Beneath the waves
References to the belief that oceans were silent can be found across the centuries. The 15th-century Spanish poet Jorge Manrique referred to the sea as ‘the silent grave’ in his poem ‘The Coplas on the Death of his Father’. Four centuries later, this idea of a silent realm beneath the waves was still considered the status quo. Rudyard Kipling wrote ‘There is no sound, no echo of sound, in the deserts of the deep’ in his poem ‘The Deep Sea Cables’ (1893), while T S Eliot referred to the ‘floors of silent seas’ in his 1915 poem ‘The Love Song of J. Alfred Prufrock’.
Despite this general consensus, a few inquisitive minds had an inkling that this may not in fact have been the case. The terrestrial soundscape was filled with the voices of thousands of creatures, from the cries of primates to the hum of insects – could it be that the marine soundscape was the same?
The Listening Project: Patrick Taggart and Michael McEvoy on underwater swimming
Wild swimming is any swimming undertaken in a natural body of water – be it a lake, pond, river or the sea. Here, Patrick Taggart and Michael McEvoy discuss what it means to be able to swim in the wild. They comment on how being immersed in water makes them feel a part of nature, and discuss what gives them a sense of achievement.
And I was as you say that sort of the level that you're in, being at the same level as the water.
You're sort of in nature, you're a part of nature, you're immersed.
Yeah, I mean I know some of the people that we swim with don't wear goggles, but for me you know I would hate to be - well I wouldn't hate it - but I'd feel like I was missing out if I didn't have my goggles with me because so much of it is about what happens underneath. That I can see you know seaweed swaying about gracefully as the sea moves you know and fish like pollock and wrasse; or you know sometimes I would see literally hundreds if not more of sand eels I think they are you know little fish no longer than, well shorter than six inches and you know very slender and they just shimmer away. That's a lovely thing. I suppose you have a good chance of spotting the jellyfish too before you get amongst their tendrils.
I haven't experienced the jellyfish. I can never really. I never really got to see a lot underneath - even with goggles.
But yeah, it's it's a magic thing to see I remember swimming, it was by the Nendrum Abbey.
In a really nice sheltered bay but I remember that -
Oh yeah, Reagh island isn't it? Out between Reagh Island and Mahee Island.
But as we swam across you could see the seabed move, so you could feel- you didn't feel you were swimming very fast, or getting anywhere but you could actually see the seaweed and the sand moving underneath. So yeah, it's nice to have that visibility.
I know, yeah. And you know you have more of a sense of progress too if you're in relatively shallow water and you can see the bottom, then you can see it moving beneath you. And you know you're getting somewhere.
Whereas if it's if you're in really deep water and you're out in the middle of a bay - and you can swim and swim and think 'Oh am I making any progress at all here?'.
Certainly swimming thing too sometimes I have to explain to friends for me, yes sometimes it's great. We'd swim a distance wouldn't we? But other times it's just you know it's - especially at this time of the year - immersing yourself and even just floating in air as we talked about that being in the nature. I love that. And you know you can literally just float on your back like an otter and just take it all in and take the difference. You know be aware of everything around you and your surroundings from a completely different perspective.
I know. Yeah.
What sound does a fish make?
Fish that inhabit the waters surrounding the British Isles are a noisy bunch. Atlantic Cod use their swim bladders to grunt like moody teenagers, Haddock knock and hum like sputtering motorboats and John Dory bark and growl like little dogs.
Mating call of a haddock
Haddock are fish found in the North Atlantic Ocean. The drumming sound in this recording, made by A D Hawkins, is the typical noise a male Haddock would make during the spawning season.
These sounds are produced through the vibration of the fish’s swim bladder, an air-filled sac in the abdomen. Vibration is usually caused by drumming muscles attached to the walls of the swim bladder, which are adapted to perform rapid contractions. As these muscles contract and relax, the swim bladder vibrates, producing all manner of hums, grunts and barks.
Early hydrophones, 1893 – 1912
Because of technological advancement we now know that the soundscape beneath the waves is rich and dynamic. One of the first mentions of using equipment to eavesdrop on the underwater realm can be found in the 15th-century writings of Leonardo da Vinci:
“If you cause your ship to stop, and place the head of a long tube in the water and place the outer extremity to your ear, you will hear ships at a great distance from you.”
Over the centuries following Leonardo’s observations, cumulative developments from many bright individuals brought about early underwater listening devices, or hydrophones.
In the late 19th century, a British naval officer named Captain Arthur McEvoy was working on submarine detection and he developed one of the first hydrophones in 1893. McEvoy’s early hydrophone drew great attention from those interested in maritime defence systems. However, McEvoy’s work was abandoned by 1903 as it was considered too unreliable and time-consuming to warrant further development.
The tragic sinking of the Titanic in 1912 renewed efforts to produce a device that could locate the presence of hazardous obstacles hidden underwater. The Canadian engineer Reginald Fessenden developed the Fessenden oscillator, an instrument that could calculate the distance of an underwater object but not its direction. During the First World War, the work of Paul Langévin and Constantin Chilowsky resolved this problem, ultimately producing a hydrophone that was able to detect both the distance and direction of a sound’s source.
During the period of the two world wars, followed by the Cold War, huge strides in underwater listening capabilities meant that technologies originally used to uncover enemy forces were gradually rolled out to the wider world.
The fishing industry was the first to utilise hydrophonic technology to track fish stocks. Soon after, scientists realised the potential of hydrophones in the study of marine life and began using the devices as underwater microphones to monitor patterns and behaviours. The clicks, whistles, chirps and melodies that could be heard completely revolutionised the scientific community’s understanding of sea life.
Underwater recording from Cromer Pier
This recording was taken by Peter Toll beneath the surface at Norfolk’s Cromer pier. At a depth of six metres, the hydrophone picks up stones being dragged onto the beach by waves, as well as the metallic sounds from the creaking pier.
In 1970, the aptly named marine biologist Marie Poland Fish co-authored a book dedicated to the sounds of the fish of the Atlantic Ocean. Sounds of Western North Atlantic Fishes identified the biological sources of underwater sounds most likely to be encountered by the sonar of the US Navy. Her book is filled with juicy descriptions such as ‘toothy clicks and many grunts’, ‘spontaneous knocks and thumps during competitive feeding’ and ‘sustained thundering rolls with mild annoyance’. This impressive piece of work provided a remarkable reference collection that helped US anti-submarine vessels differentiate between enemy targets and a harmless school of fish.
Gentle waves washing over a buried hydrophone
This recording, of waves breaking on a beach, was made by Richard Beard at Totland Bay on the Isle of Wight by a hydrophone buried in the sand.
The development of autonomous, long-term recording devices has given researchers unparalleled access into the day-to-day lives of our seas and oceans. As technology steams ahead, a growing number of oceanographic instruments help scientists keep tabs on what is going on under the waves.
Sounds from a Devon rock pool
Life in a rock pool is not for the faint-hearted. These miniature ecosystems, found in the intertidal zone, have evolved to endure extreme condition fluctuations caused by the daily movements of the tide. From full submersion to being left high and dry for hours at a time, the inhabitants of this changeable environment need to be resilient in order to survive. As with other marine gastropods, the Common Limpet (Patella vulgata) has mastered the art of rock pool life.
Underwater recording from a Rock Pool on Bantham beach
This underwater recording, made by Peter Toll on Bantham beach in Devon, features the rasping sound of these conical molluscs feeding on algae attached to the rocky surface.
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 Fundamentals of Noise and Vibration / edited by F J Fahy and J G Walker. Coming 22/07/19.
 Long-distance Submarine Signaling by Dynamo-Electric Machinery: A Lecture by Reginald A Fessenden.
 D Zimmerman, ‘“A More Creditable Way”: The Discovery of Active Sonar, the Langevin–Chilowsky Patent Dispute and the Royal Commission on Awards to Inventors’, War in History, 25(1), pp. 48–68. https://doi.org/10.1177/0968344516651308
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