After a heavy downpour, we survey the living shores next to the Landfill at Pulau Semakau South.
The seagrasses seem more lush - with signs of dugong feeding trails! A patch of healthy branching corals are forming, corals seemed to have survived mass coral bleaching. And the field of Horse mussels that infested the area seem to have totally disappeared. Perhaps the closure of the fish farm had something to do with this?
Every time we survey this shore, we check out the Barramundi Group's fish farm that is located very close to natural mangroves, reefs and seagrass meadows there.
Today, the farm seems totally abandoned. The big barge with equipment and supplies, and floating dorm for workers were gone. And cages were falling apart with derelict small boats nearby. During our last survey in
Oct 2023, the farm was not yet in this state of decay. In
Jul 2023, it was reported that Barramundi Group will stop stocking its sites off Pulau Semakau, Pulau Senang and St John’s Island until “an efficacious vaccine is available” against the scale drop disease virus (SDDV). SDDV was first formally described in Singapore farmed fish in 2011 and can kill more than half of the barramundi raised in a cage. The virus has caused “significant mortalities and financial losses” for Barramundi Group's Singapore operations, which recorded a loss of $31.9 million for FY2022.
The rest of the team saw special fishes including a juvenile Batfish and not one but two Frogfish! One appeared to have just swallowed a very large prey. There were also lots of babies (tiny horseshoe crabs, a hermit crab brooding eggs in a shell, many crabs brooding eggs too) and baby making (Noble volute laying egg capsule, sea stars in mating position). As well as many colourful nudibranchs and flatworms. The blue Giant carpet anemone was seen again, and some special corals also spotted.
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Collage of photos by the team.
Links to their albums at the end of this post. |
The seasonal bloom of Sargassum that explodes over the reef edge can make it challenging to survey. But the team find lots of animals among them, many very well camouflaged! Lots of squid, cuttlefish large and tiny. The seaweed is also a great place for their egg capsules. Also animals that look like the seaweed: nudibranchs, fish, flatworms!
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Collage of photos by the team.
Links to their albums at the end of this post. |
On the sand bar near the mouth of the stream, there were signs of the usual sand dwellers -
Olive snails,
Eggwhite moon snails. I saw one
Orange sandstar. Hidden among the Sargassum were
Bigfin reef squid. Sprinkled on the shores were the usual colourful sponges. And the large fields of
Horse mussel clams near the landfill seawall and mouth of the mangrove stream seemed to have disappeared without a trace! During our last survey in
Oct 2023, the field seemed to be expanding. I was also glad to see no nets. Perhaps the closure of the fish farm had something to do with this?
There has never been a lot of hard corals on this shore. We did not have enough low spring tides to check this shore at the height of
mass coral bleaching earlier this year. It was a relief to see that the situation seem similar to our last survey in
Oct 2023. Most of the corals here are boulder shaped corals, including a few large colonies. The ongoing seasonal Sargassum bloom (normal for this time of the year) made it impossible to check the reef edge, but I still saw the usual limited variety of hard corals:
Pore corals,
Anemone corals,
Cauliflower corals and various
Merulinid corals. Most were alright, a few had large recently dead patches.
Today, I noticed a small 'field' of
Branching montipora coral (about 6m x 6m). We first saw small clumps during our last survey in
Oct 2023. Most of the corals in the 'field' were alive and well, with only a few clumps of dead ones. How nice to see them thrive despite the recent mass coral bleaching. Perhaps the closure of the fish farm reduced some of the pressures on corals on this shore?
Other cnidarians can also bleach, so I looked out for those too. It was alarming to come across a clearly distressed
Giant carpet anemone and another that was not very normal, but the many others that I saw were alright. The rest of the team also saw the blue one that we saw on our last survey in
Oct 2023. The few
Leathery soft corals that I saw were alright. As were other anemones, soft corals and corallimorphs.
It seems our shores are past the peak for mass coral bleaching. According to the
NOAA prediction for the Singapore Strait, the bleaching situation for Singapore is at "Watch" now and we are expected to be in the 'blue' in the months ahead.
The seagrass coverage seems denser than what I saw in
Oct 2023. With dense cover of
Spoon seagrass near the Landfill seawall and in the mouth of the stream from the mangroves. Sprinkled with
Needle seagrass and other seagrasses. But the
Tape seagrass I saw remained cropped, with only a few clumps with long leaves towards the reef edge.
I missed them, but Kok Sheng saw some
dugong feeding trails in the seagrasses near the Landfill wall! It seems like the last time this was observed was in
2011.
More about Pulau SemakauIt 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.
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.
What is the fate of Pulau Semakau South?
These shores 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 survey
Loh Kok ShengChe Cheng NeoKelvin YongMarcus NgLoh Kok ShengVincent ChooAdriane LeeEugene TanLonFiora Li
