15 amazing facts you didn’t know about the ocean

7 Jun 2021
7 min read

Hidden treasure, underwater waterfalls, spooky sounds and a whole lot of life – the ocean is a thriving wonderland.

It’s World Ocean Day on 8th June – a day where people everywhere can celebrate and take action for the betterment of our shared ocean, which connects us all.

Sadly, our global ocean has never been more at risk. Plastics pollution, global warming, illegal hunting and overfishing… the ocean faces a raft of challenges and we need to make changes now to protect and restore it.

The ocean does so much more for us than provide a scenic place to enjoy a sunny day. It produces over half the world’s oxygen, helps to regulate the climate and absorbs 50% more carbon dioxide than our atmosphere. It’s home to a huge array of wildlife and biodiversity. It enables us to transport goods around the world, and provides us with food and ingredients for medicine. It’s also a major economic driver for the many communities which depend on the ocean for their livelihoods. The ocean is one of the world’s most valuable resources, so we must all play our part in looking after it. Take a look at some of the planned World Ocean Day events for a bit of inspiration.

And in case you need more of a reason to take action, check out these weird and wonderful facts that show just how special the ocean really is.

  1. The vast majority of life on Earth is aquatic

You probably already know that the ocean covers more than 70% of the Earth’s surface, so it makes sense that it would be home to a lot of lifeforms. But did you know that an incredible 94% of all of the planet’s living species exist in the oceans?

  1. We actually don’t know that much about the ocean

…because mankind has explored less than 5% of it. There’s so much of our ocean still waiting to be discovered and understood. In fact, we’ve got better maps of Mars than we do of the ocean.

  1. It’s the world’s biggest museum

There are more historic artefacts under the sea than in all of the world’s museums combined. There are around 1,000 shipwrecks lying off the Florida Keys alone, with an estimated three million dotted around the globe.

  1. The ocean is home to the world’s longest mountain chain

Earth’s longest chain of mountains, the Mid-Ocean Ridge, stretches for 40,390 miles – ten times longer than the Andes – and lies almost entirely beneath the ocean. Mankind has explored less of these mountains than the surface of Venus or the dark side of the Moon.

  1. There are lakes and rivers within the ocean

Yep, you read that right. When saltwater and hydrogen sulfide combine, it becomes denser than the rest of the water around it, enabling it to form a lake or river that flows beneath the sea. This also explains how the world’s tallest waterfall – the Denmark Strait Cataract – is also in the ocean. The 11,500-foot underwater waterfall lies between Greenland and Iceland and dwarfs Angel Falls in Venezuela, which is just 3,200 feet.

  1. Coral produces its own sunscreen

Coral depends on algae as a main source of sustenance, but too much sunlight can damage the algae that live inside coral in shallow water. To mitigate this, the corals fluoresce, creating proteins that act as a sort of sunscreen for the algae.

  1. The world’s largest living structure lives in the ocean

While we’re on the subject of coral, the Great Barrier Reef – the world’s largest living structure – also calls the ocean home. Lying off the coast of Australia, the 133,000-square-mile reef is so huge it can be seen from outer space.

  1. A single iceberg could supply a million people with drinking water for five years

An average large iceberg from Antarctica contains more than 20 billion gallons of water – enough to give one million people enough drinking water for five years. At one point a company from the United Arab Emirates launched plans to tow an iceberg to the UAE to mitigate the country’s serious risk of drought, but the project quietly disappeared.

  1. Pressure at the depths of the ocean would crush you like a bug

In the Mariana Trench – the deepest point on the planet at 35,802 feet below the surface – the water pressure is eight tonnes per square inch. If you somehow made your way down there it would feel like you were carrying nearly 50 jumbo jets. Oh, and going back to the previous point that the ocean is wildly unexplored – more people have been to the moon (12) than the Mariana Trench (three).

  1. If all the ocean’s ice melted at once we’d be in serious trouble

We already know that rising sea levels are a massive risk to humanity (read more about sea level rises here), but if all of the glaciers and sheets of Arctic sea ice melted simultaneously, the sea level would rise an estimated 262 feet, which is about the height of a 26-story building – just a bit shorter than the Statue of Liberty.

  1. Circumnavigating the ocean is a slow process

…at least it is if you’re a drop of water. It takes water 1,000 years to complete a continuous journey around the world, known as the global ocean conveyor belt.

  1. The ocean isn’t blue because of the sky

There’s a commonly-held belief that the ocean is blue simply because it reflects the colour of the sky, but this isn’t the case. The ocean’s colour is a result of water absorbing colours in the red part of the light spectrum. The water acts like a filter, leaving behind colours in the blue part of the spectrum. Light bouncing off floating sediments and particles in the water also help the ocean take on green, red or other hues. And because blue wavelengths penetrate much deeper than some other wavelengths, the ocean appears ‘bluer’ the deeper it gets.

  1. Astronauts are the nearest humans to the ocean’s most remote location

The ocean’s most remote point lies in the South Pacific. Dubbed Point Nemo (Latin for ‘no-one’), the spot is 1,600 kilometres from the nearest patch of land and around 2,700 kilometres from the nearest inhabited landmass. It’s so far from land that its nearest humans are often astronauts. It’s also used as a space agency dumping ground, with more than a hundred decommissioned spacecraft estimated to be lying under the surface here.

  1. Most volcanic eruptions happen underwater

There are an estimated one million volcanoes underwater, and while the majority of them are not active, around 80% of the planet’s volcanic eruptions nonetheless happen beneath the ocean’s surface. These volcanic structures create superheated vents that spew hot water deep below the surface, which have a special role to play in the ocean’s ecosystem as a variety of lifeforms thrive in these hot areas.

  1. The ocean makes a lot of spooky sounds

It’s not just the ocean’s flora and fauna that has scientists scratching their chins. Researchers have recorded a number of strange sounds emanating from the ocean’s depths over the years that they’ve been unable to explain. ’The Bloop’ may be the most famous underwater sound, captured in 1997 by the National Oceanic and Atmospheric Administration (NOAA). It is one of the loudest ocean sounds ever recorded, and while the noise is consistent with an underwater iceberg fracturing no-one knows for sure where it came from.

The bottom line

As you can see, the ocean is an amazing wonderland full of incredible mysteries, astonishing ecosystems and an abundance of life that’s vital for its own survival – and ours. Taking small steps to limit your impact on the climate such as recycling at home, conserving water and reducing your energy consumption will all help to protect and restore this precious global resource.



The information in this article was correct at the time of writing and is provided for guidance only. Please see the full disclaimer in our terms and conditions.

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