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  • The noisy reef takes us under the waves to the reefs of New Zealand to explore sound and noise under water. Using this unique habitat, we look at what sound is, how it travels, what changes under water and how animals use sound in their world. Find out more about studying sound under water.

    A key idea is that animals can use the sounds of the reef to navigate. Fish and crab larvae floating in currents several kilometres from shore need to find their way back to the reef before they settle and metamorphose into the adult form. We know that smell and light are important in this process, but for the first time, New Zealand scientists Associate Professor Craig Radford and Dr Jenni Stanley have evidence that sound is also used as a navigation tool. Larval crabs are attracted to the sound of a healthy reef and will use this to find their way home.

    We also explore what makes a reef such a noisy place. You can probably think of some factors – waves and wind – but the scientists we talk to also listen to kina, shrimp and fish such as John Dory. In the article New Zealand reef noise, learn more about phenomena such as the ‘evening chorus’ – the name for the cacophony of sounds that come from a reef around dusk. Kina make much of this noise, but how do they do it, and how does the sound travel?

    Key science concepts

    The concept of a noisy reef can be used to explore a range of physical concepts including the basics of sound. Scientists like Professor John Montgomery talk about how they use physics as a tool to understand a biological system. It is important that they understand the basics of sound waves, how sound travels through water, how animals hear sound and whether larval animals could actually hear the reef.

    Additional science concept articles include measuring sound (along with an animated sound wave ripple pattern), hearing (in humans and in other animals) and why scientists use models.

    The PLD article Physical World – Sound curates supporting resources for these science concepts and ideas.

    More than just physics

    While learning about the physics of sound, take some time to explore biological concepts like habitat and reef zones in Life on a reef.

    Take up the challenge

    Using the idea of the reef and navigation, our resources explore some essential physics ideas relating to sound, but in a whole new way. Student activities include:

    Explore the various survey methods used by students, scientists and iwi in the Reef Life project in this Connected article.

    Question bank

    The The noisy reef – question bank provides an initial list of questions about how underwater animals use sound in their world and indicates where their answers can be found. The questions support an inquiry approach.

    Key terms

    For explanations of key concepts, see The noisy reef – key terms.


    Explore the timeline and find out more about some important dates relating to key developments in underwater acoustics.

      Published 10 May 2011, Updated 30 November 2022 Referencing Hub articles
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