Natures Marvel: Coral Spawning 2022

It’s time to dive below the surface and experience the wonders of the annual coral spawning event on the Great Barrier Reef!

What is coral spawning?

Coral mass spawning is an annual natural phenomenon where multiple species of corals synchronise the release of sperm and eggs over several days following the full moon (Australian Institute of Marine Science or AIMS). During spawning, the coral sperm, and eggs float to the surface of the ocean, fertilise and then develop into larvae. The larvae eventually settle on the reef, creating new coral colonies and continuing to grow and expand into reef systems. The spawning and larval phase of corals is a key event for the production of future coral generations and the replenishment of coral ecosystems (AIMS).

On the Great Barrier Reef, spawning usually occurs after the full moon in October and November and can occur between one and three times annually. The spawning event also depends on a number of factors including water temperature, location, and tides. On the Great Barrier Reef, inshore reefs typically spawn in October, while outer reefs spawn during November or December (Great Barrier Reef Foundation or GBRF).


Image Credit: Jeremy Somerville (@jeremysomphoto)

Where can I see it on Lady Elliot Island?

On Lady Elliot Island for the last three years, spawning has first been noticed in the brain corals located in the lagoon, often around the fish pool after around 3pm. As you can see in the image with master reef guide Jess, the water becomes somewhat murky around the spawning site as sperm is released into the water. Image two shows a close up of the egg bundles leaving the brain coral and moving into the surrounding water. Later in the day, we begin to see the Acropora or branching corals commence spawning in the lagoon (this is visible from the reef walking pathway).  Over the last few years, this has commenced from 7:00pm onwards, but again, this varies each year depending on tides, water temperature and location (pictured below).

Image Credit: Jessica Blackmore (@master_reef_guide_jess)

When are we expecting to see the spawning on Lady Elliot Island?

Each year spawning begins around late October, with the peak event expected following the first full moon in November which falls on the 8th. Spawning is generally predicted to occur between 2-6 days following this full moon. This year, we expect to see spawning occurring between the 11th and 14th of November on Lady Elliot Island.

Image Credit: Jack McKee (@jackmckee_uwphotography)

Information from the Australian Institute of Marine Science and the Great Barrier Reef Foundation.