Coral Spawning 2011 – Great Barrier Reef

We are now in the final countdown for the Great Barrier Reef’s Coral Spawning 2011. Like any natural phenomena, an exact date is hard to pinpoint with total accuracy, but at this stage, the best guess is that will take place sometime around 14 – 15 – 16 November 2011.

Cairns offers a number of coral spawning 2011 dive trips, enabling you to witness and submerge yourself in this annual event, ranging from Cairns liveaboard trips to night trips. Be prepared to be flexible and patient though, Mother Nature does not run by our timetable.

So what is coral spawning? Basically, once a year for an intense period over a couple of days, the Great Barrier Reef conducts its annual reproduction, this is known as coral spawning and is when all of the corals release their eggs and materials into the water.

Predicting exact dates for coral spawning are difficult, but there are a few indicators which help to provide date guidelines and parameters. Basically, coral spawning is most likely to occur at night (over a few nights) shortly thereafter a full moon in October or November. The factors to look for are as follows:

1. Water Temperature. Corals will start to prepare to spawn when the water temperature starts to warm up, generally it needs to be around 27 degree Celsius for spawning to occur.
2. The Moon. This may seem strange, but the corals will synchronise their spawning around the moon cycles. Why? A few days after a full moon is when the tidal currents are at their gentlest, this is when the corals will release their eggs and sperm as it provides the greatest chance for them to mix in the waters, rather than getting washed away.
3. Time of Day. Coral spawning always occurs at night. You will not see any mass spawning during the day.

Coral spawning 2011 will be a mass event, with most of the Great Barrier Reef corals releasing their gametes (sperm and eggs) into the water at the same time. Why is this? Basically, it increases the chances of successful reproduction. Predators can only consume so much of the material – the rest will survive and help to create new corals. If the coral spawned individually, chances are the fish would consume it all and success would be limited.

Interesting Fact: 75% of the Great Barrier Reef’s 400 different types of corals have both male and female parts, but they are not able to self-fertilise. By releasing bundles of sperm and eggs during coral spawning, when the waters are relatively calm (see above on moon cycles) the gametes mingle and fertilise.

Great Barrier Reef Coral Spawning 2011 will probably last around a week. In the past, these events have created a large ‘wash’ that appears on the waters’ surface: this is known as a spawning slick and can sometimes be seen from space.

The Great Barrier Reef coral spawning phenomena was first witnessed by researchers back in 1981, since then it has become a ‘must do’ experience for scuba divers and documentary makers from around the world.

Cairns Dive Adventures is excited to be reviewing Coral Spawning 2011 and will post pictures and videos on this site. Also, once final details are revealed of dates and trips, we will also post these details on the site.