The ocean is often thought of as a silent wilderness
But under the surface is a symphony of sound
Sound that marine creatures rely on for their survival...
...to find food, to communicate, to navigate
The light vanishes metres below the surface...
...so the sound is really what supports life in water
But humans are increasingly polluting the ocean with noise...
...which is posing a threat to creatures, from the smallest to the most majestic
Now we are facing a global issue that affects thousands of species
This man is at the forefront of the science of ocean sound
He is working to dial down the volume...
...in a bid to protect marine life around the world
You can actually put it into the water
In his lab in Barcelona, Michel André is conducting an experiment...
...with an artificial ear
So this is our hydrophone, which is the artificial ear...
...that is able to capture all the sounds that will send them to our...
...artificial brain of electronics that is inside this housing
The underwater microphone is being put through its paces...
...before it is dropped into the Mediterranean Sea
The device is part of an ambitious experiment to better understand...
...how human sound is affecting marine life
Our perception of sound in the ocean is biased
Our ear is not made to listen underwater, our ear is made to listen in air
So for years and years and years, we really thought that...
...the sea was a world of silence
Michel’s team is carrying out...
...the biggest ever sound survey of the world’s ocean
Dropping hydrophones in multiple locations and at various depths
This combination of artificial ear, artificial brain plus transmission...
...is something that has given us, as human beings...
...a sixth sense that we didn’t have and now we can listen in to the ocean...
...as if we were dolphins, but also we can be anywhere
Sound is essential to marine life...
...because light doesn’t travel further than a few hundred metres underwater
Thousands of species use it to communicate, to find their way around...
...to spot their next meal or ensure they’re not someone else’s
It is a harmony of sounds that lived there for millions of years
Then, as human beings, we started to introduce...
...different sound, artificial sounds, through our activities only 100 years ago
So this is really recent that we have started to invade with our sound
Noise pollution is now recognised as a major threat to ocean life
Everything that we do in the ocean introduces sound...
...that may have an effect on the environment
There are more than 50,000 container ships...
...that sail everyday around the world
Unlike many other threats to the ocean, noise pollution is invisible...
...which means it’s often overlooked
But in 2002 the world started to take notice
14 beaked whales stranded on the holiday beaches...
...of Lanzarote and Fuerteventura
It was later discovered that multiple ships and submarines...
...were operating in the area using sonar...
...pulses of sound used to detect objects underwater
This is the first time that we could associate as...
...the cause-to-effect relationship that a noise introduced by the...
...navy sonar was leading to the stranding of these whales
Whales talk to each other through a complex language of clicks and whistles
These sounds help them to navigate and communicate
Man-made noises like sonar can disrupt this communication...
...and disorientate them
We know how sensitive people are to whales and dolphins, totem animals...
...and we’re seeing them washed on shore...
...by this human activity for the first time
This really helped understanding that this noise could have a detrimental effect
Since this incident, the use of sonar has been associated...
...with a large number of whale strandings around the world
But while beached whales continue to grab the headlines...
...Michel was keen to understand if other creatures...
...were experiencing the same fate
A group of giant squids were found stranded on the beach
The post-mortem analysis didn’t show any cause of the death
What he was about to discover would change scientists’ understanding...
...of the effects of ocean noise-pollution
This group of experts realised that a geophysics experiment...
...using high-energy sounds was performed a few days before this event
Oil-prospecting ships had unknowingly disturbed the ecosystem below them
We decided in our laboratory to recreate this situation
And we found this massive acoustic trauma...
...when we exposed this animal to sound
Although squid don’t have ears...
...their bodies contain small organs called statocysts...
...which are lined with noise-sensitive hairs
In his lab, Michel and his team discovered...
...that even low-intensity sounds destroy these hairs...
...and knock out the squids’ balance
We went through the idea that it was only affecting a few species...
...the whales and the dolphins, to invertebrates and fish...
...and we are speaking about thousands of species
So we cannot anymore consider the effect of noise as species-specific...
...but consider it as a global effect to the whole marine environment
This revelation has been the driving force behind Michel’s plan...
...to map the soundscape of the entire ocean
So this [click, click, click] they are shrimps
This is the sound of a ship passing by
So far he has built and installed 150 listening platforms around the world
What we do is we want to identify all the sounds, right
We don’t want to leave anyone out of this...
...so we want to know everything
To do that we need to train the system to recognise the features...
...that belong to one or another source
Every sound is being labelled and stored...
...in what is now the world’s biggest database of ocean sound
Using artificial intelligence, the sounds in the acoustic library...
...can be identified as natural or man-made...
...and the effects they’re having on marine life can be assessed
We aim at building trends that reflect the biodiversity of an area
If we detect an external event that could be a ship noise...
...or other human activity that will influence the area in a negative way...
...we will see how this trend changes because of this external factor
Researchers are trying to pin down the damage...
...that human activity is having on the ocean...
...and they’re revealing some concerning trends
Noise pollution is most prominent in the northern hemisphere
Every decade noise from shipping has doubled in intensity...
...which has been seen to have an effect on certain species of whale...
...reducing their ability to communicate with each other by about 60%
Air guns are the most common method...
...used to map the ocean floor for oil and gas exploration
Their impacts have been detected 4,000km from the source...
...and have been linked to multiple mass strandings
The South Pacific is the part of the ocean with the least human noise
The good news is that unlike other forms of pollution...
...the impact from noise is short-lived
If we compare sounds to other source of pollution...
...as soon as you switch off the sound, the effect is gone
But not all noise is bad and Michel and his team are trying to ascertain...
...how humans can best carry out important work...
...while limiting its effect on the ocean
Michel is now working with marine-based industries...
...to help them reduce ocean-noise pollution
In our laboratory we try to understand these effects...
...on the marine environment so we can provide the industry...
...that operates at sea with these tools that will allow them...
...to operate in the same way with a limited effect on the environment
Solutions include noise-reduction technologies...
...to lessen the sound of deep-sea drilling in the renewables sector...
...and potential alternatives to sonar
Michel André’s research is shifting science’s understanding of noise pollution
It’s just the beginning but his work could fundamentally change...
...the way in which humans operate on the ocean...
...and co-exist with marine creatures in the future