Science // Ocean Life

What Is the Ocean?

Know that oceans are huge bodies of salt water that cover most of Earth's surface, and that the ocean is home to an enormous number of living things

Ages: 5 to 7
Type: Concept
Builds on: 0 topics
Leads to: 5 topics

Quick check

If you asked the learner to point to the oceans on a globe, could they show you and explain that most of our planet is covered by salty water where millions of creatures live?

Ask this to see whether the topic is secure.

Topic // Mastery

What mastery looks like

What a learner can do once this topic is secure.

State that oceans cover more of Earth than land does
Explain that ocean water is salty, unlike the fresh water in rivers and lakes
Describe the ocean as home to a huge variety of living things

Topic // Map

Where this fits

What to learn first and what this topic opens up, with the reason for each link. Required links come first.

RequiredMust come first
HelpfulHelps, but not essential

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0 topics

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What Is the Ocean?

Ages 5 to 7 // Concept

Leads to

5 topics

Ocean Depth ZonesRequired
Ocean Life // Ages 7 to 9
Ocean zones require knowing the ocean is deep and vast
The Five OceansRequired
Ocean Life // Ages 7 to 9
Naming five oceans requires knowing what oceans are
Tides, Waves & CurrentsRequired
Ocean Life // Ages 7 to 9
Tides/waves/currents require basic ocean knowledge
The Ocean FloorRequired
Ocean Life // Ages 7 to 9
Ocean floor concept requires knowing the ocean is vast and deep
What Ocean Animals NeedHelpful
Ocean Life // Ages 5 to 7
Ocean animal needs are contextualised by knowing what the ocean is

Topic // Research-informed

Teaching notes

From the Marble Skill Taxonomy. These notes have not been validated in classrooms, so treat them as a starting point for your own judgement.

The approach

For ages 5–7, build awareness and wonder that the ocean is a huge body of salty water covering most of Earth's surface and home to an enormous variety of living things. Core moves: let children SEE on a globe/world map that there is more blue (ocean) than green (land); anchor 'salty' to sensory memory and contrast with the fresh water of taps, rivers and lakes; and reveal the teeming life beneath the surface. Keep quantities qualitative ('most', 'huge') at this age.

Common misconceptions

'There's more land than sea' — the ocean covers most of Earth (about 71%).
'Ocean water is like the water we drink' — it is salty and unsafe to drink, unlike fresh river/lake/tap water.
'The sea is just a big puddle / empty water' — it is vast, deep, and full of more life than land.
'Seas and oceans are totally separate pools' — the ocean is really one connected body of water around the world.
'Only fish live in the ocean' — mammals, invertebrates, plants/algae and countless others live there too.

Useful representations

A globe/world map with ocean vs land clearly contrasted (blue dominating green).
A salt-vs-fresh water pairing (sea beside a river/tap) with a 'don't drink me' salt cue.
A cutaway 'peek beneath the surface' teeming with varied sea life.
A simple size comparison: how much of Earth is ocean vs land.

Teaching practices

Use a globe or blue-marble image so 'covers most of Earth' is a seen fact (more blue than green), not a told one.
Anchor 'salty' to sensory memory — seawater tastes salty and can't be drunk — and contrast with the fresh water of taps, rivers and lakes so salt vs fresh is concrete.
Lead with wonder and variety (the ocean is stuffed with living things) to motivate the whole domain, not just facts about water.
Distinguish 'sea/ocean' from other water children know (puddles, pools, ponds, rivers) by size and saltiness.

Activities to try

1
Meet the ocean: globe reveal, salt flap, and dive-in
Why it works: Our planet's surface is mostly ocean; ocean water is salty (unlike the fresh water we drink); and the ocean is home to a huge variety of living things.
1. Look at a globe or world map and point to the blue parts (water) and the land parts (often green or brown — check the map's colours); say out loud which there is more of.
2. Lift a flap or reveal panel on the water to meet the question 'Why can't you drink it?' and hear the salt fact, with a river or tap pictured alongside for contrast.
3. 'Dive in' beneath the waves (turn a page, open an underwater scene, or tap a drill-down panel) to discover a world packed with creatures of many shapes and sizes — whales, fish, crabs, jellyfish, seahorses.
2
Paint the globe / sort the water (hands-on scaffold)
Why it works: 'Most of Earth is ocean' and 'salty vs fresh' become felt through doing, not just seen.
1. Paint or place blue tiles over the water parts of a world outline and green over the land, then look at how much more blue there is.
2. Sort pictures or labels of water sources into two groups: salty (the sea/ocean) and fresh (river, lake, tap).
3
Talk it through: how is the ocean different from a lake?
Why it works: The ocean is distinguished from familiar water (puddles, pools, ponds, rivers, lakes) by its saltiness and its vast, connected scale — and both facts can be held at once.
1. Respond to: 'A lake is big too. Name one thing that makes the OCEAN different from a big lake.' (Looking for salt and/or vast scale.)
2. Decide and explain: 'Is there just one ocean or lots of separate ones — what do you think?' then look at a globe to see the water is really one connected body wrapping the planet.
3. Answer the challenge: 'Someone says the ocean is just a really big lake, the water is the same as a river, and there's more land than ocean. Are they right? Tell me one way ocean water is different, and whether land or ocean covers more of Earth.'

Science // Ocean Life