For most of human history, humankind had looked up at the sky and wondered what was out there. And it wasn’t until less than a century ago that we finally got a realistic glimpse of it. Yet while scientists take pictures of black holes and send rovers to long-dead planets, one of the last unknown frontiers remains largely unexplored. Water covers more than 70 percent of the globe, and so much of the ocean is still unexplored. This persistent mystery may leave you wondering, what is the deepest part of the ocean? And what creatures dwell in those uncharted inky depths?
How much of the ocean is unexplored?
According to Oceana, more than 80 percent of the ocean still remains unexplored. It might seem a rather large number, considering that humankind has explored and settled in every other corner of the globe and beyond, but the deepest parts of the ocean are largely inaccessible by we who breathe oxygen to survive. And while oxygen is the main reason for our inability to reach these uncharted corners of the map, it is not the only one.
Human scientists are under tremendous pressure to find and explore new places, both on this planet and beyond the stars. And while there may be no physical pressure in the vastness of space, there is a great deal of pressure in the deepest parts of our own oceans. According to the National Oceanic and Atmospheric Administration, the atmospheric pressure at the bottom of the Marianas Trench (more on the trench in just a moment) is approximately 16,000 pounds per square inch (PSI). Compare that to the 14.7 PSI in say, your home office, and you’ve got a real problem for squishy human bodies — to say nothing of submersibles.
What is the deepest part of the ocean?
The deepest part of the ocean lies in the Pacific Ocean, somewhere between Guam and the Philippines. It is called the Marianas Trench and it is located at an astonishing 35,814 feet below sea level. At the very bottom of that great undersea gorge is the Challenger Deep — the deepest point known on Earth. As with the other unexplored ocean places, we don’t know much about what lives down there. Nevertheless, the things we have discovered are as alien as anything we might hope to find on another planet.
What lives in the deepest part of the ocean?
The fish, crustaceans, and invertebrates who dwell in the deepest parts of the ocean don’t look or behave like anything you might expect. Many readers may be familiar with the strange, glowing, fang-mouthed monstrosities that live in the abyssopelagic zone. Creatures like lanternfish, hatchet fish, and gulper eels live in a literal abyss, blink blindly while they shimmer in otherworldly bioluminescence.
The deepest parts of the ocean lie even deeper still. While the abyssopelagic zone is about 13,000 to 20,000 feet deep, the very deepest, the hadopelagic zone can be as deep as 20,000 feet or deeper. The fish and animals we have observed there are even more unusual. Many are small, translucent, and completely bereft of scales or sight. Yet all of them are uniquely adapted to live in those extreme pressures and without even the barest trace of sunlight.
Some, including the giant tube worm, live near hydrothermal vents and feed on tiny bacteria that get their energy directly from the chemicals in the water. The water around these vents may be boiling but it’s rich in minerals and chemicals that the creatures who have evolved to live there need to survive. The tube worms can also grow to be over eight feet tall. And they are just one of the remarkable animals that survive in these inhospitable places.
Why is it so difficult to explore the deep ocean?
According to NASA oceanographer Dr. Gene Feldman, the hardest part of exploring the oceans is due to physics. At those great depths, the zero visibility, extremely cold temperatures, and crushing pressure are a lethal combination for even the bravest and most well-equipped explorers. Feldman is even quoted as saying:
“In some ways, it’s a lot easier to send people into space than it is to send people to the bottom of the ocean... The intense pressures in the deep ocean make it an extremely difficult environment to explore.”
Underwater vehicles are also prohibitively expensive to build and to buy. They must be able to survive the high pressure and the cold, and so must their occupants. Not only that, the cameras, sonar, and delicate computer equipment that they usually carry needs to have similar durability. As a result, only a small portion of the Earth’s oceans have been explored. According to NOAA, only about 35 percent of the ocean and coastal waters of the U.S. have been mapped using modern methods of sonar.
Are the deep oceans in danger?
Unfortunately, this largely unexplored series of biomes has also proven to be the most susceptible to things like pollution, plastics, overfishing, climate change, and many more human-created environmental issues. This is where that lack of knowledge presents us with some problems. It is notoriously difficult to protect what we do not understand. Thus, only about 7 percent of the world’s oceans are designated as marine protected areas. That is according to the U.N. World Database on Protected Areas.
That means that the other 93 percent might be just as in peril — we just don’t know enough about it to recognize the danger. Like all oceans though, these deep places undoubtedly need our help. Our actions have affected every other environment on Earth in a negative way, so it stands to reason that even these unexplored places are in danger. We must preserve them and we must protect them, but meanwhile, scientists will continue to try and understand them.