Chek Jawa Mortality and Recruitment Project

Checking Chek Jawa (April 2011)

2011-05-02T10:46:00.005+08:00

It has been a really long time since I last stepped on the shores of Chek Jawa! The previous time was during January in 2010 which was more than a year ago. How has Chek Jawa been? I had a quick look at the shore while the Teamseagrass volunteers were busy surveying seagrasses.

The Carpet anemones (Stichodactyla haddoni) are one of the first organisms that I had a look to see how they are doing on the shore. These anemones are still not as abundant at the southern sand bar when compared to the northern sand bar. This photo shows the anemones at the north of Chek Jawa.

Many of the juvenile carpet anemones that I have seen back during my survey days a couple of years ago have grown bigger along the northern sand bar. This is indeed heartening.

Somehow these anemones are able to tolerate the presence of sand on their tentacle surfaces. With hope, it is possible that the northern sand bar will be home to even more of these anemones. This may probably help Chek Jawa return to its former glory where there are so many of these carpet anemones on the sand bar.

Other than those found on the sand bar, there are also many carpet anemones living within the lush seagrass meadow.

Many of these carpet anemones among seagrasses and seaweeds look healthy based on their coloration. We are glad to know that these creatures survived some extreme weather conditions, especially in January this year when there were heavy rainfall.

I only saw a small number of Peacock anemones (Order Ceriantharia) during this trip. I think it is because of the really hot weather that day.

Not sure if it is because the tide was not so low or that the seagrass meadow has shifted, there wasn't much of the southern sand bar exposed further away from the boardwalk. As such, I did not encounter many Cake sand dollars (Arachnoides placenta) in the south than in the north.

But as usual, at locations where these sand dollars are found, these echinoderms aggregate in large numbers.

Also due to the hot weather, I could only find a few of these Plain Sand stars (Astropecten indicus) which can be found in great numbers especially below dawn or after dusk.

A couple of the Common sea stars (Archaster typicus) were found near the southern sand bar. However, I did not see more of them elsewhere. Will they be able to procreate more individuals successfully to recolonize the sand bar as like before the mass flood? Only time will tell.

The sea cucumbers were well represented during the trip. There are about 7-8 different species found in this photo collage. The presence of these soft bodied invertebrates indicate that the salinity is within tolerable range.

Near the floating pontoon, I came across mats of what looks like that belonging to the Asian date mussels (Musculista senhousia). But after checking it out, I realize there were no bivalves inside the mat. I wonder what this is.

With the help of volunteers, Nparks has consistently been giving guided walks to the public to share the natural wonders of Chek Jawa with everyone. Kudos to their hardwork in raising awareness of the shore which we all love and would want to preserve.

I do agree that the ecosystems in Chek Jawa are indeed dynamic. Especially in the shifting in zonations of the sand bar and seagrass meadow. The button snails have gone MIA again. I believe it is probably a seasonal thing as they will migrate into deeper waters at certain stages of their life cycle.

Let us just continue to keep a good watch at this precious living shore.

More of what I've seen during this trip in my God's Wonderful Creation blog.

3 years after the mass mortality event

2010-01-17T08:30:00.005+08:00

It's January 16th of 2010 and almost exactly three years after the gruelsome mass mortality event that occured in Chek Jawa. Joining Teamseagrass on the shore, I went to have a quick short look at how is the shore doing for now and whether is Chek Jawa hit by the impact of the 'Dead fish zone' at Pulau Ubin.

The relative positions of the sandbar and the seagrass always seem to be rather dynamic and whenever I visit Chek Jawa after many months (my last visit was Aug 2009), it seems to have changed a bit.

This time, there were many of the Noble volutes (Cymbiola nobilis) laying eggs. But I thought I should look out for the soft bodied animals to see if low salinity has impacted them. A week ago, my friend Pamela mentioned that the salinity at Pasir Ris was 16 ppt.

The only sea star species I came across is the sand star (Astropecten indicus). Did not sight the common sea stars (Archaster typicus) but they are still around as they have been seen during CJ guided walks.

Instead, I saw a wide variety of sea cucumbers! Here's the list of them...

This is the Pink warty sea cucumber (Cercodemas anceps).

Thorny sea cucumber (Colochirus quadrangularis).

This is the Smooth sea cucumber that is usually only found buried in the sand.

There were quite a number of the large Garlic bread sea cucumbers (Holothuria scabra) that seem to be settling well for some time already.

Last but not least, this Purple sea cucumber (Family Cucumariidae) that we usually see on northern shores.

Glad that the sea cucumbers are fine! That's a good sign.

As usual, the sand dollars are teeming certain parts of the sand bars, especiall the north. They are usually covered with a thin layer of sand.

And here's a closer look at this Cake sand dollar (Arachnoides placenta).

One of my task is to find the return of the Button snails (Umbonium vestiarum). They have been missing for 1.5 years! And I'm so happy to find them back in big patches on the north. Yay!

How about the Carpet anemones (Stichodactyla haddoni)? Almost all of them look fine with no signs of bleaching. Some of them settled well among the seagrasses.

A pleasant surprise will be the north shore where many of the carpet anemones have colonized the sandy area. Can you find all five of them together in this photo?

Here's one of the prettier carpet anemone.

My impression of the number of Peacock anemones (Order Ceriantharia) remains the same though. I didn't really see an increase though it was just a general feel.

That's about all for the animals that I usually look out for to monitor. But of course, Chek Jawa is alive and there's other creatures that I found along the way.

Like this bunch of cuttlefish eggs in black.

I found these weird orange blobs on the seagrass blades. Are they ascidians or egg masses of some animals?

It was interesting to once again come across another of the giant-sized Mud crab (Scylla sp.) on the shore. I didn't dare to get too close as it was too big and scary looking.

An interesting find will be this moon snail that I don't think I have ever seen before alive. It has a brownish shell.

And here's the underside. Hope someone can provide the id.

Whereas James found a solefish that I can't really tell its exact identification too.

I was thrilled to find this featherstar clinging on the knobbly sea fans on the pillar of the floating pontoon. Have not seen featherstars at Chek Jawa for a long time!

The legs of the CJ boardwalk is teeming with sponges and ascidians.

And below some of them, once again, are many egg-laying noble volutes. Haha. Can you spot the cowrie at the pillar leg too?

That's all for a short one-hour check out. Glad to know Chek Jawa is recovering well, with no signs of being impacted by the dead fish zone or low salinity. :-)

How's Chek Jawa so far?

2009-08-23T20:56:00.007+08:00

It has been more than 2.5 years since the mass dieoff that occured due to an exceptional heavy rainfall in Dec 2006 and Jan 2007. Though my project has officially ended, recovery never ceases. I took the opportunity of today's Teamseagrass monitoring trip to take a short look at this special shore.

Time was short and I quickly made down to the coral rubble to catch the lowest tide. And it was heartening to see a pinkish Knobbly sea star (Protoreaster nodosus) just near the Chek Jawa beacon. I remember that they were not sighted for eight months after the mass death event. Many had died due to the extremely low salinity which were recorded to reach below 10ppt. Click here to see a photo of a dying Knobbly sea star shot by Ron during Jan 2007.

Aren't we glad that there are now back? Today, not only did I see one or two...

But actually three of them! I will later send these photos to Chee Kong for his Star Tracker monitoring.

More stars that can be found at the coral rubble include the various sizes of the Biscuit seastars (Goniodiscaster scaber).

But another sweet find at the coral rubble is this large adult-sized Cake sea star (Anthenea aspera). It was very much bigger than my palm!

The carpet anemones Haddon's carpet anemones (Stichodactyla haddoni) near the coral rubble facing Sekudu are doing very well.

There are many of them and it was difficult to avoid stepping on any of these large anemones.

Though much of the corals seem to be affected after the mass flooding of rainwater, two colonies of the Pore corals (Porites sp.) were found. I hope there are more of these huge corals at the deeper waters, which I didn't get to check because the tide was not exactly super low.

Zoanthids were also scarce and I only spotted two small patches of them.

That goes the same for the sponges. Chek Jawa used to be home to lots of colourful and good growths of different types of sponges. It was not too easy to find them today.

But all these does not mean that the coral rubble is not doing well. As said, the tide today was not low enough and it is possible for the more delicate animals to be found more abundantly at the deeper waters.

I went to check out the pillars of the boardwalk and was quite glad to find more sponges of different colours encrusted onto them.

More sponges and ascidians attached on the pillars.

Weirdly, I didn't spot any of the Pink flowery soft coral (Family Nephtheidea) that were previous seen at the rubble and the pillars of the boardwalk. I did see one colony of Sea fans (Order Gorgonacea) though.

I quickly went over to the seagrass lagoon and main sandbars to check out the animals there. The carpet anemones are still there as usual as well as the large numbers of the Cake sand dollars (Arachnoides placenta) that crowded many parts of the sandy shore.

These sand dollars leave imprints on the sand that are circular in shape. I didn't find any of the rarer keyhole sand dollar though.

It was day time and most of the abundant sand stars (Astropecten sp.) had burrowed into the sand since they are norturnal in nature.

I was on the lookout for the Common sea stars (Archaster typicus) by the five-arm marks on the sand but instead stumbled upon a brittlestar.

Good thing was that Adelle later showed me one of the common sea star. I heard from her that many of them have been spotted during the guided walks. This is good news.

I guess at the sand bar, the most drastic change in terms of population will be the Garlic bread sea cucumber (Holothuria scabra)! They are very common today considering many others are buried under the sand. Who knows how many is now at Chek Jawa. We do not need another mass death to suddenly see tons of these poor cucumbers die and surface on the sand.

How about peacock anemones (Order Ceriantharia).? At some parts of the seagrass lagoon, they seem to be doing well!

There's no sign of discoloration or poor growth of some sort.

I quickly walked to the north to search for the Button snails (Umbonium vestiarum) that have been missing in action for a long time.

However I couldn't find any living button snails.

There were dead shells though. A sign that they are still around somewhere, I think subtidally. They do migrate to and fro different zonations so I am not too worried.

Sunrise over Chek Jawa signifies new birth after the mass mortality event. A birth of a human being takes many years to mature, not to say an ecosystem.

Let's hope Chek Jawa has many good years more to go to recover back into its former glory, slowly but definitely surely.

Article at Nature Watch is out!

2009-08-07T16:22:00.005+08:00

Ria passed me the latest copy of Nature Watch this morning showing me that the article I've written for the magazine has been (finally) published! I remember doing this writeup end of last year.

It is a six-pages article. Feel free to purchase this latest copy from Nature's Niche if you are interested.

Would like to take this opportunity to thank Dr. Peter Todd for encouraging me to do this writing and be there to guide me along. Ria, Ron and Siva for the photos. Liana, Mei Lin and other friends whom have vetted the draft. Last but not least, the editors of Nature Watch for their great work in getting this article published.

Chek Jawa in May 2009

2009-05-07T18:02:00.009+08:00

It's been some time since I have updated this project blog. Finally got a chance to check out Chek Jawa after the Teamseagrass field session just last Saturday.

How are the animals doing?

Recovery, I must say, is slow but steady. There are not many carpet anemones on the sandbar as compared to the past, but they are slowly coming back. This photo was taken at the southern sand bar.

The northern sandbar also has many of carpet anemones, especially at the water edge. It's a good sign.

Some of them look bright...

While the most look rather pale, which I thought it's quite usual for these carpet anemones.

I do suspect that the strong solar radiation in the recent afternoons has bleached out some of the carpet anemones like this one.

And this carpet anemone too. Good thing is, these are the only two bleaching carpet anemone out of the close to fifty carpet anemones I encountered during that day.

The southern sandbar just beyond the floating platform is still littered with tubeworms!

And among the tubeworms, I spotted this geographical seahare.

How about the button snails? Are they back yet? They have been missing exactly since one year ago. At least intertidally. I saw many of these white skeletons of the button snail shells at the northern sandbar.

Did they just died recently?

I also found some of the intact button snail shells with hermit crabs. Which proves that the button snails persisted during this one year. Just that they have probably migrated to the subtidal area.

As usual, the sand dollars are just so abundant! And many of them are really big. Alas, no keyhole sand dollars could be found. They are rare as usual to be found.

I went back to the same patch where common sea stars were last found and the stars are still there!

In fact I spotted two pairs pseudo-corpulating! Good... go procreate more!

That's all for the key animals that I was monitoring for. There are also some other creatures that I stumbled upon during the survey.

Like this smooth sea cucumber...

This aggressive elbow crab...

And this yellowish bristleworm.

Beneath the floating pontoon are a huge growth of the green mussels.

The hard substrate, together with many of these mussels, created crevices where many of the thunder crabs can be found.

That's all for the update this time! :-)

A 2009 good start for Chek Jawa

2009-01-10T21:45:00.004+08:00

How is Chek Jawa two years after the massive freshwater flooding event in 2007?

There are many tubeworms that have colonized most part of the northern sand bar. Alas, button snails were missing. Could it be that both tubeworms and the button snails cannot co-exist or that the button snails have migrated to the subtidal area?

How about the southern sand bar? There are parts where you can find balls of sand left over by sand bubbler crabs.

What is most heartening is the return of juvenile and mid-sized carpet anemones on the sandbar, this time in more numbers.

Let's hope that their return will continue and we look forward to them crowding the sand bar like land mines though that might take many years though.

Today I couldn't find any peacock anemones that are showing much of their tentacles. Could it mean anything?

As usual, there are many sand stars out on the shore.

And we are all very happy to see the common sea stars back, we counted eight today in one tide pool.

These are adults that most probably escaped the flooding death toll by burrowing very deep or going deep into the subtidal area.

The biggest surprise is this rare six-armed sea star (Luidia penangensis). Read more about this special sea star and other fantastic finds on my God's Wonderful Creation blog.

Looks like Chek Jawa has a good start for 2009! Let's hope that there will be no massive rainfall event or flood for this month.

A quick check at the coral rubble

2008-10-19T09:05:00.006+08:00

It has been more than two months since I've checked Chek Jawa out. This time, I was fortunate to have Dr Dan, Siva and Airani joining to have a good look at how Chek Jawa is recovering.

Here is Chee Kong with Dr Dan and Airani. Apparently, Chee Kong and Sijie were being filmed for some programme.

It was surreal to be back at this wonderful place at a good weather. Soon, we were on a mission to check out the identification of the plentiful tubeworms at the northern sandbar, which was a success!

Quickly, I did a followup survey on the peacock anemones and there were a few more new additions in the survey plots to my previous count during January 2008. This is great.

The team seagrassers were also there to monitor the lush seagrass. Some of them alerted me and they have found a juvenile kite butterflyfish.

Time and tide waits for no man and I headed to the coral rubble area (the prominent icon of this area being the beacon) for my last agenda of the day since the tide was low enough to check this fragile and rich spot of Chek Jawa.

There were a number of these fanworms which has tentacles that swirl gracefully in the waters.

Soon, the Star trackers found a juvenile knobbly sea star which was exciting. They proceeded with the measurement. Am looking forward to their analysis of the knobblies in Chek Jawa since recently we see many juvenile ones.

The carpet anemones were doing well.

Stuck at the sandy substrate are many of these fan shells.

However, sponge recovery was not that fast, many of them were still sparsely distributed which small sizes. But it is good to see from this photo that there are quite a number of different species represented.

More sponges....

And more sponges. Be patient and I hope they will comeback in bigger numbers and sizes.

Below are many more of the marine organisms found at the coral rubble.

I was venturing deeper into the coral rubble carefully, to avoid stonefish and careless trampling. And I saw this thorny sea cucumber and a swimming crab.

There were also many of these anemones that we usually see at Pulau Sekudu.

Hydroids are man's enemies if we didn't wear longs.

Soft corals at the deeper parts of the coral rubble.

From the small colony of Porites coral.

to a bigger colony that I couldn't get a clear photo since it was deep in the water. Surprisingly, I didn't notice the colourful fish beside it until I was back!

Thundercrabs were also common foraging when the tide went out.

I also encountered a number of sea stars at the coral rubble.

Several biscuit sea stars.

The bigger Astropecten sand star, possibly Astropecten vappa.

Adult cake sea star. This photo shows a shrimp that I didn't notice till I was processing the photos. Indeed there's much life that awaits our discovery only if we decide to look closely and intently.

I found a rare find of this sand star with six arms just very near the cake sea star as well.

Towards the end of the check, I suddenly realized I was all alone in the shore while the rest has retreated back. So I quickly hurried my steps to head back.

Suddenly, this knobbly sea star caught my attention and I went to take a closer look. It has one of its arm chomped off.

Last but not least, I had a pleasant encounter with this charming Gold-spotted mudskipper (Periophthalmus chrysospilos) just beneath the boardwalk.

It was a good trip, and I believe that the coral rubble is slowly but surely recovering.

Recovery of Chek Jawa thus far

2008-08-04T18:37:00.010+08:00

5am, one small team of us left Changi jetty, volunteering selflessly to do a health check at Chek Jawa. Though all of my regular gang were busy to make it, I am very grateful that Ginny, Pamela, Tze Hwee and Han Sheng could come and help put and also experience Chek Jawa for their first time.

It has been one year since I've arrived at Chek Jawa so early. But we get to enjoy the spectacular sunrise over the horizon of Pulau Tekong.

This stretch of Chek Jawa to the west of the coral rubble, near the House No. 1 jetty has very good growths and large numbers of adult carpet anemones (Stichodactyla haddoni).

It is postulated that this part of Chek Jawa seemed to have minimal freshwater impacts due to headlands that diverted the river effect from Johor River. Therefore, numerous carpet anemones are still thriving here and that this location also acts as a seeding site for recovery to the other parts of Chek Jawa.

The way they are found on the seagrass area of this part of Chek Jawa can come in random, clusters,

and interestingly, linear fashion, where five of them forms a straight line. I guess this is just purely coincidental.

But it is also possible that the carpet anemones here could be migrated from the other parts of Chek Jawa that were badly affected by the Jan 2007 mass death.

This is because they can uproot themselves in stressful situations and drift with the currents to a less stressful area.

However, I couldn't find the colourful variety of sponges at the coral rubble that I've seen before during December 07. Only many of these long branched purple sponges, as also observed by Ria earlier on, can be found.

According to our regular trips observation from northern shores, these long branched purple sponges are very common because they are quite tough and can be found even in inconducive conditions. What happen to the other "more sensitive" sponges? Was the tide not low enough to reveal the other sponges?

Ginny and I were doing checks at the coral rubble, one of which is to find the adult knobbly sea stars (Protoreaster nodosus). I think the tide wasn't super low enough (though 0.0m) to find the adults. But Ginny found this juvenile knobbly sea star that was enough to make me excited.

This means new blood of the knobbly stars for Chek Jawa! Can't wait for them to grow up.

Other sea stars spotted included a couple of the cake sea stars (Anthenea aspera).

This is the other cake sea star found at the coral rubble area.

As usual, there are many biscuit sea stars (Goniodiscaster scaber) that we commonly find at the northern shores nowadays.

I've also found a patch of zebra coral (Oulastrea sp.) growing in the interior of an abandon tyre.

Also spotted are zoanthids and flowery soft corals that I couldn't take a photo of due to the murky waters from the returning tides.

Next, we checked the sand bar and the seagrass lagoon area.

Several groundscape photographs were taken for monitoring over time and also to compare with the state of Chek Jawa before the mass death.

Tze Hwee, alone, was posted to search for the Button Shells (Umbonium vestiarum) at a far far northern sandbar. She couldn't find them though, even at the usual spots where I once recorded GPS points.

While everyone was hard at work, Pamela and Han Sheng were searching for the mussel beds within the seagrass lagoon.

To my surprise, we could not find any mussel bed today! This was in line with the missing mussel beds from Changi and also later on I realized those at the Ubin jetty were gone too. What was left behind were the mounds of mud that I believed were once trapped by the byssus threads of the once-existent mussels. Could their absence now be due to a seasonal reason or that the predators of these Asian mussels (Musculista senhousia) have completely wiped them out?

A study was done by Kushner and Hovel (2006) to the response of native predators (gastropod Pteropurpura festiva) to an invasive marine bivalve, the Asian mussel Musculista senhousia (Mollusca: Bivalvia: Mytilidae). The results of the study suggested that in overall, "intertidal or subtidal areas with high seagrass cover and high predator abundance may be resistant to invasion by Asian mussels, but the likelihood that a population of M. senhousia will become established will depend on the relative densities of predator and prey, M. senhousia settlement and growth rates, and the spatial and temporal scale being considered."

The study by Kushner and Hovel (2006) also stated that "native predators may be able to confer invasion resistance to local communities, but are unlikely to be able to control large, established M. senhousia populations"

Similar to the native gastropod Pteropurpura festiva from Kushner and Hovel (2006), many of the drills (Thais sp.) were once found on top of the mussel beds.

And the eggs of the drills were also present on the surface of the mussel beds.

It is possible that the predation of the drills on the mussels could have slowly but surely led to the elimination of the mussels from the mussel bed. Though Kushner and Hovel (2006) stated that it is difficult to control large populations, the seemingly shrinking of the mussel beds observed in May could be a factor that aided the predation of the Asian mussels which led to control and thus elimination.

Nevertheless, the real reason behind such an elimination is difficult to account for. A better knowledge of the relative densities of predator and prey, M. senhousia settlement and growth rates, and their spatial and temporal scale will be needed to give a scientific explanation.

There are many sand dollars towards the northern sandbar that are teeming on the sand.

Some of the tubes from the tubeworms were also photographed. This one is the bigger one.

And there is another type of tubeworms that are much smaller.

There were about less than ten carpet anemones starting to be found growing at the sandbar. Before the mass death, the sandbar was filled with these carpet anemones like landmines.

Hopefully with time, more of these carpet anemones will return to the sand bars.

The seagrass lagoon has yet another surprise for us, another juvenile knobbly sea star! Ria has also found two of them in July as well. This is heartening.

Underside of the juvenile knobbly sea star.

And for the finale....

Common sea stars (Archaster typicus) are still around!

However, they seem to be only found at a specific spot that I always return to search for them through GPS. I hope there are more elsewhere that we have no chance to stumble across because Chek Jawa is too large to properly do a search.

All too soon, the tide still had to return and we left the shore promptly.

My friends couldn't resist climbing the Jejawi viewing tower and it was a good opportunity to take a group photo of them. Thank you all for your help today!

A more light hearted post with other sightings during the trip: http://wondercreation.blogspot.com/2008/08/chek-jawa-check-with-friends.html

Reference:

Kushner, R.B. and Hovel, K.A. (2006) Effects of native predators and eelgrass habitat structure on the introduced Asian mussel Musculista senhousia (Benson in Cantor) in southern California. Journal of Experimental Marine Biology and Ecology 332(2): 166-177.

Talk on "Life and Death at Chek Jawa" at IYOR launch

2008-07-30T14:20:00.004+08:00

Lauded for its high biodiversity with six distinct ecosystems, Chek Jawa received a ten year deferment from land reclamation in 2001 and has subsequently become a popular attraction among Singaporeans. However, a mass death of several marine animals occurred in January 2007. A study was later done to understand what contributed to the mass mortality event and evaluate the recovery of marine animals. It is true that a better understanding is essential to protect this fascinating shore. In this talk, Kok Sheng will share with the audience how is Chek Jawa faring and also his experiences and discoveries from the study.

About the speaker: Kok Sheng is currently an undergraduate in NUS, majoring in Life Sciences with specialization in Biology. In July 2007, he received the MOE Teaching Award. Kok Sheng has great interests in ecological work and did an UROPS (Undergraduate Research Opportunities Programme in Science) project under the supervision of N. Sivasothi, Peter Todd and Dan Rittschof. His project aimed to study the mass mortality and recruitment of macrofauna at Chek Jawa in Pulau Ubin. Since the project has application value in understanding and conserving the Singapore macrofauna at Chek Jawa, Kok Sheng's project has been featured in Protecting nature's beauty in The Straits Times (September 10, 2007), Embracing Passion Going Places, the NUS Advertorial in The Straits Times (March 25, 2008) and Tuesday Report: Children Of The Earth on Channel 8, Mediacorp TV (July 8, 2008). Kok Sheng is also a volunteer with TeamSeagrass, Naked Hermit Crabs and Raffles Museum of Biodiversity Research. He also runs the Chek Jawa Mortality and Recruitment Project blog and God's Wonderful Creation blog.

Date: 9 Aug- National Day (Sat)

Time: 10.30am

Venue: Function Hall, Botany Centre, Singapore Botanic Gardens (above Taman Serasi foodcourt), more about getting there.

Contact: iyor08singapore@gmail.com

More talks, events and fun during the International Year of the Reef (IYOR) launch here: http://iyor08singapore.blogspot.com/2008/07/9-aug-sat-reef-celebrations-launch-of.html

Chek Jawa after four months

2008-05-27T09:41:00.008+08:00

Following yesterday's post focusing on mainly button shells, sand stars and other marine animals, this post is a continuation on the other groups of animals that we have been monitoring. It has been four months since effort was taken to check the health of Chek Jawa properly.

As I entered the entrance of the sand bar, the first thing that caught my attention was the increase in the density and number of tubeworms. I remember the sand bar was quite barren last year.

Immediately, I went to check the anemone number 25 just beside the floating pontoon. Glad its still there but it doesn't look as green as it used to be. Instead it looks pale.

This photo was the last documentation we had of the exact anemone (number 25). This was taken by Ria Tan during January 2008. It shows a darker green coloration on the oral disk.

Many other anemones were also pale-looking as well. What caused this? Could it be the higher temperature in the weather this period? Could it be similar to the coral bleaching in Sentosa since carpet anemones also harbour zooxanthallae?

An interesting sight where a large volute shell is stuck to the mouth of the small carpet anemone. Could it be feeding a volute snail? I turned a bit to check, there was a striped hermit crab inside. Not sure if the hermit crab will survive hiding in the shell in the end.

Nevertheless, some anemones seem to be doing well. Yikang showed me this anemone which looks healthy in terms of colour and its size is humungeous.

Two-15cm rulers cannot even cover its diameter. It is about 35-40cm in diameter. Wow!

Now over to the peacock anemones. They seem to be doing okay.

The area where we used to survey peacock anemones still thrives with several of them. Can you see them from this photo.

The first photo of this collage is not a peacock anemone but I added it in since it is part of the previous photo.

How about sand dollars? They are doing very well mostly at the northern sand bar. Can you see the circular outlines?

A closer look reveals several sand dollar outlines and their movement.

They come in various sizes and cover a dense area of the sand bar.

How the sand dollars look like after removing the top sand.

This sand dollar is quite large as you can see with the hand of Yikang as a scale.

Ron who was guiding all along with Ubin volunteers told me that common sea stars were not spotted since the last time I did during January 2008. I believe their population has badly been depleted since the mass death. These common sea stars remaining are likely to be survival of the mass mortality event. Dr Lane suggested that they could have burrowed deep down to avoid the freshwater influx.

Good thing is that I have the GPS location of the isolated patch where common sea stars were last sighted. We took quite some time to search but to no avail. Finally I saw a star shaped thing with most part already burrowed. It is the common sea star and there's two, they were pseudo-copulating.

This is one of them.

And another one of the common sea star. Glad they are still around.

According to Run et al. (1988), the spawning season of these sea stars is in late June and July. So let's hope they will be back in larger numbers soon.

Last but definitely not the least, I went to check out the mussel beds. The mussel beds are fascinating because they were not around before the mass death. The conditions after the mass death created a niche for them to colonize since they are known to be invasive.

What intrigues me is that the huge patches of mussel beds moved westwards towards the high shore area. Can you see the patches nearer to the solitary sonneratia tree?

And more patches can be found nearer to the boardwalk and the rocks.

Though I didn't have the manpower to walk the boundaries with a GPS set, the estimated blue dotted part of the map shows the transition of these mussel beds westward. The maroon red parts are where the mussel beds were during January 2008.

Why did they move towards the higher shore direction. Well, we know that they like lower salinity. Could it be because the salinity seaward has higher and they prefer to be nearer to the high shore where there is a release of freshwater from the coastal forest or mangroves especially after a rain? This is a hypothesis.

Another discovery will be that these mussels have grown! They are about 2cm in length while those that I found in August last year were about 1cm in length.

I wonder if the sand stars eat these mussels to survive since button shells are now not around till later.

There's so much to learn from Chek Jawa given that it is really dynamic. Constant checking is important for us to understand the shore better and learn new things out from it. Let's hope the next check will reveal Chek Jawa to be recovering even better.

Reference:
Run, J. Q., C. P. Chen, K. H. Chang, and F. S. Chia. (1988). Mating behavior and reproductive cycle of Archaster typicus(Echinodermata: Asteroidea). Marine Biology 99: 247-253.

Where are the button shells?

2008-05-26T16:15:00.007+08:00

Last Thursday, most sand stars (Astropecten sp.) went missing at Changi shores. Many hypotheses were made and one of which is their food might be not around, thus explaining their absence. On Saturday, Mei lin smsed me that the Creative Kids group found about 10 sand stars and Chay Hoon found many sand stars too yesterday during their Chek Jawa guided walk.

I'm quite convinced that the sand stars are still around, but I believe in lower numbers and it might be due to the absence of button shells (Umbonium vestiarium), the food for the sand stars. I could not find any button shells at Changi last Thursday.

Thus I've decided to check out Chek Jawa with Yikang this morning to look for the button shells since Chek Jawa, as I what know, has the most extensive button shell beds in Singapore.

With the help of Adelle from Nparks, Yikang and I got a ride from the volunteer hub to Chek Jawa. At first entrance of the place, after three months since I last visited, I felt like homecoming. However, the weather did not look too good. Thank God He sustained the clouds and held the rain till we ended the trip and were back to the volunteer hub.

With the aid of GPS points made during our previous surveys, I went back to different exact plots where plentiful of button shells can be found. Berry and Zamri (1983) stated that button shells can be found hidden 0.5cm-1.5cm deep in clean sand, which is true based on my previous experiences. However, I could not find any plots like that at all today! So I dug very much deeper and saw many whitish shells. It was a tiring digging morning to check them out.

Some white shells looks quite indistinguishable of what it belongs to.

But a closer look shows that they are actually button shells.

But they are all dead.

It's not a mass mortality event caused by lowered salinity. It seems to match in line with my hypothesis stated in my God's wonderful creation blog.

According to Berry and Zamri (1983), it was stated that "progression of this cohort (of button shells) indicated that young settling in May-June grew to full size (11-13mm diameter) by January-March the following year and that virtually all died during their second year, presumably having spawned in March-May". This paper also stated "the older cohort were always more abundant upshore than downshore except in May 1982".

Does this explains the absence or death of button shells in May?

There are still some intact shells left but please do not take these shells away though the snail already died. That is because hermit crabs can also make use of the empty shell to reside in it like this one.

I am still relieved to see several sand stars around. We measured twenty over of them today. Wonder if they can survive without button shells for long. They do also feed on detritus.

These sea stars are quite easily spotted when we reached at 8am. But after 9am, it was difficult to find them! They burrow into the sand like the one on the right. This is because these stars have a circadian rhythm which I will study also soon.

That's about all for the button shells and sand stars observations. Meanwhile, other animals were found as well during our working time.

It's always heartening to see new life on the shore. The noble volute is laying eggs on the sand bar. Soon, we shall have many baby ones.

Like Changi, geographical sea hares can be found.

Yikang spotted for his first time an octopus while I was checking on my anemones.

He also chanced upon this brittlestar that is rather large in my opinion.

I'm glad to see the sandfish sea cucumbers still around. I accidentally stepped onto one since they burrowed and I couldn't see them while walking till suddenly a squirt of water flew up. Haha.

The Nparks volunteers found yet another sea cucumber.

This is not a sea cucumber but a peanut worm. My first time seeing it! Wow, Chek Jawa always reveal surprises with every visit. I never get bored with Chek Jawa. This used to be so common in the past that they take them for feeding worms.

I moved down southwards and check out the guided walk. Everyone was enjoying the session.

It's always good to restrict visitors to just the sand bar while hunter seekers bring the animals to a centralized location. Or else, Chek Jawa might be just trampled to death, or loved to death.

Low tide also means feeding time for shore birds!

I overturned rocks near the boardwalk area while approaching back to House no. 1 and found this hoof-shield limpet (Scutus sp.) like the one we found at Changi last week. Cool!

There is a Bailer volute (Melo melo) at the rescue tank of House no. 1. Wow, I've never seen it before and I wonder where it came from.

At the same time, I got my first hand experience to see the fascinating and magnificient mural done during the May Day Outreach.

House no. 1 was also airing the Remember Chek Jawa film as well.

Before leaving, a hornbill was spotted, though this was the only shot I got before it decided to fly away. Hehe.

Wow, what a great day. The rain poured like nobody's business while we were back at the jetty area. We had a good time chatting and refilling ourselves with 100 plus till the rain stopped. The sky cleared up and I took a photo of Pulau Sekudu with a mountain at Johor on the way back. Nice to also get to know some Ubin volunteers today too. Thanks Yikang for coming to help as well.

I have YET cover everything today in this single post. A trip to Chek Jawa after three months means I have to check out also the other groups of marine animals that we used to monitor. The last monitoring session was at January 2008! About four months ago and it has been some time we monitored or checked them already.

If you want to know how the other groups of animals (except button shells and sand stars discussed in this post) fare now, look out for an upcoming post on their progress.

Reference:
Berry, A.J. and Zamri bin Othman (1983). An annual cycle of recruitment, growth and production in a Malaysian population of the trochacean gastropod Umbonium vestiarium (L.). Estuarine, Coastal and Shelf Science 17: 357–363.

Talk at NUS Faculty of Science Open House

2008-05-16T13:26:00.005+08:00

Dear all, I will be sharing with prospective students during NUS Science Open House on Sat 24/5/08 regarding my experience in doing a research project on Chek Jawa. Feel free to come and listen. :-)

Date: 24 May 2008

Location: LT27

Talk Title: Life and death at Chek Jawa. A UROPs research experience in Life Sciences

Talk duration: 15 min (between 2:00-3:30pm)

Speaker name: Mr. LOH Kok Sheng

Speaker profile:

Mr. Loh graduated from Serangoon Junior College and joined NUS in 2005, majoring in life Sciences with specialization in Biology. In July 2007, he received the MOE Teaching Award. Mr. Loh has great interests in ecological work and did an UROPS project under the supervision of N. Sivasothi, Peter Todd and Dan Rittschof. His project aimed to study the mass mortality and recruitment of macrofauna at Chek Jawa in Pulau Ubin. Since the project has application value in understanding and conserving the Singapore macrofauna at Chek Jawa, Mr. Loh’s achievement has been featured in Embracing passion, NUS Advertorial and The Straits Time (March 25 2008). In this talk, Mr. Loh will share with the audience his experience in project work (UROPS) in Life Sciences and highlight those qualities that he has developed through this project as a junior scientist.

More about the Open House: http://www.science.nus.edu.sg/openhouse/index.htm

Anecdotal observations of stress recently

2008-04-13T22:32:00.009+08:00

On 12 April 2008, a group of volunteers from Team Seagrass and Chek Jawa guides were out at Chek Jawa. There were some blog postings reported about some signs of unhealthy animals especially for sea stars and a few carpet anemones. Below are a compilation of their observations from various blog posts. All photos and commentary credit to the author of that particular post.

1. Ria Tan's Wildfilm blog: Chek Jawa with TeamSeagrass

"Also rather disturbing, I encountered TWO Biscuit sea stars (Goniodiscaster scabra) that looked like they were unwell. Here's the underside of the first one. The tip of the arm looks more like it's disintegrating rather than having been chomped on by a predator."

"Here's the upperside of the same sea star."

"Nearby, I found another sea star with similar injuries. Oh dear. The last time sea stars disintegrated when there was massive flooding in Johor in early 2007, resulting in a drop in salinity at Chek Jawa. This badly affected some of the marinelife there, especially the sea stars and carpet anemones. And it has been raining quite a bit recently..."

2. Sam Yeo's Ramblings of a Peculiar Nature blog: Back to Chek Jawa: Sat, 12 March 2008

"Found this dead biscuit star under the boardwalk. It looked like it imploded and something that happened to many of the sea creatures during the mass death of Chek Jawa in 2007. Could it be due to the rain of recent days?"

3. Ron Yeo's The Tide Chaser blog: Chek Jawa Walk on 12 Apr 2008

"Some sandstars don't look that healthy though. I found at least 2 more sandstars, which look like they were disintegrating, and part of their body were turning white in colour."

"We also saw a few overturned carpet anemones, and placed them in little tidal pools."

"This poor sea cucumber also looks like it's slowly rotting.The last time we witness all the above phenomenon was during last year's flood, which brought a lot of fresh water into Chek Jawa and many animals die! That certainly got me a little worried, since we have been experiencing heavy rainfall for the past few days."

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According to my study, three areas were hypothesized to cause hyposalinity at Chek Jawa.

1. Increase in discharge of freshwater output from Johor River
2. Direct rainfall

3. Incidence of low tides when point 1 and/or 2 is occuring

Due to the Johor river water level website that is inaccessible at the moment, I can't comment on point 1. Neither do I purchase the rainfall data every month for point 2. But it is true that recently there was quite a number of heavy rain events over the week which coincidented with the low spring tides that started on Monday (7th April 2008) till Sunday (13th April 2008). Though the low tide series is well recorded in the Singapore Tide Tables Year 2008, quantitative data is needed for the rainfall, preferably from Pulau Tekong station.

Echinoderms are stenohaline (unable to withstand wide variation in salinity of surrounding water) in nature and therefore it is not a surprise to see them disintegrating when salinity is lowered beyond a certain limit, which the latter needs to be verified. Anemones like carpet anemones also respond to extreme lowering of salinity. Below is a flow chart of the effects of hyposalinity.

It is yet heartening on another side that the health of Chek Jawa is being looked after and checked by shore volunteers.

Reference

Engebretson, H and Martin, KLM (1994). “Effects of decreased salinity on expulsion of zooxanthellae in the symbiotic sea anemone Anthopleura elegantissima.” Pacific Science, Vol. 48, no. 4, pp. 446-457

Grain size distribution analysis at Chek Jawa

2008-04-12T21:44:00.002+08:00

Remember the post made in February regarding Studying substrate variability in Chek Jawa by GIS? It is a team effort made by Yikang, Yong Jian and Jing Kai from NUS Geography department. They went out in February to collect sediments from the transects my project was doing. More about their adventures in my CJ project blog and Ria's wildfilms blog.

The team has done up a website: http://www.rainmuse.com/chekjawa/ where you can conveniently have access to their work. It's interactive, informative and beautiful! Here's some screenshots from the webpage.

The homepage of the website shows the grain size distribution using a Google Map. It was done using GIS applications on the sediment data collected from the transect. I like how you can click on the right side the different sediment size classes and the distribution will be shown on the Google Earth image. Try exploring around to find out more.

You can get to know more about their background, study area, sorting of sediments and most importantly the objectives. To summarise, the main objective will be to gain an insight into the coastal processes affecting the beach at Chek Jawa, in particular the grain size sorting process and the variables that influence this phenomenon. Importantly, this project aims to show that GIS aids in data collection, visualization and manipulation.

If you are curious how they conducted their study, feel free to read more about their sampling, sieving and interpolation method. I believe you will be amazed how technology can aid in research, especially in the area of GIS, which in this project can help to do interpolations of grain distribution in Chek Jawa.

Analysis of results mainly show:

1. Velocity of less than 0.5 m/sec in this area (Wong, 1985) may prove to be significant as from the Hjulstrom curve would imply sediments between 0.01 mm and 0.15 mm may be affected due to sufficient energy of the tidal streams

2. Presence of river indicates source of sediments as well as a counteracting force to the long shore current

3. The sand bar may be the resultant feature of the tidal flow and the river flow due to the lowering of energy levels

4. Selective sorting may also have taken place as can be seen from the progressive reduction in grain sizes further away from the river where fluvial influence is the greatest (Self, 1977)

The last segment explains more about GIS, their limitations, and conclusion.

The team ended off with "This case can serve as a starting point which can be expanded to the other beaches in Singapore, especially in context of the heavy modifications to the coastline in recent years. Knowing how sand grains are sorted can possibly give an idea of the energy level of a particular beach environment (Nordstrom, 1977). This will have implications on the methods of beach protection employed. For instance, predicting the possible morphological changes to the beach should beach nourishment activities take place will help in determining the effectiveness of the activities."

Find out more about their work here: http://www.rainmuse.com/chekjawa/

a big THANK YOU

2008-03-27T12:21:00.002+08:00

Monday was the day where my report had to be submitted to the Department office by hook or by crook. Somehow having a dateline is a good thing. It compells me to tighten up my analysis and my writeup, polish it and get ready to present as an end-result. It was a huge struggle trying to complete the report. I'll probably debrief about my project experiences another time. But I want to take this opportunity to thank those who have made my project possible. My vocab and english is not so powerful, so please don't feel offended if I didnt thank you enough with my words. In my heart I am really grateful.

Firstly, would like to thank my main supervisor, Siva (in orange) and also co-supervisor Dr Dan (with a panama hat).

Another of my co-supervisor is Dr Todd from Marine lab. It was the first time he visited Chek Jawa!

Thank you supervisors for being willing to guide, lead, support and encourage me through various ways. Thanks for the great ideas and also for being there when I felt lost and helpless. I might not be the best researcher but I hope my hardwork will make you all proud of me. I have learnt a lot of skills and experiences under you all. They are really useful and invaluable. Thanks for this great journey.

Though not my supervisor, Ria has been significant in my project. She was the one who introduced me to Siva when I thought of working on the mass death at Chek Jawa. Later, she supported me through various many ways. She is also always available to come down frequently to do the monitoring work and even transect work herself. That's really very impressive! She also provided a lot of photos and anecdotal observations of CJ, updating me whenever Johor floods, bringing food and canned drinks for all the volunteers etc etc etc. Thank you Ria!

Another important group of people that I must thank are every single individual that helped me before at my field trips :-)

I am total amazed at how many people that have helped me before! Without volunteers, I can't possibly do this project. I hope you enjoyed working at Chek Jawa. Thank you everyone who helped me before.

Especially want to thank those who helped me not only once, but twice or more. They are Yijun, Pei Hao, Yuchen, Yujie, Raymond, Siyang, Bingquan, Yilin, Robyn, Robert, Liana, July, Yikang, Khairul, Geraldine, Kian Wah, Shuyi, Gerald, Alex, Sam, Nicholas, Gun Kiat and of course Ron.

Would like to thank Yikang and Siyang extra more for being there even during recce trips where we had to cycle up and down from jetty to CJ. Those were the days. We had to wait for an hour long for the boat. Both of you have really ease my project load a lot. Without partnering help like yours, I would have collapsed working alone. Haha.

I would also like to thank the NUS marine (Angie) and eco lab (Tommy) for the equipments. Especially grateful to Ewen for being there and willing to help me with statistics. Also to thank Prof Matthias Roth, Dr Lim Han She and Prof Wong Poh Poh from Geography Department for all the help with regards to the physical aspect of my project. Thanks Dr Daphne Fautin for your great advice on anemones, Joseph Lai for the GPS points from 2001, Zeehan for the photos from previous transects, Cynthia for sharing your project and ideas on salinity, Siti for giving invaluable help regarding how to design a transect sampling method and many others whom I've forgotten to acknowledge. Thank you Uncle Chu for being at all times to fetch us to and fro at Ubin. Your humility impresses me.

Thank you Nparks for allowing me to work at this great place, Chek Jawa. Thank you Choon Beng and Adelle for bridging help along the way at Ubin. Still remember during the earlier days where Choon Beng has to prepare a bicycle the night before so I can use it early next morning for dawn trips. Thank you NUS for this UROPs opportunity. Thanks for the publicities on my project, it gave me a little fame. More importantly, it gave Chek Jawa more attention, horray!

There's simply too many to thank from a blessed heart. Haha. Sorry if I missed out any. But I must also thank my family for unceasingly helping me prepare for trips in terms of logistics and also washing all the sandy and dirty equipment when I come back.

Last but definitely not the least, thank God for being the provider of everything. Thank you for being so real in this period. You have showered so much blessing onto my project, positioning people to help me, ensuring there is no rain in every monitoring or transect session irregardless if its the monsoon season or not. You are truly wonderful!

I sounded like as if this is really the end. Its NOT. Haha. Should be preparing to submit this for a journal, after examinations. Also, Yikang's substrate studies is still ongoing. Hopefully, some people will continue related works in the future after me. Continue to hear more from this blog.

NUS advertorial featuring my project

2008-03-25T10:48:00.002+08:00

The Straits Time, 25 March 2008

Thanks Siva for recommending me to be featured.

Mass death of sea star on Kent beach

2008-03-13T13:44:00.002+08:00

Amazing picture of thousands of dead starfish washed up on Kent beach
By VANESSA ALLEN at dailymail.co.uk

For five miles they stretched along the beaches, a gruesome line of dead starfish.

Fishermen and bird-watchers at Pegwell Bay near Sandwich, Kent, discovered a "carpet" of thousands of the creatures lying on the sand just above the water line.

And on the beach at nearby Sandwich Bay, thousands more were photographed by Tony Flashman.

"The dead starfish stretched as far as you could see in both directions," said Mr Flashman, of Kingsdown, Deal.

Environment Agency officials are investigating what could have killed the starfish, which had been feeding on mussel beds.

They do not believe the deaths were linked to the recent storms because they were first reported to them last week.

They have also ruled out pollution or anything to do with climate change as the cause.

The agency said officials would investigate if the starfish were discarded by fishermen after the mussel beds were dredged.

A spokesman said: "Starfish congregate in vast numbers in some areas and feed on shellfish, so if the seabed was dredged then the starfish would inevitably have been caught in huge numbers."

Another theory is that the starfish had run out of mussels to eat and had moved into shallow water in the search for food.

The starfish bodies are not harmful and will probably be eaten by seagulls, the agency said.

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Thanks for Samson's post that alerted me on this similar event to mass death of Chek Jawa, though suspected not to be caused by the recent storms.

Studying substrate variability in Chek Jawa by GIS

2008-02-29T18:38:00.003+08:00

After collecting specimens of substrate along the transects last week, Yikang, Yong Jian and Jing Kai who are working on the GIS aspect of the substrate variability in Chek Jawa were back in NUS Geo Lab throughout the midterm break.

Studying sediments of Chek Jawa is no mean feat. It first involves scrapping off the collected substrate specimens onto a metal petri dish. Looks easy?

Here are the total number of samples they had to each test for substrate composition. And Yikang told me each bottle will take them 15-30minutes.

It was quite interesting to see different colours of sand and mud and other substrate types in different samples, which reflects possible wide variations.

As the sediments are wet, the team had to dry them at an oven for 15o degrees for half an hour. It's like baking cookies.

After which, the dried sediments of each sample will have to queue up to be sieved by this machine in the lab. Each sieving process takes 15 minutes. And all these work went on for four consecutive days before the manual processes were done.

On Thursday night, the team finally could enjoy the fruits of their labour. They displayed the results onto a GIS map where data interpolation can be peformed. We were pleasantly glad to see that there was some trends where the northern part of Chek Jawa has coarsest sediments. The mangroves end of Chek Jawa has the finest sediments. What caught my attention was that the sandbar "boomerang" shape was not visible in the map. That means that there are indeed more than one can expect when we predict the substrate variability in Chek Jawa.

Personally, I'm excited to see their analysis and they will be putting up a website soon to share their data and discussions. Let's watch out for it, I'll post it here too when it is up.

Reflections on Day 2 of February Transect

2008-02-24T17:07:00.000+08:00

I was not able to be there on Day 2 of our February transect but the transect has to go on.

This is a photo showing Yong Jian setting up transect one on Day 2.

Day 2 is possible with Yikang who volunteers to help head the trip together with friends who volunteered. Yikang has written a reflection of that day of field work and I hope to share with you here.

"Today Kok Sheng is occupied with a lab session, so I have to kind of “take charge” of today’s transect session. I was a little anxious initially. But everything went smoothly thanks to the stellar team of Damien, Jingkai, Ria, Weilong and Yongjian.

Today was the first trip to Chek Jawa for Damien and Weilong, but they only took a while to get into the hang of things. Thanks Damien for volunteering and wish you all the best in your final year. I hope Weilong found the whole experience fruitful as he skipped two lectures to help out. Only got to know this today. Sorry Weilong didn’t get the opportunity to show you a sea star; couldn’t find sea stars that day in the area.

Thanks Yongjian and Jingkai for being so dependable and see you guys in geo lab. Another big thank you to Ria for covering me in T2 when I’m off video-ing T1, the mini guided walk, and the yusheng (which kind of reminds me of seagrass). Last but not least, thank you KS for the opportunity of doing useful work for the 'endangered' CJ that is close to our hearts."

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Below are more photos to share, from Day 1 taken by Yikang.

Adeline flaunts the datasheet while setting up the transect.

And all these require team work from volunteers. This is because the tide window is as short as 3 hours. Me alone will not be able to do all these.

Denise and Ron.

Siyang and Denise, chatting and resting as we finally completed the transect in time before sunset.

I would like to thank Yikang and the whole team for sacrificng your weekdays to do work on the shore. They did a wonderful job on day 2, ending the trip earlier than expected despite we were shorthanded.

The February transect trips conclude my field trips for my study at Chek Jawa and soon I will be doing analysis and writing of my report due end March.

Along the way, I will continue to share here on the progresses of the project. Do watch out for them.

February Transect Day 1

2008-02-21T10:13:00.009+08:00

Time passes fast, and its time for the last series of transect for my study at Chek Jawa. This time, we are doing something special with the help of Yikang and his team. On top of doing our usual quadrat monitoring, we are also testing the sediment type of each quadrat location so as to better understand the substrate types of the study area.

On a sunny afternoon, friends from all over the place come together at Changi as we set off for Ubin. It was a weekday yet many took leave or special time off to volunteer for today's transect.

Arriving at the jetty of Pulau Ubin, we proceeded towards Uncle Chu's van. We also noted by the rocks by the sides of the jetty are covered with layers of mussel beds which has been persisting for quite some time.

Reaching Chek Jawa, we settled the logistics and off we went to the shore. As usual, July here is carrying the research in progress signboard which is important to inform the public of why we are down at the flat.

Day 1 of transect usually mean we will head north and finish the last 4 lines first. The greenish patch you see from this photos are the coverings of the algae on top of mussel beds.

After a mock up briefing, it was time to start setting up the transect line. And wow, this task was indeed challenging since the weather was extremely windy. The lines were easily blown aside and setting a straight line means lots of tug of wars.

Nevertheless, the garang team managed to set quite decent lines with the aid of the huge colour flags that ensured line of sight from the start points to the end points that were permanent. After a few rounds of trying out, most of us managed to figure the best way to lay lines with the windy condition, and hope these improvements can be of great use for day 2 later.

Meanwhile, while working, lots of Lesser-crested terns (Sterna bengalensis) can be found feeding and resting at the tip of the sandbar.

They are very shy, like most birds, and will fly off when I tried coming closer to them.

Flying higher and higher.

The tide was not very low but thankfully just sufficient for us to conduct the transect.

Unfortunately, Chek Jawa is too big to be sampled with justice over a short tide window period. This photo shows an example of a non biased sampling method that may not capture the animals we want. This carpet anemone was just a few centimeters away from our designated quadrat. If we just put the quadrat showing the carpet anemone, it will be biased.

Some of the other animals found include this small clump of mussels stick on the sand substrate instead of the usual hard ones.

These sandfish sea cucumbers usually start appearing when evening comes.

The seahare season was not over yet, and many of them can still be spotted.

Chek Jawa also is home to a rare seagrass, Halophila beccarii which was named after the intrepid Italian botanist-explorer, Odoardo Beccari.

More marine creatures: sea cucumbers, razor shell and sandstars.

Amazingly, I spotted a few dugong feeding trails like how Teamseagrass saw them during the mass death last Jan 2007. Dugongs are still present around Chek Jawa waters and indeed seagrasses are important food staples for them. It's fascinating how these trails appear during the mass death as an encouragement that life goes on and now towards the end of my study, Chek Jawa is indeed doing well recovering.

The teams worked hard and I am deeply thankful for their effort. This is one of the two teams with Denise, Ron, Siyang and Yong Jian (left to right).

Also, not forgetting to mention Pui San, Adeline, Jing Kai and July from the other team.

Here we have the geographer, Yikang, doing the sediment collection from the quadrat sites.

That involves digging out of a thumb size of substrate, which then we will bring back to the lab to test. More work.

Soon, the sun sets and it was time to leave.

Here's a last photo of July pointing to something in the cloud.

One more day to go...

Chek Jawa survived the monsoon period

2008-01-25T22:38:00.000+08:00

On 22nd January 2008, many friends and I returned to Chek Jawa for a monitoring health check. First thing we can all happily declare (at least for now), Chek Jawa has survived the monsoon period. There was no mass death occurence.

This time, I had the honour to bring with us a team of three mediacorp personnel: namely the producer, soundman and the funny cameraman to share with the TV audience in near future about Chek Jawa, our work there, and a little more on myself.

That also means I had to also leave most of the people to do the monitoring tasks as I tried my best to share with the TV crew the facts and stories throughout the trip. Interestingly, I chanced upon a marine professor, Prof Chris Todd, from University of St Andrews. Went to approach him to check whether he had a permit to get down to the flat and I slowly understood he is doing marine work and writing an intertidal book. Exchanged contacts before he left.

During my time away with the crew, I am glad to have several trusty people that did their job well. Ria the carpet anemone head with her team-mates: Sam and Wei Ching. They did the checks for the remaining less than 20 carpet anemones as more and more went missing over the months. They are able to uproot themselves and move with the current so either they died or they migrated.

Ron, July and Alicia are those who worked on monitoring peacock anemones where we went back to the five 10x10m fixed quadrats to search for them and do measurements. We also have the intrepid and longsuffering team doing the mussel bed mapping consisting of Alex and Audrey. Armed with a GPS set, they worked the boundaries of the patches of mussel bed so that we can later find out the relative positions of these invasive species patches changing over months. One covered the northern Chek Jawa and the other southern.

Last but not the least of course, we have the salinity checks done by Yikang and Chun How. Well, from their measurements, we are relieved to know that the salinity is normal at about 28ppt, which is norm for Chek Jawa as the salinity is affected by its proximity to the river mouth of Sungei Johor. They also did the photographing of the above bird's eye view and also the other 19 photographs to compare with those taken before the mass death in Chek Jawa.

I apologise for lack of enough photos as I didn't have time to take photos due to work with the crew. Thank you Yikang for the 2 photos in this post.

To end off, share with you a photo of the crew and I. :-)

Other blog entries about the trip

Ria's wildfilm blog
July's discovery blog
Sam's blog ramblings of a peculiar nature

Christmas monitoring with the volunteers

2007-12-28T11:53:00.000+08:00

On 25th Dec 2007 Christmas Day, a gang of enthusiastic volunteers and I took a bumboat, not a cruise. We arrived at Pulau Ubin and off we went, together with Uncle Chu's van to Chek Jawa.

Greeting us in the intertidal flat were these great billed heron (Ardea sumatrana) and grey heron (Ardea cinerea). Apparently, the great billed heron caught a fish and the latter came trying to snatch the prized catch.

The tide was still receding while I was trying to show Liana where her peacock anemone study sites are. And along the way, we saw even more shore birds feeding and roaming about at the flats of Chek Jawa.

Recovery has been good. At first, carpet anemones returned mostly at areas where there are seagrasses or seaweed. It is heartening to see quite a number of new recruits at the sandbar now. Before the mass death, the sandbar was landmined with these carpet anemones. However, almost all of them on the sandbar were wiped out after the mass death this January.

Checking back to the transect 3 start point where the cake seastar (Anthenea aspera) was found the day before, we have realized it has moved about 100m away. Nevertheless, I marked its location temporarily for the volunteers to take a look after they finish their work at sunset.

Featuring the long suffering carpet anemone team, we have the good old usual strong team of Ria and Yuchen. Joining them for the first time are Sam (2nd from left) and Xiuli (extreme right).

This time, Yikang was my volunteer to do the salinity check from extreme north all the way to the House no. 1 jetty. The salinity was pretty normal at about 27 ppt, considering there was no longlasting rain.

I took the last opportunity to check the health of coral rubble extensively for this is the last of 0.0m tide till the end of my project.

Unfortunately, this fish apparently got chomped off by its predator.

The carpet anemones at the coral rubble area were as big as usual. Most are thriving well, however a few looked pretty puffed up and unhealthy.

Carpet anemone with Porites hard coral.

The mystery of the "coral" found in July has been unveiled as the super low tide uncovered the whole organism in dry land.

It is not a coral in closeup. They are zoanthids.

Quite a number of these adult sized noble volutes (Cymbiola nobilis) were spotted. And they are proliferating well. Check out Joseph Lai's flickr gallery where he posted many of his fantastic Chek Jawa photos including one noble volute laying translucent egg capsules.

A cleanup was done in Pulau Sekudu a couple of days ago. Pulau Sekudu is considered as part of the whole Chek Jawa bigger ecosystem. It is a seeding ground when Chek Jawa got impacted by the mass death. Indeed, we need to maintain these seeding areas which act as control. Another of such important shores must be Changi Beach. On Boxing day, we found many juveniles of all sorts of marine creatures on the shore of Changi. Changi is like a mini-Chek Jawa and indeed the surrounding northern shores are very interconnected. Destroying one will affect all.

At the edge facing Sekudu, there are many sponges growing well on the rocks.

The sponges come in all sorts of shapes and colours, slowly revealing the good old Chek Jawa before the mass death.

Not only does the coral rubble have the hard coral of Porites species, it also houses the flowery soft corals. This one in particular is very small in size, again showing that recovery is taking place and it is recent and ongoing at the same time.

More marine organisms thriving at the rich yet fragile coral rubble are the fanworm, colonial ascidians, warty sea cucumber and the Salmacis sea urchin (Salmacis sp.), from top left to bottom right.

Meanwhile, the volunteers are still working hard including Juanhui, having to help me take 19 specific landscape photographs.

Pausing from their conscientious work, the peacock anemone team posed for a group photo. From left to right: Liana, Shuyi, Peiya and Kenny.

I'm sorry I forgot to take a photo of the mussel bed monitoring team with Hamsa and Alex together. They had to work solo, covering the north and south of the mussel bed patches with the GPS. Alex, however pointed out to me that the shore birds were feeding on the mussel beds. As we have pondered, are the mussel beds friends or foes, I believe its a friend in this case, as food for migratory birds.

Cropping out from the above photos, I realized at home that opposite at the shores of Johor, there are groups of people at their intertidal areas too. Are they nature lovers or simply poachers? Being in close proximity and part of the interconnectedness, this mysterious Malaysia shore indeed is crucial for the ecosystem of Chek Jawa.

Juanhui pointed out to me that there are also many small sand dollars on the sandbar.

And they could be even as small as about 1cm in diameter. This proves to show that ecosystems are dynamic where the young replaces the old, with a turnover rate.

The last task for everyone will be to search for populations of sandstars after about 6.30pm. It is only during the evening then these Astropecten species of sand stars start to appear. Yuchen showed his dedicated hunterseeking skills by being on all fours.

It was nice to have many friends working together. Hamsa is on the extreme left of the photo.

Yuchen gamely and creatively used the sandfish sea cucumber and sand stars to show the Singapore flag. We as Singaporeans am proud and should continue to show to the rest of the world that conservation is possible despite developments only if we allow them to coexist just like Pulau Semakau.

We found plentiful of sandstars hiding beneath and above the sand. It is when you are bothered to look, then you will realize the natural heritage we still possess. If we dismiss everything is gone, we might just lose them forever.

With compliments to Ria, we toasted a Merry Christmas and happy New Year on the sandbar to everyone. This marks the last monitoring for 2007.

Thank you everyone for making this Christmas exceptionally meaningful. You've indeed made a difference.

Links of other blog posts related to these 3 days series of monitoring trips:

23/12/07

Sijie's nature scouters blog

24/12/07

July's discovery blog
Ria's wildfilms blog

25/12/07

Joseph Lai's flying fish friends blog
Liana Tang's nearly lucid blog
Ria's wildfilms blog
Shuyi's personal blog

December Transect Day 2

2007-12-26T15:02:00.000+08:00

Introducing the teams for day 2: here we have Khairul, Vincent and Alex with transect two. Too bad they are quite far from this photo and I don't have another shot of them in work since time was tight. On the left is July, my assistant this time. Without him, I won't be able to do a lot within a few hours of tide window.

The other team consisted of (from left to right) Yong Xiang, Qian Yue, Apple and Yikang. I salute them for their efforts. Wind was strong and the tapes were as strong as a tug of war to adjust in the correct direction. Never never underestimate the power of nature.

Chek Jawa was in perfect weather, again we were so blessed. Many different shorebirds land on the intertidal flat to rest and feed.

A flock of Great crested-tern along the sandbar with Tekong breakwater and Pengarang forest in the background.

The carpet anemones are thriving in the northern sandbar edges. This one is caught feeding on a crab.

It may be hard to imagine but carpet anemones are not flowers or plants. They are animals, inveterbrates that feed through their central mouth which is also their anus.

Day 2 proves to be starry! In an unexpected area of sandbar, something orangey and striking caught my attention despite I was walking very quickly.

It proves to be a stunning cake seastar (Anthenea aspera) in a colour I have not encountered before. It is about 15-18 cm in diameter. Ria commented that it can feed on the populations of button shells found nearby. That may explain why it is found on the sandbar instead of coral rubble.

Together with July, I found another star. The common sea star (Archaster typicus) that were wiped out totally after the mass death early this year. A month ago, Ron spotted the first one that appeared though its arms were bit broken. I'm glad to witness their return personally, in healthy state.

Their diameter is about 15cm. Will they survive through the current monsoon season till Feb 2008? We will know the next time we monitor at end January.

Given that it is the last series of 0.0m tides till April 2008 and that I had the assistance from July, I had a bit of time to check out the health of coral rubble since it has been raining quite a lot for the past weeks.

And surprise! The third star of Chek Jawa, the knobbly seastar (Protoreaster nodosus), which were also wiped out after mass death. This one is not the same as the previous first one found last month.

The coral rubble was doing well and I got to see stony boulder corals (Porites sp.) at Chek Jawa for the first time. Thanks to the very low tides especially many of these corals were exposed.

Sea squirts or tunicates were also abundant.

Sponges that melted away during the mass death returned in all sorts of colours.

And also in all types of shapes.

Juvenile growths of sea fans were also found.

Coral rubble is also the only area in Chek Jawa to find the tape seagrass (Enhalus acoroides). Other types of seagrasses grow in abundance elsewhere at the seagrass lagoon and edges of sandbars.

Ria and I found this abundant bubu trap with large fishes like the groupers inside. If we didn't save them, they will die eventually.

Before leaving, I chanced upon this seapen with an insect-like organism. Any idea what is it?

We left with a spectacular full moon and clear skies of constellations.

Big thank you to July, Yikang, Yong Xiang, Apple, Qian Yue, Vincent, Khairul, Alex and Ria for the help.

December Transect Day 1

2007-12-23T22:28:00.001+08:00

After series of floods from Johor and also the ongoing monsoon storms, we were kind of worried if Chek Jawa could survive through times of prolonged decrease in salinity. 23rd Dec finally arrive where we have this week the last series of good 0.0m tides. The next such series will be after May 2008. This afternoon, weather looks really good in the beginning. (photo by Gun Kiat)

To advance to the northern sandbar while the southern one is submerged in retreating tides, we have to cross this prominent part where many of those whom joined before will know. (photo by Liana)

After briefing, we were ready to go! This time, we were armed with flags made of corrugated material that are waterproof, no more soggy vanguard sheet that are disposable after each use. (photo by Liana)

Near the coastal side, Gun Kiat and I saw this snake. Thanks Sijie and Chee Kong for the id. This is the striped bronzeback (Dendrelaphis caudolineatus).

Near transect three endpoints, we saw many of these yellowish things. I've seen it feature in someone's blog before but forgotten. Any idea what are they?

The mussel beds never fail to amaze.

The top part where the seaweed covers becomes white. Why?

I have no idea too. The seaweed, Ulva reticulata, turns white covering the mussel beds.

I saw more baby carpet anemones at the fringes of the northern sandbar where Halophila spinulosa thrive. Will they be wiped out by the end of January next year?

The team also found a sea star. Ron and I suspected it to be a cake sea star.

To id sea stars, there is a need to turn over and take a close up photo too. Just that I am too lazy now to check the BP guidebook on echinoderms.

We also chanced upon many shorebirds feeding at the intertidal area. Overlooking the boat is Johor. If you are sharp, there are also a few people exploring the shores during low tide today. Wonder how is their side like? Is it a good seeding ground for Chek Jawa?

And drum rolls, we have the intrepid teams for today. From left to right: Samantha, Laxton, Sijie and Yikang. Nice to know Samantha and Laxton for the first time, from Naked Hermit Crabs.

I got myself this time an assistant to help me take LIT videos. He is Gun Kiat. Done a marvellous job. He also helped me to measure salinity and carry some stuffs.

And this is the other team with Yijun, Bingquan, Nicholas and Liana! Basically the 2 teams are one of the most efficient. Finished everything about an hour before hand. Perhaps we also started bit earlier. Haha.

As usual, rolling back the tapes is not an easy job. Got to ensure 100m of tape do not get entangled and also get rid of most sand and mud from their surface. Yikang obviously showed how difficult it could be in an exaggerated manner.

And as predicted, working during December means be prepared to work in the rain. (photo by Gun Kiat)

We were pretty blessed. Changi, Johor, Tekong and West from Ubin were raining. But not Chek Jawa. Thank God indeed. Or else working in the rain would be really tough since there is so many things to juggle with. (photo by Gun Kiat)

When everyone was done with work and proceeded to clean up, Gun Kiat and I proceeded to do more salinity checks. Very timely, dark clouds loomed and threatened to pour. I chanced upon a nudibranch whom the Semakau guides people saw twice today. It was curled up, and I was waiting for it to open to take a photo. While waiting, it was unfortunately both of us got soaked as rain came finally. (photo by Gun Kiat)

And this is the one I was waiting for.

Nevertheless, glad the rest were not affected by the sudden heavy outpour. Would like to thank everyone who helped out today. Hope that tomorrow and Tuesday will be also as great as today.

Checking Chek Jawa out

2007-12-09T22:44:00.000+08:00

This time, Justin and Ivan joined me to Chek Jawa to check out how is the health of the shore after all the Johor floods and monsoon rains.

As commented by Ron, there are an increase of baby horseshoe crabs in CJ. He shared that before the mass death, he only recalled seeing one only. Changes in environment means changes in ecology balances and changes in populations.

This catfish was doing fine at tidal pools.

Warty sea cucumber by the edge of the seawater.

One of the changes will be the increase in runoff towards the sea. While checking out my transect poles, that some gone missing, realized that recent increase in rain has led to more freshwater input from Ubin, the rain itself and also from the huge Johor river mouth.

We checked the salinity over different areas of CJ and realized they were as low as 19.9-23.4ppt as compared to average 27-29ppt in July. Of course, we have to factor today's rain, but imagine how low salinity can be and how it can affect the marine community.

Behind the forest front in above photo, I saw A LOT of rubbish!

Photos of Justin and Ivan trying to take salinity readings from boardwalk as tide today was not ideally low.

And the probe goes down.

Lastly, something off topic, they have cleared the way up to the rear CJ beacon.

Johor on red alert as floods hit

2007-12-06T22:35:00.000+08:00

Meera Vijayan and Farik Zolkepli, The Star 6 Dec 07

JOHOR BARU: Continuous rainfall over the last 24 hours has caused floods in five districts in Johor.

As at 2pm Thursday, over 1,000 victims had been evacuated in Johor Baru, Segamat, Batu Pahat, Kota Tinggi and Kluang. The Meteorological Services Department has also upgraded its heavy rain warning from orange to red for Kelantan, Terengganu and northern Pahang, and advised the people to be on alert for floods.

The red stage warning refers to tropical storm or typhoon with sustained wind speed of at least 60kmph accompanied by moderate to heavy rain, while orange stage means moderate monsoon rain is occurring and expected to continue for several hours.

A bridge from Labis to Segamat near Sungai Karas has been cut off and was accessible only to heavy vehicles.

Johor Police Chief Dep Comm Datuk Hussin Ismail said that police had opened their 24-hour flood operations room as of 8am on Thursday.

“We are prepared for the floods and all our men are on standby,” he said.

State Women, Family and Community Development Committee chairman Dr Robia Kosai said that the Welfare Department had already sent out food and emergency supplies to all districts as of Wednesday.

“The supplies have even been sent out to the islands off Mersing and interior areas like Kampung Peta in Endau-Rompin,” she confirmed.

For more information, the public can contact the police hotline at 07) 221-6393 and the Fire and Rescue Department hotline at 07) 224-7444.

The Meteorological Services Department also issued a first category warning on strong winds and rough seas for the coastal waters off Kelantan, Terengganu, Pahang, east Johor, Sarawak and Sabah. The first category warning shows strong northesterly winds of 4050kmph with waves up to 3.5m.

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Will Chek Jawa tide through this series of monsoon storms?

More recent reports:
7/12/07 3,200 flee Johor floods
7/12/07 Johor, Pahang on red alert as rivers breach danger levels
7/12/07 Johor floods recede, except in Segamat

Appeal for help: Have you seen them?

2007-12-04T16:40:00.000+08:00

Have you seen them this year?

Species-wise, Chek Jawa has been recovering well. Most of the key missing species have returned including the knobbly sea star, common sea star, flowery soft corals etc. However, there are some more candidates that has still been missing, from my observations. Below is a list of them that I've gathered.

keyhole sand dollar (Echinodiscus truncatus)
peanut worms (Phylum Sipuncula)
Crown sea star (Asterina coronata)
Neptune's cup sponge (Phylum Porifera)
Flatworms (Phylum Platyhelminthes)
Cake sea star (Anthenea aspera)
Synaptid sea cucumber (Family Synaptidae)
Sea apple sea cucumber (Pseudocolochirus violaceaus)
Melon or Baler Shell (Melo melo)
Fan worms (Family Sabellidae)

If you have seen anyone of these marine animals at Chek Jawa after Feburary 2007, (for example during guided walks), please leave a comment in this post. If you want to add on to the list of lost animals, please also leave your comment in this post. One thing to note, please also leave your name behind too.

Your help is very important to help me document recovery in Chek Jawa. I believe that there are some species which have returned, but no one has found them only, since Chek Jawa is big.

A big thank you in advance :-)

Photos of collage belongs to Ria Tan from her online guide and virtual gallery.

http://chekjawa.nus.edu.sg/ria/index.html
http://www.wildsingapore.com/chekjawa/index.html

Updated List of "found"s

Pencil sea urchin (Prionocidaris bispinosa)
Sea squirt (Polycarpa sp.)
Hard corals (Order Scleractinia) sea pencil (Cavernularia sp.)
Gong-gong (Strombus canarium)

It is to note, as advised by Ria, that many of the "lost" fauna as stated in the list are already rare in the first place before the mass death. Therefore, species-wise recovery has been successful.

This is not the end of the story though as Northeast monsoon has started.

Return of common sea star

2007-11-26T08:55:00.000+08:00

Photo taken by Ron Yeo on 25 November 2007.

Elated to find out that common sea star (Archaster typicus) has returned to Chek Jawa. They were missing since the mass death early this January.

Read more about Ron's account at his "A Rainy Day at Chek Jawa" post from The Tide Chaser blog.

A little more about these creatures fom Ria's Wildsingapore online Chek Jawa guide page and also at this gallery.

Now for the exciting part, will there be any changes to the huge mussel bed population after the sea star's return?

Getting wet and out of time

2007-11-02T23:57:00.000+08:00

A day after our monitoring session, I was out with the Team Seagrass gang to Chek Jawa again. And this time, I did not intend to help them with the monitoring as kindly approved by Siti, but decided to tie up any loose ends, do up unfinished work from previous days, redo some wrong stuffs, and many more housekeeping work.

Everytime when I want to do housekeeping work like checking out my points and tidying up my transect start and end points and also anemone markers, something will crop up. Unfortunately, this time either. Was happy when I set off on a sunny weather, but only to realize dark clouds over Changi and Ubin before we we set off. On the bumboat ride, rain poured like nobody's business and we were waiting at the jetty for a hour before we could finally reach Chek Jawa.

Thinking the rain's over, we all cheerfully started work. Yet again, I saw another dark cloud patch looming from Johor, now with more thunder and lightning. And what happened next was another hour plus of rain and getting trapped in poncho standing in Chek Jawa, unable to do any work. So I ended up doing a bit of seagrass monitoring with Ria. Wow, waterproof datasheet works wonders. Will try to get them for December rainy season's trips.

And finally, after the long long wait for the rain to be over, I was only left with less than 45mins to complete 3 hour plus of job. All the stress made me having to run all over the place again. Thank God that Sijie, Gaytri, Marcus and Jerald volunteered to help me out.

Above: Photo of Chek Jawa after rain.

Another photo of Chek Jawa after a rain. Leads me to think of the pre-mortality scenario where rain kept pouring down nonsense and if it coincides with a series of low spring tides, salinity will be much lower than usual, affecting the osmoregulatory systems of the marine creatures.

I had to really go and only had time to re-monitor a couple of carpet anemones to check for errors.

Close-up of these squares that were positioned for future counting of tentacles.

Sijie was kind to climb up the Jejawi tower to take a panoramic photo for October. Below are a series of photographs taken from July to October for comparison of any major changes.

Above: Taken on 15th July 2007.

Above: Taken on 16th August 2007.

Above: Taken on 28th October 2007.

One thing that is obvious from a quick scan and comparison of these three photographs chronologically will be the increase of algae cover over Chek Jawa from July to October, which is most likely due to algae bloom season.

Heartening recovery of Chek Jawa

2007-10-29T21:10:00.000+08:00

On a bright sunny Saturday, a team of 11 enthusiastic friends who volunteered to help out with the project arrived at Chek Jawa in the afternoon. This time, we were monitoring the recovery of different groups of charismatic macrofauna or marine animals. The last time we came, it was a predawn operation, so this time was easier to conduct in terms of coordination. However, doing monitoring during a hot afternoon made us realize something important... which will be talked about in a while below.

The first team featured in this post will be the peacock anemone team- Bingquan and Liana. They were setting huge quadrats to monitor the peacock anemones within it.

And viola! The quadrat has been set up. After which, it was the time the team did some searching and measuring of the colourful peacock anemones.

We were also monitoring button shells, or snails that are named as the "jewels of Chek Jawa". These animals are doing abundantly well in the northern sandbar and we have Robyn and Alex working conscientiously with these snails. It's no mean feat because there are hundreds of them in a 15 by 15cm quadrat. And surprisingly, they arranged it in the grid of the tray very neatly though I didn't told them to. Big thank you :-)

And here's Yilin and Demin with the sand dollar work. Work became harder for the couple when they approached the northern sandbar with really a lot of sand dollars. Basically, we were trying to measure the density of sand dollars within a quadrat to tell the story that these animals are back and recovery is going good.

Why is Justin and Siyang so unhappy in the photo?? This is because almost all the sand stars that they were assigned to search and measure went hiding in the scorching afternoon. They were like searching for a pin in the haystack for most of the time. It was only after about 6.30pm those sand stars started showing up like nobody's business. And then, they had to hurriedly start the real work. Will take this into consideration for the next afternoon-evening tide monitoring session.

Nevertheless, I "forced" them to smile in front of the sun. Haha.

This photo was taken when the sky started darkening and sand stars showing up. Interestingly, a flower crab decided to join into the photo by crawling in. Also found within is a peacock anemone.

Sunset glow in Chek Jawa is fabulous. And poor Nicholas has to work all alone with the mussel beds. Nevertheless he did a great conscientious job on these invasive species. Apparently, the mussel beds are still going strong. Will they stay for good? Only time will tell.

Last but definitely not the least, we have the most experienced team-the carpet anemone team. Most experienced because Ria and Yuchen decided to help again, despite their busy schedules. This time, with the number of tenacle squares to monitor increased from 2 to 8 and also other bits of new work to do, that explains the frowning or hysterical faces. Haha. Apparently, some anemones went missing! Either they died or they migrated elsewhere. Nevertheless, the carpet team is the most efficient. Hooray!

Now to the second part of the post which shows the rich diversity of fauna that Chek Jawa now has, which reflects also the recovery of Chek Jawa from the mass death early this year.

National Parks Board had a public walk that day also and I chanced upon some of their finds for the visitors to see. That includes a small baby horseshoe crab, sponge crab, brittlestar, sea cucumber etc.

More of the hunter seeker's find includes a small jellyfish, ball sea cucumber, moon snail, egg collars etc.

A close up of the sponge crab. It's the first time I see this in Chek Jawa.

And amazingly, they also found the copperbanded butterflyfish and also two juvenile kite butterflyfishes. They are beautiful fishes.

To the star part- the biscuit seastar is more common, and they not only reside in the coral rubble, but I saw them also in the seagrass lagoon.

And the find of the day-WELCOME BACK knobbly seastar. This one here is 15-20cm in diameter, an adult size. None of these charismatic seastar were seen in Chek Jawa after the mass death. This is the first one and indeed we celebrate its return.

And many more thriving in the recovering state of Chek Jawa.

Siyang, while searching for the hidden sandstars during the day, saw quite a few interesting animals. He found this close to 1cm length nudibranch (Cerberilla asamusiensis) in the sand and it is indeed exciting to see beautiful nudibranch near the sandbar and seagrass lagoon.

The second find of Siyang was this pair of crabs, apparently making love.

And the third find that intrigues me will be this seapen where the really tiny porcelain crab reside within. In fact it was also a first-time for me seeing this cute little crab.

Over at the coral rubble, while I was doing some photo-monitoring task, saw that lots of sponges returned! During the mass death, almost all were disintegrated in black.

What was even more exciting will be the return of flowery soft corals, found attached at the pillars of the boardwalk.

Stranded jellyfishes were spotted too and this one looks really like a miniskirt.

Not forgetting also this jellyfish that is so huge, yet yucky looking, that looks like the vomit of Yuchen.

Well, it was really a great trip and we look forward for Chek Jawa to return to its glorious state. Let's pray hard that this coming year end's northeast monsoon will be so as dramatic as the previous and no more mass mortality event that will further disrupt the ecosystem and ecology of Chek Jawa. Meanwhile, we have to also take efforts of protecting this precious, yet fragile shore. It can be as simple as not littering when you visit the boardwalk.

The team worked hard and as the sun sets, we wrapped up our work and here we have a lovely photo of everyone that helped out.

Thank you everyone for making the difference!

What caused the mass death?

2007-10-15T00:28:00.000+08:00

15 October is Blog Action Day and everyone is encouraged to blog about the environment on this day. I thought I can make this opportunity to share something related to environment changes.

Chek Jawa, an intertidal flat with six ecosystems within one kilometer square area, is found east of Pulau Ubin, an offshore island to the Northeast of mainland Singapore. Being a fascinating getaway from the concrete jungle, it holds a special place in the hearts of Singaporeans. Fortunately, Chek Jawa has escaped the verdict from being buried by slated reclamation through the ten year deferment.

On January 2007, an incident of mass mortality was reported at Chek Jawa by volunteers on blog posts.

Posts about the mass deaths at Chek Jawa
1. Mass Death at Chek Jawa, 18 Jan 07 on the ubin volunteers blog
2. First TeamSeagrass Field Orientation at Chek Jawa, 20 Jan 07 on the teamseagrass blog
3. Death note from Chek Jawa, 22 Jan 07 on the wildfilms blog
4. After the Chek Jawa Massacre, 22 Jan 07 on the tidechaser blog

More links to various blog posts about the Chek Jawa situation at http://www.wildsingapore.com/news/20070304/070325-1.htm compiled by Ria Tan.

Ria has also kindly posted her photos on Wildsingapore's flickr account with regards to the mass death event.

Prominent macrofauna that were affected included the carpet anemone, sea cucumbers, noble volute, sea stars and sponges.

So the BIG question is, what caused the mass death. Of course everyone pointed fingers to the heavy downpour that rain like mad during the rainy season. Because marine creatures need saline conditions to thrive, if there is too much rain, salinity will decrease, and animals more sensitive to salinity drop will take in water due to osmosis till a point they burst and die.

But the bigger question is, is the drop of salinity the cause of the mass death? This is because algal bloom, change in sea temperature, toxins, pollutants, disease or de-oxygenation also can kill the animals.

After a visual assessment at Chek Jawa in February 2007, Dr. Dan Ritshoff, of Duke University, suggested in his blog post, "Will Chek Jawa Rebound?", that salinity change was the culprit, “the easiest animals to assess at Chek Jawa are the sessile or virtually sessile signature animals. All these animals are sensitive to low salinity because they conform to the environment around them- carpet anemones, peacock anemones, sea cucumbers, and button shells. These have all been more than decimated. I saw two (20 cm diameter) small very healthy carpet anemones, several dozen Peacock anemones, two sea cucumbers and no button shells. Hopeful signs, the peacock anemones were clearly healthy and there were three new 3 cm carpet anemones.”

Last December and January, the northeast monsoon was intensified twice in 17-20 December and 11-14 January due to strong surge events over South China Sea. According to Malaysian Meteorological Department (2007), it was due to strong convergence and cyclonic wind events emanating from high pressure system over Siberia. Therefore, Kota Tinggi experienced serious flooding (picture from this link).

Then another question, if the rain is so bad, is there mass death, say at Semakau? at St John Island? at Kusu Island? Why?

In fact, not only does the rain played a role, the locality of Chek Jawa made matters worse that induces the mass death. In red is Chek Jawa on Google Earth.

In pink is Sungei Johor or Johor River. Can you compare the catchment size with the size of Singapore?

From a consultation session with Professor Wong Poh Poh, a coastal geomorphologist from Geography Department, National University of Singapore, we concluded that most the flood water gets discharged directly at Chek Jawa if you follow the suggested red arrows. The effects were emphasized as Tekong reclamation made the channel for output of river flow narrower.

In the event of a low tide and the excessively heavy rainfall, the volume of freshwater from the river, amplified by the rains will gush out and into the Straits. it is possible then that Chek Jawa will turn into a "swimming pool" of freshwater, inundating the marine creatures long enoug to pose an osmotic challenge, and even killing off the less adaptable ones.

Therefore, mass death occured in Chek Jawa and not in the Southern Islands where the latter's salinity is higher with no river output near them.

How about other northern shores?

Beting Bronok, Changi and Pulau Sekudu were also affected, but to a smaller scale as compared to Chek Jawa. Why then? If you follow the suggested discharge direction as above, it is directly mostly at Chek Jawa due to the geography of the coastal layouts. Surprisingly, it was speculated that Beting Bronok was not as badly affected (due to its location away from the main discharge flow though it is geographically closer to the river mouth) as compared to Chek Jawa because Beting Bronok's knobbly sea stars still survived! Unfortunately, those in Chek Jawa were never seen again after the mass death, the last few or one was photographed by Ron Yeo in this blog post Death Note from Chek Jawa where the knobbly sea star turned black like ashes.

Now another big question. Is global warming the cause of it?

I read a preliminary analysis by Tetsuzo Yasunari (2007) mentioning that the heavy rainfall this Jan is due to the intensified Northeast monsoon season leading to strong cold surge events, where there were strong convergence and cyclonic wind events emanating from high pressure system over Siberia, thus causing the intensification in the northeast monsoon.

However, in terms of whether global warming is the cause of it, Tetsuzo Yasunari stated that there is no clear trend from past 40 years data of rainfall data both in amount and frequency with respect to the Malaysian Peninsula. However, in Vietnam and China, a trend could be observed.

I came across another article online titled "Rising temperature in Indian Ocean may have caused Johor floods" by Royce Cheah, on thestar online news webpage, describing about the disturbed Great ocean conveyor belt being related to the heavy rainfall, and this was likely due to global warming.

In response to the above two articles, Professor Matthias Roth, a climatologist with National University of Singapore commented on an email reply to me,

"I am not sure if you can draw conclusions from these 2 articles regarding what is happening in the Singapore region. More data ( i.e. longer observational time series) are needed to conclude that the intensified NE monsoon rains early in 2007 are related to atmospheric changes induced by global warming."

Nevertheless, Chek Jawa is on the road of recovery and we welcome and embrace it to return back to its wonderful state. It is alive and it deserves our respect to understand it as a place that does not deserve to be buried with sand for reclamation. There is so much we can learn and enjoy out from it.

Reference:

Malaysian Meteorological Department (2007) Report on the second heavy rainfall episode that caused floods in Johor and southern Patang during the period 11th -14th January 2007. Web publication http://www.met.gov.my/flood_report.pdf accessed on 20 August 2007.

Tetsuzo Yasunari (2007) Local to global scale atmospheric circulation features associated with the floods in Malaysia in Dec.2006 and Jan.2007- A Preliminary Analysis. National Seminar on
"Socio-Economic Impacts of Extreme Weather and Climate Changes." June 21-22, 2007, Kuala Lumpur. http://www.met.gov.my/ClimateChange2007/session1a/Keynote%20Lecture%201%20-%20Prof.%20T.%20Yasunari/K1%20Yasunari_a.doc accessed on 20 August 2007.

More links

Posts about shores near Chek Jawa or facing similar flood situations

Northern shores health check on Changi, 23 Jan 07 on the wildfilms blog
Tuas, 1 Feb 07 on the teamseagrass blog
Tuas Transect, 4 Feb 07 on the blue heaven blog
Pulau Sekudu, 18 Feb 07 on the wildfilms blog
Changi Beach, 5 Mar 07 on the urban forest blog
Pulau Sekudu, 23 Mar 07 on the urban forest blog3.

Posts during Feb-March about Chek Jawa after mass deaths

Back to Chek Jawa, 17 Feb 07 on the tidechaser blog
How's Chek Jawa, 19 Feb 07 on the colourful clouds blog
Chek Jawa and friends, 24 Feb 07 on the wildfilms blog
Will Chek Jawa Rebound?, 24 Feb 07 on the Dr Dan in Singapore blog
Hit and Run at Chek Jawa, 24 Feb 07 on the tidechaser blog
Getting high on CJ, 24 Feb 07 on the blue heaven blog
Chek Jawa update, 1 Mar 07 on the ubin volunteers blog

More similar Singapore flood posts found here at, kindly compiled by Ria Tan:
http://www.wildsingapore.com/news/20061112/061220-1.htm
http://www.wildsingapore.com/news/20070102/070112-2.htm

September Transect Day 2

2007-09-30T09:09:00.000+08:00

It's Day 2 of our september transect! Though quite a number of volunteers could not make it on the last minute, my worry was gone when I saw today's friends working extra hard on the transects. Yesterday was also the first time I met a few of them too!

This is one of the two teams with Yilin, Demin (with the quadrat) and the experienced Siyang. While we reached the start point, the tide was still yet to be completely receded so there was a bit of wading to do.

And this is the same group in action. Transect 2 is the toughest in terms of terrain yet they broke my record and completed it very fast, of course without compromising on accuracy. Well done!

And here we have the other team in action, with Yujie, Sheong Leng, Nicholas and Jian An. They spotted a number of interesting animals along the transect and that's reassuring.

Also, Chek Jawa was kind of crowded from the boardwalk side as it was a Saturday. The Nparks guided walk was ongoing too while we see Adelle and Choon Beng on the ground too :)

And here we have Jian An and Sheong Leng with a pretty sunset backdrop while they were keeping the transect lines. Jian An's sole fell off and he had to wear Sheong Leng's booties to work the last transect, while the barefooted Sheong Leng helped us looked after our belongings at the sandbar. Working with barefoot is obviously a no no as there are many nasty sharp things hidden on the lagoon.

Nicholas and Yujie! This is Nicholas' first time (Jian An's also) down to an intertidal shore and they said they really found the place to be interesting. That's nice. This is also Yujie's second time helping me out with the transect. Thanks.

While we were moving from transects to transects, we encountered many interesting animals, including this seahorse at the seagrass lagoon.

This is a tiger moon snail. Other animals found along the way where I have no time to take photo will be lots of grown-bigger sandfish sea cucumbers, brittlestars, sandstars, hairy seahares etc.

We completed our 3 transects within target, that is before it turns totally dark. This is because yesterday's last transect photos turned out blur. It was also difficult to do video-ing of the whole stretch in total darkness with lights from the torches combined together. Therefore, work has to be done real fast while we redo one of yesterday's transect in addition. So horray! Mission accomplished. Thanks to all of the hard work of the volunteers.

We had a bit more time to spare so the guys could explore the wonderful shores a bit. Heard interesting things from them after which, including an exciting find of the warty sea cucumber which I have yet to see before in CJ. Yujie found this real small catfish. Look at the size as compared to the cockle shell. This is really cute.

Hidden beside the rock is this Salmacis sea urchin.

There is also this venus shell with the siphon sticking out a bit. Ironically, I saw many of these guys at Changi Village where they sold seafood.

Today's team was efficient and quick. The cleaning up was done in a moment, as compared to previous times of trying to untangle tapes in hours. Perhaps they heeded my warning to never entangle the tapes which will be a disaster. Haha.

As the cleaning was going on, I went to the storeroom and get our things out and realized ants invaded my big bag. Ended up washing the whole bag and getting rid of the ants, together with many bites. Soon, we hopped up to Uncle Chu's van and back we go with the bumboat. Finished everything at 9pm.

A group photo before we left for separate ways and also for well deserved dinner at Changi Village. A BIG thank you to all who came and help. Really appreciate everyone's effort, contributing to Chek Jawa in one way or another.

The story repeats where I had to sort out the enormous tons of tapes to clean and dry at home. :P

Anyway other than thanking everyone for the effort and precious time taken to help out, also want to thank God for ensuring everything run smooth when manpower was lesser. The weather for the second day was much better than the first and we could lay the line with much ease. There were no rain, so that's very optimal. Haha.

Looking forward for the next trip where we are going to monitor different groups of animals. That will be October 27. Anyone interested to join for the working trip, please email me at koksheng at nus.edu.sg. Pls take away any spacing from the email add and replace at with @, this is to prevent spamming. Thanks and take care to all. See you soon.

September transect day 1

2007-09-29T00:32:00.000+08:00

The September low tides are finally here and we have a bunch of friendly and enthusiastic volunteers who decided to help out. Here we have Raymond, Suwen and Robyn (left to right).

And then Paul and Yijun. I'm sorry Peihao and Bingquan were not in the bumboat photos.

This time, we decided to use big flags with the poles so that they can be visible for maintaining straight lines. This is one group trying to put in the flag into the tide that hasn't reached minimum yet.

And here is how the transect tape looks like with the flag.

Here is another team in action, working hard on their transect.

As you can see, the lines were easily crooked because today was really really windy. Was really tough trying to make things straight. Therefore, we decided to bury some parts of the line to make sure that they don't run away! Good idea.

This is the group that did the longest transect.... a stunning 500m or half a kilometre across. And that is Pulau Tekong's "holiday chalet" in the background.

And wow, Chek Jawa is indeed recovering. Those baby sandfish sea cucumbers have grown quite a bit! That's very encouraging. Furthermore, they are quite commonly found too at the seagrass lagoon.

I'm sure this tiny noble volute is another sign of good recovery.

Sunset is always pretty and it's the first time I appreciate it in Chek Jawa since the evening tides have just started.

This is beautiful. Don't you agree?

We worked till 7 plus and while walking back, this is the part where everyone has to cross the wooden planks across a dam-thingy (not damn).

After washing up,enjoying the bits of food and drink, Uncle Chu brings us back safely to Ubin jetty where a quick bumboat ride returns us to the concrete jungle.

Frankly speaking, I really enjoyed working with today's friends. Thank you ALL for making everything pleasurable. Hope you all have had bits of fun too. Here is a group photo at the end with Paul pointing not to a street lamp, but a moon!

Thanks everyone for the recommendations suggested for next such trip. Will keep it in mind.

Ok, here's the big and round moon. We'll see it again tomorrow! Till then.

Remember Chek Jawa

2007-09-11T17:49:00.000+08:00

Yesterday went to watch this docu-film at picturehouse. It was the closing film for the 7th Asian Film Symposium.

Because I only got a chance to know Chek Jawa in person this year, I have missed a lot of action. Especially when it was still a wonderful place before the mass death and when everyone contributed their heart and sweat to save this place.

I am so glad to watch the film and see how hard everyone worked to salvage whatever they can and each one of the volunteers that came from all walks of lives made a difference indeed!

Snippets from the 2001 transect reminded me of how tough it can get for the volunteers and helpers to "chase" against the incoming tide and work doubly hard in a terrain where you can get sunk in mud knee deep. Yet many were glad to have done something for the nature in Singapore.

Thank you Eric Lim for this great film and indeed, from all the laughter yesterday, everyone enjoyed watching it. It must have been heartfelt for those people who have done the salvage works themselves back at 2001.

More details of this film here.

And let us not only remember Chek Jawa, but to also ensure such a piece of wonder continues to exist for the younger generations. Mass death doesn't mean Chek Jawa is gone. It is obvious that recovering already occuring and estauries are very resilient and dynamic. Give it time, it will recover :-)

The mussel beds in Chek Jawa

2007-09-02T16:58:00.000+08:00

Something new appeared in Chek Jawa after the mass death early this year.

Huge patches of blackish slime looking thing were found covering huge areas of the intertidal flat.

They are usually found in the boundaries of the seagrass lagoon and the sandbars.

A closer look reveals holes in them which contains a tiny mussel with byssus threads around them, forming a mat of mussel bed over the whole area.

Gastropods like to eat these mussels. And we also bunches of pink and yellow stuff that looks like a carnation are actually eggs of a muricid snail.

And this is whole the shell of the mussel or also called the Asian date mussel looks like.

According to Joseph Lai, the person who discovered Chek Jawa, he shared that plenty of this smallish Asian Date Mussel can also be found around Pulau Sarimbun - right around the foot of the island as well as the nearby rocks of a shoal east of it.

Thanks!

From a couple of readups, this is what I got from journals (references below).

"The Asian date mussel, Musculista senhousia is an Indo-Pacific mytilid that was unintentionally introduced in the early 1990s in the north-eastern Adriatic Sea, and actually occurs with large populations also in Tyrrhenian (Gulf of Olbia) and Ionian (Mar Piccolo) coastal areas.

Mussels live semiburied in subtidal soft sediments, secrete byssal threads to attach to conspecifics, and build extended mats that alter the nature of the sediment inhabited by commercial infaunal bivalves."

Below are some FAQs for you to know more about them. They can't be ignored. Most of the facts are taken from NIMPIS, 2002.
-------------------
~FAQ~

What is its scientific name and classification?

Musculista senhousia. Phylum: Mollusca, Class: Bivalvia, Subclass: Pteriomorphia, Order: Mytiloida, Superfamily: Mytiloidea, Family: Mytilidae

What are their dimensions and how does it look like?

Maximum length of around 30mm and has a smooth, thin shell which is an olive green to brown in colour, with dark radial lines or zigzag markings.

In which part of the habitat can they be found?

From the intertidal to subtidal habitats (to a depth of 20m) and on soft or hard substrata. It prefers to settle in groups on soft substrata, but is capable of fouling wharf pilings and man made structures.

When settled on hard substrata the mussel will not form a protective cocoon. It is a highly adaptive species, and is able to tolerate low salinities.

In which part of the world can you find these mussels?

Native range: Russian Federation, Democratic People's Republic of Korea, Republic of Korea, Japan, China (CSIRO, 2000), Singapore (OBIS, 2006).

Known introduced range: USA (USGS, 2006), Canada, Mexico (Cohen, 2005), New Zealand, Australia (Allen and Williams, 2003), Israel, Egypt, France, Italy, Slovenia (CIESM, 2005), Tanzania, Madagascar (Mastrototaro et al. 2003).

What is byssus thread and what is it for?

It is used to construct a cocoon which protects the shell. This cocoon is made up of byssal threads and sediment.

How does it grow and reproduce?

M. senhousia is a species with high fecundity, rapid growth, a short life span and good dispersal ability, making it a successful invader.

It has separate sexes, with males and females spawning at the same time. The larvae of this species are planktonic, and have been recorded in the plankton for up to 55 days. It can reach an adult size in only 9 months, and its life span is typically no longer than two years.

How does it feed?

This mussel, like most mussels, is a suspension feeder. It consumes organic matter and many planktonic organisms from the water surrounding it.

What feeds them then?

Diving ducks and oystercatchers have been recorded feeding on M. senhousia, and it is also consumed by many species of carnivorous gastropods. In San Diego Bay, field experiments have indicated native gastropods may prevent M. senhousia from establishing dense beds.

What are its impact to our shores, like Chek Jawa?

It can dominate benthic communities and potentially exclude native species. It settles in aggregations and is therefore able to reach high densities.

The byssal mats formed by the mussel may restrict the growth of some species of seagrass.

The byssal mat may also cause an increase infaunal density and species richness as it provides additional habitat for many species.

References

1. Crooks, J.A. (1998) Habitat alteration and community-level effects of an exotic mussel, Musculista senhousia. Marine Ecology. Progress Series 162, 137– 152.

2. Mistri, M. (2003) The non-indigenous mussel Musculista senhousia in an Adriatic lagoon: effects on benthic community over a 10 year period. Journal of the Marine Biological Association of the UK 83, 1277– 1278.

3. Mistri, M. (2004) Prey preference of Carcinus aestuarii: possible implications with the control of an invasive mytilid and Manila clam culture in a northern Adriatic lagoon. Aquaculture 230, 261–272.

4. NIMPIS (2002) Musculista senhousia species summary. National Introduced Marine Pest Information System (Eds: Hewitt C.L., Martin R.B., Sliwa C., McEnnulty F.R., Murphy N.E., Jones T. & Cooper S.). Web publication http://crimp.marine.csiro.au/nimpis

5. http://www.issg.org/database/species/ecology.asp?si=1031&fr=1&sts by Global Invasive Species Database

Monitoring Carpet Anemones

2007-08-20T15:19:00.000+08:00

Carpet anemones (Stichodactyla haddoni) were one of the most hit fauna in Chek Jawa during the mass death. Before the mortality event this January, CJ guides have to keep reminding the visitors to avoid the landmine full of carpet anemones on the sandbar. Now, there is almost none found on the stretch of sandbar in Chek Jawa.

Does that mean the Chek Jawa is dead???

Nope. Chek Jawa is recovering. What was surprising is that at the south west end of the wetland, next to the coral rubble, there are many and many of unimpacted adults doing very well, near to the seagrasses. And at the end of the seagrass lagoon and the sandbars, we can also see some new and adult carpet anemones, though they are much fewer there. What is exciting is that many baby haddons are coming back at the extreme edge of the north of Chek Jawa. They come in very small to bigger sizes.

The plan to monitor these guys is to mark and follow the growth of 25 individuals from the impacted area and then 5 older and healthier anemones from the south west end. The idea is to measure diameter of the disc and then count tentcles in 1 cm square areas to plot it over time as we continue to monitor in the future.

I was privileged to have Ria as the photographer of these 30 anemones marked for monitoring. Her camera takes really good and sharp photos and it makes counting of tentacles easier. She has also done a great job in labelling the photos, so I can concentrate more on counting the tentacles. After cropping each photo to focus on the 1 cm squares, it is about time to start counting 30 x 2 = 60 squares of tentacles.

How did I count them? Use MS paint to dot each tentacle after counting it so I won't lose count. And after a few, lethargy sets it, it is NOT easy!

Especially when there are more than 100 tentacles in the square. Thank God that Liana helped out a bit too, making the work more bearable. She wasn't as complaining as me though...Haha.

After more than half a day of effort, finally DoNE! :-)

(All photos taken by Ria Tan)

Chek Jawa Monitoring trip

2007-08-16T22:28:00.000+08:00

Dr Dan was in town more than a week ago when he also visited Chek Jawa. After some discussions, we decided to focus on some prominent and charismatic fauna to monitor recovery from the mass death in January.

This time round, I'm heartened to see many friends volunteered despite it being on a weekday morning. Because the meeting time was kind of too early for most of us, some overnight-ed in school. Gave a briefing shortly to Ron and Gywnne who arrived first which was good because there were much to explain and its good to have people knowing what we are doing.

I'm apologetic to Ron and Shuying especially for helping me rush some logistic tasks till 1am before we take a short sleep (sorry also you all slept so little). Woke up at 4am this morning, and not too soon, got a phone call from Robert that he is approaching in 5-10 minutes. Hahaha. Quickly and sleepily, we grabbed our stuffs and pooled taxi to Changi Point Ferry Terminal. My taxi driver drove like a madman and we arrived much earlier. Upon arrival, I was searching my bag upside down for my wallet and good grief, there was no sight of it and I thought most likely it's in school. Thanks to Huijia and Shuying who paid first for me. When we proceeded to the basement waiting for others to come, I took out some food for those who wants breakfast and the wallet was in the food bag...wow!

Everyone was punctual for the trip and we left at 5.15am after YC ran to get coffee (he was kind of running from "ladies" of Changi V). Here's a group photo on Mr Chua's bumboat as we leave mainland Singapore. For a couple of them, it's their first time to Ubin and Chek Jawa.

When we were there after a van ride from Mr. Chu, it was total darkness with a clear night sky of stars. Orion constellation was well position along the way we were walking towards the shore. After some briefing and organisings, each group of people were despatched to do their allocated stations. We spent close to one hour in the dark before day break with a tinge of light. (Photo by Paul)

This is Huijia's task of finding these button shells and placing them on a tray with grid to determine their sizes and location subsequently with GPS. To our dismay, one GPS was down and I had to run all over CJ to give points, it was a great exercise though. Huijia did a great job finding these button shells though they were not obvious to find.

I passed my camera to her later to take more button shell photos. Everyone were working hard to complete their given tasks. The priority is definitely the carpet anemone team where we have Ria explaining in detail at wildfilms blog how the process goes about monitoring them.

We also have the other great groups doing peacock anemones, cyanobacteria mussel beds, sandstars and sand dollars.

There were a few featherstars (Class Crinoidea) spotted along the way and we were excited to spot the first one.

And here's more found by Dickson and Robert. Didn't see them in CJ before and they don't live on sandy areas, but on reefs. They don't look like CJ residents and definitely were washed off from a nearby reef where it might be impacted.

As I was browsing through Paul's photos, was pleasantly glad that seahorses still can be found in Chek Jawa. More creatures found by the intrepid team are the geographical and hairy sea hares, luidia eight-armed star, brittlestars, baby sandfish sea cucumbers etc etc.

We finished our job on time as the tide returned and finally everyone can take a nice slow pace to enjoy the serenity of Chek Jawa. I really like these Delek flowers that smell bit spicy yet like Tembusu flowers.

Here's a group photo (taken by Ria) where we posed at the end of the monitoring. Believe everyone had fun at the same time as we marvel at how CJ is recovering. Returning to the visitor centre, our hungry stomaches were treated to breakfast kindly prepared by Ria. Thanks.

Thank you Ria, Ron, Robert, Gwynne, Huijia, Yuchen, Yuan Ting, Pei Hao, Paul, Dickson, Yijun and Shuying for taking time out and all the wonderful help. Whatever data we have got today will be very important for us to better understand the vulnerabilities of our living shores and better appreciate their nature and response to danger.

Thanks also to Siva, my supervisor and also Choon Beng from Nparks Ubin.

Thank God no rain until immediately after we boarded the returning van! The heavy downpour was terribly heavy.

Chek Jawa Festival!

2007-08-08T16:33:00.000+08:00

Last Sunday was a festival for Chek Jawa! Not only the CJ project gang was there, Naked Hermit Crabs, Green Volunteers Network and the NIE green club were there too. Literally, it is the first time seeing Chek Jawa so lively and crowded (simply because I've not been there on a Sunday before).

Dr Dan is in town and we can't wait to visit Chek Jawa together on a cooling Sunday morning. Other than Siva and company, Dr Dan also brought along his wife too and everyone was very excited. (Photo by Ria)

Though the tide wasn't spectacular, it was good enough for us to learn so much from this trip. Dr Dan is an expert of the shores and we take this golden opportunity to learn from him.

From this photo you can see the exposed part that it is actually the opportunistic colonization of these mussel beds. It is seen as a thick 'carpet' of tiny mussels that trap a soft bed of silt by creating a communal nest of byssus threads. These mussels are probably Musculista sp. which incorporate sediments, bits of broken shells and other debris into the mussel nest. The nest is pockmarked with little slits, each housing one mussel.

Dr Dan was very excited to know that these were not seen in Chek Jawa before and he speculates that the common seastars might eat them. Siti once shared that their presence is due to freshwater influx, which I kind of doubt. Are they cyanobacteria too?? Have to really learn more about them yeah. (Photo by Ria)

What eats these mussel beds? We have to find out how transitional are these patches and will the recovery of common sea stars cause the future disappearance of these mounds? Watch out for it.

We headed towards the northern sandbar towards where the button shells are. If you slightly remove the top surface of the fine sand, you will be amazed to see these jewels of Chek Jawa! These snails are actually preyed upon by moon snails.

Dr Dan was excited, as heard from this video, that these button shells are back (or they might all along be there). Take a look at this video as Ria, Siva and Dr Dan shares the interesting facts of these button shells and how they disperse when disturbed.

I did not take many photos because was busy at work. For more information of the trip, please take a look at wildfilm's account by Ria.

We were looking out for the top 5 charismatic macrofauna to monitor. They are..drum rolls..

1. Carpet Anemone (Stichodactyla haddoni)
2. Peacock Anemone (Order Ceriantharia)
3. Button Shells (Umbonium vestiarum)
4. Mounds of mussel beds (probably Musculista sp.)
5. Cake Sand Dollar (Arachnoides placenta)
-------------------------------------------------------
6. Common Seastar (Archaster typicus)- Watching out for their comeback!

For the next field trip, we will be monitoring a maximum of 25 Haddon's carpet anemones and to study their growth (through tentacle density) and locomotion over time.

Towards the end of the shore trip, Ria found this interesting polychaete.

We proceeded for a quick boardwalk with Dr Dan and chanced upon these overly-enthusiastic visitors climbing down to the sandbar though they are not allowed to. And it is also a dangerous act for both the visitor and the animals. For the visitor because the tide can come in faster than you can imagine and you will be trapped.

Dangerous for the animal because as curious beings, we may tend to disturb the precious lifeforms of CJ. Look at how they use a stick and poke at most probably a carpet aneomne. Seriously I hope they can leave the anemone guys alone and allow them to recover.

It was an interesting first half of the morning. As we bidded farewell to Dr Dan and gang, Ria and I headed towards the mangrove boardwalk to join for the recce of Naked Hermit crabs.

Wow, another banded krait was spotted!! These snakes are very venomous, far worse than cobra.

Further towards the house no. 1 side on the coastal boardwalk, Ria introduced this portion where a landslide had occured before. Good for geography lessons.

The pong pong trees along the streets were once imported but this one here is native.

I always like to find the seashore nutmeg tree that is already rare in Singapore.

Towards the end of a 5 hour field trip, the finale was this spider with a net of orange mass.

If you look closer, they are babies!!

This hut outside CJ is so lively and it is really a wonderful end of the series of low tides last week. It's heartening to see many people coming to appreciate the beauty of nature.

Thanks Ria for the wonderful lunch you treated to the NHC people and also the urgent ride to my tuition afterward.

Thanks Siva, Dr Dan and company for coming and sharing much with us.

Recovery on the way... Let's not spoil it

2007-08-04T15:40:00.000+08:00

Just moments after the sunrise, I was accompanied by Yikang on a Friday morning to do some monitoring for my project. I'm glad that Ria and Marcus also came along. We also met Swee Cheng and Chee Kong along the way who are doing their own research work.

All seems ok and fine at first, but soon I found out that there are some litter along the sandbar shores. I didn't think too much at first and proceeded straight to the extreme north myself while Yikang helped me to take photos from the observation tower to monitor sandbar and cover changes over long periods of time.

This extreme part is remote and it was my first time going there. It looks ugly with the fence to deter illegal immigrants from swimming across from Johor. It is a narrow stretch of beach that goes on and on. Without the liberty of time, I had to start work.

There are many large oyster and shells around this part of the shore. Is this one being pried open for harvesting?

My first job is to actually take GPS readings along the edge of the sandbar so that I can get an outline of the current sandbar position.

While walking south from the extreme north part, I was pleasantly surprised to see many many of these tiny Stichodactyla tapetum, Stichodactyla haddoni and the Swimming anemones (Family Boloceroididae). The north part used to be almost completely barren of anemones.

A really good sign of recovery!

Walking a bit more south, I ignored most of the cyanobacteria patch as they are really too common. But this particular patch looks more interesting. Something struck my eye.

What are these pink and yellow things spreaded out in large numbers?

These bunches of pink and yellow stuff that looks like a carnation are actually eggs of a muricid snail! Why does the cyanobacteria favour these snails?

The echinoderms are making a good come-back to CJ including this sea cucumber.

And these baby sandfish sea cucumber too! Can't forget the sight of the mass death where many of these adult ones were found dead in huge numbers. Welcome back.

Along the apparently-lifeless sandbar, some markings were found.

Found a huge family of brittlestars burrowed into the sand! First time saw this. Hopefully, soon followed will be the common seastars.

Not only for brittlestars and sea cucumbers, we also found many sandstars that are very small. These babies are really cute and I hope they will grow up and live well in Chek Jawa.

These Halophila beccarii seagrasses can now be found near to the boardwalk instead of the extreme north end, and it is suggested that the fresher waters caused it.

What I couldn't stand is the enormous amount of litter found on the shores. We at first thought it might be drifted from elsewhere like Johor.

What confirms us the source of litter is this bowl of instant noodles with the remains noodles and soup in it! How can such a thing be from elsewhere? The content inside is still intact.

It must most probably be from the boardwalk, since it has been recently opened.

If it's true, what a shame.

After the terrible incident of stepping on a sharp object the other time, one has to be extremely careful because there are planks with rusty nails pointing upwards. Watch where you walk!

The busy day ended with a shot of the rear beacon which I have never took effort to notice it.

Ups and downs at Chek Jawa

2007-07-18T18:46:00.000+08:00

Today the sea anemone team were out in the field again and this time to Chek Jawa. Gun Kiat, Yikang and I also joined along. I have not been to CJ so early just before the sun rises and the view is really breathtaking from the coral rubble area.

Among the firsts to catch Dr Daphne's attention were the juvenile cerianthids or the peacock anemones. Judging from the seagrass blade, you can see how small they are and I have not paid attention to them before.

The team did not managed to find any of Stichodactyla gigantea which has longer tenacles that pulsate. Those carpet anemones from Chek Jawa are mostly Stichodactyla haddoni where there are long-short tentacles fringing the side of these carpet anemones. These haddoni species are doing very well at the coral rubble area.

These fifty cents coin-like "mini-carpet anemone" lookalike are not baby Stichodactyla haddoni but according to their near arrangement of tentacles near the centre, these are actually Stichodactyla tapetum which will not grow to be as big as haddoni species.

I thought that usually the residents of these disused big shells would be those hermit crabs but here there's a juvenile thunder crab living in it.

Chek Jawa is not called coral rubble for nothing. Indeed you can find the remains of the mushroom coral and this one is huge.

I was walking close to the reef edge in slight murky waters of the coral rubble trying to find something special. I chanced upon the first living coral I've ever seen in Chek Jawa. Anyone can help me with the id???

Magnificent sunrise over Johor and Tekong.

Other life sighted were this little sea cucumber and the brittlestar on the right.

Dr Daphne and team were very hardworking into finding the anemones. They found these Diadumene luciae growing on and near to the barnacles of the boardwalk pontoon. As you can see, they have red lines radiating from the centre.

More of such anemones can be seen and these ones are have white stripes. Are they also Diadumene luciae or another species?

There is this another small anemone found by Yuchen. The team will bring it back to Raffles museum to check the id of this anemone and also to store for future research or education purposes that is going to benefit many.

I was also doing some work for my project. An attempt was made to compare past photos with current ones. The one on the left was taken by Ria during 20th Jan 2007, source: Team Seagrass website. It shows the mass death event where animals and anemones turned white and died. The photo taken on the right shows the barren sandbar with no carpet anemones but just strewn with seaweed.

After my rounds of taking photographs, the team walked towards the mangrove side and I was proceeding to transect 3 area to do some checking out of the 300m stretch. And halfway through, something sharp struck through my booties and whacked my foot.

"Ouch!" I yelled. Quickly, I turned and looked what had caused that and it was a hard and sharply-pointed prop root of the mangrove. Thank God its no stonefish or whatever venomous creatures. The pain got the better of me, thus I took off my booties and examined the punctured wound. Blood was flowing profusely outward at first but thankfully it stopped soon. Followed were those first aid attempts on it and I put back my booties and tried to continue to do the work that needs to be done by today.

But I can't go on after a while. Thankfully, Gun Kiat and Yikang were there to lend a hand. After much briefing of what to do, they took the clipboard, notes, photos, GPS and compass and proceeded to help me do the work while I rested on the high shore. And they went far far away.

Because we were punctual and timely for today's trip, we also ended early without to chase after the tides.

After some washing up was done, I tooked this photo outside House no. 1 of the imminent thunderstorm that approaches.

On the bumboat trip back, the storm caught up from westward direction.

And Ria alerted us there is a water sprout! WOW. I always wanted to see with my own eyes and here it is just a short distance away from us at Serangoon Harbour. It was huge and spectacular.

Today was pretty eventful and uneventful at the same time. Come to think of it, Ria and company were discussing openly in the van about stonefishes and stingrays bites and it sort of materialized. Though this root thingy is relatively nothing compared to a stonefish sting, it taught me a painful lesson to walk more gently on the shore and open my eyes bigger to see where I thread. It's a bit swollen now but I will go and see a doctor tomorrow late afternoon, so no worries. Thank you Ria for your concern too :-)

Thanks a lot for the sea anemone team for bringing us along and thanks to Gun Kiat and Yikang for taking the time off to come. Thanks GK also for driving us back and forth.

Morning at Chek Jawa

2007-07-15T20:02:00.000+08:00

Team Seagrass was out this morning to monitor the seagrasses of Chek Jawa. Though I was a one of their member, Siti kindly permitted my request to allow me to do my own things for my project. Thanks Siti for your understanding, sorry if my absence has caused any inconvenience.

Indeed today was rather challenging because the tide was receding when we came in and the team has only about 1 hour to quickly finish all things before the tide covers the shore.

First things first before the tide comes back is to catch a good view of the entire CJ at a 0.2m tide level at 7:10am. Ran up the observation tower because there was a long list of things to do today in a short one hour. Panting and sweating, the sunrise has made it all worthwhile.

Purpose of doing this: to compare the view with the one from Google Earth and monitor for any sandbar movement if possible. Good to continue this for a long term period over years.

Next stop is to the coral rubble to start taking salinity tests from the extreme south to extreme north of CJ (CJ is big!). Met up with Ria who was checking the site out. Took a quick snapshot of a dead fish washed ashore.

There were many carpet and peacock anemones doing well there between beacon and house no. 1 jetty.

I did not have the luxury of time to search for animals but this sea star appeared near my footing. Thought it is a common sea star (Archaster typicus) but after showing Ria, she corrected to me this is Luidia maculata which is eight-armed and its the first time both of us saw this at Chek Jawa. Horray! CJ is recovering, this is a good sign.

The underside of the sea star with pointed tube feet.

Quickly, went to the other parts of the shore to take salinity test and also took this photo of the hardworking Teamseagrass team in action from afar.

Siti shouted to me when I was at the extreme north, I thought she needed some help urgently so I ran over. Found out actually she wanted to tell me tide's coming in, so time to go. However, I still have quite some stuffs to do, so tried to finish as soon as possible.

And I ended up leaving CJ by the mangrove side again since the tide has already came in by a lot when I finished :-)

And we gathered at House no. 1 to do some washing of gears and ourselves followed by a fabulous breakfast at a cosy spot facing the sea, prepared by Ria. Thank you!

Thanks also to Andy who kindly picked me up near my home.

Left early with Jingkai. Sorry couldn't be there with the rest to the boardwalk.

Can't wait for next Teamseagrass trip at Cyrene!

6th July 07- Chek Jawa Transect Day 2

2007-07-09T17:43:00.000+08:00

Good morning, good morning and good morning! :-)

Though physically tired-out on 3rd consecutive day of Chek Jawa working trip, this priceless and magnificient sunrise made the start of the day worthwhile. This time, though 3-4 backed out last minute, I am so thankful that Geraldine and Kian Wah agreed to come back again to help after much persuasion. Geraldine was down with fever and sore throat somemore. I feel really guilty! Everyone is very important to the transect because it is large scale, across 500m, not 50m. Joining us that day were Gerald (came back too), Yujie, Shuyi and Lester.

Believe it's a rare occasion for them to catch a nice sunrise.

How can we forget to capture Ubin with the beautiful sunrise? It's like a typical postcard shot, in Singapore somemore. We are still blessed with these wild places in this urban city.

After gathering a lot of feedback on why we did so slowly and a whole night of re-evaluation and re-writing of protocol, we wasted no time on the second day. At 7am sharp, we left Changi, and again we saw the friendly female driver. Nice to be able to have a morning chat with her in the van as she recollects how Chek Jawa was when she lived there years ago.

Upon reaching CJ, we promptly picked up our stores from House no. 1 (Thanks Choon Beng for arranging it) and headed straight out to transect startpoints. After giving a short and sweet intro and demo, we started nicely at 8am. My plan was to finish transect 1 and 2 by 9am and transect 3 and 4 by 11am.

Here we have the first garang team setting up the transect line for transect 1. It comprises of Yujie, Gerald and Shuyi.

And not forgetting the second garang group, with Kianwah, Geraldine and Lester!

As you can see, the mud is not fun to treach across. This photo features team 1 in transect 1. The other team in transect 2 had more not-fun-at-all mud spa. KW and Lester's shoes came off so many times that they had a lot of difficulties and trauma. In the end, they took not 1 hour as expected to complete 300m of transect 2 but a whooping 2 hrs 10 mins!!!!

So do not underestimate terrain..haha.

Being so much off schedule AGAIN, I was rushing people to work harder and faster for the last two transects like a madman. Haha. This is because the tide was receding very quickly. Even my bag was flooded in minutes when I left it at sandbar. And this datasheet fell out during state of panick and it became drenched....gosh.

I am so thankful that Shuyi is much more composed than me giving a much reassuring smile that I shouldn't worry too much because God will help and is in control. (Photo by Yujie).

And when things go wrong, it's time to improvise! The marker couldn't write on the quadrat labeller (top left photo) anymore and here we have a brillant idea. We shall have a human labeller with hand signals showing quadrat number, and KW has the honour to do it. What a cute and classic collage we have here :-)

Here we have a lovey dovey horseshoe crab. (photo by Geraldine)

And we are glad to encounter a carpet anemone near the sandbar area. Chek Jawa is recovering, slowly.

I was walking quickly between transect sites and saw this hairy seahare threading. A first time spotting in Chek Jawa. Everytime we visit there is always something new.

Miraculously, we managed to complete transect 3 and 4 in 45minutes time! Thank God. I was pleasantly surprised that though work was done so quickly, team 2 managed to lay out their transect line almost perfectly from start to endpoint! Wow.

Everyone was so so so tired that I had to force them to smile for this finally-its-over photo! Haha... be inspired by them ok? They work really hard.

The day ended with washing up of equipment and the same old story of unwinding entangled tapes for an hour. Thanks for your patience guys.

Thank God for perfect weather. Thought of planning transect on Sat, glad its not. Because on sat, there was thunderstorm and heavy rain in Chek Jawa during opening of boardwalk. Imagine that happen and we'll never finish work.

We are glad the transect was done. Everyone made a difference! Here's me, Lester and Shuyi.

Geraldine and Gerald. Sorry Kian Wah and Yujie, no close up photo of you both because you both left earlier. Haha.

Thank you so much to all who paid sweat and injuries and illnesses to help this project. Other than the endless appreciation to Kian Wah, Gerald and Geraldine for coming faithfully twice, also thanks to Lester for being so friend to come, Yujie for coming though I don't know you at first and Shuyi for putting your 101% effort to help.

Till next time!

5th July 07- Chek Jawa Transect Day 1

2007-07-07T19:25:00.000+08:00

On an early morning, many of us were found at the jetty of Pulau Ubin, an island of rustic charm.

We were out to do transect to survey the biodiversity at Chek Jawa, to monitor the recovery and recruitment of species after a mass death this Jan. And this is not a one-time event, it will be for a long-term monitoring.

Geraldine took this photo of the resident CJ dog at the mangroves upon our arrival at Chek Jawa.

Here's the classic shots taken by Robert. I was trying to go through the landward side towards the northern CJ. However, there was a big drain that separates the path. Thus, instead of endangering friends, we went down the mangrove to cross. And most of us were trapped in the mud, yes to their horror. Haha. Sorry Kian Wah for traumatising you.

Here's Geraldine looking amused at poor Kian Wah. Looks like a shortcut is not always the good thing. (photo by Robert)

And upon reaching the site, we immediately got started with the setting up procedures, wasting no time. (Photo by Robert)

And here we go....... garang warriors.

Geraldine captured this shot of me running across sites because there was seriously little time to do things in the intertidal area. Sorry if there were any careless trampling.

I wasn't taking any photos because there was no time. Geraldine managed to capture this swimming anemone which I have not encountered before in CJ.

Another of Geraldine's photo shows a very nice zoom at Changi from CJ.

It seems that horseshoe crabs are quite frequently seen these few days. Many of us were marvelled by it.

This sea pen was found drifted by the waves.

This is the quadrat along the transect line which we will make an analysis of what can be found at Chek Jawa at this point of time.

In all, we accomplished very little on the first transect day because the methods were too tedious and time consuming to perform. Furtheremore, the heavy rain poured while we were struggling to do what can be done.

I had 7 helpers this time (many more than last time 4 helpers doing 6 transects in a day), we only did the two easiest transects. There was only one gal-Geraldine.

I really wondered at that point of time how can we manage to finish the 4 harder transects the next day. Furthermore, the second day has more gals. Worry creeped me, and anxiety was uncontrollable. For more on how the second day of transect turned out, stay tuned to this blog!

I want to thank....

Yikang for coming the second time to help with the transect. You have been waking up at 4.15am for both days. Furthermore, you were rushing for an assignment to be submitted on transect day.

Geraldine for coming despite being down with fever and sore throat. Thank you for your selfless efforts and incredible help. You worked as hard as those who were not sick.

Robert for coming upon Siyang's request with the Semakau volunteers. I believed the gang learnt a lot from you along the way.

Kian Wah for the really good help you offered along the way. Sorry to make you go into the mud so deep. Thanks for your help really.

Gerald for immediately volunteer to help when realized he no need to go lab. Instead of taking a good rest at home, thanks for sweating it out at Chek Jawa.

Zhangyi for being so friend to help me! It's amazing how a violinist and a promising musician work for nature, doing a scientific survey.

Last but not the least, the veteran Khairul for coming back to help. He is the only person who have done transect with me during May and coming back. Haha. I am touched when we were tired out and soaked in the rain and I was apologising to him for such a state, he told me to not apologise because I did not force him to come, it was his choice. He added that it is still not a very tiring thing to do transect and it really heartened me.

Thanks also to my supervisors, though didnt come, but for their priceless assistance and help. Thanks Siva and Dr Peter.

Thanks to the Nparks help, esp Choon Beng.

Will update on day 2 soon yah... I have to go take a well deserved rest.. am tired out now.

Chek Jawa Recce @ 040707

2007-07-04T15:42:00.000+08:00

A beautiful sunrise at Changi while Yikang and I left for Ubin.

Near the entrance of Jetty, we were enthrilled to see four of such Oriental Pied Hornbill (Anthracoceros albirostris).

And after a streneous and panting cycling for 20 mins, we finally made it to Chek Jawa. First stop is to check the coral rubble out and see if there's any changes.

The sponges seem to be coming back, more and more. Yay.

Look what's on YK's hand, a biscuit seastar. Let's hope the knobbly seastar will make a quick comeback.

The tubeworms are aplenty, Dr Dan :-)

Did not take many photos because it is a working trip. Checked out the cyanobacteria, they are still there. Yes, Ria, the oval thingy in between are mussels... thus the carpet of mussels like those found near Commando Jetty.

I wonder how come why they are still there? Do we have a lot of rain or freshwater input nowadays? Salinity checked today was around 27 plus. Hmmm...

This looks like the rare seagrass, Halophila beccarii, and also not. Can someone help me?

Update: Yes! Thks Ria for the confirmation and other info in the comments section :)

And that's a return ride back mainland after a hard day's work. Thanks to Yikang especially for his help. Appreciate it a lot!!! And also Choon Beng and other Nparks people.

Biodiversity of Northern shores

2007-06-25T16:00:00.000+08:00

Below are a compilation of fauna found during recent trips to the northern shores. Of course, these are only what I've seen and it's definitely not exhaustive.

(Map from Google Earth)

Fauna found in recent Chek Jawa trips
(18/05/07, 20/05/07, 21/05/07, 22/05/07, 20/06/07)

1. Acorn worm, Class Enteropneusta
2. Allied cowrie or ovulid snail
3. An Unidentified sea cucumber
4. Ball sea cucumber (Phyllophorus sp.) Family Phyllophoridae
5. Biscuit sea star (Goniodiscaster scaber)
6. Brittle star, Class Ophiuroidea
7. Button shells (Umbonium vestiarum) Family Trochidae
8. Cake sand dollars (Arachnoides placenta) Family Arachnoididae
9. Carpet anemone (Stichodactyla sp.) Order Actiniaria
10. Coastal horseshoe crab (Tachypleus gigas) Class Merostomata
11. Copper-banded butterflyfish (Chelmon rostratus) Family Chaetodontidae
12. Cyanobacteria
13. Fiddler crab (Uca sp. Family Ocypodidae
14. Great-billed Heron (Ardea sumatrana)
15. Green mussels (Perna viridis)
16. Grey Heron (Ardea cinerea)
17. Grey Plover (Pluvialis squatarola)
18. Noble volute (Cymbiola nobilis) Family Volutidae
19. Ornate goby (Istigobius ornatus) Family Gobiidae
20. Peacock anemone (Cerianthus sp.) Order Ceriantharia
21. Red sea fan (Menella sp.) Order Gorgonacea
22. Sand collar of the Moon snail, Family Naticidae
23. Sand star (Astropecten sp.) Family Astropectinidae
24. Silver Sand Whiting (Sillago silhama).
25. Sponge, Phylum Porifera
26. Stranded Jellyfish
27. Striped hermit crab (Clibanarius sp.) Suborder Anomura
28. Swimming crab (Thalamita sp.) Family Portunidae
29. Thunder Crab (Myomenippe hardwickii) Family Eriphiidae
30. Toadfish, Family Batrachoididae
31. Tubeworms
32. Venus clams, Family Veneridae

Fauna found in recent Changi trips
(07/05/07, 18/05/07, 14/06/07, 18/06/07)

1. Anemone shrimp (Periclimenes brevicarpalis)
2. Ball sea cucumber (Phyllophorus sp.) Family Phyllophoridae
3. Biscuit sea star (Goniodiscaster scaber)
4. Brittle star, Class Ophiuroidea
5. Button shells (Umbonium vestiarum) Family Trochidae
6. Cake sand dollars (Arachnoides placenta) Family Arachnoididae
7. Carpet anemone (Stichodactyla sp.) Order Actiniaria
8. Common sea pen (Pteroeides sp.) Order Pennatulacea
9. Drills, Family Muricidae
10. Eel-tailed catfish (Plotosus lineatus)
11. Fan shell, Family Pinnidae
12. Flatfish, Family Soleidae
13. Flower crab (Portunus pelagicus) Family Portunidae
14. Flowery sea pen (Cavernularia sp.) Order Pennatulacea
15. Geographic sea hare (Syphonota geographica) Order Anaspidea
16. Gong-gong (Strombus canarium) Family Strombidae
17. Grey Heron (Ardea cinerea)
18. Hairy sea hare (Bursatella leachii) Order Anaspidea or Aplysiacea
19. Moon crab (Matuta lunaris) Family Callapidae
20. Moon snail, Family Naticidae
21. Noble volute (Cymbiola nobilis) Family Volutidae
22. Octopus Class Cephalopoda
23. Ornate goby (Istigobius ornatus) Family Gobiidae
24. Peacock anemone (Cerianthus sp.) Order Ceriantharia
25. Pipefish (Hippichthys sp.) Family Syngnathidae
26. Rabbitfish, Family Siganidae
27. Red sea fan (Menella sp.) Order Gorgonacea
28. Salmacis sea urchin (Salmacis sp.)
29. Sand collar of the Moon snail, Family Naticidae
30. Sand star (Astropecten sp.) Family Astropectinidae
31. Scorpionfish, Family Scorpaenidae
32. Sea slug (Armina babai)
33. Seahorse (Hippocampus sp.) Family Syngnathidae
34. Snapping Shrimp, Family Alpheidae
35. Spiral melongena (Pugilina cochlidium) Family Melongenidae
36. Sponge, Phylum Porifera
37. Stranded Jellyfish
38. Striped hermit crab (Clibanarius sp.) Suborder Anomura
39. Swimming anemone (Family Boloceroididae)
40. Swimming crab (Thalamita sp.) Family Portunidae
41. Thunder Crab (Myomenippe hardwickii) Family Eriphiidae
42. Tidal hermit crab (Diogenes sp.) Suborder Anomura
43. Toadfish, Family Batrachoididae
44. Venus clams, Family Veneridae
45. Whelk (Nassarius sp.) Family Nassariidae

Fauna found in recent Pulau Sekudu trips on 16/06/07

1. Ball sea cucumber (Phyllophorus sp.) Family Phyllophoridae
2. Black sea cucumber (Holothuria leucospilota)
3. Brittle star, Class Ophiuroidea
4. Button shells (Umbonium vestiarum) Family Trochidae
5. Cake sea star (Anthenea aspera) Family Oreasteridae
6. Carpet anemone (Stichodactyla sp.) Order Actiniaria
7. Common sea pen (Pteroeides sp.) Order Pennatulacea
8. Drills, Family Muricidae
9. Fan shell, Family Pinnidae
10. Filefish or Leatherjacket, Family Monacanthidae
11. Flower crab (Portunus pelagicus) Family Portunidae
12. Geographic sea hare (Syphonota geographica) Order Anaspidea
13. Grey Heron (Ardea cinerea)
14. Ornate goby (Istigobius ornatus) Family Gobiidae
15. Peacock anemone (Cerianthus sp.) Order Ceriantharia
16. Salmacis sea urchin (Salmacis sp.)
17. Sand collar of the Moon snail, Family Naticidae
18. Sand star (Astropecten sp.) Family Astropectinidae
19. Shrimps, Order Decapoda
20. Spiral melongena (Pugilina cochlidium) Family Melongenidae
21. Sponge, Phylum Porifera
22. Stranded Jellyfish
23. Striped hermit crab (Clibanarius sp.) Suborder Anomura
24. Swimming anemone (Family Boloceroididae)
25. Swimming crab (Thalamita sp.) Family Portunidae
26. Thunder Crab (Myomenippe hardwickii) Family Eriphiidae
27. Tidal hermit crab (Diogenes sp.) Suborder Anomura

Reference:
Ria Tan (2003). Online Guide to Chek Jawa, Animals A-Z. Accessed on 25 Jun. 2007.
<http://www.wildsingapore.com/chekjawa/text/i802.htm>

Chek Jawa Recce on 20/06/07

2007-06-21T11:22:00.000+08:00

This time, two of my supervisors for my project, Siva and Dr Peter Todd, took precious time out to visit the field site with me during the last of the low spring tides. Appreciate it a lot. We were not there to just tour but its sort of a working trip, since its for a project. It's interesting and heartening to see them taking time out and then travel in a bumboat, rent bikes, negotiating the slopes of Ubin just to get to Chek Jawa.

After a brief walkthrough of the coral rubble area to see the survivals of the carpet anemones, we were back to the main sandbar. Sand dollars which usually are found in the northern part can now be found nearer South. If you look closely at the above photo, you can see some circular outlines. And there are a lot of sand dollars dwelling below the sand.

This is what you see when your hand reaches out to pick one and turn it around. A cake sand dollar (Arachnoides placenta)! They are the most commonly seen sand dollars on Chek Jawa. Their body is divided into 5 parts with tiny spines covering the entire body.

Here is our serious-looking Siva and Dr Peter deep in thoughts on the issues of the project.

Something that caught our attention was these black patches of slime covering a huge area of the lagoon nearer to the sand bar area.

A closer look. According to Siti of Teamseagrass, she commented that they are cyanobacteria and they usually come when there are more rain and go quickly too. Bad thing about them is they cover the seagrass.

After my two supervisors left since they have something on, I lingered on to collect some water samples for salinity tests. And we can see from this photo that the boardwalk is completed! Public can now access CJ via the boardwalk from 7th July.

Adding live to CJ will definitely be this pair of dogs.

and also this grey heron that walks around the intertidal flat to hunt for food. We saw one at the beginning of the day with a fish in its mouth. Wow. Looks like the early bird catches the "fish".

After a hard day of work, I left Chek Jawa through the mangrove side since the tide was already coming in fast through sandbar. I don't want to risk walking in murky water since I was alone. What if I step onto Miss Stingray? Mangroves are interesting, esp with these mudskippers.

The boardwalk will also feature the magnificient mangrove ecosystem of Chek Jawa.

Before I say byebye, here's the fiddler crab "waving" me goodbye too.

A bumboat ride shows us the remaining kelongs you can find in Singapore.

The beach is Pasir Ris park. Can you see the city outline at the back?

This trip was a great one, because it updates me how dynamic CJ is, with the movement of sandbar, change in seagrass communities, coming and going of cyanobacteria etc etc. Ecosystems are not static and changes has to take place. It's interesting to learn and study about these changes so that we can monitor and detect what changes are those that require our alert and attention.

Changi and Pulau Sekudu

2007-06-19T16:29:00.000+08:00

The study of Chek Jawa's mortality and recruitment requires also taking a look at the surrounding northern shores for to study recruitment in terms of seeding new population of macrofauna. Which shore seeds which shore? What can be found here and not there?

How is the population of macrofauna doing from Changi, Sekudu, Johor or even Sentosa?

The answers may still be unknown of now but perhaps we can get some clues from my previous low spring tide trips to Changi and Sekudu.

Water samples were taken for salinity tests from each site.

Below are accounts of the trips from blogposts, will upload the photo gallery of each trip soon.

1. Changi Beach (site A) on 14/06/07
Changi wonders

2. Pulau Sekudu on 16/06/07
Sekudu- A frog's eye view

3. Changi Beach (site B and C) on 18/06/07
Changi surprises me again

Gallery of photos from last month's recce and January's mortality event

2007-06-19T16:04:00.000+08:00

1. Mass Mortality photos taken on 20th January 2007:
http://www.flickr.com/photos/7347996@N08/sets/72157600263629907/

2. Recce Photos taken on 18th May 2007: http://www.flickr.com/photos/7347996@N08/sets/72157600226680643/

(Note: Dimensions of scale (Silva compass) used in photo: 12.5cm x 6cm; dial of the compass- diameter: 5cm)

3. Recce Photos taken on 20th May 2007: http://www.flickr.com/photos/7347996@N08/sets/72157600233138053/

Links for an account of what happened on the previous trips

2007-06-19T15:59:00.000+08:00

Day 1 Recce (19 May 2007):

"Chek Jawa Recce" blog post by Kok Sheng which highlights the 3cm juvenile carpet anemones found in a particular pool
http://wondercreation.blogspot.com/2007/05/chek-jawa-recce.html

Day 2 Recce (20 May 2007):

"Aftermath of Chek Jawa 1" blog post by Siyang, which highlights the vibrancy of life at the southern or coral rubble area of Chek Jawa.
http://uforest.blogspot.com/2007/05/aftermath-of-chek-jawa-1.html

"More Chek Jawa Recces" blog post by Kok Sheng which highlights returns like noble volute, biscuit sea stars, ball sea cucumber and also a lot more anemones.
http://wondercreation.blogspot.com/2007/05/more-chek-jawa-recces.html

Day 3 Recce (21 May 2007):

"Chek Jawa Day II Recce" blog post by Siyang, which highlights other living creatures of Chek Jawa like mussels, lots of sand dollars, carpet anemones of different sizes.
http://uforest.blogspot.com/2007/05/chek-jawa-day-ii-recee.html

"More Chek Jawa Recces" blog post by Kok Sheng which highlights returns like noble volute, biscuit sea stars, ball sea cucumber and also a lot more anemones.
http://wondercreation.blogspot.com/2007/05/more-chek-jawa-recces.html

Day 4 Transect day (22 May 2007)

"Garang Warriors at CJ Day 3 Transect" blog post by Siyang, which highlights the selfless efforts of volunteers to document recovery in Chek Jawa.
http://uforest.blogspot.com/2007/05/garang-warriors-at-cj-day-3-transect.html

"Chek Jawa Visit from Chemistry graduate" blog post by Weilin, which highlights the different prospective of nature from a first-timer in an intertidal shore.
http://funandmemories.blogspot.com/2007/05/chek-jawa-visit-from-chem-grads.html

“Blessings for Chek Jawa Transect” blog post by Kok Sheng highlights the transect that is only possible with the help of others.
http://wondercreation.blogspot.com/2007/05/blessings-for-chek-jawa-transect.html

Welcome to this blog

2007-05-29T17:02:00.001+08:00

My name is Kok Sheng and I am from National University of Singapore. I am pursuing Life Science course and am now working on a UROPS (Undergraduate Research Opportunities in Science) project on the mass mortality and recruitment of macrofauna in Chek Jawa.

My supervisor in charge is Mr. N. Sivasothi and my co-supervisor is Dr. Peter Todd. Dr. Dan Rittschof from Duke University is also assisting this project. They have been helping me a great deal since I embarked on this project since it is my first try on research.

Will blog on anything with regards to this project and I've also transferred my previous trips' posts here.

Blessings for the Chek Jawa Transect

2007-05-26T01:43:00.000+08:00

Well, it is always good to count your blessings no matter what you do, and I do really feel blessed during the day of CJ transect on 22nd May 2007.

First blessing is with regards to the weather. The forecast given the night before says that there will be predawn and morning showers with thunder. This sent me with jitters and I quickly reminded my friends who are helping me to come regardless of bad weather or not. Thank God for answering my prayers, the weather was not stormy, only slight drizzles at the beginning and it turned hotter as time passed. Phew.... And what was surprisingly timely is that the thunderstorm and strong wind came straight after we finished the transect... wow.

Second blessing is to hire a cab in the morning at about 6:10am. This is not a good time to get a cab because it is the time for them to change shift as explained previously by a friendly cab uncle whom we chatted a lot! He even chatted about tides in Sarawak different from the diurnal ones in Singapore.. ok, before i get drifted away, straight after 6, when midnight surcharge was gone, I had a lot of difficulty waiting for a cab at Sims Ave. Normally before 6am for other predawn trips, I hardly have to wait for more than 2 mins I can get one. After waiting for quite long, I was about to call for a taxi through phone. Thank God He sent a taxi when I was about to do that. What was interesting was when I got into the taxi, the friendly uncle kept saying I'm very lucky. He wanted to pick up passengers at the right side whom was also waiting for one. But because of heavy traffic, he decided not to pick them and instead went straight ahead more and saw me at the left side. He said most passengers usually wait at the right side though. Anyway, sorrie for the long long paragraph here, but I'm really glad God helped me a great deal, even in small ways, I wanna thank Him!

Third blessing will be my friends which I'll commend them more later on in the post.

After a long long wait at the Changi point ferry terminal, even with a chat with Ria who was heading for Sekudu, we finally left the place after I decided not to wait anymore but to pay for the rest of the boatfare so it can leave. In the bumboat, I met a kind Nparks officer and he told me that the gates are opened already, so no worries. Thanks Ria for reminding me to check out on that. I'm just too blur to think of everything needed. We met Mr Chu, the van driver who drove us to CJ. He chatted with me about his mother in law family living in CJ back then and he does fishing for a living. He even shared that during a blasting of the quarry, a rock flew all the way and hit passed the roof which ended up injuring his mother in law's head. Gosh!! She was hospitalised for quite some time. So when Kekek quarry reopens, pls take heed of all warnings to avoid the place okie? It's not funny to be dangerous.

Upon reaching CJ, we quickly walked to the furthest two transects to start first after much briefing was given. Along the way while we were walking along the sandbar, I tried to talk and walk to show them some stuffs, because its the first time Khairul and Weilin came to an intertidal shore. What a waste if they totally didnt know what gems we have there.

Here's the transect set up with red poles for line of sight and 100m measuring tapes.

Also to thank Siva for helping me arrange for the logistics from Eco lab to get these tapes, GPS and the quadrats. Thanks also to Angie from Marine lab for another GPS.

Here's a good intro portion to my friends. Actually 7 are supposed to join me. But 3 of them couldn't come on the last min, so we ended up with 4. Here's Raymond and Weilin settting up the transect. Raymond is in team seagrass and he is pretty familiar with how to do it..yea. Weilin's first attempt over here but she is very helpful despite her legs come out often from her loose sport shoe that get stuck in mud. Her cheerful disposition definitely made the tiring day more enjoyable.

Here's Khairul and Siyang doing the transect. It's also Khairul's first time visiting an intertidal shore...

and look here, I was so pleasantly surprise he is very dedicated into making sure the transect is done well and accurate despite this is not his project. This photo i must definitely share over here.

Criminal photo no. 1 with Weilin...haha

Criminal photo no. 2 featuring Raymond

The middle two transects took us 1.5 hrs or more for each group. This is because it is as long as 500m and it stretches across the seagrass lagoon which is very muddy. Every step is difficult esp for Weilin. I'm so sorry she has to go through all these... falling down, mud splashed on her face, getting made fun by Raymond as a pig rolling in the mud... hahahaha. Really hilarious as she accounts all these to us.

Halfway through, towards the direction of Changi airport, we saw this.. Dunno what actually.

The tide was indeed coming in like crazy after 11am and we rushed like mad to try to complete the last two short transects. I wanted Weilin to take a rest from the last 2 transect thus told her to take our belongings and go back to the entrance to wait for us. Actually it was not so easy but instead adventurous! Do read her vivid account at her blog here.

After we slogged to fight against the tide, we finally could call it a day with blisters on our feet, mud on Weilin and Khairul's feets as they dont have booties. Thunder and rain started to tell us to get out while Siyang and I tried to retrieve all our belongings back and gathered at the info kiosk outside house no. 1 where the heavy rain immediately poured.

Wonder how all these entanglement can be solved.. it takes a lot of time and a lot of patience.

Ok, time for some photos to remember this vivid day.

Siyang smiling despite thirst, exhaustion etc.

After a good fulfilling lunch at Ubin, all is not over, it's time to clean up. Well, I'm guilty that they have to help me on that. They are really rare friends indeed that help me a lot.

I wanted to get a good rare shot of Weilin looking like an auntie. She's a city girl ok? So this is rare.

Ok lah.. here's a nice shot to cover up the aunty shot. You deserve a big award for being such a brave girl in a foreign place.

Inspired by Ria's photo at the end of Sentosa transect 06, I wanted to also share how to clean and dry so many 100m tapes in a 3 room flat. It was everywhere including kitchen, living room, bedroom etc. Was a big mess!

To end up, I want to thank God again for everything. Also thank my friends for their selfless help. We were really very tired, exhausted, irritated, thirsty, frustrated etc that day because we were shorthanded and couldnt afford to take a rest at any time throughout 3-4 hours.

Thanks for making a difference in big or small ways. Without you all, I surely cannot do all these myself. Thanks again for being true blue friends who are willing to go the extra mile. Esp to Siyang who accompanied me for 2 recce to Chek Jawa through bikes in the early mornings.

Thanks also to Siva my supervisor, Ria, Dr Dan, Joseph Lai, Zeehan and everyone who has helped me.

That day was really memorable to me.

And that marks the end of this series of low spring tide trips. Till next time...

More Chek Jawa Recces

2007-05-25T02:22:00.000+08:00

2nd Recce at May 20th 2007

After a wonderful trip to Sentosa on Sat, I was back to Chek Jawa for more recce on Sun. I could be there all alone, but Siyang volunteered to accompany me along there. Thanks buddy!

We also saw Ron and his gang of ubin volunteers there, they were there since 5.30am! And we reached only like close to 8am. Gosh, this is so because we were waiting for close to an hour for enough people to leave Changi point by bumboat.

Without delay, Ron promptly shares their find, a noble volute (Cymbiola nobilis). The colourful part or its foot can wrap bivalves to wait for the latter to finally open to breathe, which is also the moment the noble volute feed..haha.

WOW find from Ron. Several of these copperbanded butterflyfishes (Chelmon rostratus) were trapped in a bubu or a fish trap. They released these poor fishes and 2 are found here. My first time encountering them, so super excited lah.

They have a 'false eye" near the tail, and its real eye is much subtlely hidden by their orange band. If a predator really attack them, they can even swim backward!

An allied cowrie or ovulid snail (id courtesy of Chay Hoon) in a red sea fan (Manella sp.). Sea fans are not plants but colony of tiny animals just like corals. Of course, the cowrie is so small, only sharp-eyed Chay Hoon can spot it! (updated: Actually it was Ron who spotted it, but thks to CH again for pointing to us that day)

This time, we were at the west side of the CJ beacon, where abundant life were found, much to my pleasant surprise. In the background is SY also.

It is between the beacon and the jetty outside House no. 1 that LOTS and PLENTY of carpet anemones are actually found. They are like mines on the ground, and we had to thread cautiously to avoid stepping on these animals. Wow, they are really not all wiped out. Great! Thank God.

Across, we can see Pulau Sekudu, frog island. I will go there soon, hopefully!

Ok, here is it. These carpet anemones are really thriving well here instead of the sandbar areas of CJ. Take note, the ruler is 50cm long. Can you imagine their sizes?

If you think carpet anemones are not enough, here is a stunning array of peacock anemones. Pls ignore the compass, they are just there for scale.

Fiddler crab about to disappear when we approached it.

Ball sea cucumbers (Phyllophorus sp.) are found by quite a few in a specific area. They are not all dead! When siyang handled it, water was squirked out. Haha. If you encounter one, please dont touch it, because if you mistreat it, it will have repulsive vomiting such that their innards will be expelled out...

Great find! The biscuit sea star (Goniodiscaster scaber) were not just one that was found, but two. They were wrapped out without water, so we quickly put them into a pool so they can relax, for a great shot. They are pretty models arent they?

Siyang loves to play with these thunder crabs (Myomenippe hardwickii) by his chopsticks. Please dont try to touch them, their pincers are VERY strong. Hahaaaha. I can't imagine if your finger goes near them.

Tide was coming in, and the poor visibility does not allow me to identify this fish, perhaps a toadfish? (updated: Yea! its a toadfish, thks Chay Hoon for confirming)

Could this bivalve be a venus shell with siphon sticking out? Usually they will dig down.

That is what happens when a hermit crab does not have a shell! Naked hermit crab! It's dead. Found by Siyang interestingly. So pls do not collect shells okie?

A heron which the species i dont know. Perhaps a bird expert can help me with this? These birds love to come to the intertidal to feed and rest.

(updated: Ivan kindly shared that its a Great-billed Heron (Ardea sumatrana), cool! thks )

Another interesting find, a brittlestar!

Ok! This final sea cucumber is really cute, the shape and segments are interesting, first time saw this.

-------------------------------------------------

3rd Recce at May 21st 2007

Monday is my 3rd recce and also the second time Siyang kindly accompanied me for 2nd time. Where to find such a great friend and a wonderful nature lover who dont mind to wake up so early consecutively for some many days. Though we had difficulty trying to get CJ on time due to jetty delays and tiresome cycles, it was still an experience because at least there was company. Or else I would have dragged myself and rot there myself. Thanks once again man!

We were back to the beacon area to catch the low tide, before it gets covered up first

Just around the beacon, there are quite a number of carpet anemones, but not as many as those found nearer to house no. 1 and before the house's jetty.

Beautiful and graceful carpet anemone looking healthy.

We also have 3-5cm sized carpet anemones waiting to recover from the mass death. Greaty.

I started zooming elsewhere. Gosh, now Pulau Sajahat is also reclaimed, bet most of the shore wildthings are gone. sigh.

Here's the "Tekong Chalet". I always remember when I had my BMT, there seems to be stuffs down there during low tide. Of course we dont have the luxury to explore. We could only vividly remember the stinky mangrove while running 2.4km. The stinky smell is due to anoxic condition.

More reclamation to the north, facing Malaysia. It's so much reclamation that I think its not a strange thing they are complaining about it perhaps. Just a guess...

Siyang managed to cajole this hermit crab out. It seems to be enjoying and pretty relaxed.

Nice stuff found. A hole in the shell of a dead bivalve. It can be due to drills or moon snails.

I love this in chilli..opps! These mussels are living ok, quite localised in CJ, except below the boardwalk where there are plenty.

Siyang is game enough to pick up the fiddler crab. I asked him how he managed to do it, he says, its too fat to get into the hole to escape... funny right.

Lesser fun this time round cos was doing more prep work for the actual transect on 22/5 tues. Will blog on it tmr, I have to churn out a report now... haha.

Chek Jawa Recce

2007-05-19T06:51:00.000+08:00

Today Siva and I went to Chek Jawa recce for a project to study on the mass mortality and recruitment in that place. This was mainly because the heavy rain in Jan created freshwater influx which causes osmotic pressure on these animals which eventually, many died. CJ is closed for recovery, we are able to go because we have a permit.

What a wonderful great sunrise! Thank God for the great weather... In the early morning when I woke up, it was thunderous, with a sms from Siyang that they were caught in the rain. So glad it did not persist to CJ.

Beautiful and classy sand star (Astropecten sp.)

A peacock anenome in full grace in water.

Doing measurements on these baby carpet anemones.

Striped hermit crab (Clibanarius sp.) with slipper snails (Crepidula spp.)

Great! Ivan has kindly provided the id of this fish found trapped in the pool. It's Silver Sand Whiting (Sillago silhama). Thanks!

Cake sand dollars (Arachnoides placenta), they are alive. Surrounding are button shells, gems of Chek Jawa.

Jellyfish stranded on the sandbar.

Horseshoe crab! And also alive.

Anybody know what shorebirds are these? For a closer look, pls click on the photo :)

(updated: Thanks Alvin for suggesting its a Marsh Sandpiper, but I agree with Ivan thay its more like a Grey Plover in non-breeding plumage instead, based on the short bills of the birds in the photo, thanks anyway to both!!)

Flying away...whheee

Siva's territory..mangrove!