8-clam day at Terumbu Raya!

Surveying the western part of this enormous reef flat, the team find a record number of Giant clams and other amazing marine life.

Like many of our submerged reefs, Terumbu Raya is too huge to survey completely during the narrow low tide window. This is the first time we are checking out this side.

We saw 8 Giant clams today! The most number we have seen on one trip. 3 Burrowing giant clams (from left anti clockwise) a tiny pretty blue submerged one (by Jianlin), a 10cm one (by Che Cheng), a 12cm on (by me). 5 Fluted giant clam: three by Kok Sheng, one about 30cm by Kelvin. Centre photo by Che Cheng. Kok Sheng also saw a large dead one.

The team found lots of interesting colourful animals. From some rarely seen flatworms, nudibranchs and slugs, sea cucumbers, brittle stars. To familiar common ones that are always nice to see on the reef. Here's a collage of some of their finds. Check out their albums for more.

It was difficult to survey the reef edge as the Sargassum was still somewhat in bloom. But I did manage to see a variety of common corals. Including a patch of Acropora corals toward the middle of the reef flat. Most of the corals I saw were alright.

But it was a little disconcerting to see many large colonies that were pale.  I'm not really sure what this means.

I also saw many large leathery soft coral colonies of various kinds. None were bleaching. I didn't see much seagrass, most of the long leaved seagrasses I saw were cropped.

Today, we land on a jet ski thing! Much sturdier than a dinghy, and easier to get back on. We are very impressed. 

Terumbu Raya lies opposite Pulau Hantu and the petrochemical plants on Pulau Bukom, and is next to Pulau Semakau.

Although reclamation directly on Terumbu Raya is not currently planned, massive reclamation is slated all around it, as 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.

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

Kelvin Yong


Che Cheng Neo


Loh Kok Sheng: see also his full album


Richard Kuah


Jianlin Liu


Marcus Ng


On 22 Feb, some of the team surveyed other mainland shores. Thank you!

Marcus Ng checked out Changi Carpark 6


Richard Kuah checked out Pasir Ris