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Why 90_ of the Ocean Is Still a Complete Mystery _ Boring Science for Sleep · Boring Science

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Speaker 1: Welcome, dear listener, to this journey into the depths of
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Speaker 1: the ocean, a realm so vast and mysterious that it
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Speaker 1: has captivated the human imagination for centuries. As you settle
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Speaker 1: in for a restful slumber, allow me to paint a
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Speaker 1: picture of the wonders that lie beneath the waves, a
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Speaker 1: world that we have only begun to understand in recent times.
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Speaker 1: But before we dive into the abyss, I invite you
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Speaker 1: to pause for a moment and share with us where
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Speaker 1: in the world you are listening from and what time
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Speaker 1: of day it is for you. Are you nestled in
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Speaker 1: your bed? the glow of the moon filtering through your window,
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Speaker 1: or perhaps you're enjoying a quiet afternoon seeking a moment
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Speaker 1: of calm amidst the bustle of the day. Wherever you
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Speaker 1: may be, know that you are part of a global
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Speaker 1: community of curious minds all drawn to the allure of
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Speaker 1: the deep. If you find yourself captivated by the tales
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Speaker 1: of intrepid explorers and the marvels they uncovered, I encourage
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Speaker 1: you to subscribe to this channel. Here, we embark on
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Speaker 1: gentle explorations of the natural world, weaving together history and
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Speaker 1: science in a tapestry of soothing narratives designed to lull
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Speaker 1: you into a peaceful slumber. And so, as you close
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Speaker 1: your eyes and let your mind drift, imagine yourself standing
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Speaker 1: on the shore, gazing out at the vast expanse of
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Speaker 1: the ocean. The rhythmic lapping of the waves against the
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Speaker 1: sand is a lullaby, a gentle reminder of the ceaseless
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Speaker 1: motion of the sea. For millennia, humans have been drawn
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Speaker 1: to these azure waters, marvelling at their power and mystery.
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Speaker 1: yet rarely venturing far beneath the surface. It may surprise
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Speaker 1: you to learn that the oceans cover more than 70%
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Speaker 1: of our planet's surface, an area so immense that it
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Speaker 1: dwarfs the land we call home. And yet, for all
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Speaker 1: our technological advancements and insatiable curiosity, we have explored less
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Speaker 1: than 10% of these watery depths. The deep ocean remains
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Speaker 1: one of the last true frontiers on Earth, a realm
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Speaker 1: where the unknown still reigns supreme. For much of human history,
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Speaker 1: the deep sea was thought to be a lifeless void,
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Speaker 1: a cold and dark abyss where nothing could survive. The
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Speaker 1: sheer weight of the water above, the absence of sunlight,
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Speaker 1: and the crushing pressure seemed to preclude the possibility of life.
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Speaker 1: It was a place of myths and monsters, where the
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Speaker 1: imagination ran wild and the boundaries of reality blurred. But
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Speaker 1: as we shall see, the story of deep sea exploration
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Speaker 1: is one of perseverance, ingenuity, and a thirst for knowledge
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Speaker 1: that could not be quenched. It is a tale of
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Speaker 1: brave men and women who dared to venture into the unknown,
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Speaker 1: armed with little more than their wits and a burning
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Speaker 1: desire to unravel the secrets of the deep. Our journey
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Speaker 1: begins not in the modern era, with its sophisticated submersibles
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Speaker 1: and high-tech sensors, but in the mists of antiquity, with
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Speaker 1: a man whose ideas would shape the course of scientific
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Speaker 1: inquiry for centuries to come. His name was Aristotle. and
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Speaker 1: though he lived over 2,000 years ago, his insights into
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Speaker 1: the natural world continue to resonate today. Aristotle was a
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Speaker 1: Greek philosopher and polymath, a man whose insatiable curiosity led
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Speaker 1: him to explore fields as diverse as biology, physics, metaphysics
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Speaker 1: and politics. He was a student of Plato and a
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Speaker 1: teacher of Alexander the Great, a towering figure whose ideas
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Speaker 1: would form the bedrock of Western thought for centuries to come.
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Speaker 1: But it was in the realm of marine biology that
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Speaker 1: Aristotle made some of his most enduring contributions. In the
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Speaker 1: 4th century BC, he became the first scientific thinker to
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Speaker 1: reason that there might be life in the cold, dark
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Speaker 1: waters of the deep sea. This was a radical notion
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Speaker 1: at the time, for most people believed that the oceans
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Speaker 1: were a barren wasteland, devoid of any living creatures. Aristotle's
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Speaker 1: insights were based on the occasional sea monsters that washed
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Speaker 1: up on the shores of the Mediterranean. These strange, often
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Speaker 1: grotesque creatures bore little resemblance to the fish and other
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Speaker 1: marine life that people were familiar with. Some had long,
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Speaker 1: serpentine bodies, while others sported sharp teeth and bioluminescent lures.
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Speaker 1: To Aristotle, these creatures were proof that the deep sea
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Speaker 1: was not a lifeless void, but a realm teeming with
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Speaker 1: strange and wondrous beings. He reasoned that if such creatures
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Speaker 1: could exist in the shallow waters near the shore, then
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Speaker 1: surely there must be even more exotic lifeforms lurking in
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Speaker 1: the depths. Of course, Aristotle had no way of confirming
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Speaker 1: his hypothesis. The technology to explore the deep sea simply
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Speaker 1: did not exist in his time. But his ideas would
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Speaker 1: plant a seed in the minds of future generations, a
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Speaker 1: tantalising hint of the mysteries that lay beneath the waves.
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Speaker 1: It would be centuries before Aristotle's musings were taken up
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Speaker 1: in earnest. In the intervening years, the deep sea remained
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Speaker 1: a realm of myth and speculation, a place where the
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Speaker 1: imagination ran wild. Sailors told tales of sea serpents and mermaids,
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Speaker 1: of ghostly ships and lost civilizations. But amidst these fanciful stories,
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Speaker 1: there were glimmers of truth. In the first century AD,
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Speaker 1: the Roman naturalist Pliny the Elder compiled a monumental work
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Speaker 1: called the Naturalis Historia, a compendium of all the knowledge
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Speaker 1: of the natural world that had been accumulated up to
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Speaker 1: that point. In his writings, Pliny described a number of
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Speaker 1: strange creatures that had been hauled up from the depths
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Speaker 1: by fishermen, There were giant squids with eyes the size
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Speaker 1: of dinner plates, and fish that glowed in the dark
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Speaker 1: like fireflies. Pliny's descriptions were often exaggerated and embellished, but
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Speaker 1: they hinted at a world beyond the reach of human knowledge,
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Speaker 1: a realm where the normal rules of biology did not apply.
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Speaker 1: It would be another 17 centuries before the first systematic
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Speaker 1: attempts were made to explore the deep sea. In the
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Speaker 1: late 18th century, a British naval officer named Captain James
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Speaker 1: Cook set out on a series of voyages that would
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Speaker 1: revolutionise our understanding of the world's oceans. Cook was a
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Speaker 1: master navigator and a meticulous observer, a man whose scientific
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Speaker 1: curiosity was matched only by his bravery and determination. On
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Speaker 1: his first voyage, he set out to observe the transit
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Speaker 1: of Venus across the face of the Sun, an astronomical
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Speaker 1: event that would help scientists calculate the distance between the
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Speaker 1: Earth and the Sun. But Cook's interests extended far beyond astronomy.
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Speaker 1: He was also fascinated by the natural world, and he
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Speaker 1: made it his mission to collect specimens and observations of
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Speaker 1: the plants and animals he encountered on his travels. It
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Speaker 1: was on his second voyage, however, that Cook made his
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Speaker 1: most significant contributions to oceanography. Using a weighted rope, he
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Speaker 1: was able to measure ocean depths of up to 7,200 feet,
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Speaker 1: far deeper than anyone had ever done before. Cook's measurements
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Speaker 1: revealed that the oceans were much deeper than previously thought,
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Speaker 1: and that they contained a vast and unexplored realm that
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Speaker 1: was entirely unknown to science. Cook's discoveries sparked a wave
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Speaker 1: of interest in the deep sea, and in the decades
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Speaker 1: that followed, a number of expeditions were launched to explore
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Speaker 1: this mysterious realm. One of the most significant of these
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Speaker 1: was led by a British naturalist named Edward Forbes. Forbes
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Speaker 1: was a pioneering marine biologist. a man whose passion for
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Speaker 1: the natural world had led him to explore the coastlines
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Speaker 1: of Europe and the Mediterranean in search of new species.
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Speaker 1: In the 1830s, he began to focus his attention on
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Speaker 1: the deep sea, using a dredge to collect specimens from
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Speaker 1: depths of up to 1,800 feet. What Forbes found was
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Speaker 1: nothing short of astonishing. His dredges brought up a dazzling
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Speaker 1: array of creatures, from delicate sea stars and feathery anemones
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Speaker 1: to To bizarre fish with glowing lures and razor-sharp teeth,
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Speaker 1: Forbes was convinced that he had discovered a new frontier
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Speaker 1: in marine biology, a realm that was every bit as
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Speaker 1: rich and diverse as the shallow waters near the shore.
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Speaker 1: But Forbes' enthusiasm was tempered by a nagging doubt. As
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Speaker 1: he collected specimens from deeper and deeper waters, he noticed
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Speaker 1: that the number of species began to decline. By the
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Speaker 1: time he reached depths of around 1,800 feet, he found
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Speaker 1: that there was almost no life at all. Forbes concluded
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Speaker 1: that there was a limit to the depth at which
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Speaker 1: life could exist in the ocean. He called this the
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Speaker 1: azoic hypothesis, from the Greek word for without life. According
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Speaker 1: to Forbes, the deep sea was a barren wasteland, a
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Speaker 1: place where the absence of sunlight and the crushing pressure
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Speaker 1: of the water made it impossible for anything to survive.
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Speaker 1: Forbes' hypothesis was widely accepted by the scientific community of
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Speaker 1: his time. It seemed to make sense, after all. The
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Speaker 1: deep sea was a cold, dark and inhospitable place, far
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Speaker 1: removed from the warm sunlit waters where most marine life
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Speaker 1: was found. But as we shall see, Forbes was wrong.
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Speaker 1: The deep sea was not a lifeless void, but a
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Speaker 1: realm teeming with strange and wondrous creatures, adapted in ways
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Speaker 1: that defied the imagination. It would take a new generation
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Speaker 1: of explorers armed with cutting-edge technology and an insatiable thirst
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Speaker 1: for knowledge to unravel the secrets of the abyss. The
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Speaker 1: Heroic Age of Deep Sea Exploration, as it came to
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Speaker 1: be known, began in earnest in the late 19th century.
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Speaker 1: It was a time of great scientific and technological advancement,
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Speaker 1: when the boundaries of human knowledge were being pushed to
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Speaker 1: their limits. One of the most significant expeditions of this
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Speaker 1: era was the HMS Challenger expedition, which set out from
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Speaker 1: England in 1872 on a four-year mission to survey the
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Speaker 1: world's oceans. The Challenger was a state-of-the-art research vessel, equipped
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Speaker 1: with the latest scientific instruments and a crew of experienced
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Speaker 1: naturalists and oceanographers. Over the course of their journey, the
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Speaker 1: Challenger crew collected an astonishing array of data and specimens
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Speaker 1: from the depths of the ocean. They dredged the seafloor,
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Speaker 1: took water samples and measured ocean currents and temperatures, and
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Speaker 1: everywhere they looked they found evidence of life. From the
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Speaker 1: icy waters of the Antarctic to the tropical seas of
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Speaker 1: the Pacific, the Challenger crew discovered a dazzling array of creatures,
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Speaker 1: many of which had never been seen before. There were
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Speaker 1: glass sponges and feathery crinoids, bioluminescent fish and giant isopods,
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Speaker 1: and in every sample they took, no matter how deep,
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Speaker 1: they found living organisms. The Challenger expedition dealt a decisive
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Speaker 1: blow to Forber's zoic hypothesis. It was now clear that
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Speaker 1: life existed at every depth of the ocean, from the
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Speaker 1: sunlit surface waters to the cold, dark abyss. The deep
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Speaker 1: sea was not a barren wasteland, but a realm of
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Speaker 1: unimaginable diversity and complexity. In the years that followed, other
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Speaker 1: expeditions would build on the work of the Challenger crew.
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Speaker 1: In 1899, the Dutch HNLMS Sibberga set out to explore
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Speaker 1: the deep basins of the Indo-Pacific, cataloguing thousands of new
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Speaker 1: species along the way. And in the early 20th century,
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Speaker 1: the American research vessel Albatross made some of the deepest
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Speaker 1: trawls to date, using steel cable to haul up creatures
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Speaker 1: from the abyss. But perhaps the most iconic figures of
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Speaker 1: the heroic age were William Beebe and Otis Barton, two
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Speaker 1: American explorers who made history in the 1930s with their
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Speaker 1: daring descents into the deep. Beebe was a naturalist and adventurer,
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Speaker 1: a man whose passion for the natural world had led
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Speaker 1: him to explore the jungles of South America and the
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Speaker 1: coral reefs of the Caribbean. Barton was an engineer and inventor,
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Speaker 1: a man whose technical skills would prove invaluable in the
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Speaker 1: challenges ahead. Together, Beebe and Barton designed and built the bathysphere,
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Speaker 1: a steel sphere with thick quartz windows that would allow
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Speaker 1: them to observe the depths directly. It was a cramped
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Speaker 1: and claustrophobic space and barely large enough for two men
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Speaker 1: to stand upright. But it was also a marvel of engineering,
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Speaker 1: capable of withstanding the crushing pressure of the deep sea.
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Speaker 1: In 1934, Beebe and Barton made their first descent in
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Speaker 1: the bathysphere, lowering themselves into the waters off the coast
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Speaker 1: of Bermuda. As they sank deeper and deeper, the light
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Speaker 1: from the surface gradually faded away, replaced by an eerie
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Speaker 1: bioluminescent glow. Through the thick quartz windows, Beebe and Barton
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Speaker 1: beheld a world that no human had ever seen before.
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Speaker 1: Strange ghostly creatures drifted past, their bodies translucent and shimmering
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Speaker 1: in the dim light. Jellyfish pulsed and shimmered, their tentacles
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Speaker 1: trailing behind them like streamers. And everywhere they looked they
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Speaker 1: saw evidence of life, thriving in conditions that would crush
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Speaker 1: a human being in an instant. Over the course of
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Speaker 1: several dives, Beebe and Barton descended to depths of over 3,000 feet,
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Speaker 1: setting new records for human exploration of the deep sea.
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Speaker 1: They described alien seascapes of jagged rock formations and towering
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Speaker 1: underwater cliffs, populated by creatures that seemed to defy the
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Speaker 1: laws of nature. Their observations and photographs captured the public imagination,
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Speaker 1: sparking a wave of interest in the deep sea that
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Speaker 1: continues to this day. Beebe's vivid descriptions of the bathysphere
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Speaker 1: dives published in his book Half Mile Down, became a
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Speaker 1: bestseller and inspired a generation of young explorers to follow
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Speaker 1: in his footsteps. But as groundbreaking as the bathysphere dives were,
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Speaker 1: they were only the beginning. In the decades that followed,
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Speaker 1: new technologies would emerge that would allow us to explore
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Speaker 1: the deep sea in ways that Beebe and Barton could
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Speaker 1: scarcely have imagined. The advent of precision depth, echo-sounding during
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Speaker 1: World War II, originally developed for submarines and would enable
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Speaker 1: scientists to map the seafloor in unprecedented detail. Submersibles like
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Speaker 1: DSV Alvin, first launched in 1964, would allow researchers to
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Speaker 1: visit the abyss in person, collecting samples and observing the
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Speaker 1: deep sea environment up close. Remotely operated vehicles, or ROVS,
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Speaker 1: would revolutionise deep sea exploration in the late 20th century.
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Speaker 1: These unmanned robots, tethered to ships by long cables, could
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Speaker 1: be sent to depths far beyond the reach of human divers.
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Speaker 1: Equipped with cameras, sensors and dexterous manipulators, ROVs have been
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Speaker 1: used to explore everything from the wreckage of the Titanic
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Speaker 1: to the strange and wonderful creatures that inhabit hydrothermal vents
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Speaker 1: on the ocean floor. More recently, autonomous underwater vehicles, or AUVs,
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Speaker 1: have taken deep-sea exploration to new heights. These intelligent, untethered
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Speaker 1: robots can be pre-programmed to survey large areas of the
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Speaker 1: ocean independently, collecting data and images as they go. AUVs
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Speaker 1: have been used to map the seafloor, study ocean currents,
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Speaker 1: and even search for signs of extraterrestrial life on the
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Speaker 1: moons of Jupiter and Saturn. But for all the technological
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Speaker 1: advancements of the past century, the deep sea remains a
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Speaker 1: realm of mystery and wonder. Even with the most sophisticated
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Speaker 1: tools at our disposal, We have only begun to scratch
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Speaker 1: the surface of this vast and alien world. The challenges
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Speaker 1: of life in the deep sea are formidable. The darkness
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Speaker 1: is absolute, the pressure is immense, and food is scarce.
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Speaker 1: Temperatures hover just above freezing, and the water is devoid
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Speaker 1: of sunlight. It is a world of eternal night, where
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Speaker 1: the only light comes from the bioluminescent glow of the
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Speaker 1: creatures that call it home. To survive in such extreme conditions,
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Speaker 1: deep sea organisms have evolved a dazzling array of adaptations.
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Speaker 1: Many have lost their eyes, their skeletons and even their muscles,
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Speaker 1: becoming delicate and gelatinous in the process. Others have developed
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Speaker 1: huge mouths and expandable stomachs, allowing them to engulf any
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Speaker 1: rare prey that happens to drift by. Some deep sea
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Speaker 1: creatures are masters of camouflage, with transparent bodies or red
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Speaker 1: and black colouration, that makes them virtually invisible in the
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Speaker 1: dim blue light of the abyss. Others use bioluminescence to
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Speaker 1: attract prey or ward off predators, flashing and shimmering like
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Speaker 1: underwater fireworks. But perhaps the most astonishing adaptations are found
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Speaker 1: in the creatures that inhabit the hydrothermal vents on the
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Speaker 1: ocean floor. These oases of heat and chemicals, spewing from
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Speaker 1: cracks in the Earth's crust, support entire ecosystems that exist
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Speaker 1: independently of sunlight. Tube worms and giant clams thrive on
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Speaker 1: the hydrogen sulfide and other chemicals that would be toxic
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Speaker 1: to most other forms of life. And then there are
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Speaker 1: the microbes, the unseen heroes of the deep sea. These
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Speaker 1: tiny organisms, invisible to the naked eye, are found in
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Speaker 1: every corner of the abyss, from the rocks and mud
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Speaker 1: of the seafloor to the ice and sediments of the
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Speaker 1: polar regions. Some scientists believe that the biomass of the
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Speaker 1: deep biosphere, the vast network of microbes that exists beneath
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Speaker 1: the seafloor, may exceed that of all other life on
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Speaker 1: Earth combined. But the deep sea is not just a
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Speaker 1: realm of darkness and scarcity. It is also a place
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Speaker 1: of unexpected oases, where life finds a way to thrive
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Speaker 1: in the most unlikely of places. Take the whale fall,
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Speaker 1: for example. When a whale dies and sinks to the
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Speaker 1: bottom of the ocean, its massive carcass becomes a banquet
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Speaker 1: of bounty for the creatures of the abyss. Scavengers and
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Speaker 1: sulphur eaters flock to the scene. Feasting on the whale's
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Speaker 1: flesh and bones for years on end, a single whale
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Speaker 1: fall can support an entire ecosystem, a miniature world within
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Speaker 1: a world. Or consider the woodfall, a similar phenomenon that
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Speaker 1: occurs when logs and other debris from terrestrial storms sink
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Speaker 1: to the seafloor. These sunken logs provide a rare source
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Speaker 1: of food and shelter for deep sea creatures, and may
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Speaker 1: even have played a role in the animal's invasion of
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Speaker 1: the deep millions of years ago. Brine pools, basins of
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Speaker 1: heavy salt water that form lakes on the seafloor, are
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Speaker 1: another unexpected oasis in the abyss. These pools are home
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Speaker 1: to mussels and shrimp that have adapted to the harsh,
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Speaker 1: salty conditions, but are toxic to most other forms of life.
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Speaker 1: Methane seeps, like cold cousins to hydrothermal vents, are yet
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Speaker 1: another example of the deep sea's hidden wonders. These leaks
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Speaker 1: of methane gas from the seafloor fuel entire communities of
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Speaker 1: microbes and tubeworms. creating miniature ecosystems that exist independently of sunlight.
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Speaker 1: And then there are the seamounts. The darkness of the
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Speaker 1: deep sea is broken only by occasional flashes of bioluminescence,
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Speaker 1: the living light of strange, gelatinous creatures drifting through the abyss.
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Speaker 1: This alien landscape, so different from the bright, active world above,
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Speaker 1: was long thought to be a lifeless void. But as
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Speaker 1: the lights of submersibles and ROVs penetrate ever deeper, they
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Speaker 1: reveal the deep ocean to be a complex tapestry of life,
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Speaker 1: finely adapted to the harsh conditions of the eternal night.
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Speaker 1: One of the most iconic denizens of the deep is
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Speaker 1: the anglerfish, aptly named for the bioluminescent lure that dangles
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Speaker 1: temptingly in front of its cavernous mouth. This ambush predator
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Speaker 1: can engulf prey up to twice its size thanks to
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Speaker 1: its enormous gape and distensible stomach. The anglerfish was one
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Speaker 1: of the first deep-sea creatures discovered, dredged up by the
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Speaker 1: HMS Challenger expedition in the late 19th century. But it
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Speaker 1: would be many decades before its bizarre appearance and lifestyle
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Speaker 1: were fully understood. In the 1930s, American naturalist William Beebe
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Speaker 1: made history by descending into the depths in a cramped
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Speaker 1: steel sphere called the bathysphere. Through its thick quartz windows,
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Speaker 1: Beebe became the first person to observe the deep sea
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Speaker 1: with his own eyes. He described a world of glowing,
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Speaker 1: pulsating creatures moving languidly through the darkness. a league of
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Speaker 1: absolute night, where the blackness grew more intensely black and
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Speaker 1: the blue above more mauve-like and unreal. Bieber's vivid accounts
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Speaker 1: captured the public imagination and inspired a new generation of
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Speaker 1: deep-sea explorers. But it wasn't until the development of unmanned
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Speaker 1: submersibles in the 1960s that scientists could truly begin to
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Speaker 1: study the deep ocean in detail. These remote-controlled vehicles, tethered
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Speaker 1: to ships by long umbilical cords, allowed researchers to collect samples,
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Speaker 1: take measurements, and observe deep-sea life without the risks and
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Speaker 1: limitations of human-occupied craft. One of the most remarkable discoveries
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Speaker 1: made possible by this new technology was the existence of
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Speaker 1: hydrothermal vents, deep-sea hot springs that support entire ecosystems based
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Speaker 1: not on sunlight but on chemical energy. These oases in
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Speaker 1: the darkness were first glimpsed in 1977 using the submersible
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Speaker 1: DSV Alvin on a dive to the Galapagos Rift off
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Speaker 1: the coast of Ecuador. What the Alvin's pilots saw through
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Speaker 1: their tiny portholes astonished them. Towering chimneys of mineral-rich water
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Speaker 1: surrounded by lush communities of giant tube worms, ghostly crabs
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Speaker 1: and strange eyeless shrimp. The discovery of hydrothermal vents revolutionized
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Speaker 1: our understanding of life on Earth. Here, in the most
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Speaker 1: extreme environment imaginable, entire ecosystems were thriving on the heat
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Speaker 1: and chemicals spewing from cracks in the planet's crust. The
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Speaker 1: microbes that form the base of these food chains don't
21:01
Speaker 1: need sunlight or oxygen. they get their energy by breaking
21:04
Speaker 1: down sulphur compounds in a process called chemosynthesis. This realisation
21:09
Speaker 1: expanded the definition of habitability and sparked new theories about
21:13
Speaker 1: how life might have originated in the deep ocean billions
21:16
Speaker 1: of years ago. But hydrothermal vents are just one of
21:19
Speaker 1: many unexpected oases that punctuate the abyssal plain. Whale falls,
21:25
Speaker 1: the sunken carcasses of dead whales, provide a sudden bounty
21:28
Speaker 1: of food in the nutrient-poor deep sea. supporting complex communities
21:32
Speaker 1: of scavengers, opportunists and sulphure-eaters for years on end. Woodfalls,
21:38
Speaker 1: formed by trees washed out to sea during storms, play
21:41
Speaker 1: a similar role and may have facilitated the invasion of
21:44
Speaker 1: the deep ocean by wood-boring clams and other animals millions
21:47
Speaker 1: of years ago. Even in the absence of these organic windfalls,
21:51
Speaker 1: life finds a way to eke out an existence in
21:53
Speaker 1: the eternal darkness. Brine pools, basins of super-salty water on
21:58
Speaker 1: the seafloor, form toxic lakes that are home to mats
22:02
Speaker 1: of microbes and beds of mussels and shrimp. Methane seeps,
22:06
Speaker 1: like cold cousins to hydrothermal vents, fuel unique ecosystems based
22:11
Speaker 1: on methane-eating bacteria. And seamounts, underwater mountains that rise thousands
22:16
Speaker 1: of metres from the abyssal plain, disrupt deep-sea currents and
22:20
Speaker 1: concentrate nutrients, serving as oases of diversity in the otherwise
22:24
Speaker 1: barren depths. As we've only explored a small fraction of
22:28
Speaker 1: the deep ocean, Much remains to be discovered in this
22:30
Speaker 1: alien world beneath the waves. Each expedition seems to reveal
22:34
Speaker 1: creatures and ecosystems stranger than the last. In the Mariana Trench,
22:39
Speaker 1: the deepest point on Earth, shrimp-like amphipods scuttle along the
22:43
Speaker 1: seafloor under pressure more than 1,000 times that at the surface.
22:47
Speaker 1: In the oxygen-starved waters of the Black Sea, delicate carnivorous
22:51
Speaker 1: sponges chase their prey in lazy slow motion. And in
22:54
Speaker 1: the icy darkness beneath the Antarctic ice shelf, Ghostly white
22:58
Speaker 1: octopuses incubate their eggs for an astonishing 14 years, the
23:03
Speaker 1: longest known brooding period of any animal. These deep-sea creatures
23:07
Speaker 1: may seem remote from our everyday lives, but they are
23:10
Speaker 1: increasingly vulnerable to human activities. Climate change is altering the
23:14
Speaker 1: chemistry and circulation of the oceans, while the emerging industry
23:18
Speaker 1: of deep-sea mining threatens to destroy habitats before they can
23:21
Speaker 1: even be studied. As we drift off to sleep, we
23:25
Speaker 1: might spare a thought for the alien world that carries
23:27
Speaker 1: on beneath the waves, and the secrets that still lie
23:30
Speaker 1: hidden in the eternal night of the abyss. As the
23:34
Speaker 1: sun's rays fade into the twilight and finally wink out
23:37
Speaker 1: in the black abyss, utter darkness envelops the depths. Down here,
23:42
Speaker 1: night is eternal. The deep sea is a world without days, months,
23:47
Speaker 1: or years. Just an endless, lightless void. In this cold,
23:52
Speaker 1: pressurised realm, The normal rules of life are reversed. Food
23:56
Speaker 1: is scarce, so animals must make the most of any
23:59
Speaker 1: rare morsel they encounter. The usual daily cycles of activity
24:03
Speaker 1: and rest blend into a constant twilight state. Life slows
24:08
Speaker 1: down to a sluggish, energy-conserving crawl. Metabolism grinds to a
24:12
Speaker 1: bare minimum. Hearts beat only a few times per minute.
24:17
Speaker 1: Breathing nearly stops, muscles atrophy and skeletons dissolve. Deprived of calcium,
24:23
Speaker 1: bones become watery and flexible. Transparent, gelatinous forms replace solid,
24:29
Speaker 1: opaque bodies. Predators evolve into nightmare monstrosities, all teeth and
24:34
Speaker 1: expandable stomachs. The fang-toothed fish wields dagger-like teeth half the
24:39
Speaker 1: length of its head. Gulper eels can swallow prey twice
24:42
Speaker 1: their size by stretching their elastic jaws. Viperfish sport hinged
24:47
Speaker 1: teeth that fold back to store struggling victims inside their mouths.
24:51
Speaker 1: But for prey... Invisibility is the key to survival. In
24:54
Speaker 1: the faint shimmer of bioluminescence, red and black coloration offers
24:58
Speaker 1: perfect camouflage. Certain small crustaceans take transparency a step further.
25:04
Speaker 1: Their shells, muscles and organs turn completely clear. Only their
25:08
Speaker 1: eyes remain pigmented, detecting the faintest traces of light. In fact,
25:13
Speaker 1: vision reaches its peak in the depths. Down here, bioluminescence
25:17
Speaker 1: is the only source of light. Predators like the pelican
25:20
Speaker 1: eel dangle glowing lures to attract curious fish. Vampire squids
25:25
Speaker 1: squirt a distracting blob of glowing liquid to confuse attackers.
25:28
Speaker 1: Countless creatures carry blazing spotlights to pierce the veil of darkness.
25:33
Speaker 1: Perhaps no oasis of life in the abyss is as
25:35
Speaker 1: dazzling as a hydrothermal vent. Fishes in the ocean floor
25:39
Speaker 1: spew superheated water laden with hydrogen sulfide, methane and other chemicals.
25:45
Speaker 1: In this cauldron of toxicity, microbes thrive by harnessing chemical
25:48
Speaker 1: energy rather than sunlight. Giant tube worms over two metres
25:52
Speaker 1: long cluster in waving forests around the vents. Inside their bodies,
25:57
Speaker 1: specialised bacteria convert chemicals into nutrients. Mussels, clams and shrimp
26:02
Speaker 1: armour themselves against the scorching vent fluid and graze on
26:05
Speaker 1: thriving mats of microbes. Crabs prowl like wolves over the colony,
26:10
Speaker 1: snatching up stray tube worm plumes. Hydrothermal vents are just
26:15
Speaker 1: one of many unexpected havens that punctuate the bleak expanse
26:18
Speaker 1: of the deep sea floor. Whale carcasses, sunken wood, brine pools,
26:23
Speaker 1: methane seeps and seamounts all shelter oases of unique creatures
26:27
Speaker 1: found nowhere else on Earth. When a whale dies and sinks,
26:31
Speaker 1: it delivers a massive pulse of food energy to the abyss.
26:35
Speaker 1: The rotting bonanza can support a complex community of worms, mollusks,
26:40
Speaker 1: crabs and more for up to a century. slowly seep
26:43
Speaker 1: into the seafloor. Specialised bacteria even eat the bones, extracting
26:49
Speaker 1: fats and sulphur as the skeleton itself disintegrates. Sunken logs
26:53
Speaker 1: washed out to sea by storms offer a similar feast.
26:57
Speaker 1: Wood-boring clams and pill-bug-like isopods gnaw away at the waterlogged wood,
27:02
Speaker 1: excreting sawdust faeces that feed other small scavengers. These woodfalls
27:07
Speaker 1: may have been early stepping stones that allowed shallow water
27:10
Speaker 1: species to invade the deep sea. Brine pools form where
27:14
Speaker 1: extra salty water settles into depressions on the seafloor and
27:17
Speaker 1: creates lake-like seascapes. Heavier than normal seawater, the briny shorelines
27:22
Speaker 1: trap mussels, shrimp and tube worms within their confines. To
27:26
Speaker 1: other creatures, the toxic brine is lethal. Methane seeps leak
27:30
Speaker 1: from cracks in the sediment, almost like cold cousins of
27:33
Speaker 1: hydrothermal vents. Here, specialised bacteria eat the methane and provide
27:38
Speaker 1: the base of a unique food chain, supporting tube worms, mussels,
27:43
Speaker 1: and crustaceans very similar to those at vents. The icy
27:46
Speaker 1: methane can even form solid hydrate mounds that resemble stony corals.
27:51
Speaker 1: Seamounts are massive extinct volcanoes that rise thousands of metres
27:54
Speaker 1: above the abyssal plain without breaking the surface. They interrupt
27:58
Speaker 1: the flow of deep currents, causing eddies that concentrate nutrients
28:02
Speaker 1: and microorganisms. Sponges, corals, fish and other filter feeders gather
28:07
Speaker 1: in dense crowds on the rocky slopes. Many seamount species
28:11
Speaker 1: are found nowhere else, making these underwater islands hotspots of
28:14
Speaker 1: deep ocean diversity. Even away from these specialised habitats, the
28:19
Speaker 1: muddy ooze of the seafloor seethes with microbial life. Bacteria,
28:23
Speaker 1: archaea and single-celled protists live by the trillions between every
28:27
Speaker 1: grain of sediment, recycling the dead organic matter that constantly
28:31
Speaker 1: rains down from above. This deep biosphere buried in the
28:35
Speaker 1: seabed and oceanic crust may contain more than half of
28:39
Speaker 1: Earth's total biomass. As our minds drift through these alien seascapes,
28:44
Speaker 1: it's humbling to realize how little we truly know about
28:47
Speaker 1: the deep oceans. Whenever scientists venture into the depths, they
28:52
Speaker 1: discover bizarre new species and ecosystems. Over 80% of this
28:56
Speaker 1: world remains unmapped, unobserved, and unexplored. Today, new technologies are
29:02
Speaker 1: finally shining light into the depths. Fleets of robot submersibles
29:06
Speaker 1: crisscross the seafloor, streaming video and collecting samples. Autonomous underwater
29:12
Speaker 1: drones scout the abyss for months at a time. Manned
29:15
Speaker 1: submersibles carry explorers to the deepest trenches for face-to-face encounters.
29:20
Speaker 1: Bit by bit, the mysteries of the deep are coming
29:23
Speaker 1: into focus. But as we uncover the treasures of the abyss,
29:27
Speaker 1: we are also learning how fragile they can be. Deep-sea
29:30
Speaker 1: trawling scrapes clear 2 million square kilometres of seafloor habitat
29:34
Speaker 1: per year, an area the size of Mexico. Seabed mining
29:39
Speaker 1: looms as an emerging threat to the vent and seep
29:41
Speaker 1: communities we barely understand, and climate change is altering the
29:45
Speaker 1: very chemistry of the oceans faster than in millions of years.
29:49
Speaker 1: The bizarre and wonderful life of the deep hangs in
29:51
Speaker 1: a delicate balance. As much as any other species, our
29:55
Speaker 1: fate is tied to the health of the oceans and
29:57
Speaker 1: the myriad creatures that inhabit them, from the sunlit shallows
30:00
Speaker 1: to the midnight zone. So as we drift off to sleep,
30:03
Speaker 1: dreaming of the alien world far below the waves, we
30:07
Speaker 1: can rest a bit easier knowing that with exploration comes awareness,
30:11
Speaker 1: and with awareness comes the drive to understand and protect.
30:14
Speaker 1: The dark depths may be out of sight, but thanks
30:17
Speaker 1: to the curiosity and ingenuity of scientists around the world,
30:20
Speaker 1: they are no longer completely out of mind. Piece by piece,
30:24
Speaker 1: drop by drop, we are shedding light on the largest,
30:27
Speaker 1: least known habitat on Earth, the mysterious realm of the
30:30
Speaker 1: deep oceans. The vast, dark abyss of the deep sea
30:33
Speaker 1: has long haunted the human imagination. For centuries, the inky
30:37
Speaker 1: blackness of the depths conjured tales of mysterious leviathans, ravenous
30:42
Speaker 1: sea serpents, and mythical behemoths drifting in an unseen world
30:46
Speaker 1: beneath the waves. Even as recently as 200 years ago,
30:50
Speaker 1: most scientists believed the deep ocean to be a freezing,
30:52
Speaker 1: lightless void, a dark desert utterly devoid of life. How
30:57
Speaker 1: could anything, they reasoned, hope to eke out an existence
31:00
Speaker 1: in such a hostile environment, cut off from the sun's
31:03
Speaker 1: nourishing rays? It took a series of intrepid explorers, armed
31:07
Speaker 1: with ingenuity, fortitude and an unquenchable thirst for knowledge, to
31:12
Speaker 1: gradually pierce the veil of mystery shrouding the deep sea.
31:16
Speaker 1: Their discoveries would forever transform our understanding of the world's
31:19
Speaker 1: oceans and the life they contain. One of the first
31:22
Speaker 1: to hint at the strange organisms lurking in the depths
31:25
Speaker 1: was Pliny the Elder, an ancient Roman naturalist who lived
31:29
Speaker 1: in the first century AD, in his sprawling encyclopedia Natural History,
31:35
Speaker 1: Pliny recounted the tales of fishermen who spoke of hauling
31:38
Speaker 1: up bizarre creatures entangled in their nets from the deep.
31:41
Speaker 1: Monstrous sharks, sawfish, giant squid. While some of these accounts
31:47
Speaker 1: no doubt sprang from seaside legend and the human penchant
31:50
Speaker 1: for exaggeration, others hinted at genuine denizens of the deep
31:53
Speaker 1: that were rare or unknown to science at the time.
31:56
Speaker 1: For over a thousand years after Pliny, little progress was
31:59
Speaker 1: made in exploring the oceans. The seafloor was simply too
32:03
Speaker 1: deep and inaccessible to the technologies of the age. This
32:06
Speaker 1: all began to change in the 18th century, however, with
32:09
Speaker 1: the voyages of Captain James Cook. A brilliant navigator and explorer,
32:14
Speaker 1: Cook commanded three epic expeditions that sailed to the far
32:17
Speaker 1: reaches of the globe, filling in vast swathes of the
32:20
Speaker 1: world map. During his first voyage, Cook deployed weighted lines
32:24
Speaker 1: to measure the depth of the ocean at various points.
32:28
Speaker 1: To his astonishment, the lines revealed that the oceans were much,
32:31
Speaker 1: much deeper than anyone had previously imagined. Cook recorded depths
32:36
Speaker 1: of over 7,200 feet, and even then his crude weight
32:40
Speaker 1: and rope had failed to strike bottom. For the first time,
32:44
Speaker 1: humans began to grasp the sheer immensity and volume of
32:47
Speaker 1: the world's oceans. If the seas were so incomprehensibly deep,
32:51
Speaker 1: What strange creatures might dwell in that chilly abyss, far
32:55
Speaker 1: from the reach of fishermen's nets? In the early 19th century,
32:59
Speaker 1: the British naturalist Edward Forbes set out to answer that question.
33:03
Speaker 1: Between 1841 and 1842, Forbes conducted a series of pioneering
33:08
Speaker 1: dredging operations in the Aegean Sea, dragging a metal scoop
33:11
Speaker 1: along the seafloor to collect samples of mud, rocks and
33:15
Speaker 1: any organisms living on the bottom. At depths of up
33:18
Speaker 1: to 1,800 feet, Forbes discovered an astounding menagerie of novel creatures,
33:24
Speaker 1: delicate sea lilies, luminous glass sponges and bizarre fish found
33:29
Speaker 1: nowhere else on Earth. Yet below about 1,800 feet, Forbes'
33:35
Speaker 1: dredges came up largely empty, containing little more than mud
33:38
Speaker 1: and sand. From these results, Forbes developed his infamous azoic hypothesis.
33:44
Speaker 1: He postulated that life simply could not exist below a
33:47
Speaker 1: certain depth, with the eternal darkness freezing cold and crushing
33:52
Speaker 1: pressure of the abyss imposing an impenetrable barrier to living organisms.
33:56
Speaker 1: For a time, the Ozoic hypothesis was widely accepted in
33:59
Speaker 1: scientific circles. The oceans, it seemed, were not bottomless, and
34:04
Speaker 1: neither was the variety of life they contained. As is
34:07
Speaker 1: so often the case in science, however, this tidy consensus
34:11
Speaker 1: would not last for long. In the 1860s, researchers began
34:15
Speaker 1: to take a closer look at the mud and ooze
34:17
Speaker 1: recovered from Forbes' supposedly Ozoic dredges. To their amazement, they
34:22
Speaker 1: discovered that these samples were actually teeming with living organisms.
34:26
Speaker 1: They were just far too small to be readily visible
34:28
Speaker 1: to the naked eye. Microscopic foraminifera, radiolarians and other protists
34:34
Speaker 1: abounded in seafloor sediments from even the greatest depths. The abyss,
34:39
Speaker 1: it appeared, was far from lifeless. It would take the
34:43
Speaker 1: voyage of HMS Challenger to shatter the azoic theory once
34:46
Speaker 1: and for all. Launched in 1872, the Challenger expedition was
34:50
Speaker 1: the world's first global oceanographic cruise, circling the globe for
34:55
Speaker 1: four years to systematically catalogue the mysteries of the deep.
34:59
Speaker 1: Under the scientific supervision of Charles Wyville Thompson, the Challenger's
35:03
Speaker 1: crew dredged up thousands of samples from the far reaches
35:06
Speaker 1: of the Atlantic, Pacific and Indian Oceans. Everywhere they looked,
35:11
Speaker 1: Thompson and his colleagues discovered life. From the abyssal plains
35:14
Speaker 1: to the hadal depths of oceanic trenches over five miles deep,
35:18
Speaker 1: the Challenger expedition recovered a breathtaking diversity of deep-sea organisms.
35:23
Speaker 1: Delicate sea stars, luminous anglerfish and nightmare-inducing viperfish were among
35:28
Speaker 1: the fantastical creatures hauled up from the deep. Even more
35:32
Speaker 1: shocking were the otherworldly invertebrates clinging to the slopes of
35:35
Speaker 1: underwater mountains. Crimson-lipped tubeworms, giant clams and armoured snails thriving
35:43
Speaker 1: in the total absence of sunlight. With each passing day,
35:47
Speaker 1: the Challenger's crew realised they had stumbled upon an alien world.
35:51
Speaker 1: A deep sea, in Thompson's words, as rich in variety
35:55
Speaker 1: of life as the shallower waters. The age of deep
35:58
Speaker 1: sea exploration had begun in earnest. In the wake of
36:01
Speaker 1: the Challenger expedition, an international race commenced to probe ever
36:05
Speaker 1: deeper into the ocean abyss with bigger ships and better technology.
36:09
Speaker 1: In the Netherlands, the HNLMS Ceboga expedition, 1899-1900, undertook a
36:16
Speaker 1: three-year survey of the deep basins around Indonesia, revealing the
36:20
Speaker 1: incredible biodiversity of the Coral Triangle region. Across the Atlantic,
36:24
Speaker 1: the US Fish Commission vessel RV Albatross mounted a series
36:28
Speaker 1: of ambitious cruises in the early 1900s, using steel cable
36:32
Speaker 1: to sink its trawls to the abyssal seafloor. Among the
36:36
Speaker 1: albatrosses' many discoveries were the gulper eel, pelican eel and
36:39
Speaker 1: abyssal holothurians, the bizarre sea cucumbers that would later be
36:43
Speaker 1: nicknamed sea pigs for their plump, pink, translucent bodies. Yet
36:48
Speaker 1: as fascinating as these specimens were, they represented only fleeting
36:52
Speaker 1: glimpses of the deep, dead organisms wrenched from their habitat
36:56
Speaker 1: and hauled up to the harsh light of the surface.
36:59
Speaker 1: To truly know the deep sea would require observing these
37:02
Speaker 1: creatures in their natural environment, a feat long thought impossible
37:07
Speaker 1: due to the immense pressures of the deep. In the 1930s,
37:12
Speaker 1: a daring engineer and adventurous naturalist joined forces to conquer
37:15
Speaker 1: that final frontier. Otis Barton was a Harvard-trained engineer gripped
37:20
Speaker 1: by an audacious dream to build a diving capsule that
37:24
Speaker 1: could transport humans into the deepest reaches of the ocean.
37:28
Speaker 1: William Beebe was a prominent naturalist and early pioneer of
37:31
Speaker 1: scuba diving. determined to become the first scientist to observe
37:35
Speaker 1: the abyss with his own eyes. Together, they would make history.
37:39
Speaker 1: Combining Barton's technical ingenuity with Beebe's scientific knowledge, the duo
37:44
Speaker 1: constructed a revolutionary vessel, the Bathysphere. A tiny steel ball
37:49
Speaker 1: less than five feet in diameter, the Bathysphere boasted walls
37:53
Speaker 1: more than an inch thick, with a trio of inward-curving
37:56
Speaker 1: quartz windows to withstand the crushing pressures of the deep.
38:00
Speaker 1: Equipped with spotlights... a telephone line and oxygen tanks, the
38:04
Speaker 1: cramped capsule was just large enough to accommodate two people,
38:08
Speaker 1: Barton and Beebe. Beginning in 1930, Beebe and Barton conducted
38:13
Speaker 1: a series of manned descents off the coast of Bermuda,
38:16
Speaker 1: lowering their bathysphere into the depths on a steel cable.
38:20
Speaker 1: With each plunge into the abyss, they crossed new thresholds,
38:23
Speaker 1: 800 feet, then 1,400 feet, then 2,200 feet. Peering out
38:25
Speaker 1: through the thick quartz windows, They marvelled at the alien
38:32
Speaker 1: seascapes scrolling by, bioluminescent fireflies drifting past like underwater stars,
38:39
Speaker 1: spectral anglerfish luring prey with their luminous lures, and ethereal
38:43
Speaker 1: siphonophores pulsing by like living chandeliers. In 1934, Barton and
38:48
Speaker 1: Beebe made their deepest dive yet, a harrowing plunge to 3,028
38:53
Speaker 1: feet beneath the waves. There, in the dim blue void,
38:56
Speaker 1: they glimpsed a surreal creature unlike any they had seen before.
39:00
Speaker 1: a strange pale-bodied fish with wing-like fins, a whip-like tail
39:06
Speaker 1: and oval eyes that glowed a spectral green in the
39:09
Speaker 1: bathysphere's floodlights. Beebe dubbed it the abyssal hatchet fish for
39:13
Speaker 1: its hatchet-shaped body and marvelled that here, in this otherworldly
39:17
Speaker 1: realm of eternal darkness, were creatures even his scientific imagination
39:22
Speaker 1: had never conceived of. I knew I should never again
39:25
Speaker 1: look upon the stars without remembering their active, living counterparts,
39:29
Speaker 1: swimming about in that terrific pressure, Beebe later wrote. The
39:34
Speaker 1: bathysphere dives of the 1930s cracked open a portal to
39:37
Speaker 1: the deep sea, but only a tiny aperture. The vast
39:41
Speaker 1: majority of the abyssal ocean remained unexplored, a lightless mystery
39:45
Speaker 1: lurking beneath the waves. It would take the development of
39:48
Speaker 1: new technologies— in the crucible of world war, to truly
39:52
Speaker 1: illuminate the largest and most alien habitat on our planet.
39:56
Speaker 1: The advent of sonar, sound navigation and ranging, in the
40:00
Speaker 1: 1940s revolutionized our understanding of the deep ocean floor. Originally
40:04
Speaker 1: developed to detect enemy submarines, sonar used pings of sound
40:08
Speaker 1: to map out the contours of the seabed in astounding detail,
40:12
Speaker 1: revealing for the first time the serrated topography of the seafloor.
40:16
Speaker 1: Contrary to previous beliefs, the ocean bottom was anything but
40:19
Speaker 1: a featureless plain. Instead, it was riven with plunging trenches,
40:24
Speaker 1: soaring seamounts, and vast underwater mountain ranges to rival any
40:28
Speaker 1: on land. This new knowledge of the variegated deep sea
40:32
Speaker 1: floor would soon yield profound discoveries. In 1977, a team
40:37
Speaker 1: of geologists diving in the DSV Alvin submersible happened upon
40:41
Speaker 1: a jarring sight near the Galapagos Islands. Clouds of billowing
40:45
Speaker 1: black smoke gushing from volcanic vents in the seafloor. As
40:50
Speaker 1: the sub drew closer, the scientists were stunned to find
40:53
Speaker 1: these cracks teeming with life. Giant tube worms, ghostly crabs
40:58
Speaker 1: and blood-red octope, thriving in the total absence of sunlight.
41:02
Speaker 1: In time, these oases would become known as hydrothermal vents,
41:06
Speaker 1: deep-sea hot springs where superheated water surges out of cracks
41:10
Speaker 1: in the Earth's crust. The scalding vent fluid, it turns out,
41:14
Speaker 1: is rich in dissolved minerals and chemicals that can sustain
41:17
Speaker 1: life even without the Sun's energy. Microbes oxidize hydrogen sulfide
41:22
Speaker 1: to harness energy, forming the basis for whole ecosystems of
41:26
Speaker 1: larger creatures that feed on the microbes or each other.
41:29
Speaker 1: The discovery of hydrothermal vents was a revelation. For the
41:33
Speaker 1: first time, we understood that life could flourish independently of
41:36
Speaker 1: the Sun, relying instead on the Earth's internal heat and
41:39
Speaker 1: chemical energy. If such oases could exist on our own planet,
41:44
Speaker 1: Might they not also arise on alien worlds, in the
41:47
Speaker 1: dark oceans of Europa or Enceladus? The hydrothermal vents of
41:52
Speaker 1: the deep sea had given us a new understanding of
41:54
Speaker 1: the tenacity of life, and a new place to search
41:57
Speaker 1: for it beyond Earth. As remarkable as hydrothermal vents are,
42:01
Speaker 1: they represent just one facet of the rich tapestry of
42:04
Speaker 1: the deep sea. The abyssal plains, those vast muddy expanses
42:09
Speaker 1: that cover over half of Earth's surface, harbour their own
42:12
Speaker 1: unexpected oases of life in the lightless depths. In the 1980s,
42:17
Speaker 1: marine biologists exploring the abyssal seafloor stumbled upon an astounding sight.
42:22
Speaker 1: The scattered skeletons of dead whales, some the size of
42:26
Speaker 1: school buses resting on the ocean bottom. Far from being
42:29
Speaker 1: stagnant boneyards, however, these whale falls were hubs of activity,
42:34
Speaker 1: veritable banquets of bounty on the desolate abyssal plain. When
42:38
Speaker 1: a massive whale dies and sinks to the seafloor, its
42:42
Speaker 1: carcass offers up a sudden jackpot of food in a
42:45
Speaker 1: realm where meals are agonisingly scarce. A single whale fall
42:49
Speaker 1: can provide sustenance to deep-sea scavengers for years or even decades,
42:54
Speaker 1: supporting a complex succession of opportunistic organisms. First to arrive
42:59
Speaker 1: are the mobile scavengers, deep-sea sharks, rat tails and hagfish,
43:03
Speaker 1: eagerly stripping the most nutritious flesh from the carcass. In
43:07
Speaker 1: their wake come the bone-eating worms and zombie crabs, specialized
43:11
Speaker 1: to bore into and feed on the tough whale skeleton itself. Finally,
43:16
Speaker 1: as the bones decompose, they release a burst of sulfides
43:19
Speaker 1: that can sustain mats of bacteria and tube worms for
43:22
Speaker 1: a decade or more, until the very last of the
43:25
Speaker 1: carcass is gone. These insights into whale fall ecology were
43:28
Speaker 1: hard won. In 2006, marine biologist Craig Smith of the
43:32
Speaker 1: University of Hawaii conducted a daring experiment. Smith and his
43:37
Speaker 1: colleagues hauled a 30-ton gray whale carcass out to sea
43:40
Speaker 1: and deposited it on the deep seafloor off the California coast. Then,
43:45
Speaker 1: they monitored this whale fall with remotely operated vehicles, ROVs,
43:50
Speaker 1: and autonomous seafloor landers over the course of six years,
43:53
Speaker 1: documenting in time-lapse the arrival of different scavengers and succession
43:57
Speaker 1: of organisms. Smith's experiment shed light on a phenomenon that
44:01
Speaker 1: would have been impossible for the Challenger or Albatross expeditions
44:05
Speaker 1: to study. After all, whale falls are unpredictable, widely scattered,
44:10
Speaker 1: and slow to unfold. Yet they likely play a key
44:13
Speaker 1: role in the dispersal and evolution of deep sea life,
44:16
Speaker 1: serving as stepping stone habitats for creatures to hop across
44:19
Speaker 1: the abyssal plains. Remarkably, whale falls are not the only
44:23
Speaker 1: oases of food on the deep ocean floor. The abyss
44:26
Speaker 1: also harbours dense thickets of life crowded around sunken logs,
44:30
Speaker 1: beds of kelp and even shipwrecked boats, all rare bonanzas
44:34
Speaker 1: of food and shelter in the deep sea. Perhaps most
44:38
Speaker 1: intriguing of all are the so-called brine pools, lakes of dense,
44:43
Speaker 1: ultra-salty water that occasionally form in depressions on the seafloor.
44:48
Speaker 1: In the Gulf of Mexico, for example, brine from ancient
44:51
Speaker 1: salt deposits sometimes seeps up through the sediment, accumulating in
44:55
Speaker 1: seafloor basins. There, it forms pools of water up to
44:58
Speaker 1: four times saltier than the overlying ocean. To most marine life,
45:02
Speaker 1: these hypersaline lakes are toxic dead zones. Any creature that
45:05
Speaker 1: swims into one will perish within minutes, as the salt
45:08
Speaker 1: sucks the water from its cells. But where there are
45:11
Speaker 1: rules in nature, there are also bizarre exceptions. In the 1980s,
45:16
Speaker 1: oceanographers exploring brine pools off the coast of Florida discovered
45:20
Speaker 1: lush beds of mussels growing around the edges of these
45:22
Speaker 1: salt lakes, despite the lethal salinity of the brine. Genetic
45:27
Speaker 1: studies later revealed that these mussels belonged to the genus Bathymodiolus,
45:32
Speaker 1: the same group of deep-sea mussels found at hydrothermal vents.
45:36
Speaker 1: it appears these muscles have evolved to tolerate extreme salinity
45:39
Speaker 1: as well as searing heat, allowing them to exploit yet
45:43
Speaker 1: another niche of chemical energy on the seafloor. The deep
45:46
Speaker 1: oceans continue to yield such surprises with each passing year,
45:50
Speaker 1: as marine scientists develop new technologies to explore this alien realm.
45:55
Speaker 1: Autonomous underwater vehicles, AUVs, intelligent deep-sea drones, now roam the
46:01
Speaker 1: depths for months at a time, mapping the seafloor and
46:04
Speaker 1: collecting samples beyond the reach of any ship Networks of
46:08
Speaker 1: seafloor observatories, like the Neptune Array off the coast of
46:11
Speaker 1: Washington State, bring the deep ocean onto the internet with
46:14
Speaker 1: live video feeds and real-time data on everything from whale
46:18
Speaker 1: songs to the chemistry of the water. Yet for all
46:21
Speaker 1: these advances, we have still barely scratched the surface of
46:24
Speaker 1: the deep sea. Scientists estimate that over 90% of the
46:28
Speaker 1: ocean remains unexplored, and that for every known species living
46:31
Speaker 1: in the depths, there may be dozens or even hundreds
46:34
Speaker 1: yet to be discovered. the abyssal plains likely conceal untold
46:38
Speaker 1: legions of microbes, some of which may hold the key
46:41
Speaker 1: to new antibiotics or cancer drugs. The slopes of deep-sea
46:45
Speaker 1: seamounts almost certainly harbour thousands of unique species found nowhere
46:49
Speaker 1: else on Earth. Perhaps most exciting of all are the
46:53
Speaker 1: tantalising hints of life in the deepest deep sea, the
46:56
Speaker 1: Hidal realm of oceanic trenches. In the early 2000s, robotic
47:01
Speaker 1: landers deployed by the Japanese Kaiko Project returned fuzzy images
47:05
Speaker 1: of large white shrimp-like creatures skittering across the floor of
47:08
Speaker 1: the Mariana Trench, seven miles down and under bone-crushing pressures
47:13
Speaker 1: a thousand times that at the surface. Later expeditions would
47:17
Speaker 1: recover these enigmatic organisms and determine them to be a
47:20
Speaker 1: new genus of snailfish. Translucent, jelly-bodied fish, apparently uniquely adapted
47:26
Speaker 1: to the immense pressures of the Hadal Depths. What other
47:29
Speaker 1: wonders might await discovery in the inky canyons of the
47:31
Speaker 1: Mariana Trench and other Hadal zones? Only further exploration will tell.
47:37
Speaker 1: For all its vastness and all its strangeness, however, the
47:40
Speaker 1: deep ocean is far from immune to human influence. As
47:43
Speaker 1: our technologies grow more advanced, so does our reach into
47:46
Speaker 1: the abyss and our capacity to damage its delicate ecosystems.
47:51
Speaker 1: Bottom trawling, the practice of dragging weighted nets across the seafloor,
47:55
Speaker 1: gouges scars in ancient deepwater corals and sponge fields that
47:59
Speaker 1: may take centuries to heal, seabed mining, an emerging industry
48:04
Speaker 1: still in its infancy, threatens to dredge up vast swathes
48:08
Speaker 1: of the abyssal plains in the hunt for rare metals
48:10
Speaker 1: and minerals. A changing climate already seems to be altering
48:14
Speaker 1: the chemistry of the deep sea, making its waters more
48:17
Speaker 1: acidic and less oxygenated even as the surface warms. If
48:21
Speaker 1: there is one lesson to be drawn from the centuries-long
48:23
Speaker 1: quest to, the darkness of the abyss was long thought
48:27
Speaker 1: to be a barren void, devoid of life, but the
48:30
Speaker 1: heroic age of deep sea exploration would gradually reveal the
48:33
Speaker 1: hitherto unimagined creatures and oases hidden within that perpetual night.
48:38
Speaker 1: In the closing decades of the 19th century, the first
48:42
Speaker 1: systematic survey of the world's oceans was launched aboard the
48:45
Speaker 1: HMS Challenger. For four years, this grand expedition circled the globe,
48:51
Speaker 1: sounding the depths and dredging up samples from the sea
48:54
Speaker 1: floor at hundreds of stations. Hauling up their trawling nets
48:57
Speaker 1: from as deep as five miles down, The Challenger's naturalists
49:01
Speaker 1: were astounded to discover living creatures at every depth they sampled.
49:06
Speaker 1: From delicate glass sponges to nightmare-inducing fang-toothed fish, a pageant
49:11
Speaker 1: of life was unveiled from those abyssal plains so recently
49:15
Speaker 1: thought azoic. The Challenger expedition marked a paradigm shift. as
49:20
Speaker 1: biologists came to accept that the deep ocean harboured life
49:23
Speaker 1: despite its cold, darkness and crushing pressure. But glimpsing these
49:29
Speaker 1: marvels second-hand, pickled in preservative jars, was a poor substitute
49:33
Speaker 1: for laying eyes upon them in their natural deep-sea habitat.
49:37
Speaker 1: That feat would not be achieved until the 1930s and
49:41
Speaker 1: the advent of William Beebe and Otis Barton's revolutionary bathysphere.
49:45
Speaker 1: Dangling from a steel cable, this cramped hollow sphere of
49:48
Speaker 1: inch-thick cast iron was the frail cocoon that carried the
49:51
Speaker 1: first humans into the abyss. Sinking into the void off
49:55
Speaker 1: the coast of Bermuda, Beebe and Barton peered out the
49:58
Speaker 1: bathysphere's fist-sized quartz windows as the sunlight faded to endless
50:02
Speaker 1: blue and then utter blackness. In the dim glow of
50:06
Speaker 1: their floodlight, an alien seascape materialised. Strange, phosphorescent creatures drifted
50:12
Speaker 1: past the windows, shimmering tenophores, spectral hatchetfish with tubular telescope eyes,
50:19
Speaker 1: and gelatinous worms undulating like living lace. Beebe, a poetic soul,
50:25
Speaker 1: was moved to describe this fantastic spectacle as a slow,
50:29
Speaker 1: unending dance of fragile dreams. Over a series of dives,
50:33
Speaker 1: Beebe and Barton pushed ever deeper into that eternal night,
50:36
Speaker 1: culminating in a record-breaking descent to over 3,000 feet. But
50:41
Speaker 1: even as they celebrated their achievement, they knew their brief
50:45
Speaker 1: visitations were but the barest glimpse into that uncharted world.
50:48
Speaker 1: The technology to linger in the abyss and explore its
50:52
Speaker 1: furthest reaches was still decades away. It would take a
50:55
Speaker 1: world war and the military imperative to hide submarines in
50:59
Speaker 1: the ocean depths to spur the development of sonar, precision
51:03
Speaker 1: depth sensors and high-pressure engineering. The bathyscaphe Trieste, applying these
51:09
Speaker 1: wartime innovations, would not conquer the deepest point on Earth,
51:13
Speaker 1: the Mariana Trench, until 1960. The age of the submersible
51:17
Speaker 1: had dawned, granting scientists their first real access to the abyss.
51:22
Speaker 1: Craft like DSV Alvin, launched in 1964, enabled researchers to
51:27
Speaker 1: spend hours on the seafloor, collecting specimens and surveying the
51:31
Speaker 1: terrain with their own eyes. Robotic cameras and manipulator arms
51:35
Speaker 1: expanded their reach, while unmanned tethered and autonomous underwater vehicles
51:39
Speaker 1: opened up vast swathes of the deep for efficient exploration.
51:44
Speaker 1: After centuries of straining to sound out the shape of
51:47
Speaker 1: that hidden world from above, humanity could finally wade out
51:50
Speaker 1: into the abyss and illuminate its secrets. That light has
51:55
Speaker 1: revealed wonders stranger than the speculative imaginings of early naturalists.
51:59
Speaker 1: Delving into the darkness, we've discovered not a barren seascape
52:03
Speaker 1: but an intricate tapestry of deep sea habitats. each populated
52:07
Speaker 1: by exquisitely adapted creatures. The abyssal plain, though sparsely inhabited
52:12
Speaker 1: compared to the sunlit surface, nonetheless crawls with blind white
52:16
Speaker 1: crustaceans and gelatinous fish with recurved teeth. Seamounts thrust up
52:21
Speaker 1: from those muddy flatlands, their rocky flanks encrusted with vibrant
52:25
Speaker 1: deep-water corals and sponges. Hydrothermal vents gush scalding mineral-rich water
52:31
Speaker 1: into the icy depths, sustaining oases of giant tube worms,
52:35
Speaker 1: ghostly crabs and eyeless shrimp in the endless night. Perhaps
52:39
Speaker 1: most marvellous of all are the denizens of the Hadal depths,
52:42
Speaker 1: the ocean trenches that plunge to 20,000 feet and more. Here,
52:46
Speaker 1: in the deepest places on Earth, the pressure exceeds 1,000
52:50
Speaker 1: times that at sea level, enough to crush a human
52:53
Speaker 1: body to pulp. Yet even here, life finds a way.
52:58
Speaker 1: The Mariana snailfish, translucent and delicate as gossamer, thrives at
53:03
Speaker 1: the bottom of its namesake trench, flitting over the silty
53:06
Speaker 1: seafloor on wing-like fins. Amphipods, distant relatives of sand fleas,
53:11
Speaker 1: scuttle about in armoured exoskeletons, some grown grotesquely large in
53:16
Speaker 1: the absence of predators, and the enigmatic xenophyophories, giant single-celled
53:21
Speaker 1: organisms sheltered in honeycomb towers, may be the most abundant
53:25
Speaker 1: lifeform in the Hadal realm. From the haunting wails of
53:29
Speaker 1: a pod of sperm whales diving to battle giant squid
53:32
Speaker 1: in the lightless depths, to the frenetic twinkle of a
53:35
Speaker 1: pyrotechnic display of bioluminescence, the abyss is not a silent,
53:40
Speaker 1: barren place, but a world vibrant with life. Its inhabitants,
53:45
Speaker 1: long adapted to that unending night, face new perils as
53:48
Speaker 1: the impacts of human activity reach down from the sunlit surface.
53:52
Speaker 1: Bottom trawling gouges, scars in the seafloor, acidification erodes the
53:57
Speaker 1: skeletons of abyssal coral gardens, and mining interests eye the
54:01
Speaker 1: mineral riches that could be ripped from the deep. As
54:04
Speaker 1: we continue to explore this last great wilderness of our planet,
54:08
Speaker 1: we must also strive to preserve it and its myriad denizens.
54:12
Speaker 1: The deep ocean remains the least known environment on Earth,
54:16
Speaker 1: a realm where every expedition discovers new species and unimagined landscapes.
54:21
Speaker 1: From the first intrepid naturalists who dared to imagine life
54:24
Speaker 1: in the depths, to the revolutionary technologies that carry us
54:27
Speaker 1: down into the darkness today, we've only just begun to
54:30
Speaker 1: fathom the secrets of the abyss. The wonders we've glimpsed
54:33
Speaker 1: so far are but a fraction of what still lies
54:36
Speaker 1: waiting in that alien world below. As you drift off
54:40
Speaker 1: into the comforting darkness of sleep, ponder for a moment
54:43
Speaker 1: that hidden universe beneath the waves, where, in the words
54:47
Speaker 1: of William Beebe, myriad creatures joyfully and colourfully live their
54:51
Speaker 1: lives in an eternal night. Through the quartz windows of
54:56
Speaker 1: the bathysphere, the inky void of the abyss pressed in
54:59
Speaker 1: from all sides. William Beebe and Otis Barton, suspended by
55:03
Speaker 1: a slender cable from the research vessel far above, peered
55:07
Speaker 1: out into an alien world no human eyes had ever seen.
55:11
Speaker 1: As they descended deeper and deeper, the sunlight filtering down
55:15
Speaker 1: from the surface grew ever dimmer, until at last only
55:18
Speaker 1: the glow of their flashlight pierced the eternal, frigid night.
55:23
Speaker 1: The date was August 15th, 1934, and Beebe and Barton
55:27
Speaker 1: had just become the first humans to lay eyes on
55:29
Speaker 1: the denizens of the deep ocean. When their bathysphere, a
55:33
Speaker 1: hollow steel ball less than five feet in diameter, reached
55:36
Speaker 1: a depth of 3,028 feet, 923 metres, they stopped to
55:42
Speaker 1: gaze out in wonder at a realm that had previously
55:44
Speaker 1: only been glimpsed in fleeting net trawls and dredge samples
55:47
Speaker 1: hauled up by ships far above. Through the thick quartz
55:51
Speaker 1: and steel, Bibi beheld visions that seemed to defy reality.
55:55
Speaker 1: Billowing veils of bioluminescence rippled past in the darkness, emanating
56:00
Speaker 1: from creatures so delicate and diaphanous they seemed scarcely more
56:04
Speaker 1: than living light. Nightmarish fish with gaping maws lined with
56:09
Speaker 1: needle-like teeth appeared suddenly out of the blackness, before vanishing
56:13
Speaker 1: again like spectres. And all around, suspended in the water
56:17
Speaker 1: like constellations, countless sparks of light flickered on and off,
56:21
Speaker 1: hinting at a world of abundance beyond the reach of
56:23
Speaker 1: their probing flashlight beam. For over a century before Beebe's
56:27
Speaker 1: landmark dive, scientists had been gradually piecing together a picture
56:31
Speaker 1: of what lay in the uncharted depths. In 1818, the
56:35
Speaker 1: British researcher Sir John Ross was the first to sound
56:38
Speaker 1: the deep ocean using a weighted line, recording an astonishing
56:42
Speaker 1: depth of 2,700 metres in the Arctic basin. Subsequent expeditions
56:47
Speaker 1: using improved hemp ropes and eventually steel cables would reveal
56:51
Speaker 1: that the oceans were far deeper than anyone had imagined,
56:54
Speaker 1: plunging down over 10,000 metres in the deepest trenches. These
56:58
Speaker 1: early-sounding weights occasionally returned with clumps of mud or clay
57:01
Speaker 1: clinging to them, sometimes containing shells or worm tubes hinting
57:05
Speaker 1: at life on the abyssal seafloor. But most scientists at
57:08
Speaker 1: the time believed that the immense pressure, pervasive darkness and
57:13
Speaker 1: frigid cold precluded the possibility of life existing in the
57:16
Speaker 1: depths of the abyss. The prevailing theory was promoted by
57:20
Speaker 1: the British biologist Edward Forbes in the 1840s, was the
57:23
Speaker 1: Ozoic Hypothesis, which held that no life could exist below
57:27
Speaker 1: about 600 metres deep. It was the voyage of HMS
57:31
Speaker 1: Challenger from 1872 to 1876 that would begin to overturn
57:35
Speaker 1: this assumption. Over the course of their pioneering oceanographic expedition,
57:41
Speaker 1: which circumnavigated the globe and covered nearly 70,000 nautical miles,
57:45
Speaker 1: Scientists aboard the Challenger dredged up thousands of deep-sea specimens
57:50
Speaker 1: from every depth and region they sampled. Delicate glass sponges,
57:55
Speaker 1: otherworldly cephalopods, and creatures that seemed to be living fossils
57:58
Speaker 1: from bygone eras were pulled from the abyss, painting a
58:02
Speaker 1: picture of the deep ocean as an oasis of life
58:05
Speaker 1: rather than a barren underworld. In the decades following the
58:09
Speaker 1: Challenger expedition, new technologies would allow researchers to probe ever
58:12
Speaker 1: deeper and paint an increasingly vivid picture of the abyss.
58:17
Speaker 1: In the early 1900s, the research vessel Albatross used steel
58:20
Speaker 1: cables to lower trawl nets down to unprecedented depths, hauling
58:24
Speaker 1: up creatures like gulper eels and anglerfish that would capture
58:28
Speaker 1: the public imagination and cement the deep sea's reputation as
58:32
Speaker 1: a realm of monsters. But it was Beebe and Barton's
58:35
Speaker 1: bathysphere dives that would open a new era of deep
58:38
Speaker 1: ocean exploration. allowing humans to observe the abyss with their
58:42
Speaker 1: own eyes for the first time. As Beebe descended into
58:46
Speaker 1: the depths that fateful day in 1934, he marvelled at
58:50
Speaker 1: the parade of lifeforms drifting past the bathysphere's windows. Bioluminescent
58:56
Speaker 1: fireworks displays from creatures ranging from delicate jellyfish to bristling
59:00
Speaker 1: shrimp lit up the darkness. A phantasmagorical bestiary of deep
59:05
Speaker 1: sea fishes appeared as if in a dream. Fanged viper
59:08
Speaker 1: fish with sinister glowing lures, rotund gulper eels with cavernous mouths,
59:13
Speaker 1: and eerie anglerfish waving bioluminescent lures of their own to
59:17
Speaker 1: attract unwary prey. But perhaps most remarkable were the glimpses
59:22
Speaker 1: Beebe caught of the abyssal seafloor itself, an alien landscape
59:26
Speaker 1: of rippled ooze and jutting rock formations untouched by the
59:29
Speaker 1: sun's rays for eons. In that cold, lightless world, Beebe
59:35
Speaker 1: observed delicate creatures going about their lives as they had
59:38
Speaker 1: for millions of years, indifferent to the world above. Gossamer
59:42
Speaker 1: sea spiders tottered over the bottom on stilt-like legs. Gelatinous
59:47
Speaker 1: sea cucumbers ingested mouthfuls of nutrient-rich mud. and scuttling brittle
59:52
Speaker 1: stars picked their way among forests of glass sponges. It
59:56
Speaker 1: was a realm of unearthly calm and slow, dreamlike motion,
1:00:00
Speaker 1: where the usual rules of the sunlit world seemed not
1:00:03
Speaker 1: to apply. In the absence of light, many creatures had
1:00:06
Speaker 1: evolved to be transparent or clad in shades of black
1:00:09
Speaker 1: and red that rendered them all but invisible. Metabolisms had
1:00:13
Speaker 1: slowed to a crawl in the icy cold, with meals
1:00:16
Speaker 1: few and far between in the food-poor abyss. and all
1:00:19
Speaker 1: the while a gentle rain of organic detritus, marine snow,
1:00:24
Speaker 1: drifted down from the prolific surface waters miles above, providing
1:00:28
Speaker 1: sustenance to the abyssal plain. As Beebe and Barton ascended
1:00:32
Speaker 1: back to their world after half a mile of sinking
1:00:34
Speaker 1: into the deep, they carried with them a newfound appreciation
1:00:37
Speaker 1: for the wonders that lay hidden beneath the waves. Even today,
1:00:41
Speaker 1: with all our advanced technology, we have still explored less
1:00:44
Speaker 1: than 10% of the global ocean floor, The depths remain
1:00:48
Speaker 1: the largest and least understood habitat on our planet, a
1:00:52
Speaker 1: final frontier holding mysteries we can scarcely imagine. Modern oceanographers,
1:00:57
Speaker 1: following in the footsteps of pioneers like Beebe, continue to
1:01:01
Speaker 1: push the boundaries of our understanding of the deep. High-resolution
1:01:05
Speaker 1: mapping systems have revealed the abyssal plains to be anything
1:01:08
Speaker 1: but featureless. They're riven with mountain ranges, trenches and vast
1:01:12
Speaker 1: underwater canyons. Remotely operated vehicles, ROVs, And autonomous underwater vehicles, AUVs,
1:01:20
Speaker 1: allow us to survey the depths for longer periods and
1:01:22
Speaker 1: across greater distances than any human crewed vehicle. And each
1:01:27
Speaker 1: time they venture into the abyss, they return with images
1:01:30
Speaker 1: of creatures and seascapes more wondrous than the last. Perhaps
1:01:35
Speaker 1: most fascinating are the oases of life that punctuate the
1:01:37
Speaker 1: abyssal desert. Hydrothermal vents, first discovered in 1977, spew superheated
1:01:44
Speaker 1: water laden with minerals and chemicals from cracks in the seafloor,
1:01:48
Speaker 1: and host thriving communities of organisms found nowhere else on Earth.
1:01:52
Speaker 1: Tube worms, clams and crabs have all adapted to harness
1:01:56
Speaker 1: the energy from these vents, forming the basis of unique
1:01:59
Speaker 1: food chains that require no input from the sun above. Similarly,
1:02:03
Speaker 1: cold seeps and whale falls provide hotspots of nutrients that
1:02:06
Speaker 1: draw in scavengers and settlers from miles around, capitalising on
1:02:09
Speaker 1: these sporadic feasts. It is a world that operates on
1:02:13
Speaker 1: its own timeless rhythms, indifferent to the frenetic pulse of
1:02:16
Speaker 1: life in the sun. In the deep, many creatures live
1:02:20
Speaker 1: for decades or even centuries, growing slowly in the frigid dark.
1:02:25
Speaker 1: Some corals and sponges are thought to be among the
1:02:28
Speaker 1: oldest animals on the planet, with specimens dated to over 4,000
1:02:32
Speaker 1: years old. In the lightless depths, beyond the reach of
1:02:36
Speaker 1: the sun's nourishing rays, life has carved out its own
1:02:39
Speaker 1: rules for survival. As we drift off to sleep, we
1:02:42
Speaker 1: might imagine sinking down into that world ourselves, leaving the bright,
1:02:46
Speaker 1: busy realm of the surface behind. Down and down we go,
1:02:50
Speaker 1: past the warm, sunlit layers, through the twilight zone where
1:02:53
Speaker 1: the last rays of light fade to black. Deeper still,
1:02:57
Speaker 1: to the abyssal plain, a world of eternal night, where
1:03:01
Speaker 1: pressure crushes down with the weight of miles of water overhead.
1:03:05
Speaker 1: And yet, even here, life finds a way. As our
1:03:09
Speaker 1: eyes adjust to the darkness, the abyss gradually reveals itself
1:03:12
Speaker 1: in all its strange splendour. Sinuous shark silhouettes glide past
1:03:16
Speaker 1: with nightmare grace, their soulless eyes reflecting pinpricks of bioluminescence.
1:03:22
Speaker 1: Fist-sized amphipods scuttle over dunes of diatomaceous ooze, filter-feeding on
1:03:27
Speaker 1: the snow of organic detritus sinking from above. A dumbo
1:03:31
Speaker 1: octopus flaps its ear-like fins and drifts off into the gloom,
1:03:35
Speaker 1: a spectral Cheshire cat grin dissolving in the dark. This
1:03:39
Speaker 1: is a world beyond our daily cares and struggles, a
1:03:42
Speaker 1: liminal space between the surface and the unknown. As slumber
1:03:46
Speaker 1: takes hold and the waking world recedes, the siren song
1:03:50
Speaker 1: of the abyss beckons us down to lightless realms. It
1:03:53
Speaker 1: is a soothing void, a dreamscape of liquid midnight where
1:03:57
Speaker 1: time seems to hold no sway. Even as we sleep,
1:04:00
Speaker 1: that alien world carries on in its ceaseless rhythms far below.
1:04:05
Speaker 1: A reminder that the planet we inhabit holds wonders beyond
1:04:08
Speaker 1: our imagining in its most remote reaches. So let the
1:04:11
Speaker 1: deep sea's eternal dream cradle us in its darkened depths.
1:04:15
Speaker 1: Let the miles of water above us become a caress,
1:04:18
Speaker 1: a cocoon against the world of light and air. And
1:04:22
Speaker 1: let sleep become a journey to that final, fathomless frontier
1:04:26
Speaker 1: where monsters and marvels still roam undisturbed. Here in the
1:04:30
Speaker 1: abyssal night, cradled in a lullaby of slow tides and
1:04:33
Speaker 1: settling snow, we can abandon the frenetic tempo of life above.
1:04:38
Speaker 1: As we slumber, the denizens of the deep carry on
1:04:41
Speaker 1: their patient vigil, as they have for eons. Someday we
1:04:45
Speaker 1: may yet unravel all the mysteries these sightless depths conceal,
1:04:49
Speaker 1: but for now we can only visit in our dreams,
1:04:52
Speaker 1: sinking into the soft, silent abyss where time, light and
1:04:56
Speaker 1: life all fade to black. Sweet dreams, from the eternal
1:05:00
Speaker 1: night of the deep, The deep sea is truly Earth's
1:05:03
Speaker 1: last great unexplored frontier. With every expedition, researchers discover completely
1:05:09
Speaker 1: new species, ecosystems and mysteries that overturn our understanding of
1:05:14
Speaker 1: life on this planet. Just recently in 2020, a joint
1:05:18
Speaker 1: US-UK expedition to the Clarion-Clipperton zone of the Pacific Ocean
1:05:23
Speaker 1: uncovered over 30 new species, from glass sponges to sea
1:05:27
Speaker 1: cucumbers to octopuses. And yet this survey only scratched the surface.
1:05:32
Speaker 1: Scientists estimate there could be millions more unknown creatures dwelling
1:05:35
Speaker 1: in the abyss. But even as we marvel at the
1:05:38
Speaker 1: richness of deep sea life, this alien world is increasingly
1:05:42
Speaker 1: under threat from human activities. Climate change is warming the
1:05:46
Speaker 1: oceans and acidifying the water, putting stress on delicate deep
1:05:50
Speaker 1: sea corals and other temperature-sensitive creatures. Bottom trawling by fishing
1:05:55
Speaker 1: fleets scrapes 2.5 million square miles of seafloor each year.
1:05:59
Speaker 1: ripping up slow-growing sponges and decimating seamount communities. Proposed deep-sea
1:06:05
Speaker 1: mining operations for valuable metals could soon carve up vast
1:06:09
Speaker 1: swaths of pristine abyssal plain. If there's one thing the
1:06:13
Speaker 1: history of deep-sea exploration has taught us, it's how much
1:06:16
Speaker 1: we still have to learn about the depths. Over 80%
1:06:20
Speaker 1: of the ocean remains unmapped and unobserved by human eyes.
1:06:24
Speaker 1: The creatures down there have existed for eons in the darkness,
1:06:27
Speaker 1: under crushing pressures, on meager rations. Now their realm faces
1:06:32
Speaker 1: a threat like never before. How many wondrous animals will
1:06:36
Speaker 1: vanish before we even know they exist? What marvels of
1:06:40
Speaker 1: evolution will be lost forever to the insatiable human appetite
1:06:43
Speaker 1: for exploitation? Perhaps one day, tourism to the deep sea
1:06:47
Speaker 1: will be as common as voyages to outer space. Already,
1:06:51
Speaker 1: submersible joyrides to the Titanic wreck and Challenger Deep are
1:06:55
Speaker 1: available to those with means. Maybe in the future, vacationers
1:06:59
Speaker 1: will flock to the thermal spa vents of the Mid-Atlantic Ridge,
1:07:02
Speaker 1: or marvel at the eerie, bioluminescent light shows of the
1:07:05
Speaker 1: Benthic Zone. With new battery technology and lightweight materials, AUVs
1:07:10
Speaker 1: could glide for months in the abyss, live-streaming the sights
1:07:14
Speaker 1: via digital telepresence. But for most of us, the abyssal
1:07:17
Speaker 1: realm will always remain a mysterious otherworld, as remote as
1:07:21
Speaker 1: the moons of Jupiter. A place we may only visit
1:07:24
Speaker 1: in our most fanciful dreams, as we drift off into
1:07:27
Speaker 1: the welcoming darkness of sleep. Down there, in the endless
1:07:31
Speaker 1: night of the deep, the bone-white crabs and eyeless fish
1:07:33
Speaker 1: carry on their lives as they have for millennia. Slow lives,
1:07:37
Speaker 1: pared down to the essentials, metered out over centuries. The
1:07:42
Speaker 1: deep sea is a reminder of how fleeting our own
1:07:44
Speaker 1: existence is in the grand scheme. While we slumber, the
1:07:48
Speaker 1: eternal dance of predator and prey, life and death, plays
1:07:52
Speaker 1: out in the void as it has since the first
1:07:54
Speaker 1: creatures invaded the abyss. It's a humbling thought, that there
1:07:57
Speaker 1: are beings on our own planet so utterly unlike us,
1:08:00
Speaker 1: so far removed from the reality we know. And yet,
1:08:04
Speaker 1: we are connected to that world in ways we're only
1:08:07
Speaker 1: beginning to understand. The deep ocean is the crucible that
1:08:11
Speaker 1: forged all life on Earth. Every living thing can trace
1:08:15
Speaker 1: its ancestry back to the primordial soup of chemicals that
1:08:17
Speaker 1: first gathered around those ancient hydrothermal vents. The story of
1:08:22
Speaker 1: life's odyssey from sea to land is written in every
1:08:25
Speaker 1: bone of our bodies, in every twitch of our muscles.
1:08:28
Speaker 1: So as you nestle into your blankets, ready to slip
1:08:31
Speaker 1: into the comforting oblivion of sleep, spare a thought for
1:08:35
Speaker 1: the creatures of the deep. They may be out of
1:08:37
Speaker 1: sight and out of mind, but they are always there,
1:08:40
Speaker 1: living their unfathomable lives in the abyss. In a way,
1:08:44
Speaker 1: the deep sea is the closest thing we have to
1:08:46
Speaker 1: an alien world right here on Earth. A place of
1:08:49
Speaker 1: eternal darkness, filled with bizarre creatures that seem to defy
1:08:53
Speaker 1: the laws of nature. But the more we learn about
1:08:56
Speaker 1: the Abyss, the more we realise how inextricably linked we
1:08:59
Speaker 1: are to that alienation. realm. The fate of the oceans
1:09:02
Speaker 1: is the fate of all life on this planet, from
1:09:04
Speaker 1: the plankton that produce the oxygen we breathe to the
1:09:07
Speaker 1: whales that fertilise entire ecosystems with their falling carcasses. What
1:09:12
Speaker 1: happens in the depths affects us all, whether we realise
1:09:15
Speaker 1: it or not. So as you finally surrender to the
1:09:18
Speaker 1: irresistible pull of sleep, drifting off into your own personal abyss,
1:09:23
Speaker 1: remember that you are part of something much larger. A
1:09:27
Speaker 1: tapestry of life that extends from the sunlit shallows to
1:09:31
Speaker 1: the stygian depths, woven over billions of years of evolution.
1:09:36
Speaker 1: The mysteries of the deep may never be fully solved,
1:09:39
Speaker 1: but in our dreams we can imagine ourselves there, floating
1:09:43
Speaker 1: weightless in the infinite darkness, at one with the wonders
1:09:46
Speaker 1: of the abyss, As we've seen, the deep oceans are
1:09:49
Speaker 1: a realm of eternal darkness, where the pressure is immense,
1:09:53
Speaker 1: food is scarce, and temperatures hover just above freezing. In
1:09:58
Speaker 1: this harsh world, animals have evolved some truly extraordinary adaptations
1:10:02
Speaker 1: to carve out their existence. Take the Mariana snailfish, for instance.
1:10:07
Speaker 1: This small, tadpole-like creature holds the record for the deepest
1:10:10
Speaker 1: living fish ever discovered, found swimming a staggering 8,200 metres
1:10:14
Speaker 1: beneath the waves. At that depth, the pressure is over 1,000
1:10:20
Speaker 1: times greater than at the surface, enough to crush a
1:10:22
Speaker 1: human like an aluminum can. Yet the snailfish's delicate, gelatinous
1:10:27
Speaker 1: body is perfectly adapted to withstand the squeeze. Its skeleton
1:10:31
Speaker 1: is light and flexible, its muscles are infused with special
1:10:35
Speaker 1: oils to prevent them from locking up in the cold,
1:10:38
Speaker 1: and its cell walls are packed with molecules called piezolytes
1:10:41
Speaker 1: that keep them from getting crushed. Snailfish spend their lives
1:10:44
Speaker 1: drifting gently through the abyss. grazing on tiny crustaceans and
1:10:48
Speaker 1: marine snow. Many other deep-sea creatures have evolved to be
1:10:52
Speaker 1: extremely gelatinous and fragile. This is because, in the deep,
1:10:57
Speaker 1: it's advantageous to invest precious energy into muscles and sensory
1:11:01
Speaker 1: organs rather than heavy skeletons and armour. The gulper eel,
1:11:05
Speaker 1: for instance, has a jaw and stomach that can stretch
1:11:08
Speaker 1: to engulf prey nearly as big as its own body,
1:11:11
Speaker 1: while the vampire squid has huge globular eyes that to
1:11:14
Speaker 1: detect the faintest shimmer of bioluminescence. But bring these animals
1:11:18
Speaker 1: up towards the surface and they rapidly deteriorate as their
1:11:22
Speaker 1: bodies cannot withstand the reduction in pressure. Bioluminescence is another
1:11:26
Speaker 1: common deep-sea adaptation. In a world of permanent darkness, producing
1:11:31
Speaker 1: your own light can help you attract prey, find mates
1:11:35
Speaker 1: or camouflage yourself against predators. It's estimated that around 90%
1:11:40
Speaker 1: of deep-sea creatures can glow in one way or another.
1:11:43
Speaker 1: The anglerfish is perhaps the most famous example, with its
1:11:46
Speaker 1: long head stalk tipped with a luminous lure to draw
1:11:49
Speaker 1: curious prey into its cavernous, tooth-filled mouth. Some squid and
1:11:53
Speaker 1: crustaceans can even squirt clouds of glowing ink to distract
1:11:56
Speaker 1: predators while they make their escape. The deep is also
1:11:59
Speaker 1: home to some of the oldest animals on Earth. In
1:12:02
Speaker 1: the stillness and stability of the depths, many species are
1:12:05
Speaker 1: thought to live for hundreds or even thousands of years.
1:12:09
Speaker 1: The Greenland shark, for instance, is estimated to live over
1:12:11
Speaker 1: 400 years, making it the longest-lived vertebrate. The deep-sea sponge
1:12:17
Speaker 1: Monohaphis tuni has been found towering up to three metres tall,
1:12:21
Speaker 1: and with a growth rate of just a few millimetres
1:12:23
Speaker 1: per year, the largest individuals may have been slowly filter-feeding
1:12:27
Speaker 1: for over 10,000 years. In the abyss, life tends to
1:12:31
Speaker 1: be slow, stretched out, and sustainable. But even in this
1:12:36
Speaker 1: realm of darkness, oases of life and colour can be
1:12:39
Speaker 1: found erupting from the seafloor, Hydrothermal vents are cracks where
1:12:43
Speaker 1: superheated water, rich in dissolved minerals and chemicals, comes geysering
1:12:48
Speaker 1: out of the Earth's crust. The scalding fluids can reach
1:12:51
Speaker 1: up to 400 degrees Celsius and are laden with toxic
1:12:55
Speaker 1: substances like hydrogen sulfide. Yet life thrives here in abundance.
1:13:00
Speaker 1: Entire ecosystems flourish around the vents, bathed in the warm,
1:13:05
Speaker 1: mineral-rich flow and sheltered from the cold, crushing pressure of
1:13:08
Speaker 1: the deep. The secret lies in chemosynthetic bacteria, microbes that
1:13:13
Speaker 1: can harness the energy in the hydrothermal fluid to make food,
1:13:16
Speaker 1: much like plants use sunlight. These bacteria form the base
1:13:20
Speaker 1: of the food chain, fuelling lush communities of giant tube worms, clams, mussels,
1:13:25
Speaker 1: crabs and fish that can withstand the harsh conditions. Some
1:13:29
Speaker 1: tube worms can grow up to two metres long, sheltering
1:13:32
Speaker 1: the bacteria inside their bodies in a symbiotic relationship. The
1:13:36
Speaker 1: microbes produce sugars for the worm, while the worm supplies
1:13:39
Speaker 1: them with oxygen, carbon dioxide and a safe haven. Over
1:13:44
Speaker 1: 700 species have been discovered at hydrothermal vents since they
1:13:47
Speaker 1: were first stumbled upon in 1977. Each vent has a
1:13:51
Speaker 1: unique combination of mineral composition, temperature and fluid chemistry that
1:13:57
Speaker 1: shapes the community living there. And when a vent eventually
1:14:00
Speaker 1: stops flowing and dies out, the entire ecosystem collapses and decays,
1:14:05
Speaker 1: leaving behind a whale-fall-like oasis on the seafloor for years
1:14:08
Speaker 1: to come as scavengers flock to feast. Perhaps even more
1:14:12
Speaker 1: peculiar than the vents are the deep hypersaline basins, or
1:14:16
Speaker 1: brine pools, that dot the bottom of the Gulf of
1:14:18
Speaker 1: Mexico and Red Sea. These are literally lakes within the ocean,
1:14:23
Speaker 1: with the heavy salt water forming distinct shores and depressions
1:14:26
Speaker 1: on the seafloor. The brine is so dense that submersibles
1:14:30
Speaker 1: can float on the surface and sampling bottles can be
1:14:33
Speaker 1: filled from the lake like on land. but this water
1:14:36
Speaker 1: contains almost no oxygen and is loaded with toxic methane
1:14:39
Speaker 1: and sulphur. It's deadly to most life. However, a few
1:14:43
Speaker 1: highly specialised creatures do thrive along the shores, like mussels
1:14:46
Speaker 1: and shrimp that have adapted to withstand the harsh chemistry.
1:14:51
Speaker 1: Predatory fish will sometimes drift over the brine to hunt,
1:14:54
Speaker 1: but must be careful not to stay too long or
1:14:56
Speaker 1: accidentally touch the surface, lest they be pickled to death
1:14:59
Speaker 1: by the deadly waters. In the brine itself, only a
1:15:03
Speaker 1: few hardy microbes make their living, forming a living scum
1:15:06
Speaker 1: that coats the lake floor like a salty bacterial mat.
1:15:10
Speaker 1: It's thought that these brine pools formed from the evaporation
1:15:13
Speaker 1: of ancient seas that once covered the area tens of
1:15:16
Speaker 1: millions of years ago. As plate tectonics shifted and oceans receded,
1:15:21
Speaker 1: massive salt deposits were buried under sediment and squeezed by
1:15:24
Speaker 1: the pressure into concentrated brine. This brine then seeped up
1:15:28
Speaker 1: through the seafloor at faults and collected in the depressions
1:15:31
Speaker 1: we see today, salty time capsules from a long-lost past.
1:15:36
Speaker 1: But brine pools aren't the only evidence of microbial life
1:15:38
Speaker 1: far beneath the seabed. All throughout the deep oceans, a
1:15:42
Speaker 1: deep biosphere of microbes ekes out a living buried inside
1:15:45
Speaker 1: the mud and rock of the seafloor. These hardy organisms
1:15:48
Speaker 1: survive without sunlight or oxygen, slowly munching away at nuggets
1:15:52
Speaker 1: of organic matter or sips of chemical energy. They live
1:15:56
Speaker 1: life in extreme slow motion, with a single cell division
1:16:00
Speaker 1: taking hundreds to thousands of years in the most barren sediments.
1:16:04
Speaker 1: it's estimated that the total biomass of the deep biosphere
1:16:08
Speaker 1: could exceed that of all other life on Earth. After all,
1:16:11
Speaker 1: the ocean floor is a vast continuous habitat, with cracks
1:16:15
Speaker 1: and crevices extending kilometres down into the crust. If you
1:16:19
Speaker 1: took all the water out of the oceans, the dried-out
1:16:21
Speaker 1: seabed would be a global desert of mud, ooze and rock,
1:16:26
Speaker 1: pockmarked with hypersaline lakes, hydrothermal geysers and minerals leaching from
1:16:30
Speaker 1: the sediment, and it would be crawling with an astronomically
1:16:33
Speaker 1: large underground ecosystem of bacteria, archaea and fungi. Recent expeditions
1:16:40
Speaker 1: have even found life in the deepest, most inhospitable corners
1:16:43
Speaker 1: of the abyss. The Mariana Trench extends almost 11,000 metres
1:16:47
Speaker 1: down into the crust. If you placed Mount Everest inside it,
1:16:51
Speaker 1: the peak would still be over a mile underwater. The
1:16:54
Speaker 1: pressure at the bottom exceeds 1,000 atmospheres, or the equivalent
1:16:57
Speaker 1: of having 50 jumbo jets stacked on your head. The
1:17:01
Speaker 1: water temperature hovers just a few degrees above freezing. It's
1:17:04
Speaker 1: hard to imagine life surviving in this most extreme environment
1:17:07
Speaker 1: on Earth. Yet when James Cameron made his historic solo
1:17:11
Speaker 1: dive to the bottom in 2012, he was stunned to
1:17:14
Speaker 1: see life through his tiny window. Delicate, ghostly fish flitted
1:17:18
Speaker 1: through his lights, and shrimp-like amphipods danced along the seafloor.
1:17:23
Speaker 1: Later analysis would find that these Mariana snailfish and Hirondelia
1:17:27
Speaker 1: gigas amphipods were distinct species. superbly adapted to the unique
1:17:31
Speaker 1: conditions of the trench. The snailfish had high levels of
1:17:35
Speaker 1: the pressure-stabilising molecule TMAO in their muscles, while the amphipods
1:17:39
Speaker 1: had evolved aluminium suits of armour to withstand the squeeze.
1:17:43
Speaker 1: Even more shocking was the discovery of microbes living in
1:17:45
Speaker 1: the sediment at the bottom of the trench. Despite the
1:17:49
Speaker 1: immense pressure, total lack of light and scarcity of nutrients,
1:17:53
Speaker 1: bacteria and archaea were found in higher abundances than expected.
1:17:57
Speaker 1: slowly metabolising the detritus that rained down from miles above.
1:18:02
Speaker 1: Some were even able to survive and reproduce samples brought
1:18:05
Speaker 1: back to the surface. The Mariana Trench was not a
1:18:08
Speaker 1: lifeless void, but an alien oasis at the furthest reaches
1:18:11
Speaker 1: of where life could take hold. This may have profound
1:18:15
Speaker 1: implications for the possibility of life on other worlds. If
1:18:18
Speaker 1: bacteria and archaea can survive in the deepest, darkest, most
1:18:21
Speaker 1: hostile places on our planet, then perhaps we shouldn't rule
1:18:24
Speaker 1: out the existence of life in the more extreme corners
1:18:27
Speaker 1: of the solar system. Could there be microbes lurking in
1:18:30
Speaker 1: the underground oceans of Europa, or clinging to hydrothermal vents
1:18:34
Speaker 1: on the seafloor of Enceladus? Might there be entire ecosystems
1:18:38
Speaker 1: sheltered beneath the frozen surface of Pluto, powered not by
1:18:41
Speaker 1: the sun but by radioactive elements and chemical reactions in
1:18:45
Speaker 1: the depths? The incredible tenacity of life in Earth's abyss
1:18:49
Speaker 1: suggests we should keep an open mind. As we've seen,
1:18:52
Speaker 1: the history of deep-sea exploration is one of continually having
1:18:55
Speaker 1: our expectations overturned. Two centuries ago, Edward Forbes proclaimed the
1:18:59
Speaker 1: oceans below 1800 feet to be a lifeless ozoic zone,
1:19:03
Speaker 1: yet now we know that life thrives all the way
1:19:05
Speaker 1: down to the deepest trenches. We used to think that
1:19:08
Speaker 1: the deep was a vast, continuous void of mud and ooze.
1:19:13
Speaker 1: Yet now we know it's dotted with hydrothermal wonderlands, brine
1:19:16
Speaker 1: lakes and whale-fall oases rich in unique species. And we
1:19:20
Speaker 1: used to think that the seafloor was a static, barren place.
1:19:24
Speaker 1: Yet now we know it's home to an enormous underworld
1:19:27
Speaker 1: of microbial activity, cycling nutrients and energy in the darkness.
1:19:31
Speaker 1: There is still so much left to discover about the
1:19:33
Speaker 1: alien world far beneath the waves. Whenever a new expedition
1:19:37
Speaker 1: ventures into the abyss, they invariably come back with footage
1:19:40
Speaker 1: and samples of creatures never before seen by human eyes.
1:19:44
Speaker 1: We've only explored and mapped a tiny fraction of the
1:19:47
Speaker 1: deep sea floor, and even less of the water column
1:19:50
Speaker 1: above it. Every submersible dive has the potential to stumble
1:19:54
Speaker 1: upon strange new ecosystems, living fossils from bygone eras, or
1:19:58
Speaker 1: novel biochemistries and survival strategies. The Deep holds answers to
1:20:03
Speaker 1: some of the biggest remaining questions in science. the origins
1:20:07
Speaker 1: of life, the extremes of habitability, the future effects of
1:20:10
Speaker 1: climate change. The abyss beckons. Perhaps someday, in the far future,
1:20:16
Speaker 1: we may establish permanent colonies on the seafloor, as we're
1:20:19
Speaker 1: now attempting to build on the Moon and Mars. Imagine
1:20:22
Speaker 1: cities under the sea, nestled in protective domes near hydrothermal
1:20:26
Speaker 1: vents and brine pools, harvesting the chemical and mineral riches
1:20:30
Speaker 1: gushing from the Earth, while studying the extremophile lifeforms up close.
1:20:35
Speaker 1: Maybe we'll even develop ways to modify our own biology,
1:20:39
Speaker 1: to withstand the pressure and breathe the fluids, becoming true
1:20:42
Speaker 1: citizens of the deep. It's a captivating thought to drift
1:20:46
Speaker 1: off to sleep to, but for now we can marvel
1:20:49
Speaker 1: at the wonders that await us in the inky depths
1:20:51
Speaker 1: of our own planet, an alien landscape more spectacular than
1:20:54
Speaker 1: anything dreamed up in science fiction. As you slip into slumber,
1:20:59
Speaker 1: picture yourself sinking slowly into that endless velvet night of
1:21:03
Speaker 1: the abyss. watching as the shimmering life of the surface
1:21:06
Speaker 1: gives way to the glowing specks and sparks of bioluminescence
1:21:11
Speaker 1: in the darkness below, like the stars emerging in the
1:21:14
Speaker 1: night sky. Sink past the concealing red-black skin of the
1:21:18
Speaker 1: crunchied squid, the watchful eyes of the viperfish, the twinkling
1:21:23
Speaker 1: lure of the anglerfish. Sink past the bone-eating worms and
1:21:27
Speaker 1: crabs swarming over a whale fall, the tubeworms and crabs
1:21:31
Speaker 1: basking in the glow of a hydrothermal vent. the microbial
1:21:34
Speaker 1: mat shimmering along the shore of a brine lake. Sink
1:21:38
Speaker 1: and sink until even the Mariana snailfish and TMAO-laden amphipods
1:21:43
Speaker 1: cannot follow, and you are engulfed by the primordial ooze
1:21:46
Speaker 1: of the deeper seafloor, where the bacteria toil silently in
1:21:50
Speaker 1: the depths, as they have for billions of years. Down here,
1:21:54
Speaker 1: in the cold eternal darkness of the abyss, a whole
1:21:57
Speaker 1: alien world carries on, and the mysteries it still holds
1:22:00
Speaker 1: for us are beyond our most extraordinary dreams. as you
1:22:04
Speaker 1: finally let sleep overtake you, remember that the deep is
1:22:07
Speaker 1: not a dead empty void, but a living, breathing, endlessly
1:22:12
Speaker 1: fascinating hidden realm, ready and waiting for when humanity next
1:22:16
Speaker 1: dares to take the plunge into the unknown. For now,
1:22:20
Speaker 1: rest well and dream of the marvels in the deep.
1:22:24
Speaker 1: As we've seen, the deep oceans are not the lifeless
1:22:27
Speaker 1: voids they were once thought to be. They are home
1:22:29
Speaker 1: to an astonishing diversity of lifeforms, each exquisitely adapted to
1:22:34
Speaker 1: the challenges of their extreme environment. One creature that perfectly
1:22:38
Speaker 1: embodies the alien nature of the abyss is the anglerfish.
1:22:41
Speaker 1: Imagine a gaping mouth filled with needle-sharp teeth, attached to
1:22:45
Speaker 1: a body that seems to be all head and no tail.
1:22:49
Speaker 1: Sprouting from its forehead is a long, thin appendage tipped
1:22:53
Speaker 1: with a glowing lure. This is the anglerfish's bioluminescent fishing rod,
1:22:58
Speaker 1: used to attract curious prey in the darkness. There are
1:23:01
Speaker 1: over 200 species of anglerfish, and some of the most
1:23:04
Speaker 1: fascinating are the deep-sea varieties. In a stunning example of
1:23:08
Speaker 1: evolutionary adaptation, the tiny male anglerfish actually fuses to the
1:23:13
Speaker 1: much larger female, becoming a permanent sperm-producing appendage. This bizarre
1:23:18
Speaker 1: reproductive strategy ensures that when the female is ready to spawn,
1:23:21
Speaker 1: a mate is always at hand, or rather, at body.
1:23:26
Speaker 1: Another icon of the deep is the giant squid. For centuries,
1:23:29
Speaker 1: this elusive creature was the stuff of legend, with tall
1:23:33
Speaker 1: tales of tentacled monsters dragging ships to their doom. But
1:23:37
Speaker 1: in truth, the giant squid is a more fragile beast.
1:23:41
Speaker 1: Growing up to 13 metres long, its eyes are the
1:23:44
Speaker 1: size of dinner plates, the largest in the animal kingdom.
1:23:47
Speaker 1: Yet for all its bulk, the giant squid's body is
1:23:50
Speaker 1: remarkably soft and gelatinous. That's because in the deep sea,
1:23:54
Speaker 1: bones and dense tissues are a liability. The immense pressure
1:23:58
Speaker 1: at depth would crush a heavily built creature. So many
1:24:02
Speaker 1: abyssal animals have adapted by trading firmness for flabbiness, developing watery,
1:24:06
Speaker 1: almost transparent bodies held together by not much more than collagen.
1:24:10
Speaker 1: We see this taken to the extreme in jellyfish and
1:24:13
Speaker 1: comb jellies, or tenophores. These delicate, ghostly creatures are little
1:24:17
Speaker 1: more than pulsating bells of a jelly, trailing long tentacles
1:24:21
Speaker 1: to ensnare tiny prey. Some... like the bloody belly comb
1:24:26
Speaker 1: jelly flash with bioluminescent light, putting on dazzling displays in
1:24:30
Speaker 1: the eternal night. Speaking of eternal night, most of the
1:24:35
Speaker 1: deep ocean is shrouded in utter darkness, beyond the reach
1:24:38
Speaker 1: of even the dimmest sunlight. In this lightless world, the
1:24:42
Speaker 1: only illumination comes from the creatures themselves. Bioluminescence is remarkably
1:24:47
Speaker 1: common in the deep sea, with an estimated 90% of
1:24:50
Speaker 1: animals producing some form of living light, There are a
1:24:53
Speaker 1: myriad of reasons why deep sea creatures flash and glow.
1:24:57
Speaker 1: For some, like the anglerfish, bioluminescence is a lure to
1:25:01
Speaker 1: attract prey. For others, it's a defence mechanism to confuse
1:25:05
Speaker 1: predators or a way to communicate with potential mates. Some
1:25:09
Speaker 1: creatures even use bioluminescent cloaks to disguise their silhouettes against
1:25:14
Speaker 1: the faint light filtering down from above. One of the
1:25:17
Speaker 1: most astonishing light shows in the depths is the shimmering
1:25:20
Speaker 1: display of a startled vampire squid. When threatened, this strange
1:25:25
Speaker 1: cephalopod unfurls a cloak-like web of skin between its arms,
1:25:28
Speaker 1: which is dotted with glowing photophores. As it undulates gracefully
1:25:33
Speaker 1: through the water, the vampire squid appears to vanish and
1:25:36
Speaker 1: reappear in a mesmerising game of hide and seek. But
1:25:40
Speaker 1: light isn't the only way to hide in the deep sea.
1:25:43
Speaker 1: In a world without colour, many creatures have evolved to
1:25:45
Speaker 1: be completely transparent. This allows them to blend into the
1:25:49
Speaker 1: featureless background and avoid the probing eyes of predators. One
1:25:53
Speaker 1: such master of invisibility is the glass squid, whose entire
1:25:57
Speaker 1: body is as clear as crystal, with only its shimmering
1:26:00
Speaker 1: eyes and flickering chromatophores giving it away. At the other
1:26:04
Speaker 1: end of the spectrum are creatures cloaked in red and black.
1:26:08
Speaker 1: In the dim blue light of the twilight zone, these
1:26:10
Speaker 1: colours appear almost identical to the empty void. A prime
1:26:14
Speaker 1: example is the deep sea dragonfish, whose jet black skin
1:26:18
Speaker 1: and dagger-like teeth make it a phantom of the abyss.
1:26:20
Speaker 1: So why is the deep sea dominated by these particular hues?
1:26:24
Speaker 1: It all comes down to the physics of light in water.
1:26:28
Speaker 1: As sunlight filters through the depths, the long red wavelengths
1:26:31
Speaker 1: are quickly absorbed, leaving only the shorter blue wavelengths behind.
1:26:36
Speaker 1: That's why the open ocean appears a vivid blue from above,
1:26:39
Speaker 1: but fades to a murky twilight, and finally complete blackness
1:26:43
Speaker 1: as you descend. For creatures seeking to hide in this
1:26:46
Speaker 1: alien world, red and black are the perfect camouflage. but
1:26:50
Speaker 1: there's a twist. Many deep sea predators have actually evolved
1:26:54
Speaker 1: the ability to produce and detect red light. The dragonfish,
1:26:57
Speaker 1: for example, wields red bioluminescence like a sniper scope, illuminating
1:27:02
Speaker 1: hapless prey while remaining invisible to others. It's just one
1:27:06
Speaker 1: of the many remarkable adaptations that allow life to thrive
1:27:09
Speaker 1: in one of the most inhospitable environments on earth. From
1:27:12
Speaker 1: the delicate wisps of a siphonophore's tentacles to the cavernous
1:27:16
Speaker 1: maw of a gulper eel, Each creature is a marvel
1:27:19
Speaker 1: of evolutionary engineering, shaped by the relentless pressures of the deep.
1:27:23
Speaker 1: And yet, for all their alien strangeness, there is a
1:27:26
Speaker 1: haunting beauty to the inhabitants of the abyss. As they
1:27:29
Speaker 1: drift through the inky depths, these creatures seem almost dreamlike,
1:27:34
Speaker 1: more akin to the fanciful imaginings of a sleeping mind
1:27:37
Speaker 1: than flesh and blood organisms. Perhaps that's what makes the
1:27:41
Speaker 1: deep sea such an enduring source of fascination. It's a
1:27:44
Speaker 1: realm where the boundaries between reality and imagination seem to blur,
1:27:48
Speaker 1: where the familiar rules of life are suspended in favour
1:27:51
Speaker 1: of something altogether more otherworldly. As we continue our journey
1:27:55
Speaker 1: into the depths, we'll encounter even more wonders and mysteries.
1:27:59
Speaker 1: From the towering hydrothermal vents that sustain entire ecosystems in
1:28:03
Speaker 1: the lightless abyss, to the haunting graveyards of sunken whales,
1:28:07
Speaker 1: each new discovery reveals just how much we still have
1:28:10
Speaker 1: to learn about the alien world beneath the waves. But
1:28:14
Speaker 1: for now, as we drift off to sleep, we can
1:28:17
Speaker 1: let our minds sink down into the inky darkness, marvelling
1:28:21
Speaker 1: at the extraordinary creatures that call this strange realm home.
1:28:25
Speaker 1: In the deep, dreams and reality intertwine, and the impossible
1:28:29
Speaker 1: becomes simply another facet of the endlessly surprising tapestry of
1:28:32
Speaker 1: life on earth. As we've seen, the deep oceans remained
1:28:37
Speaker 1: a mystery for much of human history, with the prevailing
1:28:40
Speaker 1: belief being that no life could possibly exist in the
1:28:42
Speaker 1: eternal darkness and crushing pressures of the abyss. It took
1:28:47
Speaker 1: a series of intrepid expeditions, each venturing deeper than the
1:28:50
Speaker 1: last to gradually reveal the alien world thriving beneath the waves.
1:28:55
Speaker 1: One of the most ambitious and revealing of these expeditions
1:28:58
Speaker 1: was the voyage of HMS Challenger from 1872 to 1876.
1:29:03
Speaker 1: Funded by the British Royal Society and the Admiralty, Challenger
1:29:07
Speaker 1: was a floating laboratory, kitted out with state-of-the-art scientific equipment
1:29:11
Speaker 1: and a crew of expert naturalists. Over the course of
1:29:15
Speaker 1: four years, the ship crisscrossed the globe, covering nearly 70,000
1:29:19
Speaker 1: nautical miles and sampling the oceans at regular intervals down
1:29:23
Speaker 1: to the unprecedented depth of five miles. At each of
1:29:27
Speaker 1: the Challenger's 362 sampling stations, weighted sounding lines would be
1:29:31
Speaker 1: lowered over the side to measure the depth of the seafloor. Then,
1:29:35
Speaker 1: large trawl nets and dredges would be dragged along the bottom,
1:29:38
Speaker 1: scooping up samples of mud, rocks and any creatures unlucky
1:29:43
Speaker 1: enough to be caught. These samples would be hauled back
1:29:46
Speaker 1: to the surface for the scientists to eagerly examine, and
1:29:49
Speaker 1: what they found defied their wildest expectations. In every net,
1:29:54
Speaker 1: at every depth, the Challenger crew discovered life. From delicate,
1:29:58
Speaker 1: transparent sea cucumbers to nightmarish viperfish with dagger-like teeth, from bizarre,
1:30:05
Speaker 1: tentacled comb jellies to giant, single-celled organisms called xenophophores, the
1:30:10
Speaker 1: diversity of deep-sea life was astounding. Even in mud dredged
1:30:14
Speaker 1: from the deepest trenches, the naturalists were amazed to find
1:30:18
Speaker 1: living bacteria, disproving Forbes' theory that life could not exist
1:30:22
Speaker 1: below 1,800 feet once and for all. The sheer volume
1:30:27
Speaker 1: of discoveries from the Challenger expedition was staggering. By the
1:30:30
Speaker 1: end of the voyage, over 4,700 new species had been catalogued,
1:30:36
Speaker 1: a number that has only grown as modern taxonomists continue
1:30:39
Speaker 1: to sift through the pickled specimens. The final report on
1:30:42
Speaker 1: the expedition filled 50 immense volumes, and perhaps most importantly,
1:30:47
Speaker 1: the Challenger showed that life could thrive even in the
1:30:50
Speaker 1: most extreme and inhospitable environments on Earth. Building on the
1:30:54
Speaker 1: Challenger's success, other nations launched their own deep-sea expeditions in
1:30:58
Speaker 1: the early 20th century, each probing the depths more thoroughly
1:31:02
Speaker 1: than the last. From 1899 to 1900, the Dutch HNL
1:31:08
Speaker 1: Marissiboga explored the basins of the Indo-Pacific cataloguing thousands of
1:31:13
Speaker 1: new species of crustaceans, corals and mollusks. Around the same time,
1:31:17
Speaker 1: the US Fish Commission ship Albatross was making record-breaking trawls
1:31:21
Speaker 1: with a new steel cable, pulling up nets bursting with
1:31:24
Speaker 1: strange deep-sea fishes from down to 3,000 fathoms. But there
1:31:29
Speaker 1: was only so much these expeditions could learn from brief
1:31:32
Speaker 1: glimpses of deep-sea life, mangled and dying, pulled from the
1:31:36
Speaker 1: depths in nets. To truly understand how these creatures lived,
1:31:41
Speaker 1: someone would have to go down and observe them in
1:31:42
Speaker 1: their natural habitat, a feat long thought to be impossible.
1:31:46
Speaker 1: The pressure at just 1,000 feet down was enough to
1:31:49
Speaker 1: crush a human body, and the deepest reaches of the
1:31:52
Speaker 1: trenches could pulverise submarines like tin cans. Who would dare
1:31:56
Speaker 1: to descend into this blackness? The answer came in the 1930s,
1:32:00
Speaker 1: in the form of two daring explorers, the American naturalist
1:32:04
Speaker 1: William Beebe and the engineering prodigy Otis Barton. Together, they
1:32:08
Speaker 1: designed a revolutionary vessel called the bathysphere, essentially a hollow
1:32:12
Speaker 1: steel ball with tiny inset windows of fused quartz, the
1:32:16
Speaker 1: only material strong enough to withstand the pressures of the deep.
1:32:20
Speaker 1: Beebe and Barton would seal themselves inside this claustrophobic sphere
1:32:24
Speaker 1: and be lowered into the depths on a steel cable
1:32:26
Speaker 1: from a ship above, quite literally dangling their lives by
1:32:30
Speaker 1: a thread. It was a daring gambit, rife with potential
1:32:33
Speaker 1: for disaster. If the cable snapped or the windows cracked,
1:32:38
Speaker 1: the two men would be instantly crushed. The air inside
1:32:41
Speaker 1: the sphere could turn toxic from their own exhaled carbon dioxide,
1:32:45
Speaker 1: and if the telephone line used to communicate with the
1:32:47
Speaker 1: ship above broke, they could drift untethered until their oxygen
1:32:50
Speaker 1: ran out, doomed to a slow, dark demise. Despite the risks,
1:32:56
Speaker 1: Beebe and Barton completed several successful dives in the bathysphere,
1:33:00
Speaker 1: becoming the first humans to lay eyes on the deep
1:33:02
Speaker 1: ocean realm. As they peered out through the thick quartz windows,
1:33:06
Speaker 1: they entered an alien world of eternal night, where even
1:33:09
Speaker 1: the strongest searchlights could only penetrate a few dozen feet. Strange,
1:33:14
Speaker 1: bioluminescent creatures drifted past in the darkness, flashing an electric blue.
1:33:20
Speaker 1: Gelatinous catenophores pulsed with rippling cilia. A gulper eel gaped
1:33:25
Speaker 1: its massive sail-like jaws. It was a glimpse into a
1:33:28
Speaker 1: world utterly unlike our own, and Beebe's vivid accounts of
1:33:32
Speaker 1: these dives captured the public imagination. On August 15th, 1934,
1:33:38
Speaker 1: Beebe and Barton made history with a record-breaking descent to 3,028 feet,
1:33:44
Speaker 1: deeper than any human had ever ventured. Though a stray
1:33:47
Speaker 1: swordfish punctured the cable on the way down, nearly dooming
1:33:50
Speaker 1: the mission, the bathysphere held firm against the crushing pressure.
1:33:55
Speaker 1: And as Beebe looked out into the gloom, he spied
1:33:58
Speaker 1: a small, dark form drifting past, its light glowing and
1:34:02
Speaker 1: entrancing violet before fading to embers. It was a previously
1:34:06
Speaker 1: unknown species of anglerfish, luring prey with its bioluminescent lamp,
1:34:11
Speaker 1: later named Bathysfera Intacta, in honour of Beebe's intrepid vessel.
1:34:17
Speaker 1: The bathysphere dives of the 1930s cracked open a window
1:34:20
Speaker 1: into the deep sea, but much of this dark realm
1:34:23
Speaker 1: still remained inaccessible and unexplored. It would take the advent
1:34:27
Speaker 1: of new technologies, advances in sonar, submersibles and robotics forged
1:34:32
Speaker 1: in the pressures of World War II and the Cold War,
1:34:34
Speaker 1: to truly begin to plumb the ocean depths. But Beebe
1:34:38
Speaker 1: and Barton had taken the crucial first steps, proving that
1:34:41
Speaker 1: the abyss was not the barren wasteland that Forbes had imagined.
1:34:44
Speaker 1: It was a thriving oasis of life, stranger and more
1:34:48
Speaker 1: spectacular than the most fanciful myth or fable. As you
1:34:52
Speaker 1: drift off into the soothing darkness behind your eyelids, try
1:34:56
Speaker 1: to picture Beebe's and Barton's first glimpse into the void.
1:34:59
Speaker 1: Imagine the faint cobalt glow of a viperfish flashing past
1:35:02
Speaker 1: the windows, its diaphanous fins fluttering gently in the current,
1:35:07
Speaker 1: or the spectral dart of a phantom anglerfish, luring unseen
1:35:11
Speaker 1: quarry toward its needle-like teeth. Even now, we have only
1:35:15
Speaker 1: seen a fraction of the creatures that call the abyss home.
1:35:18
Speaker 1: Every submersible dive and remote robotic mission reveals new species
1:35:21
Speaker 1: beyond human imagination. The deep holds endless mysteries yet to
1:35:26
Speaker 1: be discovered, a prospect to mull over as you slip
1:35:29
Speaker 1: into the restful abyss of sleep. As we've seen, the
1:35:32
Speaker 1: oceans conceal a realm so alien and inaccessible that for
1:35:37
Speaker 1: much of human history it was scarcely even known to exist.
1:35:41
Speaker 1: What little was hauled up from the abyss, the occasional
1:35:44
Speaker 1: bizarre creature entangled in a fisherman's net, or a monster
1:35:47
Speaker 1: carcass washed ashore, was the stuff of myth and wild speculation.
1:35:52
Speaker 1: It seemed impossible that life could flourish in the frigid
1:35:55
Speaker 1: sunless depths, but flourish it does. as improbable as it
1:36:00
Speaker 1: seemed to early scientific thinkers, we now know the deep
1:36:03
Speaker 1: ocean to be teeming with life. It's an ecosystem of
1:36:06
Speaker 1: unfathomable scale and complexity, sheltering creatures more diverse and more
1:36:11
Speaker 1: numerous than all the world's rainforests and reefs combined. To
1:36:14
Speaker 1: truly appreciate just how remarkable this is, we must remember
1:36:18
Speaker 1: the formidable challenges that confront life in the deep. Chief
1:36:22
Speaker 1: among them is the crushing weight of water overhead. For
1:36:25
Speaker 1: every 10 metres of depth, Pressure increases by about the
1:36:28
Speaker 1: equivalent of Earth's entire atmosphere. Descend to the average depth
1:36:32
Speaker 1: of the ocean, around 4,000 metres, and you'd be pinned
1:36:36
Speaker 1: beneath a mass 400 times that of the air at
1:36:39
Speaker 1: sea level. Few creatures from the surface could survive such
1:36:42
Speaker 1: a squeeze. But as the pioneering oceanographers of the 19th
1:36:46
Speaker 1: and early 20th centuries would discover, life finds a way.
1:36:50
Speaker 1: Aboard the HMS Challenger in the 1870s, Wide-eyed scientists hauled
1:36:55
Speaker 1: up thousands of deep-sea species never before seen by human eyes. Fish, mollusks, crustaceans, corals, sponges,
1:37:04
Speaker 1: an entire menagerie of life adapted to conditions that seemed
1:37:07
Speaker 1: intolerably harsh. Many of these animals looked downright bizarre to
1:37:11
Speaker 1: their collectors, all flabby flesh, gelatinous and translucent, with feeble
1:37:17
Speaker 1: muscles and watery blood. At the surface they swiftly perished.
1:37:21
Speaker 1: but this is the paradoxical secret to their survival in
1:37:24
Speaker 1: the abyss. Where pressure would rupture the gas-filled swim bladders
1:37:28
Speaker 1: of surface fish, deep dwellers simply do away with these
1:37:31
Speaker 1: buoyancy aids entirely, their tissues instead laced with lightweight fats
1:37:35
Speaker 1: and oils. The scarcity of food is another defining feature
1:37:39
Speaker 1: of the deep and another driver of strange anatomical adaptations.
1:37:44
Speaker 1: In the lean times between rare feasts, many predators simply
1:37:47
Speaker 1: allow their bodies to waste away, their bones demineralising, their
1:37:51
Speaker 1: muscles atrophying to a bare minimum. Some, like the pelican eel,
1:37:56
Speaker 1: evolved gargantuan mouths and expandable stomachs to engulf prey as
1:38:00
Speaker 1: big as themselves when the opportunity arises. Prey, too, have
1:38:04
Speaker 1: their bag of tricks. To elude the gape of predators' jaws,
1:38:09
Speaker 1: they turn to camouflage. In the gloaming of the twilight zone,
1:38:13
Speaker 1: around 1,000 metres down, silvery scales reflect the remnant blue
1:38:17
Speaker 1: light filtering from above, rendering the animals all but invisible.
1:38:21
Speaker 1: Deeper still in the umbral darkness, the colour palette turns
1:38:24
Speaker 1: to black and red, hues that are absorbed rather than reflected,
1:38:28
Speaker 1: and therefore imperceptible in the blackness. But of all the
1:38:31
Speaker 1: deep sea's visual marvels, none is more ubiquitous than bioluminescence.
1:38:36
Speaker 1: Everywhere you look, creatures carry their own onboard lights, like
1:38:39
Speaker 1: the phosphorescent paint daubed on a watch face. Delicate jellies
1:38:43
Speaker 1: pulse with an internal glow, shrimp wave lanterns to attract mates,
1:38:48
Speaker 1: Anglerfish dangle luminous lures to draw prey into toothy traps.
1:38:52
Speaker 1: Down here, light is life. So much so that even
1:38:56
Speaker 1: in the deepest trenches and abyssal plains, as much as
1:38:59
Speaker 1: 90% of creatures are thought to wield some form of bioluminescence,
1:39:03
Speaker 1: by far the highest proportion of any environment on Earth.
1:39:06
Speaker 1: Some use it for camouflage, projecting light downwards to blend
1:39:10
Speaker 1: in against the faint glimmer filtering from above. Others deploy
1:39:13
Speaker 1: dazzling light shows as a distraction, or a lure, or
1:39:17
Speaker 1: a warning. There's so much more to the strange ways
1:39:20
Speaker 1: of deep sea life than we can cover here. The
1:39:22
Speaker 1: sawtooth eels with their hunting lights mounted on stalks, swivelling
1:39:27
Speaker 1: like spotlights. The barrelly fish with transparent heads, their eyes
1:39:31
Speaker 1: perpetually gazing upwards through their skull. The hairy anglerfish, trailing
1:39:37
Speaker 1: whisker-like filaments from bulbous protrusions all over its body. One
1:39:41
Speaker 1: could devote an entire documentary to the anglerfish alone, those
1:39:45
Speaker 1: hideous poster children of the deep and surely some of
1:39:48
Speaker 1: evolution's most whimsical creations. You might be familiar with the females,
1:39:53
Speaker 1: with their cavernous jaws and dangling bioluminescent lures. But what
1:39:57
Speaker 1: of the males? In some species, these diminutive creatures latch
1:40:02
Speaker 1: onto the females with their teeth, then permanently fuse to
1:40:05
Speaker 1: their mates' bodies, taking nourishment from her bloodstream. A single
1:40:09
Speaker 1: female may accumulate multiple males this way, hauling them around
1:40:13
Speaker 1: like a harem of parasitic spouses. Such is life in
1:40:17
Speaker 1: the deep as fascinating as it is outlandish, where even
1:40:21
Speaker 1: the craziest of adaptations have some crucial survival role. But
1:40:25
Speaker 1: it would be a mistake to think of these creatures
1:40:27
Speaker 1: as perfectly at peace in their eternal darkness. They too
1:40:30
Speaker 1: have their trials and tribulations, their booms and busts, their
1:40:33
Speaker 1: feasts and famines. We see this most dramatically at sites
1:40:37
Speaker 1: of occasional bounty on the abyssal plains, those great flat
1:40:41
Speaker 1: expanses of ooze that cover much of the deep ocean floor,
1:40:44
Speaker 1: typically about as barren as deserts. When a whale dies
1:40:48
Speaker 1: and sinks, its carcass delivers to these plains an unthinkable
1:40:52
Speaker 1: windfall of food, equivalent to thousands of years' worth of
1:40:55
Speaker 1: the usual detrital rain from above. Scavengers swarm to the whale,
1:41:00
Speaker 1: fall from miles around. Hagfish, sleeper sharks and crabs strip
1:41:04
Speaker 1: the skeleton clean, before an ecosystem of worms, snails and
1:41:07
Speaker 1: bacteria move in to feast on the fats, saturating the sediment.
1:41:12
Speaker 1: A single whale can sustain such a community for decades,
1:41:16
Speaker 1: an oasis of abundance on the abyssal sands until the
1:41:19
Speaker 1: meal is finally spent. Similar boons come from sunken logs,
1:41:24
Speaker 1: which provide a rare resource for wood-boring clams and other
1:41:27
Speaker 1: deep-sea opportunists. Some scientists even speculate that such woodfalls might
1:41:32
Speaker 1: have provided stepping stones for the first shallow water species
1:41:35
Speaker 1: to colonise the deep, a theory lent credence by the
1:41:39
Speaker 1: presence of wood-eating limpets in the Hadal zones of ocean trenches.
1:41:44
Speaker 1: More dependable bounty can be found at hydrothermal vents and
1:41:47
Speaker 1: methane seeps, where volcanic heat and chemical energy sustain thriving
1:41:51
Speaker 1: communities in the absence of sunlight. The iconic giant tube
1:41:55
Speaker 1: worms of the vents were only discovered in 1977, to
1:41:58
Speaker 1: the astonishment of the Alvin Submersible's crew, who watched in
1:42:02
Speaker 1: awe as these three-metre spaghetti monsters swayed in the shimmering
1:42:05
Speaker 1: vent fluids. Equally peculiar are the seeps' ice worms, which
1:42:09
Speaker 1: tunnel through methane ice, not frozen water, but methane trapped
1:42:14
Speaker 1: in a crystalline cage. These worms graze on bacteria that
1:42:18
Speaker 1: in turn feed on the methane, a deep-sea symbiosis powered
1:42:21
Speaker 1: not by the sun, but by the Earth's internal heat.
1:42:25
Speaker 1: Other oases are less dependent on geothermal energy, or scarce
1:42:28
Speaker 1: influxes of food from above. Seamounts, those underwater mountains thrusting
1:42:33
Speaker 1: up from the ocean floor, deflect deep currents and corral nutrients,
1:42:38
Speaker 1: attracting swarms of plankton, fish and higher predators. Some are
1:42:43
Speaker 1: capped with lush gardens of filter-feeding corals and sponges, which
1:42:47
Speaker 1: strain sustenance from the passing flow. Similar deep-water coral gardens
1:42:52
Speaker 1: are found on the continental slopes, where they structure habitat
1:42:56
Speaker 1: for countless other species. But unlike the ephemeral communities of
1:43:00
Speaker 1: the abyssal plains, these corals are extremely slow-growing and long-lived.
1:43:04
Speaker 1: Some are thought to exceed 4,000 years in age. It's
1:43:08
Speaker 1: a reminder that while some parts of the deep sea
1:43:10
Speaker 1: pulse to the rapid cadence of feast and famine, Others
1:43:13
Speaker 1: live life in the slow lane, where animals measure their
1:43:16
Speaker 1: lives in centuries or millennia. And then there are the
1:43:20
Speaker 1: creatures that seem scarcely to live at all, like the
1:43:23
Speaker 1: infamous living fossils of the deep, which persist almost unchanged
1:43:27
Speaker 1: since the age of the dinosaurs or beyond. The keelacanth,
1:43:31
Speaker 1: a hulking, armour-scaled fish, was thought extinct for 66 million years,
1:43:37
Speaker 1: until a specimen was hauled up off South Africa in 1938.
1:43:41
Speaker 1: a prototype for all the world's terrestrial spiders and scorpions,
1:43:45
Speaker 1: the horseshoe crab tramps along the seabed much as its
1:43:48
Speaker 1: ancestors did more than 400 million years ago. What is
1:43:52
Speaker 1: it about the deep that has preserved these species in
1:43:54
Speaker 1: seeming evolutionary stasis for so long? Part of the answer
1:43:58
Speaker 1: may lie in the stability of their environment. Down here,
1:44:02
Speaker 1: temperatures have scarcely wavered since the age of the dinosaurs.
1:44:05
Speaker 1: There are no seasons to speak of, no ice ages
1:44:08
Speaker 1: come and go. While the continents above have wandered and collided,
1:44:12
Speaker 1: while mountain ranges have thrust up and eroded away, the
1:44:16
Speaker 1: deep ocean basins have endured largely unchanged for hundreds of
1:44:19
Speaker 1: millions of years. Perhaps in an environment so constant, in
1:44:24
Speaker 1: a world where the pace of life creeps so slowly,
1:44:26
Speaker 1: the forces of evolution likewise take a more leisurely course.
1:44:30
Speaker 1: The deep sea is in many ways a window into
1:44:32
Speaker 1: the past. sheltering not just individual relic species but whole
1:44:36
Speaker 1: ecosystems that have persisted since the dawn of complex life
1:44:40
Speaker 1: on Earth. But this is not to say that the
1:44:42
Speaker 1: deep is beyond our influence. On the contrary, human activities
1:44:46
Speaker 1: already reach into every last recess of the ocean, even
1:44:49
Speaker 1: if our understanding of these environments still lags far behind.
1:44:53
Speaker 1: Bottom trawlers scrape great furrows through the silt, pulverising centuries-old
1:44:58
Speaker 1: coral gardens. Seabed mining threatens to dredge up metal-rich nodules.
1:45:03
Speaker 1: along with the unique creatures that depend on them. Carbon
1:45:06
Speaker 1: dioxide from our cars and factories finds its way to
1:45:09
Speaker 1: the deepest trenches, slowly acidifying the water and dissolving the
1:45:14
Speaker 1: calcium carbonate shells and skeletons on which so much of
1:45:18
Speaker 1: abyssal life depends. Our imperative to understand the deep has
1:45:22
Speaker 1: never been more urgent. Every expedition reveals completely new species,
1:45:27
Speaker 1: ecosystems and even branches on the Tree of Life. we're
1:45:31
Speaker 1: still discovering creatures that defy our understanding of what life
1:45:34
Speaker 1: even is, like the Xenophyophores, those plate-sized amoebas that are
1:45:38
Speaker 1: the world's largest single-celled organisms, or the microbes living inside rocks,
1:45:44
Speaker 1: which may constitute a deep biosphere, rivaling all the rest
1:45:47
Speaker 1: of Earth's biomass. As we lie in bed, drifting off
1:45:51
Speaker 1: to sleep, it's a strangely comforting thought that the alien
1:45:54
Speaker 1: world of the deep carries on as it has for eons.
1:45:58
Speaker 1: sheltering forms of life beyond our wildest imaginations. It's a
1:46:02
Speaker 1: realm scarcely touched by the rhythms of our hectic world above,
1:46:06
Speaker 1: a bastion of constancy, where change is measured in the
1:46:09
Speaker 1: slow dance of currents, the gradual rain of sediments, the
1:46:14
Speaker 1: unhurried adaptations of evolution. But even here, in the stillness
1:46:19
Speaker 1: of the oceanic night, we're joined in some small way
1:46:22
Speaker 1: to the creatures of the abyss, the darkness behind our eyelids,
1:46:26
Speaker 1: the slow rhythm of our breath, the warmth of our bed,
1:46:29
Speaker 1: they're all part of the same elemental backdrop against which
1:46:32
Speaker 1: all of life plays out from the surface to the
1:46:34
Speaker 1: sea floor. In sleep, as in the deep, we surrender
1:46:39
Speaker 1: to forces larger than ourselves, the fundamental pulse of life
1:46:43
Speaker 1: on earth which has endured for billions of years and
1:46:46
Speaker 1: will continue long after we're gone. Perhaps there's solace to
1:46:49
Speaker 1: be found in that. In the knowledge that however tumultuous
1:46:52
Speaker 1: the world may seem, however insignificant we may feel, We're
1:46:56
Speaker 1: part of an unbroken continuum of life that stretches back
1:46:59
Speaker 1: to the very origins of our planet. The same deep
1:47:03
Speaker 1: ocean that cradled the first living cells now buoys us
1:47:06
Speaker 1: in our slumber, imparting some sense of its own timeless rhythm.
1:47:11
Speaker 1: As we relinquish our conscious minds to sleep, we too
1:47:15
Speaker 1: enter a kind of abyssal realm, where the concerns of
1:47:18
Speaker 1: our waking lives recede into darkness and dreams hold sway.
1:47:22
Speaker 1: and like the creatures of the deep, will eventually emerge
1:47:25
Speaker 1: from this state refreshed, renewed, and ready to face the
1:47:28
Speaker 1: world above once more. But for now, we can simply
1:47:31
Speaker 1: marvel at the richness and complexity of life, in all
1:47:34
Speaker 1: its myriad forms from the surface to the seafloor. And
1:47:38
Speaker 1: as we finally slip into the restful oblivion of sleep,
1:47:42
Speaker 1: we can carry with us the knowledge that, even in
1:47:44
Speaker 1: the deepest, darkest places on earth, life still finds a way.
1:47:50
Speaker 1: Good night. Seamounts are oases of life in the abyssal desert.
1:47:55
Speaker 1: These towering underwater mountains, born from ancient volcanic eruptions, rise
1:48:00
Speaker 1: thousands of metres from the seafloor, their rocky flanks encrusted
1:48:04
Speaker 1: with corals and sponges in a kaleidoscope of colour. Like
1:48:08
Speaker 1: islands in the sky, seamounts punctuate the seascape, disrupting the
1:48:12
Speaker 1: languid flow of deep currents. As water masses collide with
1:48:16
Speaker 1: these submerged summits, nutrients are thrust up from the depths,
1:48:20
Speaker 1: nourishing blooms of plankton that in turn feed an extravagance
1:48:24
Speaker 1: of life. Schools of vibrant fish swirl around the seamount's
1:48:28
Speaker 1: craggy peaks, while sharks and tuna prowl the fringes, drawn
1:48:32
Speaker 1: from miles around to these bastions of sustenance in the
1:48:35
Speaker 1: oceanic wasteland. In the crevices and caves of seamounts, smaller
1:48:40
Speaker 1: creatures find shelter. Lobsters, crabs and octopuses squeeze into rocky nooks,
1:48:46
Speaker 1: their red and white carapaces contrasting with the muted tones
1:48:50
Speaker 1: of their surroundings. On the summits of underwater mountains that
1:48:53
Speaker 1: reach into the sunlight zone, kelp forests sway to the
1:48:57
Speaker 1: rhythm of the currents as parrotfish crunch on coral and
1:49:01
Speaker 1: sea stars cling to the rugged substrate. The isolation of
1:49:05
Speaker 1: seamounts makes them crucibles of evolution, where animals and plants
1:49:09
Speaker 1: adapt to their unique circumstances over millennia. Some seamounts host
1:49:13
Speaker 1: species found nowhere else on Earth, having diverged from their
1:49:17
Speaker 1: relatives in the uninterrupted flow of time in their secluded
1:49:20
Speaker 1: alpine keeps. Even as we marvel at the wonders of
1:49:23
Speaker 1: seamounts and abyssal plains, it's humbling to consider just how
1:49:27
Speaker 1: much of the deep ocean remains unexplored. the watery realm
1:49:31
Speaker 1: that blankets our blue planet largely eludes our grasp. When
1:49:36
Speaker 1: you contemplate the fact that Mount Everest would be lost
1:49:38
Speaker 1: beneath the waves if placed in the Mariana Trench, you
1:49:41
Speaker 1: begin to fathom the immensity of this liquid universe. And yet,
1:49:45
Speaker 1: for all the deep sea's inaccessibility to humans, it is
1:49:49
Speaker 1: far from untouched by our actions. The abyss is no
1:49:52
Speaker 1: longer out of sight and out of mind. Deep sea
1:49:55
Speaker 1: trawling scrapes the seabed smooth, wiping out ancient coral groves
1:50:00
Speaker 1: before we even lay eyes upon them. Pollution and discarded
1:50:04
Speaker 1: plastics swirl into the depths, ensnaring and choking wildlife. Rising
1:50:10
Speaker 1: global temperatures and ocean acidification threaten to unravel the delicate
1:50:14
Speaker 1: balance of abyssal ecosystems. Perhaps most troubling are the nascent
1:50:18
Speaker 1: campaigns to mine the seabed for precious metals, potentially inflicting
1:50:22
Speaker 1: irreversible damage on the dark domain's habitats. The creatures of
1:50:26
Speaker 1: the deep have flourished for eons in obscure tranquility, but
1:50:30
Speaker 1: they now face an uncertain future as human influence extends
1:50:33
Speaker 1: into even the most remote recesses of the planet. Still,
1:50:37
Speaker 1: there is reason for hope. Just as our species' unquenchable
1:50:41
Speaker 1: thirst for knowledge led the earliest oceanographers to probe the deep,
1:50:45
Speaker 1: so too does that same curiosity inspire new generations of
1:50:48
Speaker 1: scientists and explorers to dedicate their lives to studying and
1:50:52
Speaker 1: protecting this final frontier. With every crude submersible dive, every
1:50:57
Speaker 1: robotic probe, and every high-resolution seafloor map, we pull back
1:51:01
Speaker 1: the watery veil just a little more, exposing hidden wonders
1:51:05
Speaker 1: and kindling new questions. Initiatives to create massive marine protected
1:51:10
Speaker 1: areas limit the scope of deep-sea exploitation and combat climate
1:51:14
Speaker 1: change gain traction with each passing year. The future of
1:51:18
Speaker 1: the abyss is not yet written. Even as we drift
1:51:21
Speaker 1: off into slumber, researchers and advocates carry on the work
1:51:24
Speaker 1: of safeguarding the deep, ensuring it remains a realm of
1:51:28
Speaker 1: marvels for generations of humans and fish to come. Perhaps someday,
1:51:33
Speaker 1: when science has illuminated more of the ocean's secrets, our
1:51:37
Speaker 1: dreams will be filled not only with fanciful mermaids and krakens,
1:51:40
Speaker 1: but with the phantasmagorical and very real creatures that haunt
1:51:43
Speaker 1: the depths. This video is but a glimpse into a
1:51:46
Speaker 1: world we barely understand, an invitation to ponder the mysteries
1:51:50
Speaker 1: that lurk beneath the waves. With any luck, our voyage
1:51:54
Speaker 1: through the history and majesty of the deep ocean has
1:51:56
Speaker 1: piqued your curiosity as well as lulled you into a
1:51:59
Speaker 1: restful state. If you enjoyed this aquatic odyssey, be sure
1:52:03
Speaker 1: to like the video and subscribe to the channel. We
1:52:06
Speaker 1: have plenty more seaworthy science to explore together. Until next time,
1:52:10
Speaker 1: sweet dreams, and may your deepest dives be filled with wonder.