6

Human Activity Is Ruining The Ocean In Sometimes Adorable Ways

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You probably picture coral as bright and colorful:

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And, yeah, I used to see plenty of coral like that. But on returning to the Bahamas in 2010, after previously diving there in 2006, I saw the coral had gone totally white, like this:

Duke

That's called coral bleaching, when coral lose their algae and starve. Temperature rise is one cause. Another surprising one: sunscreen. Sunscreen blocks the sun by design, but thousands of tons of it wash into the ocean every year. That keeps sunlight from penetrating the water, killing algae. Chemicals in the sunscreen also activate dormant viruses. I haven't worn sunscreen since 2008; I'd rather risk skin cancer than give it to the ocean.

Of course, it's not all terrible: One of the largest hermit crabs I ever came across was wearing a bright red shaving cream cap as his protective shell. It's a bit bittersweet to watch sea creatures using our trash to protect themselves. The cap likely didn't help him in camouflage, but that guy loved his plastic home. Floating flotsam is also used as safe havens for juvenile fish and sea life; often, they'll hide under a milk crate for protection, like they would with seaweed. It's strangely adorable, if you can look past how awful and sad it is.

5

You Interact With Fish In The Strangest Ways

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Unicorn fish love wriggling in divers' bubbles. It's not known why, but one theory is that they might be using the bubbles to dislodge or suffocate parasites ... or they could just be perverts molesting our mouth secretions.

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Other fish and invertebrates can service you, too, though this isn't necessarily sexual (unless you start moaning all weird and make it that way). Cleaner shrimp and some species of fish have developed a symbiotic relationship with larger sea creatures, feeding on their dead skin and parasites. You can see cleaning stations along the reef in prominent areas, and some places are so popular there is a visible line up for service. Divers who are patient can have shrimp manicures, where the shrimp will pick bits off of your fingers and nails, and those who aren't too squeamish can go to the shrimp dentist.

Drew Kaplan

4

Diving Is Massively Complicated

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3

The "Scariest" Creatures Are Cute

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Sharks might be notoriously fearsome killing machines, but they're also super shy. Like Michael Myers standing awkwardly in the corner at a junior high dance. In Thailand, I came around a bommie (an upward-growing outcrop of coral) and surprised a 2.5-meter leopard shark that was sleeping on the sand. When it realized I was there, its first reaction was to swim away. Large sharks can kill people, of course, but not because they want to eat us. They're just totally confused about what we are. You don't smell or swim or feel like a fish -- so what the hell are you doing in the ocean? I've spotted sharks in about 60 percent of my 2,500-plus dives and haven't encountered serious danger with any of them. The coolest sighting was in the Maldives, a school of 70-plus grey reef sharks feeding and circling. The smallest of them were 7 feet, while the bigger ones were anywhere from 10 to 13 feet.

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2

The Cutest Creatures Are Deadly

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Lionfish look incredible -- they're just the sort of critter you'd reach out and stroke if you didn't know any better. But they're an invasive species and extremely venomous to boot. They were accidentally introduced to the Caribbean ecosystem and are now attacking the environment. And it's the divers who are fighting them.

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1

Oxygen Can Kill You

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That thing on your back isn't an oxygen tank; if you were really breathing out of an oxygen tank, you'd be dead. Scuba tanks aren't filled with oxygen. They have common air, which is a little oxygen and a whole lot of nitrogen, just taken out of the atmosphere then jammed so tightly that stabbing a hole into the tank can blow out the hull of a ship or KO Jaws.

With a tank filled with pure oxygen, you'd find yourself overdosing at a measly 6 meters of water depth. One of my mentors in the industry, with over 10,000 deep and technical dives to his name, died when he accidentally switched over to the wrong cylinder at 43 meters. Yes, friendly neighborhood oxygen will jack you up if you mess with it. But before it turns murderous, it will cause oxygen toxicity. When diving beyond 40 meters, the first effects are the ear disturbances. I get a squeaky sound like someone is rubbing a finger on a balloon, and when it's more pronounced my aural senses start to slow down and stagger, then my vision starts to get shaggy.

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If you don't ascend at that point, you could suffer collapsed lungs and detached retinas, but don't worry, because you'll likely get a seizure, spit out your regulator, and drown first. If that doesn't happen, then your dive buddy can take you to the surface before you have any serious effects. Oh, but don't ascend too quickly, or else gas will form bubbles in your blood and kill you. Yes, managing oxygen is a delicate dance, like a waltz ... on a thin, slippery beam, over a pit of lava.

Ryan Menezes is an editor and interviewer here at Cracked. Follow him on Twitter for stuff cut from articles and other things no one should see.

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