Scientists capture rare fish 'singing' thanks to underwater audio technology

The weird and wonderful sounds of fish communicating with each other have been captured for the first time ever in the UK, revealing a strange array of vocalisations such as gurgles, clicks and croaks.

The sounds were recorded by Professor Steve Simpson, a marine biologist and expert in bioacoustics from the University of Exeter, using special underwater recording equipment at the London Aquarium.

The team recorded clownfish, crayfish, triggerfish and seahorses as they fed, argued and communicated with one another in the water tanks.

With a little help from sound engineers at the world-famous Abbey Road Studios, Professor Simpson and aquarium staff have remastered the fish orchestra into a festive track for Christmas. 

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Professor Simpson was able to take recordings in an aquarium for the first time 

‘Sound plays an important role in the health of our oceans and we were curious to find out how the diverse fish species at London Aquarium use language to communicate with one another or at the very least find a fish that had a vocal range like Mariah Carey in time for Christmas,’ said James Wright, Displays Curator at SEA LIFE London Aquarium

‘No-one expected to hear a school of clownfish croak or a crayfish hoot like a trumpet – it’s truly amazing.

‘Thanks to Professor Simpson and Abbey Road Studios we can now listen to our fish for the very first time and teach our guests just how important sound is to the ocean.’

Professor Simpson, a marine biologist specialising in fish ecology and bioacoustics, used specially designed hydrophone which can detect soundwaves underwater. 

Clown fish were recorded ‘cracking and purring’ to assert their dominance in a group of about 300

From left, University of Exeter marine biologist Professor Steve Simpson, Abbey Road sound engineer Andrew Walker and James Wright from SEA LIFE London Aquarium mix the new track

He starred in the final episode of David Attenborough’s Blue Planet II with his directional hydrophone – a machine designed to capture the underwater soundscape in surround sound. 

Using the equipment, Professor Simpson and aquarium staff captured a recording of 300 clownfish ‘cracking and purring’ as a way of asserting their individual dominance in the group.

Two native crayfish were recorded arguing over food before one surrendered, making a trumpet-like hooting noise.

‘The family squabble at Christmas’: Crayfish were recorded arguing over food ‘in a high pitch’  

A triggerfish was recorded making a growling noise, while another group of seahorses were captured making clicking sounds as they opened their mouths to capture food.

Professor Simpson said there are many reasons fish make noise, including defending territories, warning against predators and during courtship. 

‘What we discovered is truly fascinating and highlights how fish are using sound to communicate to one another in an aquarium environment just like in more natural habitats,’ he said.

‘The more we listen the more we discover and I’m really happy to be working with SEA LIFE London Aquarium and Abbey Road Studios to educate more people about these amazing underwater soundscapes.’ 

To produce the new track Andrew Walker, Abbey Road sound engineer, used a computer system called CEDAR – Computer Enhanced Digital Audio Restoration – to remove unwanted background aquarium sounds of filters and pumps that were drowning out the fish’s vocal performance. 

‘I never imagined having spent 30 years mastering music at the world-famous Abbey Road Studios that I would be remastering the hidden orchestra of fish sounds into a festive Jingle Bells track,’ he said. 

‘The equipment we’d normally use in a certain way – it’s very different with fish.’