Human ears don’t work well underwater, so most of us don’t realise just how full of sound our oceans are! Scientists use underwater microphones (called hydrophones) to investigate these sounds. Where do they come from? What do they mean?
Healthy coral reefs are noisy!
Listen to the Coral Reef underwater story.
Healthy reefs are full of life – and sound! In places like Ningaloo and the Great Barrier Reef, scientists are using underwater speakers to play sounds from healthy reefs to damaged coral reefs.
The healthy reef recordings attract some of the fish life that has been lost from damaged reefs. These fish help corals grow back. Some fish species eat the algae that competes with corals, and fish dung adds nutrients to the reefs. Scientists are using sound recordings as part of new coral restoration projects! We still know very little about how these sounds influence reef life.
Learn more about the Australian Institute of Marine Science’s Reef Song Project.
Songs of Giants
Listen to the Singing Humpback Whales underwater story.
Humpback whales migrate further than any other mammal on Earth! Twice a year, humpbacks travel more than 5,000 km up and down the east and west coasts of Australia. Humpbacks were close to extinction in the 1960s, but now that they are protected, they have recovered.
To help protect whales and dolphins:
- Don’t litter! Rubbish that goers into our oceans can end up in a whale’s or a dolphin’s stomach.
- Always stay at least 100 m away from whales and dolphins. Don’t touch or feed them, even if they approach you.
- Report any injured or stranded whales or dolphins to your local environment agency.
Too much noise can be painful
Listen to the Noise Pollution underwater story.
In busy shipping lanes, natural sounds are being drowned out by human-made noises, which are making animals behave differently.
To discover exactly how many ships are at sea at any given moment, check out the Marine Traffic live map.
Shipping noises are stressful for many marine animals. Loud noises like sonar can damage a whale’s hearing or make it hard for them to communicate with each other.
But, there are some solutions. New laws limit some types of noise pollution in the ocean, and new propeller and sonar designs can help make ships a bit quieter.
Listen to the Sea Urchins underwater story.
Long-spined sea urchins mostly eat algae. They are an important part of a healthy ecosystem, but there is such a thing as too many sea urchins! Sea urchins can devour entire kelp forests, leaving nothing but bare rock behind. And they’re getting more common…
Climate change has changed the ocean’s currents. Now, the currents are carrying urchin larvae from New South Wales, their usual home, south into Tasmania.
These invading sea urchins are destroying large areas of kelp forest in Tasmania. This can cause the local food chain, which wildlife and fisheries rely on, to collapse. By protecting our rocky shores and making sure there are plenty of natural predators around to keep urchin numbers down, we can help tackle this challenge.
With thanks to:
- Dr Mark Meekan, Australian Institute of Marine Science
- Dr Tim Gordon, University of Exeter
- Dr Nathan Knott, NSW Department of Primary Industries
- Prof Maria Byrne, University of Sydney
- Dr Natalie Soars, University of Sydney
- Sea urchins – Dr Natalie Soars, University of Sydney
- Layered reef sounds – Dr Tim Gordon, University of Exeter
- Snapping shrimp and sergeant major – Prof Steve Simpson, University of Exeter
- Ambon damselfish – Prof Eric Parmentier, University of Liège
- Humpback whale songs – Prof Robert McCauley, Curtin University
- Icebergs underwater – Centre for Marine Science and Technology, Curtin University
- Sounds of Rainfall, Sonatech Inc. CC BY-NC 3.0
- Sound of Lightning, Henry Bass, Roy Arnold and Anthony Atchley, National Center for Physical Acoustics, CC BY-NC 3.0
- Large Commercial Ship, Thomas R. Kieckhefer, CC BY-NC 3.0
- Merchant Vessel, Peter M. Scheifele, Department of Communication Sciences and Disorders and Medical Education, University of Cincinnati Medical Center, CC BY-NC 3.0
- Coral reef – Dr Tim Gordon
- Humpback whale migration data – Department of Environment
- Long-spined sea urchins – Dr Natalie Soars