Corals and sea anemones are related to jellyfish. They live fixed to the seabed instead of swimming free.

Above: Staghorns, Plate and Brain Coral

Coral spawning or reproduction is a nocturnal phenomenon that happens annually in late spring or early summer. Colloquially know as "sex on the reef", egg-engorged corals simultaneously release masses of pretty pink eggs and sperm into the sea to become free-floating larvae. While its timing is thought to be related to the water temperature and phases of the moon, it is impossible to predict exactly when it will occur.

Coral's most voracious natural predator is the Crown of Thorns Starfish. Outbreaks of these starfish have been known to strip reefs of nearly all living coral. Fortunately new corals generally re-establish after an outbreak.

Captain James Cook discovered the Great Barrier Reef in 1770. He found it accidentally when his ship ran aground on the reef whilst he was charting the eastern coast of Australia.

His ship, the Endeavour, managed to stay afloat for another week whilst the crew sought desperately for land, eventually sighting the harbour formed by the Endeavour River. The ship was landed on 10 June 1770, and Cook spent almost two months repairing it, thus giving rise to the fledgling township of Cooktown.