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 2012.
Brain corals, one of the corals that started spawning early.
Photo by Karenne Tun
Karenne shares that "It appears that Symphyllia does not release egg/sperm bundles but eggs and sperm en masse. Each tiny visible speck would be a single egg and the cloudy soup the specks are swimming around in, they would be sperm."
Karenne comments that "Favites is one faviid that has really amazing setting stage. The egg/sperm bundles slowly rise and congregate just below the oral cavity. Just before the bundles are released, the entire colony looks like a heavily swollen pink mass."
Although mass coral spawning occurs worldwide, it is especially meaningful in the Singapore context.
Dr James Guest, a coral reef research fellow at the Nanyang Technological University, said that in addition to the high sedimentation caused by development, reefs here are greatly impacted by high seaweed growth, thought to be detrimental to coral life.
Yet, past spawning events have shown that the corals here are 'capable of replenishing themselves', he said.
Furthermore, there is another reason to keep a close watch on the corals this year: to see how the reefs have recovered from the mass coral bleaching of 2010, when unusually warm ocean temperatures ravaged reefs around the world, including those off Singapore's coast.
Ms Karenne Tun, a PhD candidate at NUS, whose research is related to coral reef management, noted that the coral spawning last year was 'rather muted'.
She is one of the eight divers who will be going underwater this week to observe the event.
Ms Tun said: 'This year will be important to see if the corals have fully recovered from the bleaching by assessing the magnitude of the spawning.'
So far, of the 255 coral species recorded in Singapore, only 69 have been documented to release their reproductive cells this time of the year.
This is because many coral species in Singapore are rare, and some complete spawning very quickly, so 'trying to catch them in the act is very difficult', said Dr Guest.
The marine biologist, who is not taking part in this week's dive, said he will use the available data here to publish a 10-year data set on Singapore's reefs. In doing so, he hopes others will use the information to better manage Singapore's reef ecosystem.
So it's a huge relief that our corals have spawned again this year!
