Rottnest Island Coral Reefs
Rottnest Island sits just offshore from the city of Perth, in Western Australia. A protected nature reserve that tells the story of sea-level change over the last 140.000 years — when the sea was both higher and lower. Most of the island is Tamala Limestone, formed from coastal wind-blown sand dunes that built up when sea level was 130 metres below today’s level. With the extensive reefs surrounding the island, many tropical species of coral and fish can be found along its 20 secluded bays. The reason Rottnest’s unique coral reefs form is because of the Leeuwin Current, making Rottnest home to the most southern outcrop of tropical coral. The Leeuwin Current brings warm water and coral spawn from tropical areas down the Australian coast, creating warmer temperatures which are suitable for the spawn to settle and build coral reefs.