What Happens In The Deep Ocean?

It’s dark, cold, and wet. No, we’re not talking about your winter commute to work, but the depths of the ocean – and while we might know the route to the office like the back of our hand, there’s still plenty to find out about the deep sea.

Hydrothermal vents

The deep ocean is a busy place when it comes to chemistry, particularly in the case of the hydrothermal vents that litter the sea floor.

Hydrothermal vents are a bit like the hot springs you see in places such as Yellowstone , but are instead found at the bottom of the ocean. They’re usually found in places where tectonic plates are on the move, creating fissures in the oceanic crust.

Seawater is able to get into these cracks and picks up materials and minerals within the crust – but it also gets heated up by the super-hot mantle below, which sends the water shooting back out of the sea floor. There, colder water causes the minerals that were picked up to precipitate, and they settle into the chimney structures that we characterize with these vents.

This activity is thought to potentially hold the key to understanding how life on Earth began. Evidence of microbial life around hydrothermal vents has been found dating back as far as 3.42 billion years ago and even today, researchers have found evidence of tiny inorganic structures that appear to be converting energy in a life-like process .

That doesn’t mean for sure that hydrothermal vents in the ocean deep are the source of life as we know it, but it certainly helps us along in figuring out what was.

Creatures of the deep

Microbes are one thing, but it would be easy to assume that nothing bigger could possibly live in the deepest parts of the ocean – it’s cold, dark, and if you happened to accidentally teleport there, the pressure would crush you to death before you’d even realized you were there.

But, as Dr Ian Malcom once wisely said, life… uh, finds a way, and there’s no better illustration of that than the creatures that live down in the Mariana Trench , the deepest oceanic trench on the planet.

To thrive down here, life has had to get a little creative with the blueprints and by that, we mean the organisms that live in the trench usually look pretty damn bizarre. Take black seadevils ( Melanocetus ), for example, the source of inspiration for that scary scene in Finding Nemo . They feature a large, gaping mouth lined with barbed, fang-like teeth, and a bioluminescent lure to attract unsuspecting prey.

One key element that unites all of these creatures, however, is how little we know about them. As mentioned, the conditions down in the deep aren’t exactly the most hospitable to humans, making it difficult to find deep-sea specimens to study.

On rare occasion, however, scientists are able to find out more when they wash up on our shores. Sure, getting jumpscared by the deep-sea football from your nightmares on your morning beach walk might not be the calmest way to start your day, but we’d argue it’s worth it to know more about them.

“Deep” doesn’t just have to mean organisms that live on the seafloor either – scientists have recently discovered that an array of animals can be found living beneath it too, challenging the long-held idea that only microbes can live beneath the surface.