Giant clam overdose on Terumbu Pempang Laut

This humungous submerged reef lies next to Jurong Island and major shipping lanes. And yet, it has seagrass meadows, corals and lots and lots of Giant clams.

Today, we also saw lots of dugong feeding trails, special anemones and the usual colourful marine life. The corals seem alright, and seagrasses remain the same.

Today, we saw the most number of Giant clams ever in one trip: 14 Burrowing clams and 3 Fluted giant clams. Teresa Tay and her Giant clam team deconflicted our sightings (thank you!) and came up with the total number. Her team of course made the bulk of the sightings, but our team also contributed a few. Well done everyone! 

As usual, the rest of the team make all the special finds. Two anemones that might be rarely seen ones, we are still not sure. Also a lively swimming file clam, special brittle star, a little pipefish. There were lots of stingrays, also colourful slugs and flatworms. As well as Marine spiders and even large octopuses even though we visited in full daylight.

With Jurong Island taking up the entire northern horizon, how amazing to see lots of dugong feeding trails on the seagrasses growing on this large submerged reef! So glad the dugongs are back. The last time we saw the trails was in Dec 2018. The first time I noticed them was in May 2012.

As in Jul 2025, I saw many dugong feeding trails here. These trails are formed when dugongs chomp up seagrasses including their roots, leaving a shallow meandering furrow of about equal width and depth.  I also noticed that the seagrass seems to grow more densely next to one of the feeding trails.

The seagrass situation seems good! Similar to our survey in Jul 2025, there is a meadow of Spoon seagrass in the sandy centre of the reef flat. Although the leaves are tiny, they are fresh and green. So much so that a band of green could be seen from a distance. There were sprinkles of seagrass on almost the entire reef flat from the reef edge to the centre. On the sand bars and among the more reefy parts. In some large parts, the seagrasses were growing more densely. Most were fresh and green. The most common were Spoon seagrass (mostly small leaves, but also some with large leaves) and small sparse patches of Sickle seagrass leaves also cropped. I saw some clumps of Tape seagrass, still cropped short.

There has never been a lot of hard corals on this shore. Most are boulder shaped corals.

I checked out the area near the beacon today. Here, there is a good variety of common corals with some forming quite large colonies. Similar to our survey in  Jul 2025, I saw scattered colonies of Sandpaper corals, Cauliflower corals, Anemone corals, Disk corals. Also a few clumps of Branching montipora, sparsely distributed - not yet forming a 'field'. Most seemed healthy and were not bleaching.

Similar to our survey in  Jul 2025, towards the reef edge near the Beacon, I saw a wider variety of colonies of leathery soft corals. Some of them formed quite large clusters. But not as large as those on nearby Terumbu Pempang Tengah.

Today, I saw two abandoned fish traps in the middle of the reef flat, one was more broken than the other. Richard saw what looks like a functing fish trap on the reef edge. 

The ongoing Sudong reclamation is still busy with many large vessels in the water and vehicles on the land. But it seems the sand pile is no longer as tall as what we saw in May 2026 from Terumbu Pempang Tengah. Thanks to Zen Xuan He for this great shot of the reclamation site today. 

From Port Marine Notice No. 55 of 2026 "Reclamation at Pulau Sudong" with effect from 08 Apr 2026 to 07 Oct 2026. The works involve the installation of navigational buoys, removal of metallic debris, demolition of abandoned jetty, dredging works, installation of marine staging platforms for soil instrumentation, infilling works, marine vibrocompaction, stone revetment works, and jetty construction to facilitate the reclamation and jetty construction works at Pulau Sudong.

Here is the location of Terumbu Pempang Laut and other nearby shores in relation to the Sudong reclamation.

What is the fate of Terumbu Pempang Laut?

Pulau Hantu and all the terumbus west of it are slated for massive reclamation outlined recently in the Long-Term Plan Review. Singapore's submerged reefs are often out of sight under the high tide and thus forgotten.

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.

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

Richard Kuah


Jaeden Lim


Zen Xuan He


Rui Quan Oh


Rachael Goh


Others on this survey: Mud Nasry, Ian Mun, Jason Ooi, Tommy Tan, Dylan Sng, Yan Le Su, the Giant Clam team