Orgy in Singapore waters: Mass Coral Spawning 2015

Singapore's corals are alive and well and very sexy too. Their annual orgy of explosive sex just happened!

New life explodes out of our corals!
Photo by Karenne Tun on facebook.

Once a year, on the fourth month, about four days after the full moon, our corals seed the seas with new life! Thanks to the dedicated team who have been keeping an eye on this event every year, we get a glimpse of what happened in 2015.

What is Mass Coral spawning?

Some corals release their eggs and sperm all the same time. Called broadcast spawners, these mass spawning events usually occur once a year, a few nights after full moon. Tiny packets of eggs and sperm pop out of the coral polyps.

Packets of eggs and sperm inside a coral polyp, about to pop out.
Photo by Karenne Tun on facebook

These packets drift to the water surface where they open up, releasing the eggs and sperm for fertilization. After a few days, the embryos will have developed into coral larvae that drift about and eventually settle down on a hard surface to form new corals.

The packets of eggs and sperm then pop out and float to the surface.
Photo by Toh Chay Hoon on facebook

While bazillions of eggs and sperms are released during a mass spawn, most don't make it. Hordes of marine creatures gorge on the spawn, from fishes and crabs to jellyfishes. As the tiny coral larvae develop, they have to survive the countless predators that constantly sieve the water for plankton and edible bits.

Some of the colourful reef fishes seen munching
on the coral spawn.
Photo by Koh Kwan Siong on facebook.

The coral larvae also have to overcome many other challenges that we are still learning about. Excessive sedimentation, for example, can interfere with fertilisation and other aspects of coral larvae survival and successful settlement.

Besides corals, other sea creatures also spawn!

This year, large sea anemones were also see releasing sperm and eggs from the mouth. Like a smoking volcano!

Photo by Koh Kwan Siong on facebook

As usual, there is lots to see during the dive besides just corals spawning. Including some stunning reefscapes. Singapore's corals are alive and well and very sexy too.

Photo by Toh Chay Hoon on facebook.

Why is coral mass spawning in Singapore a big deal?

From Sex in the Tropics 2008 on the blooooooooooo blog

Coral mass spawning in Singapore was first recorded by Dr James Guest in 2002. It was the first record of coral spawning in the tropics. At least 18 different coral species from ten genera and five families (Acroporidae, Faviidae, Merulinidae, Oculinidae and Pectiniidae) have been observed to spawn in our waters! Mass spawning occurs on the third to fifth nights after the full moon between 8 and 10 p.m.

In interviews with the media, Dr James Guest emphasised that corals are part of Singapore's biodiversity and natural heritage. "There are 255 species of corals recorded here, and there may be some corals here that were around before Stamford Raffles arrived."

The fact that our corals mass spawn shows that our reefs are functioning well! According to Dr James, the number of coral species in Singapore that mass spawn is "as high as on other Indo-Pacific reefs, like the Great Barrier Reef... " This shows how rich Singapore's natural heritage is. We can find right at our doorstep: "diverse, functional and fascinating coral reefs, that people would normally associate only with countries like Australia."

Some observations on Mass Coral Spawning in 2015

Dr Karenne Tun shared on facebook: "On a more serious note, the 2015 Mass Coral spawning event was not as vibrant as the 2010 event, which was one of the best spawning observed in Singapore. Will need to crunch some data to see how the 2015 event compared to those from 2011 to 2014, but our preliminary assessment is that the mild coral bleaching events in 2013 and 2014 following the massive event in 2010 may have had a direct impact on the reproductive capacity of the corals over the last 5 years."

MORE Photos and stories of mass coral spawning in 2015

• Karenne Tun on facebook
• Koh Kwan Siong on facebook: Night 1, Night 2, Night 3.
• Toh Chay Hoon on facebook.

Previous posts about previous coral spawning

• Mass coral spawning 2014
• Orgy in the Sea: Mass coral spawning 2012!
• A spawn of articles on coral spawning in Singapore!
• Orgy on our reefs: Coral spawning 2011
• Sex in the Sea: Singapore style
• Spawn of coral on video!