Buzz
We have a solid grasp of much of the natural world, with our understanding expanding each year. Scientists journey across the globe to uncover insights about animal behavior, ecosystems, weather trends, climate change, migration, and more. Their vast knowledge grows every year, thanks to the diligent work of wildlife biologists and other researchers devoted to solving Earth's mysteries. Meanwhile, the public benefits from captivating documentaries like Planet Earth and Blue Planet that share these crucial discoveries.
Yet, one vast region of our planet remains largely unknown: the inky, remote expanses of the world's largest oceans. The deepest trenches, valleys, and bottoms of the oceans continue to baffle scientists. It's nearly impossible to send humans to these extreme depths—and even more challenging to keep them there long enough to make meaningful observations. The robotic vehicles we use offer only fragmented glimpses, leaving the enigma of the ocean's depths far from solved.
This brings us to today’s list. We’ll explore ten chilling and intriguing facts about the ocean’s deepest zones. These are the things we either don’t know at all or only understand partially, and are working tirelessly to learn more about. The eeriness of the unknown adds to the allure of these fascinating mysteries.
10. Could a Deep Sea Bigfoot Exist?
We hate to break it to you, Bigfoot enthusiasts, but the creature doesn’t exist. Yes, we know, it’s a tough pill to swallow. But realistically, if Bigfoot were real, we’d have found him by now—at least his bones, which would provide undeniable proof that creatures like him roamed the forests. We’ve got no bones, no concrete evidence, and it’s high time to put that theory to bed. Sorry to burst your bubble!
That said, there’s one place where we might still find something akin to Bigfoot, or perhaps multiple species with similar traits. Below a depth of 656 feet (200 meters), the ocean’s darkest depths are largely unexplored, and the life forms thriving there remain a total mystery.
The size of the deep ocean is absolutely mind-blowing—it accounts for around 85% of the Earth’s living space. While the struggle for food is brutal and sustenance is far scarcer than nearer the surface, the sheer volume of space means there’s a vast and largely unknown diversity of life down there.
Some researchers speculate that the deep sea could be home to as many as ten million different animal species. This would make the ocean’s deepest zones as biodiverse as the densest tropical rainforests, but on a much grander scale.
What’s even more astonishing is that most of these ten million species have never been seen, let alone documented. So, is there an underwater equivalent of Bigfoot lurking in those uncharted waters? Could there be several creatures that fit the description? As scientists continue their exploration of the ocean’s depths, only time will tell what they might uncover.
9. The Bio-Duck
Back in 1960, while on a submarine voyage off the coast of Western Australia, the crew recorded a peculiar sound emerging from the depths of the Southern Ocean. This strange noise had an eerie cadence, almost like the sound of a duck quacking, but originating from the ocean’s depths. No one could identify where it came from or what was producing it.
This unfamiliar sound was dubbed the “Bio-Duck.” For over fifty years, its origin remained a mystery. Nobody knew who or what was behind the strange quacking noise, making it one of the ocean’s most intriguing and unresolved enigmas.
Then, in 2014, scientists made a breakthrough of sorts: they determined that Antarctic minke whales were the source of the “Bio-Duck” call. However, many questions remained unanswered—why these whales make the sound, and for whom, was still unclear.
The sound is most commonly heard during the austral winter in the Southern Ocean off Australia. Interestingly, it tends to be detected in shallower waters, after which the minke whales plunge into the deeper, darker parts of the ocean. What motivates them? Is it a mating call, a feeding signal, or something else entirely? The answers remain a mystery that we may never fully understand.
8. The Beginning of Life?
Around four billion years ago, life began on Earth, but the exact location and circumstances of the first simple cells coming together to create what we have today is still unknown. Experts suggest it may have occurred deep within the oceans. In 2017, a team of paleontologists discovered tiny tubes and filaments made of hematite, an iron-rich material, embedded in rocks dating from 3.77 to 4.28 billion years ago.
The rocks themselves are a known, long-lasting feature of Earth’s early oceanic crust. Typically, much of the sea floor is dragged back into the Earth’s mantle and recycled into new crust through a slow, continuous process. These particular rock fragments, however, didn’t undergo this cycle. The preservation of these microscopic tubes inside them provided a potential breakthrough for scientists—perhaps.
In the 1990s, a NASA chemist first proposed the idea that life on Earth may have originated in the rocky pores inside the chimneys of hydrothermal vents deep in the ocean. For life to begin there, the conditions would have to be just right. The fluids rushing through the vents couldn’t be too hot, and they would need to have a sufficiently high alkaline content to generate the energy necessary to create the first living cells.
Most ocean vents are too hot and highly acidic, ruling them out. However, a rare set of vents located deep in the Atlantic Ocean, known as “The Lost City,” provided the ideal conditions for the creation of microscopic tubes identical to the ones found in 2017. While the link to the origin of life can never be fully confirmed, some scientists believe they may have found the key to life’s source on Earth.
7. Where Has All the Plastic Gone?
It’s well known that plastic pollution is being dumped into the ocean, either directly by people littering or indirectly as it flows from rivers and streams. But once it reaches the ocean, where does it end up? While this might seem like an easy question, the answer is surprisingly elusive.
There are massive accumulation zones like the Great Pacific Garbage Patch, which collects much of the plastic entering the ocean at alarming rates. However, there are still tons of plastic entering the oceans each year that environmental scientists can't account for. Where is it all going? And how does it seem to just vanish?
Oceanographers are still struggling to figure out where all the plastic dumped into the oceans ends up. Could some be ingested by marine animals? Does it sink deep into the ocean and become hidden in remote areas of the seafloor? With no clear answer, oceanographers have started calling this phenomenon “dark plastic.” The truth remains elusive.
“Ninety-nine percent of all the plastic is missing,” said oceanographer Erik van Sebille in a recent Vox podcast. “We have dark plastic. Just like astronomers have dark matter and dark energy, we oceanographers… have no idea where most of the plastic in our oceans is. It’s gone.” Well, that’s eerie!
6. Living on Plastic?
When it comes to plastic in the ocean, there’s another big question: How is life not only surviving but even thriving on the plastic waste accumulating in the sea? In 2018, two scientists studying debris collected from the Great Pacific Garbage Patch stumbled upon something very surprising.
Amidst the debris they gathered from the massive garbage mass in the middle of the Pacific Ocean, they discovered tiny marine creatures, such as crabs and anemones. These creatures typically live on beaches and coastal areas but somehow managed to travel thousands of miles to the Great Pacific Garbage Patch. What’s more, they were not just surviving but multiplying rapidly and flourishing within the GPGP.
The open ocean is typically a hostile environment for small marine animals like crabs and anemones. They usually seek out the coastlines for the shelter of sand and rocks, which serve as natural defense. But it seems that they might now be using plastic in the world’s ocean trash heap in a similar way. The real mystery is how they managed to get there in the first place. Did they hitch a ride on plastic debris when it first entered the ocean through rivers and streams, clinging to it for months or even years before reaching the GPGP?
And even more puzzling: How are these creatures thriving in the midst of non-biodegradable trash? The materials that should harm most life don’t seem to affect these tiny marine animals at all. It’s as though they’ve created an entirely new ecosystem in an unnatural setting. The problem? Scientists have no idea how they’ve done it.
5. What Defines a Rogue Wave?
For centuries, sailors from all around the world have reported encountering rogue waves. These mysterious waves seemed to appear out of nowhere, defying the predictable patterns of the ocean. The sea would be calm, with waves of normal size, and then—without any warning—BOOM!
A rogue wave would suddenly surge from the sea, cresting much higher than the surrounding waves. In many instances, these waves would sweep sailors from their ships, sending them to their doom in the water. In the most extreme cases, rogue waves would capsize entire vessels, causing entire crews to vanish into the ocean’s depths.
Science remained highly skeptical of these long-standing sailor accounts. For as long as rogue waves had been reported, scientists could not find any concrete evidence that they truly existed. They speculated that sailors were exaggerating the height of these waves or possibly misremembering them under the stress of dealing with a rough sea.
Everything changed on January 1, 1995, when the most famous rogue wave ever recorded was detected at the Draupner Gas Platform in the North Sea. This wave measured a shocking 25.6 meters (or nearly 90 feet) in height, which was astonishing since the surrounding waves at the time were only about half that size. It truly appeared out of nowhere.
Here’s the eerie part: Science has now confirmed the existence of rogue waves. Those countless sailor reports stretching back centuries appear to be accurate. There really are rogue waves—unpredictable, unexplainable, and out there in the ocean. Even now, nearly 30 years after the Draupner event, we still can’t explain what causes them.
Despite oceanographers’ certainty that rogue waves are real, the mystery remains: What makes a wave go rogue? The hope is that experts will eventually find a way to predict these waves and warn ships. But as of now, that breakthrough hasn’t happened, and it may never.
4. Octopus Companions?
In 2020, the documentary *My Octopus Teacher* was released, telling the story of Craig Foster, a man who spent a year forming a bond with a wild octopus in the Great African Seaforest. The film became a major success, streaming on Netflix and captivating audiences worldwide.
The documentary won Academy Awards for its heartfelt story, stunning cinematography, and its portrayal of Foster’s surprising and profound relationship with the octopus. It raised a deep question: Can humans and wild animals truly become friends? And when it comes to octopuses, are they intelligent and sensitive enough to connect with a human who enters their world?
While *My Octopus Teacher* suggested that humans and octopuses can indeed form meaningful bonds, scientists remain divided on whether such friendships are truly possible. Marine biologists are well aware of the impressive intelligence of octopuses, and they’ve confirmed that these creatures can recognize humans and even develop trust over time.
But the deeper question still lingers: How strong can this bond really be? Just how deeply can a wild octopus connect with a human entering their underwater world? The truth is, we may never know. However, any further discoveries about this bond could reveal important insights into the emotional and psychological lives of other deep-sea creatures and wild animals in general.
3. Got Mud?
As if the deep-sea mysteries weren't bizarre enough, there's another enigma lurking at the very bottom of the ocean: What’s the deal with the mud found under the water’s surface?
This layer of mud and settled silt is known as the Mohorovicic Discontinuity. It's one of the most enigmatic places on Earth, yet it holds significant importance in understanding the planet's workings, from tectonic plate movements to the origins of earthquakes and beyond.
Around sixty years ago, a group of scientists embarked on a bold idea: they wanted to drill through the ocean's floor and reach the bottom of the sea bed. Their goal was to access the Mohorovicic Discontinuity and retrieve a sample of the Earth's mantle, a layer that no human has ever observed before. The hope was that this experiment could give them a glimpse into something profoundly hidden beneath the surface.
Sadly, the experiment didn’t succeed, and the experts weren’t able to extract a piece of the mantle. Still, scientists today remain optimistic that better technology may one day make this possible. Until that time comes, we must remain satisfied with what little we know about the Mohorovicic Discontinuity: almost nothing at all!
2. Have You Used GPS?
Despite the vastness of the ocean floor, only a mere 20% of it has been mapped. This means that while a significant portion has been charted using advanced technologies such as multibeam sonar systems, there’s still a massive portion we know nothing about—its shape, its depth, or even its direction.
To put that into perspective, the fact that so much of the ocean floor remains unmapped makes the depths of the sea far more enigmatic than the surface of the moon or Mars. Moreover, whenever explorers venture into these uncharted areas, or use high-tech underwater cameras, they invariably discover places on Earth that no one has ever seen before. It’s both awe-inspiring and eerie.
By late 2023, just 24.9% of the global ocean floor had been mapped. This means that three-quarters of the seafloor remains entirely unexplored. And this isn’t confined to remote areas of the Pacific Ocean far from land—this uncharted territory exists all around the globe.
Even within the United States' own territorial waters, only about half of the ocean floor has been mapped with precision using sonar systems mounted on ships. To say that we are largely unaware of what lies beneath is, well, a massive understatement!
1. What's Found in the Twilight Zone?
The deeper you go into the ocean, the less sunlight can penetrate the water. After descending just a few hundred meters, visibility becomes much more difficult. At around 656 feet (200 meters) below the surface, you enter a region known as the 'mesopelagic' zone, more commonly called 'the twilight zone.'
Here, sunlight nearly vanishes, and any further descent plunges you into total darkness. As the light fades, our understanding of what happens in this depth also diminishes. While 200 meters might seem shallow compared to the vast depths of the oceans, this is where our scientific expertise essentially comes to a halt.
We’re not joking about this. Just ask Andone Lavery from the Woods Hole Oceanographic Institution. As he put it on a recent Vox podcast, 'It’s almost easier to define it by what we don’t know than what we do know. It’s remote. It’s deep. It’s dark. It’s elusive. It’s temperamental.' Getting cameras and equipment down that deep in the ocean is both challenging and expensive.
Moreover, shining lights to see what’s floating around down there instantly changes the environment, influencing how the fish and creatures interact with the light that’s now part of their ecosystem. This makes it extremely difficult to collect accurate data or observations about life in this twilight zone. As it stands, it remains largely an unsolved mystery to this day!
