Eastern and Northern reefs of Pulau Semakau

This is an overdue post of our survey at the natural reefs of Semakau during the last low tide season. In fact, the team covered three different areas of Pulau Semakau though I only went for the eastern and northern shore (missing out the southern shore).

We do not often visit the Eastern reefs of Semakau until recently. This huge stretch of reefs facing Terumbu Semakau and close to Pulau Bukom is rich in hard corals, soft corals, anemones and other amazing marine life.

When I first took this photo, I thought that the water was murky as the photo was slightly blurry. Subsequently, I also noticed this in other underwater shots and did not think much because when sediments are stirred, visibility drops.

It was only when I processed the photos at home that I realised that those "specks of sediments" are actually tiny fishes or fries! Really very cute! And the fact that I saw them in so many of my underwater shots means that they are found along a wide expanse of the reefs.

Though the reef edge of the Eastern shore tends to be submerged and hard to negotiate, one can still catch glimpse of the thick growths of hard and soft corals at the edge.

The stretch of fringing reefs closer to the rock bund is full of different types of soft corals! Here's a collage of some of them in their own element underwater.

Another distinctive feature of the eastern reef would be plenty of these Magnificent sea anemones (Heteractis magnifica).

Also commonly found on the reefs would be the Bubble tip sea anemones (Entacmea quadricolor) and some of them are home to the Tomato anemonefish (Amphiprion frenatus).

Here's a colourful collage of what you can find underwater on the reefs of Eastern Semakau, ranging from barrel sponges, anemones, zoanthids, sea fans, hard corals and sea urchins.

A special find on the edge would be this Burrowing Giant Clams (Tridacna crocea)! This fellow is sometimes also called as the Boring Giant Clam as it can bore into rocks. No worries ok because it doesn't bore its friends!

It's never too boring for me to find these Cushion stars (Culcita novaeguinea) that can come in various colours and patterns.

This pretty in pink anemone is known as the pink version of the Wiggly reef star anemone. It is very shy and disappears instantly at the slightest sign of danger. I like this shot as it is found among the colourful zoanthids.

Someone found this anemone which we do not know its identity.

While flipping rocks, I found these three Chitons (Class Polyplacophora) underneath a rock. These creatures do cling on tenaciously. Don't even try to pry them off.

The following day we went to the northern shores of Semakau. We enjoyed a lovely sunrise!

This stretch facing both Terumbu Raya and the oil refineries of Pulau Bukom is also especially rich in corals. It's heartening to know that nature and development can coexist.

Here's a collage of the underwater splendour of the northern reefs of Semakau. Lots of critters and marine life ranging from hard corals, sea urchins, anemones and nudibranch.

A special nudibranch found would be this charismatic Varicose phyllid nudibranch (Phyllidia varicosa). It is bigger than the other usual phyllid nudibranchs that we see.

Wow! This is the biggest mass gathering of the Black-margined nudibranch (Doriprismatica atromarginata). I wonder if they are mating?!

This uncommon sea anemone is known as the Pizza anemone (Cryptodendrum adhaesivum). I wonder if the yellow colouration is due to bleaching.

Though the Red feather stars (Himerometra robustipinna) are found abundantly on certain reefs, I only saw one at the edge on this trip. The ends of the arms seem to have fallen off before.

 

Talking about dropping off "limbs", I witnessed for the first time the shedding of Dragonfish sea cucumber (Stichopus horrens) after touching them. This is actually a response to stress. Lesson learnt from this incident is to leave them alone!

I was delighted to find this huge and long sea cucumber which I do not exactly know its identity. It does not exactly look like the Herrmann's sea cucumber (Stichopus herrmanni).

A special find for this trip would be this Fluted giant clam (Tridacna squamosa)! Mei Lin's infectious love for these pretty clams have also caused us to be thrilled when we come across them. 

Another special find would be this flatworm that may look black and boring from far but if you were to take a closer look, it seems to be home to a galaxy of stars! How amazing isn't it?

Here's a tribute photo of the never-say-die team mates queuing like a typical Singaporean while waiting for departure!

More photos of the trip can be found here:
Eastern Semakau- https://www.facebook.com/media/set/?set=a.10153494442908158.1073741888.547198157&type=1&l=12bf68a711
Northern Semakau- https://www.facebook.com/media/set/?set=a.10153498818898158.1073741889.547198157&type=1&l=9d8e11f3be