Pasir Ris mangroves briefly with Naked Hermit Crabs

In mid-December, I was out with the Naked Hermit Crabs and my two student councillors, Clarabelle and Kai Sing, from Dunman High School to guide at Pasir Ris Mangrove boardwalk.

It's always amazing to show participants what one can find in close proximity to the housing estate at Pasir Ris. The mangroves here are alive! Here is Alyce sharing some of the nature facts and stories with the rest.

Pasir Ris mangroves with Naked Hermit Crabs

It has been a long while since I have last visited Pasir Ris mangroves. So long that I couldn't even recall when was my previous visit. As such, I am glad to revisit this place while guiding with Naked Hermit Crabs.

There are several nests where you can spot herons from close distances and I arrived earlier to have a look at the grey herons. It began with these two juveniles chatting or quarreling with each other.

Pandan Mangrove field trip

This morning, the marine biology class with lecturers and teaching assistants were out somewhere in the southwest.


Isn't this Pandan reservoir? What has a reservoir got to do with marine biology?!


We are actually visiting Pandan mangrove organized by Siva. I really appreciate his effort in converting a classroom lecture on mangroves into a field trip. That's why we were all so happy today. In orange is our wonderful TA, Yujie!


Just at the reservoir itself, there is already life, I saw a monitor lizard or water monitor, too bad it wasn't photogenic enough to stay so long.


Distancing ourselves from the reservoir we are near the mangroves.

According to Siva, "Pandan mangroves is typical of the sort of mangrove strip that peppers several areas in Singapore, often escaping the public eye. Their presence is a footnote to a much larger expanse of forest that gave way to development. Thus these strips are all in close proximity with the urban areas that ate in to the original forest Although these are thin strips, they contain all of the symptoms of a mangrove ecosystem and are host to an an interesting diversity. Zonation inevitably overlaps in such small areas but can still be differentiated. Bordering Pandan mangroves is a clay-ey estuarine flat that hosts shorebirds and a different community of organisms from the mangroves."

To some, Pandan mangrove is special because it houses Api-api jambu (Avicennia marina) which is now thought to be only found at offshore islands like Tekong and St John Island. This rare mangrove tree that is considered endangered was not sighted by me though. Perhaps it is there and I've seen it, just that my mangrove id skill is still not there yet.


Nevertheless, I still got to encounter another mangrove plant that is considered rare also. This is called the Chengam (Scyphiphora hydrophyllacea) and what you see are the flowers.


These are its fruits. Chengam is a shrub that grows both in the mangroves and along sandy beaches. It has waxy leaves which reduce water loss through transpiration (A common feature for some plants found in the mangroves, along sandy beaches and coastal forests)

This plant also has durable wood which is useful for making small, hardy objects. Indigenous people are known to use the warm extracts from the leaves to treat stomach aches.


There also also many sea hibiscus with their pretty yellow flowers.


Unfortunately, one of our buckets started to float away but we have a hero to save the day!


Soon, we went more inland into another part of the mangrove.


At this zonation, we can still walk on the substrate despite the not so low tide. It was definitely an experience for many first timers down the mangroves. We saw many interesting organisms like snails, crabs, worms, mudskippers etc etc.


Not forgetting this TV junk! Which was later coined (in a corny fashion) as the water monitor.

All too soon, we completed our field trip!

What should one do while waiting for the bus to pick you up?


Take out your umbrella/big hat and start the anti-sun/glare/UV campaign.


Or embrace the nature by lying and relaxing on the grass, suntaning yourselves.


Or start talking to each other to exchange ideas.


I guess all of us enjoyed the trip and thank God for there is no rain. Nice first time visiting this special patch of mangroves.

Mangrove Ecology at Sungei Buloh

Thursday afternoon, a big bunch of learning "ecologists" from NUS went to Sungei Buloh Nature Reserve for a field trip to study mangrove ecology. And believe me, everytime you go, there is something new for you to be marvelled at.


If you enter through Kranji, you might come across this railway crossing which has only one lane for a two-way traffic. Therefore, traffic jam always occurs near here though this place is not every populated.

Upon reaching the nature reserve, we were introduced to zonations based more on topography than species since our "compressed" mangroves are more heterogenous as compared to other undisturbed mangroves elsewhere from Singapore. From landward to seaward, the zonation goes like this: Back mangrove, mud lobster mound system, main forest, sandbank and then mudflat. One thing about the diversity of mangrove plants as compared to that from tropical rainforest is that species diversity is low as few plants can tolerate low oxygen, high salinity conditions.

Our first station is the back mangroves where it is found at tidal heights beyond where the highest water spring tide occur. What dominates the back mangrove will be Sea Hibiscus.


The next zonation will be the mud lobster mound and pool system.


Over here, the mud lobsters dig mud and unknowingly, they create huge mounds which are analogous to condominiums, even with swimming pool, in the forms of water pool. The height of the mound is advantageous to those plant which cannot tolerate salt because these plants can grow on the sides or on top of these mounds and be higher up from the salty water of the incoming tides. Growing on these mounds are mangrove ferns...


and sea holly. These plants can be identified by its jagged edges.


The main forest zone of Sungei Buloh is highly disturbed and therefore has more species of plants in a small area as compared to undisturbed mangroves. The common mangrove trees include the Rhizophora tree with stilt aerial roots, Bruguiera with knee like roots (as shown above) , and Avicennia with thin pencil-like roots.

And this is the flower of one of the Bruguiera species.

Even the huts along the boardwalk is so cute, with all the collages of drawings.

And hey, we saw this monitor lizard basking under the sun. Monitor lizards are the cleaners of the shores as they can feed on almost anything they catch. They also can "smell" the air with their tongue to track down prey. In Chek Jawa, we even saw one swimming and they are known to even swim underwater for half an hour.

Here is a fly on a leaf that has gotten my attention to take a snapshot before moving on as the teaching assistant shows us the different parts of mangroves.

This is a giant mudskipper which is actually a fish that can stay on land. How do they do it? They have hold water in their mouth and also breathe through moist skin. These fearsome predators even have two rows of teeth in their upper jaw, feeding on small fishes and crabs.

Talking about crabs, we have the tree climbing crabs. Why? Because they climb on trees! Duh. They climb high up during high tide to avoid being preyed upon. These guys eat mangrove leaves and seedlings and sometimes scavenge for meat.


The furthest seaward zone is where you can find the sandbank, as shown here. You can see many herons resting and feeding on the sandbank and also have a great view of Johor from here.

A close-up of the birds on the sandbank.

We then proceeded to the bridge over Sungei Buloh Besar and this photo shows the upstream portion where nutrients input into the mangrove ecosystem. There is a big name to explain this: allochthonous nutrient input.

And downstream, we find the river leading to the Straits of Johor.


Across again, another view of Johor. Sadly, we did not see natural shores along, but with modifications.

Here again we chanced upon this resident monitor lizard at the side of Sungei Buloh Besar. It is evident that there are the pencil-like thin roots which mainly belonged to the Avicennia trees.

Archer fish is interesting because they can feed on insects near the water surface by pumping out forceful jets of water to knock insects off leaves.

Our last stop was the main hide where we were told that many telescopium Rodongs can be found on the flat when the sluice gate drains the water out.

The whole trip was summarized with a short test and we were of course stressed over it for that short moment. Other than that, was a great trip. Thank God for wonderful weather despite nasty forecast from meterological station.

Anemone finale at Sungei Buloh

Today is the last day of our sea anemone "expeditions" and guess what, we are at the mangroves over at Sungei Buloh Nature Reserve.


Siva leads us to his territory via the accessible boardwalk system. And at first sight, I saw a few giant mudskipper wading across the wetland and pools of water.

Not too soon, we navigated ourselves down to the mud and dirt where the real work starts!


It is a very nice place after all, in this photo with a stream leading out to Johor Straits.


Ria did not get down at first and was happily taking photos of us dredging across the mud. Of course, Siva also took a photo of her up there before she joins us.


Huaqin found this delicate anemone with its tentacles opened along the side of a stream. Mangrove anemones are pretty either.


We were looking more for those anemones that burrow deeper into the substrate and this is how it looks like out of the mud. It has a orangey or brown column with white stripes running parallel to the it. The tentacles, when out of water, are retracted into its body.


The team works hard to get these anemones where no one bothers about them in the past. We are so glad that Dr Daphne is here to help us know more about these anemone guys, as we can better appreciate and document the rich biodiversity Singapore has.


Trixie is one of the very garang anemone team member and together with Ivy, they assist Dr Daphne with collection and identification. Who says girls can't do such stuffs?


Throughout the search, we found many of these blobs, mostly stuck on hard surfaces.

Dr Daphne told us that these are actually Anthopleura handi. And these anemones are actually named after her professor, called Professor Hand. They are tough guys and live well in the anoxic mangrove conditions.

Swee Hee found another type of anemone which I have forgotten the id. It has white lines radiating from the centre.

And to Ria's curosity, she found out surprisingly that the whole place is full of these rare Halophila Beccari! So far I only knew they can be found in Chek Jawa. And to think that we were all stomping them all over. Haha.

We brought a bit of specimen back to Siti, the expert of seagrass, who will take a good good look at these rosey tiger seagrass.

Today we had a well assorted gang of team members...


working hard and also learning valuable information from Dr Daphne.

Very soon, earlier than expected, we managed to complete our work and reached the objectives. We were pleasant that the park has prepared pools of water with sponges so that we can have a proper washup after getting ourselves down and dirty in the mud. It was a fruitful and enriching experience getting to learn so much from Dr Daphne.

After almost everyone left, Andy, Ron, Alvin, Robert and I stayed behind. We spotted this white-breasted waterhen (Amaurornis phoenicurus) near the edge of the pond.

I thought this was a pretty shot of a red-ear slider "looking" at the edge of the pond of small fishes.

We also stopped by the main bridge and with the assistance of Ron and Alvin, I get to see this beautiful Stork-billed Kingfisher resting on the branch, and it stayed there for really some time, even after we left.

We were talking about otters and tried to sight for one. I saw something moving from afar and I can't recognise what is it. Thus, I took out my camera and make a zoom. To my dismay, from what I saw from my camera, it is only a monitor lizard. Well, better than nothing. We know these otters are still there before Robert saw it some time ago.


That marks the end of the day, thanks to the anemone team for the trip and also Andy for the interesting drives which few people now appreciate the rustic charm of these winding roads.