22 April 2019

Return to Sentosa Serapong after mass dying

We return to Sentosa Serapong for the first predawn trip of the year. On our last survey in Jun 2018, there was mass dying on this shore. With a heavy smell of death (like a badly run fish market) as we saw large corals and sponges that were bleaching, or had dying, rotting tissue.
Today, we didn't see any bleaching or dying corals. While the leathery soft coral garden seems to be doing well near the beacon, and the area nearer the old jetty seemed mostly alright, we didn't see as much live coral in the area facing the spillway. We saw familiar favourites like the red feather stars in abundance, also the Fluted giant clam. There were also many anemonefishes in almost every large anemone. So we can still hope for this shore to return to its full glory!

Here's a brief video clip of what I saw, including a Giant carpet anemone and Magnificent anemones, many with small anemonefishes.
Living shores of Sentosa Serapong, Apr 2019
The area near the beacon is like an underwater garden with pastel blooms of a variety of leathery soft corals.
Leathery soft coral (Family Alcyoniidae)
The area in front of the spillway was covered in dense growths of Sargassum seaweed. The tide was also a little high. So I didn't see much hard corals. Let's hope this doesn't mean that the profuse growths of corals last seen here is merely hidden and isn't completely wiped out. We can only be sure by visiting again.
Sargassum seaweed (Sargassum sp.)
The Boulder pore corals were doing poorly on our last survey in Jun 2018, and today I didn't see many. Some were alright, others were pale or yellowing and pinkish - a sign of stress? I also saw several large colonies of Anemone corals that seemed alright, although one was rather pale. Some of the plate corals had pinkish portions.
There was a wide variety of leathery soft corals and flowery soft corals. All seemed to be doing alright. The large leathery soft coral is still there, though somewhat submerged as the tide wasn't very low.
I was glad to come across one small colony of Acropora coral (not sure if green is a healthy colour though). I saw a few small Cauliflower corals, one large colony of Sandpaper coral and some clumps of Branching montipora coral. There were also some small Disk corals. All were not bleaching. The large colonies of Ridged montipora corals capped by Red feather stars are still there.
Jianlin saw a large patch of Acropora!
It was great to see many colourful Anemone corals, one large happy Galaxy coral, some encrusting Montipora coral and some Merulinid corals that were not bleaching. I saw one Lettuce coral, but didn't see any Carnation coral, Anchor coral, Trumpet coral and Brain coral like I did on our last survey.
I saw a few small Barrel sponges that were alright. During our last survey in Jun 2018, almost all the large Barrel sponges here were turning brownish and grey and appear to be disintegrating.
Abel saw a large Barrel sponge that seems alright. Hurray!
It was great to see a small Fluted giant clam. It looks like the same one we saw rolling about in the waves in the same area during our last survey in Jun 2018.
Fluted giant clam (Tridacna squamosa)
There are still some sprinkles of Spoon seagrass (with small leaf blades) near the old jetty, some Sickle seagrass near the beacon. Also a small clump of Tape seagrass, alas, badly cropped short. It had female flowers and long leaves on our last survey in Jun 2018.
The rest of the team saw amazing nudibranchs, cowries, conch snails and more! Like this small sea star found by Abel.
Jianlin and the rest of the team also saw the Slender Ceratosoma nudibranch that we often encounter here.
It still remains a mystery to us what has caused the mass dying here last year, but it appears to be limited to the Serapong shore. We didn't see anything this drastic during our surveys of reefs elsewhere since then.

Let's hope this shore recovers soon from whatever is affecting the corals.

Thanks to Shao Wei and friends of Sentosa Development Corp and Sheila of Serapong Golf Course for arranging our survey this morning.

Posts by others on this trip

Abel Yeo


Jianlin Liu


Liz Lim


Chris Wong


Meanwhile, Richard Kuah checked out Coney Island