These Creatures Live In the Deepest Water on the Planet

Challenger Deep is the deepest part of all the oceans on Earth. Animals that live there have to deal with the most hostile living conditions and pressures. Yet, life there is thriving. Click through our slideshow to meet the creatures who live in the deepest part of the Mariana Trench.

The Challenger Deep is the deepest known point in the earth’s crust. It lies within the southern end of the Mariana Trench (the deepest trench on earth) in the Western Pacific Ocean.

The Mariana Trench is a crescent-shaped oceanic trench, and the Challenger Deep is a slot-shaped depression on the bottom of this trench.

Its description consists of an elongated seabed with three distinct sediment-filled pools. The deepest part recorded was 35,827 feet, almost seven miles below the ocean’s surface.

From 1872 to 1876, a scientific program laid the foundation of oceanography. It made remarkable discoveries about our planet. Challenger Deep was named after the HMS Challenger, a British Royal Navy survey ship.

This expedition was the first to discover the Mariana Trench, just 15 miles from the Challenger Deep. Pioneers aboard the ship happened by chance upon the area near Guam. They used a weighted rope to conduct “soundings” and measured the depth of the sea floor.

The first time humans ventured to the deep was in 1960. During this time, NASA sent people to space, and oceanographers decided to conquer the last natural frontier. Their mission was successful, and they spotted the very first signs of life at a depth of this magnitude. Scientists were unsure if creatures could survive this deep, but these pioneers confirmed that life always finds a way.

Now that you know who first discovered the trench, let’s discuss why the Challenger is so deep and if anything on the earth is deeper.

The Challenger Deep is so exceptionally profound that you could fit five Grand canyons from the surface to the cavern floor or 13 of the tallest building in the world stacked from end to end. As humans, that’s hard to fathom. It took five hours for the first vessel in 1960 to sink to the bottom!

Subduction, the process of one tectonic plate drilling over the top of another, caused the Mariana Trench’s formation. Scientists confirmed seismic evidence of a tear in the subducting plate, which causes a deformation of the overriding plate. This tear caused greater depths along the southern end of the Mariana Trench, right where the Challenger Deep sits. A survey (2003) of part of the ocean floor speculates another deep may rival the Challenger.

The Horizon Deep in the Tonga Trench in the Southwestern Pacific Ocean is 35,433 feet deep, making it the second deepest trench in the world by less than 400 feet. The third deepest is the Sirena Deep, also in the Mariana Trench. The Sirena Deep measures 35,151 feet and is approximately 120 miles east of the Challenger Deep.

Microorganisms, shrimp, marine worms, and sea cucumbers live at the bottom of the Challenger Deep.

In 1960, when scientists descended to the depths of the hadal realm, they noted that this may be the first light to ever pierce through the darkness. Their light beams illuminated diatomaceous ooze on the sea floor and a type of flatfish they believed to be a highly evolved invertebrate. Scientists later disputed this theory and thought the explorers were most likely seeing a sea cucumber.

While the terms “shrimp” and “prawn” are typically used interchangeably among different nations, the two types of crustaceans are much different. Both shrimp and prawns are decapods, which means that they both have ten legs. However, while shrimp are closely related to the lobster, crayfish, and crab, prawns are in their own suborder – dendrobranchiate.

Prawns have longer legs, and they don’t bend in the same flexible way that the shrimp can. While the prawn will release eggs into waters to eventually let them hatch and live alone, shrimp carry their eggs with them after fertilization.

Several sea worms play a role as decomposers in the ocean. There are 17,000 types of seaworms. Seaworms are commonly called segmented worms or marine worms.

Sea cucumbers are part of echinoderms’ animal group, containing urchins, sand dollars, and starfish. They are found in nearly all marine environments throughout the world. 

While you may feel disappointed (or relieved) to know no giant sea monsters are swimming in these trenches, there have only been a few expeditions to these far-reaching places in the earth’s crust. Robotic probes were lowered to the Challenger Deep throughout the years to bring back specimens. Their findings included scale worms, shrimp, microorganisms, and polychaeta worms.

One of the fascinating discoveries of the deep is the seeps in the sea floor. These seeps are in the rocks where water is heated by chemical reactions and bubbles up into the ocean. It also may hold the answer to how life began and how life’s evolution could begin on other planets.

Over 600 people have been to outer space, but only 22 have ventured to the depths of our planet. Why have we explored more of the cosmos than the ocean? The main reason involves pressure.

The world record for the deepest free dive in the ocean is 830 feet. Herbert Nitsch completed this deep dive and suffered multiple strokes and had to receive immediate medical attention and ongoing rehabilitation. Nitsch would have had to do that same dive 50 times over to reach the bottom of Challenger Deep.

The pressure is so intense in the trench that a single breath would shrink your lungs to the size of a few peas. The pressure is over 1,000 times that of sea level, applying 15 pounds per square inch. Though the pressure above the earth’s atmosphere is zero, scientists believe it’s safer to go to space than to the bottom of the ocean.

Creatures that live at the bottom of the Challenger Deep evolved to withstand extreme temperatures, lack of food, complete darkness, and intense pressure. And even with all the odds against life forming in the darkest trenches in the world, that may be precisely where life began.