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Coral
Spawning
A Spectacular Dive Experience
One of the more spectacular, but rarely witnessed, events taking place
on the Great Barrier Reef is the mass spawning of Coral.
Only a couple of nights each year:
Taking place at very specific evenings in November and December, great
numbers of coral colonies synchronize the broadcast of packets of eggs
and sperm, which mingle in the open ocean to produce their young.
Described by scuba divers as something like an underwater snowstorm, these
millions upon millions of packets of reproductive cells can form great
pink and white clouds underwater, and are seen as pink slicks on the water
the next day.
It is thought that this synchronized spawning increases the chances of
eggs being fertilized, and overwhelms the many organisms that prey on
coral eggs and larvae. There are so many in the water that there is no
way that all can be eaten.
Tides, Ocean Temperatures, Day Length are factors:
Somehow, all the corals on a reef synchronize the timing of their spawning.
The main cues seem to be ocean temperatures, the lunar cycle, and tides.
Rising early summer ocean temperatures trigger the formation and development
of sperm and eggs. The ideal time to release them is a few days after
the great tide differences caused by the full moon, when tides and ocean
currents caused by them are lower. Whether it’s the brightness of
light, length of day or tidal conditions that corals are using as cues
to time their reproduction is still not clearly understood.
Plan Ahead:
Want to get in the water and witness coral spawning? The predicted
spawning dates for coral spawning in the Northern Half of the Great
Barrier Reef are:
| 2007 | Nov.28-30 on the Local, Ribbon, and Far Northern Reefs
Dec
28-30 on Osprey and Coral Sea Reefs |
| 2008 | Nov. 17-19 on the Local, Ribbon, and Far Northern Reefs
Dec.
17-19 on Osprey and Coral Sea Reefs |
| 2009 | Dec. 6-8 on the Local, Ribbon, and Far Northern Reefs, Osprey
and Coral Sea Reefs |
The dates above are your best bets to planning your dive trip. Keep in
mind that variation in ocean temperatures, currents, and other factors
can disrupt this event, usually causing the spawning events to be a lunar
cycle (28 days) earlier or later, or cause them to be less dramatic. There
are no guarantees when you work with Mother Nature! The mass-spawning
corals on the Great Barrier Reef spawn at night, so you will want to book
an overnight trip.
Most dive operators are well aware of this event, and will have their
staff diving during the nights where coral might be spawning, and be communicating
with other boats on the reef to time your night dive to maximize your
chances of witnessing this event at it’s peak.
One dive operator, Undersea Explorer offers special itineraries that
focus on coral spawning. Their trips are listed in the table on your right.
However, any overnight trip onto the reef during the coral spawning dates
will give you this opportunity, you can search our index for them at this
link: Dive Trip Search Page
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| Coral
Spawning
Dive Trips |
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