Dominica’s Sperm Whales Change Their Clicks Around Ships

Do ships change the way sperm whales talk? Off Dominica, the answer seems to be yes, at least in rhythm. In 2026, researchers reported that the whales’ patterned click sequences, called codas, shifted when vessel noise was nearby. A Guardian report on the study described shorter gaps between clicks, and changes in which coda patterns were used more often.

It is a story about a soundscape most visitors never hear. You can sit on a boat in calm blue water and have no idea that, below you, a family of whales is adjusting its conversation to the engine of a ship far away.

What is a sperm whale coda?

Sperm whales make sequences of clicks to stay in touch with each other. Different family groups have their own patterns, a little like accents. But scientists do not have a word-for-word translation of any of them.

You may have seen headlines that call some sounds “vowels”. It is a catchy idea. It does not mean that researchers have decoded whale sentences, and it does not mean we know what any coda says.

Do ships change how sperm whales talk? What the study found

In this study, Project CETI researchers followed 15 whales over four years. They compared the recordings with shipping noise and with data on where vessels were. When ships were nearby, coda timing and patterns changed.

That is a link, and it is an interesting one. It does not yet tell us what the whales meant, or whether the new rhythm is a message about the ship at all. The study does not answer that, and I will not guess for it.

Why noise matters on a whale route

Sound is at the centre of a sperm whale’s life. They use powerful clicks to find prey in deep, dark water, and patterned codas in their social moments at the surface. More ship noise can change the acoustic space they live in, even when a boat never comes close enough for anyone to see it.

This is why quiet, well-managed whale tourism matters. Dominica has strict legal and permit rules for sperm whale encounters. This article is a science story, not a promise that you will hear whales underwater, and we do not offer swims there.

Wildlife encounters are unpredictable. Whale watching in Dominica should always follow local regulations and experienced professional guidance.

The sound is fascinating because the answer is still open

Sometimes the most interesting thing science can say is what it has not translated yet. I like that. It leaves the whales their own language, and it leaves us a reason to keep the sea a little quieter while we listen. To learn more, read our article on sperm whales in Dominica, how sperm whales differ from humpbacks, and the sperm whale page in the Ocean Atlas.

Questions people ask

Wildlife encounters are never guaranteed and never forced. Ocean Calling works only with vetted, ethical local operators, and every animal is free to approach, or not, entirely on its own terms.