When we last surveyed in
Jul 2024, the shore was impacted by
mass coral bleaching. We estimate 50% of hard corals and 70% of leathery soft corals were bleaching. Today, it was such a relief to see that the shore was NOT dotted with white. Most of the corals were okay and the reef seems have recovered to its usual vibrant self.
The team found 4 Giant clams, encountered shark and snakes as well as many other interesting marine life.
Kok Sheng and some of the team thoroughly surveyed the reef edge. As in the past, they found it densely covered in corals, with large well formed colonies of
Galaxy coral,
Anemone corals,
Anchor corals. There were many clusters of
Mushroom corals of all kinds. Kok Sheng also saw the
Pearl bubble coral which we seldom see, usually only on Semakau and nearby submerged reefs.
 |
Collage of photos by Loh Kok Sheng and the team.
Links to their albums at the end of the post. |
I surveyed the pools at the mid-water mark. The corals seem to be returning to what I saw in
Jul 2023, the year before mass coral bleaching. The scattered patches of
Branching montipora corals near the Landfill seawall are mostly alive and seems like they might eventually form a dense 'field'. I first noticed them in
Feb 2019. Similarly, today I noticed many clusters of
Galaxy coral in the pools in the mid-water mark, perhaps also about to form dense fields like those seen on the reef edge. There were also several large colonies of
Anemone corals,
Lettuce corals,
Anchor corals. All seemed fine. Some of the
Brain corals were rather pale though.
As in the past, the shore is dominated by large colonies of
Leathery soft corals of various kinds. While in
Jun 2024, many were stressed or even dying, today I only saw a small cluster that were pale. The rest seem alright. There remained many
Asparagus flowery soft corals with some Spiky flowery soft corals. In
Jun 2024, about half were pale or bleaching, today I only saw a few that were oddly coloured or pale. I also saw a pale corallimorph and some pale zoanthids. But most of the zoanthids were alright.
This shore has always been full of clams! Today, the team found 4
Fluted giant clams! Kelvin found 3 and Kok Sheng 1! Kelvin also found a big dead one.
 |
Collage of photos by Kelvin Yong and Loh Kok Sheng.
Links to their albums at the end of the post. |
As usual, the rest of the team make all the special finds. Cushion star and Tiger cowrie! Also two Banded file snakes (which are often seen on Pulau Semakau because of the proximity of mangroves). As well as octopus, nudibranchs and their egg ribbons.
 |
Collage of photos by the team.
Links to their albums at the end of the post. |
In the large shallow pool left behind at low tide, there was a small shy Black-tipped reef shark. It absolutely did not try to bite any of us as we quietly waded through the water. It did bump into a few of us, but immediately turned around. Here's Kelvin's video of the graceful animal.
The huge clusters of
Magnificent anemones continue to dominate the shore, from the reef edge to the mid-water mark! They were not affected by mass coral bleaching and look even more numerous today.
The rest of the team also saw
Bubble tip anemones,
Pizza anemones. As well as the usual commonly seen
Giant carpet anemones (some with 'Nemo'),
Haddon's carpet anemone,
Frilly anemone,
Fire anemone. Kok Sheng saw three
Leathery sea anemones - which we seldom encounter. All seemed alright.
 |
Collage of photos by the team.
Links to their albums at the end of the post. |
Since we started surveying, there has never been a lot of seagrass on this part of Pulau Semakau. The situation is simliar to what I saw in
Jul 2023, Many small clumps of
Tape seagrass scattered everywhere on the shore from the seawall to the reef edge. Those growing near the reef edge had long leaf blades (about 40cm), but those growing nearer the high shore remains cropped short. But I was relieved the bloom of
cyanobacteria - clumps of fine black hairy organisms, covering a large area near the seawall we saw in
Jul 2024 is no longer there.
More about Pulau SemakauJust as Changi Airport and Changi Beach are not the same even though they are near one another and share a name, Pulau Semakau is NOT the same as the Semakau Landfill. The Landfill was created by destroying all of Pulau Saking, and about half of the original Pulau Semakau by building a very long seawall. Fortunately, the landfill was constructed and is managed in such a way that some of the original mangroves, seagrass meadows and reefs on Pulau Semakau were allowed to remain. It is NOT true that the construction of the Landfill created the marine life found on Pulau Semakau. The marine life was there long before the Landfill was built.
Long ago, two sections of mangroves were replanted behind shorter seawalls to compensate for the loss of original mangroves on Pulau Semakau due to the construction of the Landfill . Today, I had a look at eastern section, walking along outside the seawall. I noticed many other species have settled naturally among the planted mangroves - a monoculture of
Bakau Pasir. On the edge of the seawall were large and small trees of
Api-api species. There were also different species of Bakau. But I didn't see anything special that would make me climb the wall. I saw a far more diverse array of mangroves that settled naturally on the Pulau Hantu seawall earlier in
Jun 2025. Including the rare and Critically Endangered
Nyireh laut. I wonder why?
Here's a view of the shore we surveyed. This was taken on our
Jul 2023 survey when
Kelvin flew the drone and gave us awesome new perspectives!
What is the fate of Pulau Semakau (East)?Pulau Semakau (East), Terumbu Semakau and even Pulau Jong and Pulau Sebarok are slated for massive reclamation outlined recently in the
Long-Term Plan Review.
The Singapore Blue Plan 2018Pulau Semakau and nearby islands and submerged reefs have been recommended by the Singapore Blue Plan 2018 for Immediate Conservation Priority. The Blue Plan recommends the intertidal and subtidal marine areas of Pulau Semakau and adjacent Pulau Hantu, and Pulau Jong to be designated Marine Reserve.
The Blue Plan highlights that Pulau Semakau and its associated patch reefs comprise many ecosystems: coral reefs, mangrove areas, intertidal sandflats, seagrass meadows, and coral reefs. The subtidal area of Pulau Jong is larger than the terrestrial area.
Pulau Hantu is a popular dive site has seen increasing interest in the past decade due to biodiversity awareness. If protection is accorded to these three islands, zonation plans for use can be implemented to manage tourism and human impacts.
DOWNLOAD the Plan, SUPPORT the Plan! More on the
Singapore Blue Plan 2018 site.
Photos by others on this surveyLoh Kok ShengKelvin YongChe Cheng NeoRichard KuahMathias LukAdriane LeeTommy TanLonOthers on this survey: Jayden.
