The architecture of the reef
The bustling underwater metropolis
First Nations custodianship
The modern battle for survival
matilda Single-celled zooxanthellae algae form a vital partnership inside living coral tissues

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

matilda Coral polyps, which are related to sea anemones, extract calcium carbonate from the ocean to build connected, protective shells over thousands of years.
What tiny, soft-bodied organisms are responsible for building the hard, limestone structures of the Great Barrier Reef?

matilda Zooxanthellae algae trade essential nutrients for a safe home inside Great Barrier Reef corals.
What percentage of a coral's energy needs can be met by its symbiotic algae partners through photosynthesis?
Reef space visibility: The Great Barrier Reef is so massive that astronauts can easily see its outlines from the International Space Station.
During which months does the spectacular mass coral spawning typically occur on the Great Barrier Reef?
Which celestial body triggers the annual mass spawning event of the Great Barrier Reef?
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.
In which body of water off the coast of Queensland, Australia, is the Great Barrier Reef located?
The Great Barrier Reef is roughly comparable in total land area to which of the following countries?
