Australia’s Great Barrier Reef is associated with more than 900 islands.
These islands are not all the same type. Some are continental islands, which are fragments of land separated from the mainland, while others are low coral cays built from reef material, sand and accumulated biological debris. Their landscapes range from forested hills to small, sandy nesting sites.
The island count can vary depending on the definition used and whether tiny cays and permanently exposed features are included. That is why descriptions often use “over 900” rather than presenting a single exact total.
The islands are also distinct from the reef structures themselves. A reef may surround an island, sit offshore as a platform, or form a narrow barrier without any permanent land above sea level. This variety helps explain the region’s exceptionally diverse coastal habitats.