Alex Mustard - The Great Spawn

For 364 days of the year, corals do a very good impression of a rock. But on one magical night they explode into effervescent life.



Most species of reef corals spawn synchronously in a massive release of gametes that gives the best chance of successful fertilization and overwhelms any potential predators on their eggs. But for the photographer this offers a tiny window to have your camera pointed at the right place at the right time. The star coral in this photo releases all its gamete bundles (the tiny balls of eggs and sperm) in about 10 seconds. That is ten seconds in a whole year. Oh and it happens late, late at night. Underwater, obviously.



Fortunately the event is predictable, to a degree. Success depends on your ability to decipher the combination of the annual cycle of temperature, the (lunar) monthly cycle of tides and the daily cycles of light. You make your call and then jump in the water to time your night dive to overlap the spawn. Scuba air tanks don’t last forever, so there is always a gamble involved. But when you do get it all right, it is a thrilling spectacle to experience.

Location: Cayman Islands, Caribbean Sea.