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Facts about the Ocean for Children

Facts about the Ocean for Children

With World Ocean Day on 8th June, why not challenge yourself to learn as much as you can about our world’s oceans?!

facts about the ocean for kids
How many facts do you already know about the ocean?

What is an ocean?

An ocean is a large body of saltwater. Oceans cover over 70% of the Earth’s surface and are a habitat to over 200,000 known species. 

The name ‘Ocean’ originates from Greek mythology. One of the elder titans Ōkeanós [O-kay-an-AWS] was believed to be the divine personification of an enormous river that encircled the world. 

ocean facts for kids
Ōkeanós was the offspring of Gaia (Earth) and Uranus (Sky)

Did you know that around 80% of the ocean hasn’t been explored? It’s so big and deep in places that we don’t have the technology to reach them to map out the areas. We’ve explored more of the moon than we have the oceans!

What is the difference between an ocean and a sea?

An ocean is different to a sea. Seas are smaller and are part of an ocean. They are usually partially or completely enclosed by land and can be found where an ocean meets the land. 

How many oceans are there?

There are five oceans. In order of size, from biggest to smallest, they are:

  • Pacific Ocean
  • Atlantic Ocean
  • Indian Ocean
  • Southern Ocean
  • Arctic Ocean
Ocean facts for kids
There are five oceans around the world.

The oceans can sometimes be combined and referred to as the World Ocean. 

The Pacific Ocean

The largest ocean, the Pacific, makes up around 47% of the world’s oceans. It is 168,723,000 km2 and has an average depth of 3,970 m. It separates the continents of Asia and Australia from North and South America. The Pacific Ocean is home to the deepest place on Earth: the Mariana Trench. This underwater trench extends more than 11,000 m. This is more than the height of Mt Everest (8,849 m)!

The Atlantic Ocean

The Atlantic has an area of 85,133,000 km2 and makes up around 23% of the world’s oceans. It separates the Americas from Europe and Africa. Did you know that Leif Erikson, a Norse explorer who lived between 970-1020 AD is remembered as the first ‘European’ to reach North America more than 500 years before Christopher Columbus!

The Indian Ocean

The Indian Ocean is around 20% of the world’s ocean area at 70,560,000 km2. It is the body of water that borders southern Asia and separates the continents of Africa and Australia. It is the warmest of all the oceans, which means that species such as phytoplankton (which is a key food source for many marine animals) find it difficult to grow in most areas. 

The Southern Ocean

The Southern Ocean encircles Antarctica. It’s relatively small in comparison to the oceans, making up only 6% of the world’s oceans (21,960,000 km2). Its cold temperatures mean that icebergs are common and can be hundreds of metres high! The Southern Ocean is home to the world’s largest invertebrate: the giant squid. This massive creature can grow up to 15 m in length!

The Arctic Ocean

The Arctic Ocean is the smallest ocean, making up only 4% of the world’s ocean area. It is 15,558,000 km2 and covers the Arctic. The Arctic Ocean derives its name from the word 'arktos' which means 'bear' in Greek. The Arctic Ocean is home to whales, walruses, polar bears and seals. The Arctic region is an area of concern for climate change studies. It’s currently warming twice as fast as the rest of the planet, melting the ice caps. This is concerning as it can change the amounts of freshwater entering the ocean and affects the ocean current patterns which many climates around the world rely on. 

What is World Ocean Day? 

On World Ocean Day, people everywhere can celebrate and take action for our shared ocean, which connects us all. Get together with your family, community, and /or your company, and join with millions of others around our blue planet to start creating a better future.

World OceanDay
World Ocean Day - 8th June 2021

World Ocean Day Activities

Plastic Replacements

Plastic waste pollution is one of the biggest threats to our oceans. Tonnes of plastic gets dumped into the ocean every day, harming wildlife and destroying the beauty of these important habitats. 

Ocean facts for kids
Plastic waste is one of the biggest threats to our oceans.

 Investigate the plastic you use on a daily basis. How many plastic objects can you spot in your bedroom? In your classroom? How many of these are single-use plastics? These are plastics that we use once and then throw away such as a plastic bottle or some packaging. 

Can you find any alternatives to these plastics? Are you disposing of them in a responsible way?

Water Investigations

Where does our water come from? Investigate the role our oceans play in the water cycle and how the water can travel from the ocean, to rivers and lakes, to our taps! 

Think carefully about how you use water. Are you being wasteful or responsible? Design a poster to help you, your family or your school to think about how they can save water.

Nautical Language

Ocean facts for kids
Ships were used for exploration, military missions and trade.

Many nations with an ocean or sea border have a strong history of nautical (sea-faring) trade, exploration and military power. Sailors would spend most of their lives at sea, sometimes for months at a time. During this time, they would often adopt their own words for things and some of our language has adopted these into everyday sayings.

For example:

  •  ‘All hands on deck’ means to prepare for action or to get into position for a task.
  • Bite the bullet’ During a painful medical procedure a sailor was given a hard object, such as a bullet to bite down on to help them handle the pain. Now we use this saying to describe someone bravely facing up to something unpleasant. 
  • Isn’t enough room to swing a cat’ Sailors would be punished using a whip called a ‘Cat O’ Nine Tails’. In cramped conditions, there wasn’t enough room to swing the whip or ‘Cat’. Now we use this saying to describe a cramped space. 
    • ‘Let the cat out of the bag’ Is used today to describe when someone has said something that will result in them, or someone else, being punished. The 'cat' which was being let out of the bag used to refer to the whip (Cat O’ Nine Tails) that was used to punish sailors. 
    • Feeling under the weather’ Rough seas such as those that may happen during a storm would cause people aboard ships to feel unwell. Often they were instructed to go below decks or ‘under the weather’ where the rocking wouldn’t be as bad. Today we use this to describe someone who isn’t feeling well. 
    • ‘Showing your true colours’ Ships at sea would fly a flag or ‘colours’ to identify themselves and the country they belonged to. Sometimes, in an attempt to deceive other ships, they would fly a different flag right up until the last moment where they would ‘show their true colours’. Now we use this saying to describe someone who has revealed their true nature or intentions. 
    • 'Three square meals a day' When used today, this saying describes having three good, nutritious meals a day in order to stay energised and healthy. It comes from the fact that in the Royal Navy, sailors used to have their meals served on square plates. 
    • ‘Whole nine yards’ Today this means to do everything you can to achieve a goal. Some old ships had three masts with three yards of sails on each. Letting every sail out (nine yards) would give them all the power they had.

    Can you investigate some common sayings or words that have a nautical origin?

    Read an Ocean-themed Book

    Can you think of any books you’ve read recently that are about or have had the ocean in them? Would you recommend any of them to a friend? 

    Check out some of these books below!


    Shark Lady: The True Story of How Eugenie Clark Became the Ocean's Most Fearless Scientist


    Somebody Swallowed Stanley: A beautifully illustrated picture book with a powerful message about plastic pollution from environmental expert Sarah Roberts.


    Oceans Explored Series: Take a deep dive into the depths of our blue planet with this stunning book all about the ocean - Earth's largest biome.


    Where's the starfish?: Find the whale, the clownfish and the starfish on every page - until the piles of rubbish start to make it much too difficult


    Beach Clean or Litter-picking

    Why not do your part in making sure plastic and other waste end up in the right place, rather than in our oceans? If you’d like to do this, make sure you’re safe and wear protective gloves. Who else can you get involved?

    You could create a piece of artwork out of some of the plastic you find. Just make sure it’s washed first!

    World Ocean Day activities
    This artwork was made using collected plastic bottle caps.

    Get creative!

    Try writing a poem or short story about the ocean. What about creating a beautiful painting or picture? Many authors, artists and poets have taken inspiration from the beauty of the ocean and its unique setting. 

    World Ocean day is an annual event on the 8th June. Find out about some more activities you can take part in here: 

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    Christine - September 5, 2023

    Thank you! This will really help with my oceans unit!

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