25 Things You Didn't Know About the World's Oceans

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iStock

In 2008, the United Nations recognized World Oceans Day on June 8 as a time to celebrate the immense bodies of water that make up roughly 70 percent of the surface of the Earth. The goal of the day is to promote conservation efforts and engage activists in preserving these five crucial areas—the Pacific, Atlantic, Indian, Arctic, and Southern (Antarctic) Oceans—and their inhabitants.

If you don’t know much about the deep blue sea—like why it's not actually blue, for example—check out 25 facts we’ve culled about the world’s largest and most fascinating real estate.

1. THE SUN GIVES IT THAT BLUE TINT.

A look at calm, blue ocean waters
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One of the most indelible features of the oceans is the deep blue waters that are continually churning, rolling, and coming in waves. The color is the result of the sun’s red and orange wavelengths being absorbed by the surface and its blue wavelengths penetrating deeper, giving way to a blue tint. And because those wavelengths can travel further down, the ocean will tend to appear more blue the lower you go. Why isn't water in a glass blue when you're sitting outdoors? There aren't enough molecules to absorb the light.

2. THEY'RE KEEPING THE INTERNET ONLINE.

If you could catch sight of the miles of cable criss-crossing the world’s oceans, it would look like a giant, submerged web. Communications companies maintain international connections by feeding cables down to (hopefully) flat surfaces on the ocean floor. Some require shark-proof layers to prevent predators from biting into your Netflix stream (although the danger of sharks has been vastly overhyped—human activity is a far bigger threat).

3. THE DEEPEST PART IS REALLY, REALLY DEEP.

The Mariana Trench is considered to be the deepest part of the world’s oceans. Inside of the Trench is a valley known as Challenger Deep that extends roughly seven miles (36,070 feet) below the surface. For comparison, the entirety of Mount Everest—at 29,029 feet—could easily be accommodated there. Manned explorations haven’t gone any further than 35,797 feet below the surface, a record set by two oceanographers in 1960. In 2012, filmmaker James Cameron explored roughly the same depths in a solo mission. It’s considered the deepest point on Earth.

4. SOUNDS CAN TRAVEL TO THE DEEPEST EXPLORED AREAS.

Researchers once lowered an underwater microphone called a hydrophone to almost the bottom of the Mariana Trench to see what sounds—if any—it might pick up. After feeling relieved the immense pressure at those depths—about 8 tons per square inch—didn’t implode the equipment, they discovered that sound from earthquakes, passing baleen whales, and other ambient noise was audible.

5. LAKES AND RIVERS LIE BENEATH THE SURFACE.

Some surfaces in the ocean feature sights that don’t seem to make any logical sense—rivers and lakes, some of them miles long, can stretch across the ground even though they’re submerged. How can a body of water exist in a body of water? Water from under the sea floor seeps up and dissolves salt layers, forming depressions. Because the water in the depression is more dense than the water all around it, it settles into the depression and forms a distinct pool.

6. THERE ARE 20 MILLION TONS OF UNTOUCHABLE GOLD IN THE OCEANS.

If you’re hoping to find a fortune in gold prospecting, don’t expect the ocean to cooperate. You may be able to plunder a shipwreck, but you won’t be able to collect much of the 20 million tons of gold estimated to exist in the water. That’s because it’s so diluted that it’s measured in parts per trillion. One liter of seawater might net you a 13-billionth of a gram.

7. WE KNOW MORE THAN YOU MIGHT EXPECT.

A dolphin swims in the ocean
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You might see mentions that we’ve "mapped" more of Mars than we have the Earth’s oceans, but that’s not quite true. Oceanographers have been able to visualize almost 100 percent of the ocean floors, albeit in a resolution that makes it difficult to spot a lot of detail. In that sense, images of Mars and other planets have been able to offer more information because they’re not covered in water that can block radar. Although we haven't explored the vast majority of the oceans first-hand, technology has enabled us to have a rough idea of their layouts.

8. THE BIGGEST WATERFALL ON EARTH IS IN THE ATLANTIC.

Putting Niagara Falls to shame is the Denmark Strait, a waterfall below the Atlantic Ocean that, in terms of water volume, is the equivalent of 2000 of the world’s most notable waterfalls, with cascading liquid pouring 11,500 feet down. The Strait’s cold water on the eastern side is more dense than the warm fluid coming from the west. When the two waters mix, the colder supply sinks, creating a waterfall.

9. WE DON'T KNOW ANYTHING ABOUT MOST OF THE MARINE LIFE.

An octopus is photographed by an ocean photographer
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Size and water pressure conspire to limit our exploration of the oceans, so much so that it’s estimated we’ve identified only one-third of the potential marine life lurking beneath the surface. It’s possible most of those are smaller organisms, but it’s likely that some whales and other mammal species have yet to be discovered. We’re making progress, though: An average of 2000 new species are described each year.

10. MAGELLAN NAMED THE PACIFIC OCEAN.

When Ferdinand Magellan crossed the Atlantic beginning in 1519, he eventually found his way to another body of water—what he dubbed the Pacific, or peaceful, ocean due to the calm surface. He didn’t know it at the time, but the Pacific would eventually be recognized as the largest ocean on the planet at 59 million square miles.

11. THE MOST REMOTE PLACE ON EARTH IS IN THE SOUTH PACIFIC.

Point Nomo is illustrated
Courtesy National Oceanic and Atmospheric Administration

Known as Point Nemo, the area is roughly 1000 equidistant miles away from the coasts of three neighboring islands and so remote that astronauts are often closer to any theoretical occupants than anyone on dry land.

12. MOST VOLCANIC ERUPTIONS ARE UNDERWATER.

Up to 80 percent of volcanic eruptions go unnoticed by land-dwellers. That’s because they’re erupting underwater. An estimated one million volcanoes—some extinct and some very active—spew molten hot lava. Despite the heat, creatures can still be found near their superheated vents. Researchers believe these areas harbor several undiscovered species that are invulnerable to the harsh conditions, including water temperatures up to 750 degrees Fahrenheit.

13. THERE MAY BE BILLIONS IN SUNKEN TREASURE DOWN IN THE DEEP.

A sunken ship sits on the ocean floor
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It’s impossible to offer an accurate estimate of how many shipwrecks and accompanying treasures are lurking in the oceans, but a few people have made an honest effort of it. The National Oceanic and Atmospheric Administration (NOAA) thinks a million sunken ships lurk in the dark; others peg the total value of the unrecovered treasures at $60 billion. So why don’t we hear more stories of watery grave-robbing? Because governments or private parties are likely to make a legal claim to those funds, making an expensive expedition for treasure a gamble at best.

14. THEY KEEP US BREATHING.

Forget all the beauty and wonder of the world’s oceans: At the bare minimum, they’re responsible for supplying us with oxygen. Oceans produce 70 percent of the oxygen supply in the atmosphere thanks to marine plants releasing it as a byproduct of photosynthesis. One phytoplankton, Prochlorococcus, is estimated to be solely responsible for one in every five breaths a human will take.

15. "DEAD ZONES" CAN BE BARREN OF ANY LIFE.

Dark ocean waters can be devoid of life
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One reason pollution is such an issue for oceans: It can rob them of the oxygen needed to support life. When run-off from waste disposal gets into the water, it can feed an overabundance of algae, which then dies, sinks, and as it decomposes, consumes the available oxygen in the water. That creates hypoxic areas, or hot spots with a lack of oxygen. If fish and other marine life don’t find a new space to dwell in, they’re toast.

16. THE FISH ARE EATING A LOT OF PLASTIC.

With over seven million tons of plastic winding up in the ocean each year, it’s inevitable that a lot of it winds up as part of an unwelcome addition to a fish’s diet. For fish in the northern Pacific, researchers at the University of California, San Diego once estimated they swallow between 12,000 and 24,000 tons every year.

17. KEEPING TROPICAL PET FISH MIGHT BE HARMING THE OCEANS.

Colorful tropical fish swim in the water
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Those aquariums in pet stores and dental offices might remind you of marine life, but they might also be having a negative impact. When tropical fish are caught, fishermen use sodium cyanide to make them float out of the reef for easy scooping. While the hope is that it just stuns them, the residue of the chemical can bleach coral reefs and kill scores of other fish.

18. TSUNAMI WAVES CAN REACH 100 FEET...

When waves reach shallow water near land, energy that would normally be dispersed goes up, elongating the wave. A 1958 earthquake and landslide in Alaska generated a tsunami 100 feet high and destroyed all vegetation up to 1720 feet, the largest in recorded history.

19. ...BUT THE BIGGEST WAVES ARE UNDER THE SURFACE.

Called internal waves, these water walls have been found three miles below the surface. The waves are part of water layers with different densities and can reach heights of 800 feet before collapsing. Scientists believe these massive forces can help move heat and nutrients to other areas.

20. WE'RE TRYING TO MAKE THE OCEAN DRINKABLE.

As most everyone knows, drinking salt water is perilous at best and deadly at worst. In a process called desalination, that salt is removed, leaving fresh water. But building facilities and the energy required to process water this way has traditionally been more expensive than sourcing water from potable sources.

21. THE BRISTLEMOUTH IS THE MOST ABUNDANT VERTEBRATE IN THE WORLD.

A bristlemouth snacks on a shrimp
Courtesy National Oceanic and Atmospheric Administration

Not familiar? If you saw one, you’d know. The bristlemouth is a fish a little smaller than your average human finger that has a mouth full of fangs and can glow in the dark. It’s also the most common vertebrate in the world. For comparison? Chickens could number as many as 24 billion on land, while bristlemouths are said to add up to the hundreds of trillions.

22. GIANT KELP GROWS VERY QUICKLY.

Giant kelp, or Macrocystis Pyrifera, is a type of seaweed that experiences an astonishing growth spurt. To reach its usual height of 100 feet, the species can grow up to two feet in a single day.

23. RUBBER DUCKS HAVE HELPED OUR UNDERSTANDING OF THE OCEANS.

A rubber duck floats in the water
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In 1992, a shipment of bath toys was headed from China to the U.S. when the cargo ship dropped a container. More than 28,000 rubber ducks—or duckies, depending on your preference—and other play-animals were dumped into the North Pacific Ocean. Oceanographers tracked where the ducks wound up in order to better understand the water currents, with some landing ashore in Europe and Hawaii. The duck sightings didn’t ease up until the mid-2000s.

24. ANTARCTIC FISH HAVE NATURAL ANTIFREEZE.

Curious how aquatic life can survive the temperatures at the poles? Antifreeze proteins in the fish prevent ice crystals from growing, preventing their blood from being overcome by the chill and allowing it to continue flowing.

25. SEASHELLS DON'T ACTUALLY SOUND LIKE THE OCEAN.

A child holds a seashell up to her ear
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Seashells have long been perceived as the iPods of the sea, tiny little devices that can mimic the static, hissing noise of the water. What they’re actually doing is acting as a resonator, or a cavity that allows sound to vibrate. By holding up the shell to your ear, you’re hearing the ambient noise around you amplified. All that whooshing air typically sounds a lot like the movement of cascading waves. If you can't make it to beach, though, it might be the next best thing.

Lost Your Wallet? You Might Be More Likely to Get It Back If There's Cash Inside

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iStock/tzahiV

Few things can incite more panic than discovering you’ve lost a wallet or purse containing money, identification, credit cards, and/or keys. You wonder if anyone will find it—and if they do, whether they’ll decide to retain your cash using the playground ethics of the "finders keepers" rule.

An ambitious new study in the journal Science has provided at least a partial answer. If your wallet has cash inside, it’s actually more likely for people to return it than if it didn’t have any.

Researchers at the University of Michigan conducted an exercise in civic honesty, dispatching 13 assistants to 355 cities in 40 countries across the globe. At each destination, the assistants were armed with clear wallets that held things like grocery lists and business cards along with an email address. Some wallets had no money inside. Others contained about $13.45 in the local currency. The assistants gave the wallets to employees at banks, hotels, post offices, museums, and police stations, explaining they had “found” the wallet and were in too big of a hurry to contact the owner themselves. They passed the responsibility to the person receiving the wallet. All told, 17,303 wallets were left as proverbial bait to see what the employees might do.

Of the wallets without cash inside, researchers received an email seeking to return roughly 40 percent of them. About 51 percent of the employees attempted to return the wallets containing $13.45 in cash.

These percentages fluctuated by country. In Denmark, 82 percent of wallets with cash were returned. In the United States, the figure was 57 percent. When researchers upped the stakes by including $94.15 in wallets for areas in the U.S., Britain, and Poland, the return rate went up to 72 percent.

It’s difficult to infer motivations for why people returned wallets with more money than less, or none. In a survey, researchers found that people in general described wanting to avoid feeling like a thief by keeping the money. (Respondents were different than the employees who were left with the wallet.) That would explain why returns increased as the dollar amount went up.

The study was limited by the fact that the wallets were left with people who could have presumably been held accountable for not returning them. The research assistant could have returned to inquire about the wallet’s status, while no such concern exists for people finding a wallet in the street. Still, it does indicate that people feel a measure of sympathy for—and moral obligation to—lost money and will make an effort to see it returned.

[h/t Science News]

Some Fish Eggs Can Hatch After Being Pooped Out by Swans

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iStock/olaser

A question that’s often baffled scientists is how certain species of fish can sometimes appear—and even proliferate—in isolated bodies of water not previously known to harbor them. A new study has demonstrated that the most unlikely explanation might actually be correct: It’s possible they fell from the sky.

Specifically, from the rear end of a swan.

A study in the journal Ecology by researchers at the Unisinos University in Brazil found that killifish eggs can, in rare cases, survive being swallowed by swans, enduring a journey through their digestive tracts before being excreted out. This kind of fecal public transportation system explains how killifish can pop up in ponds, flood waters, and other water bodies that would seem an unlikely place for species to suddenly appear.

After discovering that some plants could survive being ingested and then flourish in swan poop, researchers took notice of a killifish egg present in a frozen fecal sample. They set about mixing two species of killifish eggs into the food supply of coscoroba swans living in a zoo. After waiting a day, they collected the poop and dug in looking for the eggs.

Of the 650 eggs they estimated to have been ingested by the swans, about five were left intact. Of those, three continued to develop. Two died of a fungal infection, but one survived, enduring 30 hours in the gut and hatching 49 days after being excreted.

Because killifish eggs have a thick outer membrane, or chorion, they stand a chance of coming through the digestive tract of an animal intact. Not all of what a swan ingests will be absorbed; their stomachs are built to extract nutrients quickly and get rid of the whatever's left so the birds can eat again. In rare cases, that can mean an egg that can go on to prosper.

Not all fish eggs are so durable, and not all fish are quite like the killifish. Dubbed the "most extreme" fish on Earth by the BBC, killifish have adapted to popping up in strange environments where water may eventually dry up. They typically live for a year and deposit eggs that can survive in soil, delaying their development until conditions—say, not being inside a swan—are optimal. One species, the mangrove killifish, can even breathe through its skin. When water recedes, they can survive on land for over two months, waddling on their bellies or using their tails to "jump" and eat insects. A fish that can survive on dry land probably doesn't sweat having to live in poop.

The researchers plan to study carp eggs next to see if they, too, can go through a lot of crap to get to where they’re going.

[h/t The New York Times]

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