A quick view of the Sentosa Integrated Resort worksite

Despite the torrential rain and lightning, I joined the Naked Hermit Crabs for a quick walk on the natural shores of Sentosa when the weather eased for a while.The delighted visitors enthusiastically explored the shores despite the weather and we found lots of fascinating example of marine life such as large soft corals, several kinds of hard corals and of course seagrasses and other common animals such as sponges, crabs and even two special nudibranchs.As we washed up at the Underwater World Sentosa, I had a quick look around at the natural shores just around the corner from where we were having the nature walk.
Reclamation has started there on 18 Jun, and the area surrounding the shore has become a worksite.Trees are also being cleared there.

The entire Sentosa Integrated Resort site is a giant pit full of excavation and other activity. We had a quick look as we were leaving the island.The merlion and sky tower are on the horizon for scale of the humungous hole in the ground.Here's more of the worksite.And another view with the monorail in the horizon.On the shore front, the old pier has been replaced with a sea wall right up to the base of the cable car tower. Reclamation is now underway on the other side of the cable car tower, on top of probably the last sandy natural shore of Sentosa.

These works are near not only Sentosa's natural shore, but also Labrador's which lie just opposite Sentosa.

Exploring Labrador with Prof Leo Tan

This morning we had the pleasure of exploring Labrador with Prof Leo Tan. Labrador is very special to Prof as he succeeded in getting it declared a Nature Reserve (more about Prof Tan in today's ST article "Green Urbanites")Here he is showing Dr Vilma D'Rozario and Chay Hoon a crab.

When we last visited Labrador in March 08, the shore wasn't doing too well. So I was prepared for the worst.

The shore was very silty today but it was a rather pleasant surprise to find signs of life on the shore. The tide was very low, so we could go quite far out into the intertidal.

Here, we saw some living large hard corals. This one is probably a Porites sp. which was the most commonly encountered kind of living coral we saw today.Here's another large colony of Porites sp.
There was one large Turbinaria sp. which was half alive. The upper part of the hard coral was taken over by a large carpet of Sea grape seaweed (Caulerpa lentillifera). This kind of coral is usually very common on Labrador, but we didn't see very many today.
I'm not sure what kind of coral this is, but this was also previously seen on Labrador.There were also little colonies. Another Porites sp.?Several small colonies of the super tough Zebra coral (Oulastrea crispata), a hard coral that is also commonly encountered on silty shores like Changi.
This one is probably a favid (Family Faviidae).There were little colonies of Goniopora sp. corals with tiny polyps, in various colours.
This one was pink. These corals were previously very commonly seen on Labrador.And one colony of Goniopora sp. with large and long polyps.
Everywhere, there were tiny little clumps of hard coral starting to grow. This is a good sign.A not so good sign was coral bleaching on some of the hard corals. We also came across some dislodged hard corals, which Prof placed carefully back into a firmer position in deeper water.

Some portions of the shores also had zoanthids, while we also encountered these sea anemones with branched tentacles (Phymanthus sp.).I also saw one transparent sea anemone-like animal that is probably a peacock anemone (Order Ceriantharia)And Chay Hoon and I saw several of these star-like sea anemones with a few wriggly tentacles.

Some sponges were also seen on the shore, including this special one named after Singapore.This sponge is possibly Coelocarteria singaporensis.

I chanced upon this wriggly fish in the murky water.I'm not sure what it is but the pair of tubular nostrils suggests it's a member of the moray eel family (Family Muraenidae).At the area where gravel was laid down over the submarine cables, there are now deep pools full of colourful seaweeds and tiny fishes.A pair of Ornate gobies (Istigobious ornatus) played tag with one another, while a tiny juvenile Brown sweetlips (Plectorhinchus gibbosus) looked just like a dead leaf!There were also small groups of little Yellow-banded damselfishes (Dischistodus fasciatus) nervously darting about in the pools.

A strange encounter at this area were little Thorny sea cucumbers (Colochirus quadrangularis)!While these sea cucumbers are commonly seen on our Northern shores like Changi, they are not seen on our Southern shores, except for Cyrene Reef. What does this mean for Labrador?

We headed out right to edge of Labrador.Work is currently already underway for massive reclamation just at the jetty that Vilma is pointing at. This work is to create new wharves at the Pasir Panjang container terminals.

Here, Prof finds a scallop!At first we thought it was dead, but when we put it in the water, it was clearly very much alive! The valves of the shell parted and the mantle lined with tiny eyes peeped out with little tentacles poking out. And then it claps the valves together and jetted off backwards! Wow, this is my first time seeing this in action!

As we head back, we met Chay Hoon who has found nudibranchs!They are of course extremely tiny and Prof has to put on his glasses to have a look at them.These are probably Dermatobranchus sp.

We also see lots of snails on the rocky shores: Turban snails (Family Turbinidae), Top shell snails (Family Trochidae), Drills (Family Muricidae) and of course, lots of Nerites (Family Neritidae).

Prof found this very special Nerite that I've never seen before!I have no idea what it is. More about Nerites in another blog entry.

We also came across this snail.At first we thought it was dead as the more commonly seen Spiral melongena (Pugilina cochlidium) when alive has a furry shell. This one was clearly alive, but hairless and seemed to be a different shape. Again, I have no idea what it is.

Prof also found lots of crabs!Colourful swimming crabs (Family Portunidae) and cuddly hairy crabs (Pilumnus sp.). We saw several Brown egg crabs (Atergatis floridus) , one Red egg crab (Atergatis integerrimus) and one brightly marked Mosaic crab (Lophozozymus pictor). The egg crabs and the Mosaic crab are all highly toxic. Prof shares a story of his early days when during a field trip, some students added Mosaic crabs to a pot luck of seafood. Fortunately, he saw the crabs before everyone ate or he would not be telling us the story today.

And on the high shore, another kind of crab!
A white crab spider was patiently lying in ambush on a flower!

We had a quick look at the seagrass area and the Sickle seagrasses (Thalassia hemprichii) seemed alright.

Alas, a portion of the seacils left behind by the Singapore Polytechnic project was STILL on the shore.And there were still some ENORMOUS marine debris like giant tyres on the shores.We shall just have to keep an eye on this, our last mainland rocky shore and reef. And hope that it will survive the upcoming major works nearby at Pasir Panjang and the Sentosa IR reclamation.

Nerites of Changi and Labrador

Over the last two days, we've been doing rocky shores at Changi and Labrador. Nerites (Family Neritidae) are very commonly encountered in this habitat.Nerites have a distinctive semi-spherical, globular shell. The shell is quite thick and heavy. When alarmed, these snails may just let go and they will drop off the rocks and bounce around like little marbles. This is probably how they may escape from crabs who try to eat them.

The hole in the shell is closed with a door called an operculum. The operculum has an internal peg to lock firmly in place against the teeth at the shell opening. This makes it difficult for a crab to stick a pincer in and dig out the snail.

A preliminary identification of the various species of Nerites can be made by looking at the underside of the shell and the teeth-like structures at the shell opening (these do not actually function as teeth to chew food), and the shell's general shape and texture. But very similar-looking Nerites can only be positively distinguished by looking at internal features of the shell and animal.

When looking at a nerite's underside, do it gently and remember to put it back where you first found it.
This is probably Nerita chamaeleon or the Chameleon nerite.

This is probably Nerita undata.

This is definitely Nerita lineata or the Lined nerite.

While these are probably Nerita squamulata.
Nerites of the same species may have very different patterns and colours on the shell.

Prof Leo Tan found this nerite on Labrador. I have no idea what it is and I've never seen this nerite before!
Unlike the other more commonly seen nerites, this one does not have 'pimples' on the operculum. Instead, the operculum is smooth. It also has a very smooth shell without the rough ribs seen on the other nerites we usually see.