How many individual reefs are commonly counted within the Great Barrier Reef system?

More than 2,900 individual reefs are commonly counted within the Great Barrier Reef system. These reefs are distributed along Queensland’s northeastern coast across a huge area of shallow and deeper marine habitat.

The count helps explain why the Great Barrier Reef is called a reef system rather than a single reef. Individual formations differ in shape, age, depth and biological communities. Some are close to islands or the mainland, while others stand offshore beyond the continental shelf.

The reef system also includes about 600 continental islands and roughly 300 coral cays, although exact totals can vary with classification and mapping methods. A reef, an island and a coral cay are not interchangeable terms: reefs are submerged or partly submerged structures, while islands and cays rise above sea level.