Shockingly, the ocean covers the majority of our planet, but the absolute majority of it remains unexplored to this day. The waves hide many mysteries, but countless hardworking researchers shed light on what happens underwater and in coastal areas.
Some of the coolest, creepiest, and weirdest science facts about the “deep dark seas” get featured on the popular ‘The Weird Unknown’ Instagram account. We’ve curated the most intriguing posts to expand your mind, give you a fresh perspective about Planet Earth, and even shock you with how bizarre nature can be. Scroll down to keep diving.
#1
A biologist has developed a biodegradable plastic alternative made from cassava, a plant widely grown in tropical regions. Unlike conventional plastics, the material can break down in water and is designed to be non-toxic to marine life, reducing the long-term accumulation of waste in oceans and rivers.
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37points
#2
The green sea turtle has been officially reclassified from Endangered to Least Concern on the International Union for Conservation of Nature's Red List, the result of more than four decades of coordinated conservation work. The IUCN announced the change in October 2025 at the World Conservation Congress in Abu Dhabi, citing a roughly 28 percent global population increase since the 1970s.
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36points
The irony is that we have mapped the Moon in much more detail than we have the Earth’s seafloor. BBC Science Focus explains that the seafloor is incredibly huge (roughly 335 million square kilometers or 129.3 square miles) and inaccessible far offshore, which is why only a tiny fraction of it has been explored, despite the advancements in technology.
“Recently, a team of scientists put together a Global Dive Dataset containing information from around 44,000 dives into the deep. These were carried out by scientists inside submersibles, as well as remotely operated vehicles (ROVs) and autonomous robots that steer themselves,” the BBC writes.
“Collectively, these deep submergence vehicles, as they’re known, filmed and photographed an area equal to less than 0.001 per cent of the deep seafloor.”
One issue with this is bias. Nearly two-thirds (65%) of these exploratory dives have taken place within 200 nautical miles of the United States, Japan, or New Zealand. Furthermore, the absolute majority (97%) of these deep-seafloor observations have been carried out by those countries, as well as France and Germany.
#4
Michael Packard, a 56-year-old lobster diver from Cape Cod, experienced what sounds like something out of a biblical tale—but it happened in 2021. While diving 45 feet below the surface, the water around him suddenly turned dark. At first, he feared a shark attack, but soon realized there were no teeth—just pressure. He was inside the mouth of a humpback whale. For nearly 30 seconds, he was trapped in total darkness, surrounded by muscle and water, convinced he wouldn’t survive.
Then, just as quickly as it happened, the whale surfaced and spit him out. His crewmate watched in disbelief from the boat as Packard flew back into open water, bruised but alive. Doctors treated him for soft tissue injuries, and marine experts later confirmed it was likely a feeding accident—the whale mistook him for a school of fish. Packard called it the closest he’s ever been to the end. Incredibly, just weeks later, he was back in the water, diving again.
Then, just as quickly as it happened, the whale surfaced and spit him out. His crewmate watched in disbelief from the boat as Packard flew back into open water, bruised but alive. Doctors treated him for soft tissue injuries, and marine experts later confirmed it was likely a feeding accident—the whale mistook him for a school of fish. Packard called it the closest he’s ever been to the end. Incredibly, just weeks later, he was back in the water, diving again.
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26points
#5
The mimic octopus is one of the ocean’s most skilled illusionists, with the remarkable ability to impersonate over 15 different marine species. Its talent goes far beyond simple camouflage—it actively changes its shape, color, and movement to mimic dangerous animals like lionfish, jellyfish, and sea snakes to avoid predators.
What makes its disguises especially impressive is how it mimics behavior, not just appearance. For example, when pretending to be a sea snake, it hides most of its body in the sand and waves two arms to create a convincing snake-like motion. This strategic flexibility allows the mimic octopus to tailor its disguise to the threat it faces, making it one of the most adaptable and deceptive creatures in the sea.
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25points
#6
When pandemic lockdowns emptied the shoreline at Tin Can Bay in 2020, volunteers witnessed an unusual pattern from a wild dolphin known as Mystique. The Indo-Pacific humpback dolphin began approaching the shore carrying objects in his beak, including shells, coral fragments, and bits of debris from the ocean. Each time he surfaced, he gently presented the item to the people nearby.
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25points
Another problem is that of depth. Deep-sea exploration, in recent years, has been opting for shallower dives. By the 2010s, only a quarter of all dives were going deeper than 2 kilometers (roughly 1.2 miles) beneath the waves, compared to half of all dives half a century ago, in the 1960s. This is significant because around 75% of the ocean lies between 2 kilometers and 6 kilometers (1.2 miles to 3.7 miles) below sea level.
“It’s clear that modern day deep-sea explorers are missing an awful lot of the seafloor. Most countries are not involved in deep-sea exploration, and most regions of the deep remain completely unseen and unknown.”
The upside is that there are efforts to change the situation and make deep-sea tools more accessible and cheaper, and by organizing dives in lesser-known sites.
#7
Mount Everest stands as the tallest point on the planet today, yet rocks near its summit contain marine fossils such as brachiopods. Their presence shows that the peak was once part of the floor of the ancient Tethys Ocean millions of years ago.
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25points
#8
In Italy, specially trained Newfoundland dogs work alongside the Coast Guard and beach lifeguards as part of one of the only formal canine sea rescue programs in the world. The Italian School of Water Rescue Dogs, founded in 1989 and based near Milan, certifies roughly 350 dog and handler teams across the country each year. Newfoundlands are the breed of choice for their water-resistant double coats, webbed feet, and ability to swim for hours in cold and rough seas.
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25points
#9
Seventeen-year-old Addison Bethea was scalloping in shallow waters near Grassy Island by Keaton Beach, Florida, when a shark suddenly attacked. Remembering advice she had once seen on Animal Planet about striking a shark on the nose, she tried to defend herself, but the way the shark had bitten her made it impossible to reach its head.
That’s when her older brother, 22-year-old Rhett Willingham, a firefighter and EMT, leapt into action. He jumped in, punching and kicking the shark until it released Addison, then hauled her onto his boat. Addison suffered severe injuries and was flown about 80 miles to Tallahassee Memorial Hospital, where she was listed in critical condition. Friends have since gathered by her ICU bedside, and despite the trauma, those close to her say she’s keeping her spirits up.
That’s when her older brother, 22-year-old Rhett Willingham, a firefighter and EMT, leapt into action. He jumped in, punching and kicking the shark until it released Addison, then hauled her onto his boat. Addison suffered severe injuries and was flown about 80 miles to Tallahassee Memorial Hospital, where she was listed in critical condition. Friends have since gathered by her ICU bedside, and despite the trauma, those close to her say she’s keeping her spirits up.
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24points
‘The Weird Unknown,’ which has a following of 1.7 million users on Instagram, has been entertaining, enlightening, and unnerving people with its posts since 2019. And we hope this never changes.
What are some fascinating, weird, or even disturbing science, history, and nature facts that you recently learned that completely shocked you? How do you like to stay up to date with new scientific breakthroughs and research? What is your relationship with the ocean like?
Once you’ve read through these ‘dark and scary’ posts, share your thoughts in the comments.
#11
A Fata Morgana isn’t just a trick of the eye—it’s a complex atmospheric phenomenon that reshapes the horizon. Caused by layers of hot and cold air bending light, it creates distorted and elevated images of objects far away, often seen at sea or in polar zones. These illusions can make ships appear to float midair, ripple into ghostly silhouettes, or even stack like layered towers.
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21points
#12
Female octopuses have been observed attacking and sometimes eating males, particularly when they feel threatened or reject mating attempts. As solitary, territorial animals, their interactions are often cautious and can quickly turn aggressive.
In response, males have evolved strategies to reduce risk, including mating from a distance using a specialized arm. The behavior reflects how survival pressures shape even basic interactions in species where cooperation is limited.
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21points
#13
Jorge, a loggerhead sea turtle, spent most of his life in captivity in Argentina. He swam tight circles in a tank, fed from a bucket, and looked out at the world through glass. But everything changed on April 11, 2025, when a team released him 15 nautical miles off the coast of Mar del Plata. As waves rocked the boat, steady hands guided him to the edge. Then he slipped into the Atlantic, and disappeared.
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20points
#14
In 2014, a fisherman in the Philippines unknowingly stumbled upon a $100 million treasure during a routine trip at sea. Tangled in his anchor was a massive pearl weighing 34 kilograms (about 75 pounds), which he brought home and casually stored under his bed for over a decade, believing it to be a good luck charm. For ten years, the fisherman had no idea he was sleeping beside what may be the largest natural pearl ever discovered.
It wasn’t until 2016, when a relative urged him to have it evaluated, that he brought the pearl to tourism officials in Puerto Princesa, Palawan. The irregularly shaped “baroque” pearl—later dubbed the “Pearl of Puerto” or “Puerto Princesa Pearl”—stunned authorities. Estimated to be worth up to $100 million, the gem has since been on public display at city hall. Still, the fisherman has chosen not to sell it, and its future remains an open question—part cultural artifact, part unsold fortune.
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19points
#15
In 1966, six Tongan teenagers who had vanished over a year earlier were unexpectedly found alive on the desolate island of Ata in the South Pacific. Presumed lost at sea, the boys had survived 15 months in isolation, sparking amazement when Australian sailor Peter Warner stumbled upon them during a routine voyage.
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19points
#16
More than 2.6 million glowing golden eggs have been discovered nestled around a hydrothermal vent off Canada’s Pacific coast—one of the largest deep-sea nurseries ever recorded. Believed to be from the elusive Pacific white skate, the eggs were found concentrated on the slopes of an underwater volcano, where natural heat likely acts as an incubator.
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19points
#17
After years of anxiety around its survival, the North Atlantic right whale is showing signs of a fragile comeback. A 2025 report from the North Atlantic Right Whale Consortium estimates the population at 384 whales, a 2.1 percent increase from the previous year. More notably, the number reflects steady growth over four consecutive years, adding up to more than a 7 percent rise since 2020. Researchers point to targeted conservation measures, especially efforts to reduce ship strikes and entanglements along key migratory and feeding routes, as central to the turnaround.
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19points
#18
Thailand shut down parts of its coastline, including Maya Bay, for several years to allow severely damaged coral reefs to recover. Years of heavy tourism had led to pollution, boat damage, and collapsing marine ecosystems, forcing authorities to halt access entirely.
The closure worked. Marine life began returning, coral systems showed signs of regrowth, and the area reopened under strict limits on visitor numbers and boat access, turning it into a controlled example of how ecosystems can rebound when pressure is removed.
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19points
#19
It sounds like something from a storybook, but an extremely rare pink bottlenose dolphin was recently spotted in Louisiana’s Calcasieu River, leaving boaters and scientists stunned. The dolphin is believed to be the same individual nicknamed “Pinky,” an albino first seen in 2007. She lacks melanin, the pigment that gives dolphins their typical gray color, so her skin appears bright bubblegum pink due to blood vessels visible beneath the surface.
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18points
#20
For the first time ever, scientists have captured an image of a live newborn great white shark in the wild—likely just hours old. While researchers have previously found newborns inside deceased mothers or encountered slightly older pups, this marks the first documented sighting of a fresh birth in open water.
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17points