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Dolphin echolocation is powered by SNOT: Mucus is the secret behind marine mammals' ability to tracking their prey

Dolphins make a series of clicking sounds to help them track their prey
Mucus could provide the sticky surface necessary to make these noises
These findings could inspire human engineers looking for new ways to create high-frequency sounds

Published: 19:30 GMT, 24 May 2016 | Updated: 19:30 GMT, 24 May 2016

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They can pick out a fish from more than 650 feet away by producing a rapid-fire stream of clicks as they race through the water in search of prey.

But now the secret behind dolphins' amazing ability to navigate and hunt using echolocation has been discovered - mucus.

Researchers at the Scripps Institution of Oceanography in San Diego has found that the wet sticky surface provided by mucus could help dolphins to make their loud, high frequency sounds.

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Dolphins use high frequency clicking sounds to work out where their prey is located, as well as the shape and size of it

Aaron Thode, one of the researchers, said: 'It's harder than you might think to make loud, high frequency sounds.

'Wet, sticky surfaces could serve a purpose in this.'

Previous studies have found that dolphins create sounds by forcing air through nasal passages located just beneath their blowholes.

ECHOLOCATION - HOW DOLPHINS FIND THEIR PREY

Dolphins use a process called 'echolocation' to help them identify where objects are located.

The animals send out clicking noises in the form of sound waves, which hit an object and bounce back vibrations.

The amount of time it takes for the sound waves to come back helps the dolphins to identify their distance from the object - the longer the sound waves, the further away the object.

It also gives them information about the location of the object and some indication of the shape and size of it.

Within the nasal passage are dorsal bursae - lumps of tissue - that collide and vibrate, producing the dolphin's unique clicks, chirps and whistles.

However, until now, the finer details of what happens in these nasal passages remained unclear.

The problem with studying the inner workings of these sounds, is capturing the motions - some of which happen as quickly as a thousand times per second.

To counteract this issue, the researchers used a 'lumped element model' - a technique that scientists often use to simplify complex systems.

The model captured the essential characteristics of the vocal system, like the frequency at which the vocal cords vibrate, while remaining simple enough to easily study.

Using the model, researchers were able to accurately reproduce two distinct parts of a dolphin click - an initial loud thump, followed by an extended ring.

Previous studies have found that dolphins create sound by forcing air through nasal passages located just beneath their blowholes (shown above). However, until now, the finer details of what happens in these nasal passages remain unclear

DOLPHINS HAVE ACCENTS TOO

Dolphins that live in pods in certain areas off the coast of the UK have been spotted communicating with unique sounds - regional accents - off the coat of Wales.

And now a group of marine biologists is studying dolphins in the water around Jersey to determine if these 'accents' are widespread.

Researchers from the Marine Biology Section of Societe Jersiaise in the Channel Islands will compare the noises made by dolphins off the Channel Islands with those from elsewhere.

To do this, hydrophones - microphones designed to be used underwater - will be placed in the waters around Jersey, which is home to the UK's largest resident dolphin population.

They will be fitted with SD cards to record noises, which scientists say will help them identify 'numbers, species and movements' of the mammals.

Their results suggest the thump is caused when the dorsal bursae collide and then pull apart, and the ring develops from the lingering vibrations of the tissue.

Additionally, to produce the loudest, highest frequency parts of the call, the bursae must stick slightly to each other before separating.

Mr Thode described this as: 'kind of like pulling apart silly putty - if you pull it hard it will resist, but then snap apart.'

Dolphins use a process called 'echolocation' to help them find their prey. They send out clicking noises, which bounce back from the prey. The amount of time it takes for the sounds waves to return helps the dolphins identify the distance

The researchers suggest that this stickiness could be provided by the mucus coating of the nasal passage.

Using this model could potentially inspire human engineers looking for clever new ways to create high-frequency sounds.

It could also yield insights into how other animals, such as whales, make their sounds.