Coral spawning Agincourt Reef 2025

Capturing the amazing and mesmerising natural phenomenon of coral spawning. Right on cue with the sun setting, water temperature and lunar conditions just right, Agincourt Reef set about creating new generations of corals for our reefs. This year is extra special as we’re expecting not one, but two mass coral spawning events on the Great Barrier Reef, with the second expected in mid December, providing an extra boost and resilience for our magnificent reefs. Thanks to Jesse Oberholzer, Indepth Video & Photography, for capturing this spectacular underwater symphony of coral spawning and night life at Quicksilver’s Agincourt Reef pontoon. What is Coral Spawning? While corals have a year-round form of asexual reproduction where coral polyps can divide to become two separate but identical coral polyps, spawning takes place externally with mass fertilisation release into the ocean. You might hear it referred to as Sex on the Reef, or even an upsidedown snow storm! Coral spawning is an annual mass reproductive event where corals release egg and sperm bundles into the ocean for external fertilisation. This phenomenon was first witnessed on the GBR by marine biologists in 1982. It is vital to the Reef’s continual adaptation and long term survival. It usually occurs 2-6 days after the full moon in November or December. For spawning to occur, a variety of factors come in to play. We know the moon cycle and specific water temperatures (greater than 26 degrees celcius) play a role, but also tides, salinity levels and day length can also affect the timing. Spawning usually happens 2 - 3 hours after sunset, which scientists believe is timed to ensure most of the plankton feeders are asleep, creating a greater chance of pollination.