Sharks at Semakau!

There is a rich reef on the northern corner of Pulau Semakau near Pulau Hantu and Pulau Bukom. 

Kelvin gives us a new perspective of the shore from a drone! The survey team saw lots of sharks, giant clams, 'Nemos', tiny sea horse and other amazing marine life. The corals seem to be doing well, but the seagrasses have not recovered.

It's good to know that sharks are alive and well in abundance at Pulau Semakau! Kelvin got lovely drone views of many Black-tipped reef sharks patrolling the reef edge, some in groups. They are probably waiting for the tide to rise so they can rush in to hunt for fishes. The rest of the team even managed to see them from the shore! Check out Che Cheng's video. There are also lots of Blue-spotted fantail rays here, they can go higher up the shore than the sharks, in the shallows during low tide. Kelvin's drone video also captured a stingray (yellow circle) and a shark (blue circle). The shark didn't harass the stingray. It is important to look out for sharks and stingrays and avoid stepping on them, especially during an incoming and outgoing spring tide.

The last time I was at Semakau in May 2023, I saw 14 dead sharks trapped in a net laid at Semakau South near the Barramundi Asia Fish Farm. After I posted about them, the mainstream media immediately carried stories about the incident. Sadly, the sighting of live sharks probably won't lead to similar interest...sigh.

The reef edge facing Terumbu Raya is very rich with many well formed healthy corals, some colonies were large. Including some kinds which are not often seen on our shores. From the team photos, it appears similar to what I saw on our last survey here in Jul 22. It's nice to see many healthy mushroom corals. There doesn't seem to be any coral bleaching.

A collage of photos shared by the team.
Links to their albums below.

The team saw many large leathery soft corals and other soft corals. Doesn't seem like any were bleaching.

The team saw the usual Clown anemonefishes in Giant carpet anemones as well as the Magnificent anemones. And Tammy got gorgeous video of a big mama Tomato clown anemonefish and her bright red papa. These are only found in Bubble tip anemones. The team also saw Frilly anemones, Fire anemones. Marcus spotted a Merten's carpet anemone, could be different from the one Kok Sheng spotted in 2020. Marcus also spotted two of the more rarely seen Leathery sea anemone.

So nice to know that two Fluted giant clams were seen! Kelvin saw one about 15cm long in the middle of the reef flat. While the rest of the team saw a smaller one near the reef edge.

Special finds include a super tiny hairy sea horse by Richard! Marcus spotted a very lively Black frogfish. In deeper water, also Razorfishes. There were also Cushion sea stars and a pair of Orange-spotted nudibranchs close to one another - these nudis eat other nudis, including their own kind...

Che Cheng took great videos of this super large sea hare that Kok Sheng had seen before as well. Like other sea hares, it emits a purplish dye when it is upset. Thanks to Che Cheng, we know it has a yellow foot too. With the recent sightings, I've made new fact sheet for this Wedge sea hare. 

Kelvin's drone overview of the northern shore suggests that long Tape seagrasses have not returned as the shallow long channel along the midshore appear to be mostly bare sand. TeamSeaGrass was also monitoring on the shore at the same time, and reported that the seagrasses have not returned

The team did share sightings of seagrasses nearer the edge, with some long Tape seagrass and other seagrasses.

More about Pulau Semakau

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.

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 2018

Pulau 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.

Photo by Tammy Lim
See her panorama video here.

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 those on the surveys

Kelvin Yong's drone views of sharks


Kelvin Yong's drone overviews


Kelvin Yong's biodiversity sightings


Che Cheng Neo


Richard Kuah


Tammy Lim


Marcus Ng


Tommy Arden