sound travels much faster and farther in water than in air. So, when ships, oil drilling, or underwater blasts make loud noises, it is like a never-ending Diwali for them—loud, confusing, and stressful.

How it works

1. Marine animals like whales and dolphins use sound to talk to each other over long distances.
2. Some fish use sound to find mates or warn others of danger.
3. When humans make loud noises underwater (like ships, sonar, or explosions), these sounds mix with the natural sounds.
4. The animals get confused, cannot find each other, or cannot hear danger coming.
5. Sometimes, the noise is so loud it can damage their hearing or even kill them.

The story behind it

Scientists started noticing whales and dolphins getting stranded on beaches more often in the late 20th century. They found that these strandings often happened after loud underwater activities, like navy sonar tests or oil exploration. Researchers studied the animals’ ears and brains and found signs of damage from loud noise. This led to more studies about how sensitive marine animals are to sound, and how important quiet oceans are for their survival.

Where you see it in real life

• Whales (especially blue whales, humpback whales, and beaked whales): Use low-frequency sounds to talk over hundreds of kilometres. Ship noise blocks their calls.
• Dolphins: Use high-pitched clicks for echolocation (finding objects by bouncing sound waves). Sonar and boat engines can confuse or harm them.
• Porpoises: Similar to dolphins, use sound for hunting and communication. Sensitive to high-frequency noise.
• Squid and octopus: Some studies show they can be harmed by loud blasts, damaging their soft bodies.
• Fish (like cod, herring, and drum fish): Use sound to find mates and warn of danger. Noise pollution can stop them from breeding.
• Coral reefs: Many reef fish larvae use reef sounds to find their way home. Noise can lead them away or make them lost.

Why it matters

• Biodiversity: Many sensitive species are already endangered. Noise makes survival harder.
• Fisheries: If fish cannot breed or find each other, fish populations drop, affecting fishermen.
• Ecosystem balance: Whales and dolphins control fish and squid populations. If they suffer, the whole food chain is affected.
• Human safety: Some navy sonar tests have caused mass whale strandings, which can also affect coastal communities.

Common mistakes

• Thinking only whales are affected: Many fish, squid, and even tiny shrimp can be sensitive to noise.
• Believing animals will "get used to it": Many cannot adapt and may die or leave the area.
• Assuming only very loud sounds matter: Even moderate, constant noise (like ship engines) can cause stress and problems over time.
• Ignoring the distance: Sound travels far underwater. A ship 50 km away can still disturb a whale.

Remember it

If it’s noisy underwater, animals that use sound to live—like whales, dolphins, and many fish—are the first to suffer.