Jul 20, 2008

Chek Jawa with TeamSeagrass

5am and the intrepid Seagrassers were gathered again for another round of monitoring, this time at Chek Jawa.It's our first time going to Chek Jawa so early in the morning, just to catch the low tide.This year, there are not many good low tides during daylight on a weekend.

The seagrasses were doing very well indeed!But how is the rest of Chek Jawa faring? We've always been concerned about recovery since the mass deaths of some key Chek Jawa marine life following massive flooding in 2007.

This is my first predawn trip to Chek Jawa so it was a good opportunity to check out the marine life that is more active in the dark.
Carpet anemones and peacock anemones seemed to be doing fine. They festooned the shores like many-coloured flowers.There were also some of these maroon sea anemones that infest Pulau Sekudu. But they were not so plentiful on Chek Jawa.And one sea anemone that I've not seen before. Or is it some kind of peacock anemone? Hmmm...

The coral rubble was very bare. While there were many clumps of these long branched purple sponges, there were very few other sponges.

Chek Jawa is best known for its echinoderms: a group which includes sea stars, sand dollars and sea cucumbers.
There were lots of biscuit sea stars (Goniodiscaster scaber).Several cake sea stars (Anthenea aspera).Including this very pretty pink cake sea star!Even the rarely spotted Nepanthia sp. sea star was spotted.
As expected, sand stars (Astropecten sp.) were particularly plentiful, especially near the North sand bar.And two of these bluish baby knobbly sea stars (Protoreaster nodosus) were seen in the seagrass area! This is the first time for me!

Alas, we were unable to find any of the Common sea stars (Archaster typicus).

Sea cucumbers were also plentiful today.There were several of the warty sea cucumbers (Cercodemas anceps) which are usually less commonly seen.
Elsewhere, thorny sea cucumbers (Colochirus quadrangularis) are usually more common, but today on Chek Jawa only a few were seen.

It was good to see lots of ball sea cucumbers (Phyllophorus sp.) and a few smooth sea cucumbers.It was particularly heartening to see several large sandfish sea cucumbers (Holothuria scaber). These edible sea cucumbers are very rare on our other more accessible shores.

The shores of Chek Jawa were teeming with sand dollars!!There were countless cake sand dollars (Arachnoides placenta) especially on the North sand bar.A huge surprise were the large numbers of keyhole sand dollars seen (Echinodiscus truncatus). These sand dollars are usually rather rare. And those seen today included a huge one that measured 9cm across!Nobel volutes (Cymbiola nobilis) were wiped out in the flood of 2007 so it was nice to see a small one today. The snail in the photo on the right is an olive snail (Family Olividae), my first sighting on Chek Jawa. I also saw one Miliaris cowrie (Cypraea miliaris).
I didn't see any nudibranchs except for the large Armina babai. Several were seen by the Team. But Chay Hoon said a Cerberilla was also seen, while I did see one egg ribbon on a rock so the nudis are around.At first I thought the little black things under this peacock anemone was strange looking Phoronid worms. But it turned out to be a tiny sea pen!Besides this flowery sea pen (Family Vertillidae), there were also a few of these white 'sea pencils' (which have yet to be identified). But the sea pens with the orange 'root' (Pteroides sp.) were not seen.

Still Missing in Action: Besides the missing Common sea stars (Archaster typicus), no Button snails (Umbonium vestiarum) were seen, and the area where they used to be is now full of tubeworms.
As we head home, we take a closer look at the beautiful Memecylon edule tree which is in full bloom.This rare coastal tree was once thought to be lost to Singapore, until these specimens were rediscovered on Chek Jawa. Another rare coastal tree is Barringtonia racemosa with these pendulums of delicate flowers. This tree was planted at Chek Jawa as part of efforts to conserve our native plants.

The terrestrial elements of Chek Jawa are more obvious to visitors. But what is truly special about Chek Jawa is the intertidal marine life. It is not only precious but also vulnerable as the mass deaths demonstrated. Regular studies such as TeamSeagrass and other documentation efforts help keep track on what is happening on this shore.

3 comments:

Anonymous said...

Ria,
Spectacular! Highly diverse area like CJ seems also t o be resilient. you didn't mention the mussels are they still on the sand flat? I'm impressed with your beautiful photography and the beauty that is Check Jawa.
Thank you.
Dr. dan

stan rule said...

Ria and Team Seagrass--great to see an upgate on ChekJawa after my visit in March made me aware of issues impacting sea life. I learned so much from you, Dr. Dan and many others which lets me see my local estuary and mudflats in Beaufort, NC, Us with better perspective. Rachel Carson Reserve Estuary is a good parallel to ChekJawa. I participated in a survey last week here looking at impact of visitors to our estuary/mudflats and the trash and debris from visitors and nearby activites impacting local waters. Your survey efforts will hopefully raise awareness of the value of Chek Jawa and the need to preserve the area and those similar. I was able to see the building interest in environmental issues among Singaporeans while visiting there. Thanks again for what your group helped teach me and our group. Dr. Dan said I would meet singular special people in Singapore that would surprise me with knowledge and activism--he was correct.

Best Regards

Stan

ria said...

Dr Stan, what a pleasure to hear from you!

And thanks for sharing about the parallels with your shore. It does give us pause for thought, about how global the problems are. Sigh.

Dr Dan is just amazing and has boundless energy and ideas and keeps us motivated in working for our shores. Even though he's so far away, he is so close at heart to Chek Jawa and to us.

We miss him and you and the US team. Hope we can do another shore trip next year?