Last year, coral spawning period was in the middle of COVID lockdown, so we didn't get a glimpse of what happened. Thus it's a relief to know that they Did It again this year.
What is Mass Coral Spawning and why is it a big deal? More below!
This year, mass coral spawning peaked a month after their usual time. More in "Hard coral spawning peaks a month after usual period" by Audrey Tan, Straits Times.
Long-term monitoring of such spawning vital, with oceans warming due to climate change.
Some highlights ...
"The hard coral spawning event over the Labour Day weekend was the second one this year to be documented by researchers at the National Parks Board (NParks).
The first occurred at the end of March, after the full moon folowing the March 20 spring equinox. This is usually the peak spawning season in Singapore.
Dr Karenne Tun of NParks said the recent spawning event could even be considered the main one this year - since the spawning was much more robust this time around.
The reasons for the apparent change in spawning peak this year are less clear.
The peak coral spawning season was last observed to have taken place outside the usual time rame in 2017. At that time, hard corals were still recovering from the longest bleaching on record the year before."
What is Mass Coral spawning?
Once a year, on the fourth month, around four days after the fourth full moon of the year, our corals seed the seas with new life! This year, volunteers went back at the next full moon in May and found more corals were mass 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. 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. 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. 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.
Other marine creatures may also join in and spawn too.
Why is mass coral 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."
MORE photos of Mass Coral Spawning in 2021
Chay Hoon
Video by Jonathan Tan
Chay Hoon checked out mass coral spawning at Raffles Lighthouse on 1 May.
Previous posts about previous coral spawning
- Mass coral spawning 2019
- Mass coral spawning 2018
- Mass coral spawning 2017
- Mass coral spawning 2016
- Orgy in Singapore waters: Mass Coral Spawning 2015
- 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!
