A small team returns to this submerged reef lies right next to Singapore's only landfill and near the petrochemical plants on Pulau Bukom, and less than an hour away from the Central Business District.
We return to check on the impact of
mass coral bleaching here. We estimate only about 10% of hard and soft corals were bleaching. The big anemones and other cnidarians were fine. The seagrass situation seems unchanged, and the rest of the team saw two Giant clams and a snake!
The rest of the team found two Fluted giant clams. One large one (42cm) near the reef edge, another smaller one higher up on the shore. Lon spotted a
File snake - those on and near Pulau Semakau are often seen covered with bright green algae! A
Snake eel was also spotted (we know it's a fish because of the little fins near the head). A large cushion star and many other colourful marine life were also seen.
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Collage of photos by the team.
Links to their albums below. |
There were many Diadema sea urchins on the reef edge, with small fishes swimming near them. I also saw nudibranchs, crabs, flatworms and an octopus.
There were many healthy branching colonies like Pocillopora, Acropora, Montipora. Also crinkly colonies like Psammocora, Pavona, Pectinia. Only a few were still bleaching or had large dead portions.
The big colony of Galaxy corals opposite the landfill seawall is still alive - though rather pale. I saw two healthy colonies of Anchor corals, many healthy mushroom corals of various kinds. Most of the plate-forming corals and Goniopora corals I saw were alright. Most Brain corals I saw were a little pale or yellowish but not outright bleaching.
There were still many medium to large colonies of
leathery soft corals of various kinds. Only about 10% were outright bleaching or showing signs of stress (melting, more yellowish than usual). There were also still a lot of
Asparagus flowery soft corals - most were yellowish but I didn't see any that were bleaching.
Other cnidarians can also bleach, so I looked out for those too.
Magnificent anemones remain abundant and I didn't see any that were bleaching.
Bubble-tip anemones are often the first to bleach and I saw one. I also saw some
Giant carpet anemones, many
Button zoanthids,
Sea mat zoanthids,
Leathery sea fan,
corallimorphs and
Xenia soft corals all were alright.
There is still some bleaching on Pulau Semakau (East) just opposite Terumbu Semakau. In our survey there
last month, we estimate 50% of hard corals and 70% of leathery soft corals were bleaching.
The
NOAA prediction for the Singapore Strait seems to suggest that sea temperatures will ease in the weeks ahead. Let's hope we have indeed passed the peak of mass coral bleaching and that our reefs will start to recover.
The seagrass situation seems not much worse but not much better. I saw similar situations in
Apr 2024 and
May 2023 and every annual survey since
May 2019. Although heavily covered with epiphytes, there was good cover of
Spoon seagrasses in many of the pools. There were many clumps of
Tape seagrass with longish leaf blades (about 40-50cm) especially those growing nearer the reef edge. But most elsewhere were still short (about 10-20cm).
More about Terumbu SemakauTerumbu Semakau lies next to the Semakau Landfill and close to the petrochemical plants on Pulau Bukom.
Just 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 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.
What is the fate of Terumbu Semakau?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 the survey
Liz LimLonRichard KuahTammy LimTommy Tan
