Play Tiny Reef Builder Game
Chapter 1

The architecture of the reef

Chapter 2

The bustling underwater metropolis

Chapter 3

First Nations custodianship

Chapter 4

The modern battle for survival

Ch 1 · The architecture of the reef
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matilda Single-celled zooxanthellae algae form a vital partnership inside living coral tissues

57m ago

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matilda How coral polyps construct massive ocean reefs.

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Tiny Reef Builder
BETA

matilda Place diverse coral species to learn how tiny polyps build the Great Barrier Reef.

58m ago

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The tiny builders of the giant structure

matilda Coral polyps, which are related to sea anemones, extract calcium carbonate from the ocean to build connected, protective shells over thousands of years.

59m ago

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Quiz

The Great Barrier Reef is composed of how many individual reefs and islands?

59m ago

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Quiz

What tiny, soft-bodied organisms are responsible for building the hard, limestone structures of the Great Barrier Reef?

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The greatest structures are built from the accumulation of tiny, unseen efforts.

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The perfect underwater partnership

matilda Zooxanthellae algae trade essential nutrients for a safe home inside Great Barrier Reef corals.

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Quiz

What are zooxanthellae, the vital partners that live inside coral tissues?

59m ago

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Quiz

What percentage of a coral's energy needs can be met by its symbiotic algae partners through photosynthesis?

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Fun Fact

Reef space visibility: The Great Barrier Reef is so massive that astronauts can easily see its outlines from the International Space Station.

59m ago

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Quiz

During which months does the spectacular mass coral spawning typically occur on the Great Barrier Reef?

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Quiz

Which celestial body triggers the annual mass spawning event of the Great Barrier Reef?

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Glossary
coral polyp (noun)
A tiny, soft-bodied marine invertebrate that secretes a calcium carbonate skeleton to form reefs. These tiny organisms built the vast 2,300-kilometer-long marine system off Queensland's coast.

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Quiz

In which body of water off the coast of Queensland, Australia, is the Great Barrier Reef located?

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Quiz

The Great Barrier Reef is roughly comparable in total land area to which of the following countries?

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Gossip

Which reef phenomenon would you most want to see in person?

59m ago