It’s common knowledge that we know more about outer space than we do about our own oceans. And it’s not for lack of all the plastic we’re dumping into them. But even what we do know is fascinating, scary, and beautiful all at once. And there’s probably a lot you’ve never heard of yourself. Let’s take a look at some of the weirdest facts about the ocean that’ll blow your mind.
10. The World’s Largest Mountain Range
Yeah, it ain’t the Himalayas. And it’s not the Andes either. The largest mountain range on Earth is actually mostly under the ocean, and it’s called the Mid-Ocean Ridge. It spans over 40,000 miles (64,000 kilometers) across the globe, making it longer than any mountain range on land. Despite its enormous size, it’s not a widely recognized wonder because, well, you can’t see it.
The Mid-Ocean Ridge is essentially a chain of underwater mountains, hills, and rift valleys that encircle the Earth like the seams on a baseball. It’s the result of tectonic plates moving away from each other, allowing magma from the Earth’s mantle to rise and solidify, creating new crust. As the magma cools and solidifies, it forms new sections of the ridge. In some places, the Mid-Ocean Ridge rises above the ocean’s surface, forming huge and notable islands like Iceland. It’s weird to think about land masses like that being part of underwater mountain ranges, but that’s literally what land is: underwater mountains that rise above the surface of the water.
9. Underwater Waterfalls
It doesn’t sound possible, but underwater waterfalls are very real. Well, kind of. It’s mainly an illusion of cascading water beneath the ocean’s surface. They’re not actual waterfalls as we commonly know them on land, you see. Instead, they are optical illusions caused by a combination of currents, varying water densities, and dramatic changes in seafloor topography.
One of the most famous examples of an “underwater waterfall” can be found near Mauritius in the Indian Ocean. The illusion occurs at the point where a steep, underwater drop-off plunges into the depths, creating a stark contrast in water density. Sand, silt, and other sediments get carried by ocean currents, giving the impression of water cascading down, mimicking a waterfall.
These underwater waterfalls are not fixed and don’t behave like terrestrial waterfalls. They’re influenced by shifting currents and the movement of water masses, creating an ever-changing spectacle. While they’re not actual waterfalls, these underwater phenomena offer a fascinating glimpse into the intricacies of ocean currents and underwater geography.
8. The Turritopsis dohrnii
The immortal jellyfish, scientifically known as Turritopsis dohrnii, is exactly what it sounds like. This thing, found mainly in the Mediterranean, can revert its aging process and essentially start its life cycle anew, a theoretically infinite number of times.
When facing unfavorable conditions, injury, or even natural aging, the jellyfish can transform its adult cells back into their earliest form, known as a polyp. This process, called transdifferentiation, allows the jellyfish to regenerate and essentially turn back the biological clock. As a polyp, it can then grow into a new jellyfish, restarting its life cycle. Over and over and over.
This ability to reverse aging and essentially achieve potential immortality sets the Turritopsis dohrnii apart from any other animal. Now “immortal” isn’t the same thing as “invincible” – you could still smash it with your foot if you wanted – it’s still an adequate description of one of the most fascinating animals in existence.
7. The Sargasso Sea
Located in the North Atlantic Ocean, the Sargasso Sea is known for its vast stretches of golden-brown Sargassum seaweed. What sets this sea apart is the absence of shores and boundaries, making it unique among the world’s maritime bodies. It’s essentially a large gyre, an area of rotating ocean currents, and it’s where several major ocean currents converge.
One of the most intriguing features of the Sargasso Sea is the distinctive seaweed itself. This free-floating seaweed forms dense mats on the ocean’s surface, providing a habitat for a wide array of marine life, from tiny crustaceans to larger animals like fish and turtles. These mats of Sargassum create a distinctive and vital ecosystem in what might otherwise seem like a desolate part of the ocean.
Interestingly, the Sargasso Sea is renowned for being a spawning ground for European and American eels. Eels, born in the Sargasso Sea, journey thousands of miles to rivers and lakes in North America and Europe, where they spend most of their lives before returning to the Sargasso Sea to reproduce and start the cycle anew.
6. Glacial Underwater Lakes
Glacial underwater lakes, also known as brine pools or brine lakes, are found in deep ocean basins around the world. These underwater lakes are a result of processes related to salt concentrations and temperatures, creating a surreal underwater environment.
These lakes are formed when dense, saline water, which is heavier than the surrounding ocean water due to its high salt content, settles at the bottom of the ocean floor. The specific composition of these brine lakes is a result of various factors, including the dissolution of ancient salt deposits and hydrothermal vent activity.
What makes these underwater lakes even more fascinating is their resemblance to terrestrial lakes, complete with “shorelines” and “beaches” made of salt deposits. The distinct ecosystems that have evolved around these brine pools are of particular interest to scientists, offering some pretty amazing insights into one of earth’s most remote and extreme environments.
5. Red Tide
Scientifically known as harmful algal blooms (HABs), Red Tide is a natural phenomenon caused by the rapid multiplication of certain species of microscopic algae, often discoloring the water and sometimes producing harmful toxins. These algal blooms typically contain high levels of single-celled algae, such as Karenia brevis, which can produce toxins harmful to marine life and even humans.
The term “red tide” comes from the reddish-brown color the water can take on during an algal bloom, although blooms can also appear green or even purple. The toxins released by these algae can have detrimental effects on marine ecosystems, including fish kills and harm to birds and mammals that feed on marine organisms.
In addition to its ecological impact, red tide can have severe economic consequences, particularly in areas dependent on tourism and seafood industries. Human exposure to the toxins produced during a red tide event can result in respiratory irritation, shellfish poisoning, and other health issues. Sadly, as climate change worsens, so will this.
4. The Bloop
There are plenty of weird things to see and hear in the ocean. But “the Bloop” is on another level. This mysterious and anomalous ultra-low-frequency sound was detected in the Pacific Ocean in 1997. It’s a deep and powerful noise captured by underwater microphones, called hydrophones, deployed by the National Oceanic and Atmospheric Administration (NOAA). The sound was so loud that it could be heard over 5,000 kilometers away and puzzled researchers for years.
Initially, some speculation attributed the Bloop to enormous sea creatures or undiscovered marine life. However, further investigation revealed that it was likely of geological origin. Scientists eventually identified the sound as consistent with icequakes, caused by the cracking and movement of large icebergs as they fracture and break apart.
The Bloop’s discovery highlighted the vast and still largely unexplored nature of the ocean and its ability to produce sounds that can be heard across entire ocean basins. While it turned out to have a natural explanation related to ice movement, the Bloop sparked imagination and fueled interest like few other phenomena have.
3. Whale Falls
Whale falls can be found on the ocean floor, where the carcass of a whale becomes an ecosystem unto itself. When a whale dies and its massive body sinks, it creates what scientists refer to as a “whale fall.” These events are significant because they provide a sudden and concentrated source of nutrients to the deep-sea ecosystem, initiating a complex ecological process.
As the whale carcass begins to decompose, it supports a diverse community of organisms. Scavengers like hagfish and sharks are usually the first to arrive, consuming the soft tissues. Over time, the whale’s bones become enriched with lipids and proteins, attracting other organisms such as bone-eating worms, mollusks, and specialized bacteria that aid in decomposition. These creatures form a unique ecosystem around the whale fall, sometimes lasting for decades.
Whale falls contribute to the understanding of deep-sea biodiversity, nutrient cycling, and the role of large marine organisms in shaping underwater habitats. Sadly, with whales frequenting endangered species lists, these phenomena won’t last forever.
2. Blue Holes
Blue holes are underwater sinkholes or caves, typically found in the shallow coastal waters of limestone-rich regions like the Bahamas, Belize, and the Great Barrier Reef. What sets them apart is their mesmerizing deep blue color, often in stark contrast to the lighter waters that typically surround them. These holes can vary in size, from a few meters to hundreds of meters in diameter and can extend to immense depths.
The unique hue of blue holes is explained by the stark difference in water depth and the way light is scattered and absorbed. When sunlight penetrates the surface and goes deeper, it gets absorbed by water molecules, giving it a blue color. The effect is intensified in blue holes due to their extreme depth.
Aside from their appearance, blue holes also hook scientists and divers because of the potential secrets they hold. They can preserve valuable information about the Earth’s past, including ancient climate changes and long-extinct species. But be careful: they’re not always safe to explore, requiring specialized training and equipment due to the depths involved.
1. The “Tongue-Eating” Parasite
Now for a scary one. The tongue-eating parasite, scientifically known as Cymothoa exigua, is exactly what it sounds like. This parasitic isopod is known to seek out and parasitize fish, particularly the spotted rose snapper and the California sheephead.
The life cycle of this creature begins when it enters the fish through the gills. Once inside, it latches onto the fish’s tongue and feeds on the blood vessels, causing the tongue to atrophy and eventually fall off. Surprisingly, the isopod then attaches itself to the tongue stub and therefore replaces the fish’s missing tongue. Yes. Read that again. Or maybe don’t. Anyway, it continues to live inside the fish’s mouth, acting as a functional, though rather eerie, replacement for the original tongue. Weirdly enough, this parasitic arrangement doesn’t seem to hurt or kill the fish. On the contrary, the host animal seems relatively unaffected and continues to eat and function with the isopod in place.