Mariana Trench | WWF

Mariana Trench

Into the abyss

It's dark down there, really dark!
At 10,911m below sea level, the Mariana Trench in the western Pacific Ocean - east of the Mariana Islands - is the deepest point in the ocean. To put things in perspective, Mt Everest, the world's highest mountain, is a mere 8848m.

What's down there?

Scientists have only explored 1% of the sea floor. Indeed, less is known about the sea floor than the surface of the moon.

From what we do know, life is on the depths of the ocean is scarce; but there is life.

There are starfish, sea urchins, sea lilies, brittle stars, sea cucumbers, sea daisies and others. Crabs, shrimp, angler fish and bacteria are but few of the many species found even as deep as the Mariana Trench.
Deep-sea angler fish collected by a scientific trawl at a depth of over 1,000m in the Porcupine ... 
Deep-sea angler fish collected by a scientific trawl at a depth of over 1,000m in the Porcupine Seabight, North East Atlantic Ocean.
Gorgon&#8217;s head <em>Gorgonocephalus caputmedusae</em> in the Selligrunnen, a ... rel=
Gorgon’s head Gorgonocephalus caputmedusae in the Selligrunnen, a protected cold-water coral reef in the Trongheimsfjorden, Norway.
© WWF / Erling Svenson

Protecting the unknown

Despite being largely unknown, the deep sea is nevertheless extremely important.
Intrinsic value: Every expedition to the depths of the ocean results in new species being found. Sometimes entire new ecosystems are discovered or new life forms such as the ancient microbes, archaea.

Scientific value: The specialized adaptations of deep-sea organisms are not just interesting for interest’s sake. An understanding of their biochemistry could also lead to biochemical, medical and other scientific advances.

Commercial value:
The deep sea is increasingly being targeted by commercial fisheries in national waters and on the high seas. Populations of deep-sea species like Patagonian toothfish and orange roughy, for example, have already been fished to commercial extinction in just a few years. Currently, most deep-water species are likely to be over-exploited if not protected and better managed.

Find out what WWF is doing to protect the deep sea.

Deap-sea Facts & Figures

    • 60% of the planet is covered by water over 1600m deep, and nearly half the world's marine waters are over 3000m deep.
    • At a depth of 150 meters below the sea, there is little if any light left, and colours are no longer visible to the human eye.
    • The deepest part of the ocean is called the abyssal zone.
    • Although there seems to be an abundance of life at these depths, no human being could withstand the pressure extremes.
    • Many deap-sea species have a lifespan of over one hundred years.

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