MASS SYNCHRONISED CORAL SPAWNING ON THE GREAT BARRIER REEF

One of the most spectacular events to occur on the Great Barrier Reef is the annual synchronised spawning of corals.

This mass reproduction only happens once a year. It involves different species of coral simultaneously releasing tiny egg and sperm bundles into the water.

By expelling the eggs and sperm at the same time, the coral increases the likelihood that fertilisation will take place.

The mass spawning occurs after a full moon and only after rising water temperatures have stimulated the maturation of the gametes.

The spawning lasts between a few days and a week. The phenomenon — which only happens at night — resembles an underwater snowstorm. But rather than being all white, there are also clouds of red, yellow and orange. All the bundles rise slowly to the surface where the process of fertilisation begins.

While spawning takes place on a large scale, it doesn’t happen across the entire Reef all at once.

Instead, the time of year that corals spawn depends on their location. Those on inshore reefs usually start spawning one to six nights after the first full moon in October, whereas those in outer reefs spawn during November or December.

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For more info check out the Great Barrier Reef Marine Park Authority website