Aug 16, 2007

Monitoring Chek Jawa's recovery

Early this morning, some of us joined Kok Sheng to visit Chek Jawa. There were 13 of us, which on hindsight, isn't such a good number especially since the Hungry Ghost month just started.

Earlier this year, there was mass death of many kinds of animals on Chek Jawa due to the large inflow of freshwater following massive flooding in Johor. Chek Jawa lies very close to the mouth of the Johor River. Kok Sheng's Chek Jawa project aims to study how marine life recovers from such an event.

We were split up into teams. Each team would focus on a particular 'charismatic' animal, i.e., the 'Bambis of the shores'; which were selected following Dr Dan's recent visit to Chek Jawa. Dr Dan is one of the supervisors for this project.

I got assigned to the carpet anemone team!

Shu Ying, Yuan Ting, Captain Anemone aka YC, and I headed off to find those BIG 'nems. After searching for tiny 'nems, how difficult would it be to find ones bigger than your head?, I thought (foolishly)

It was hard! There were so few of them. This is tragic. Before the flood, there were so many carpet anemones the guides had a hard job getting visitors to avoid stepping on them.

Finally one of the ladies on the team found one!

OK, the plan is to take a photo of the animal with a ruler (placed pointing North, I always consistently pointed it 30deg off. I still think the compass is off...grump.), plus a tag.
That's a snap, no problem.

Then measure the diameter three ways, a breeze.

Then count the tentacles...WHAT!! There must be gazzilions of them! I woke up a little (this was during the briefing) then realised we were only required to take a photo of a 1cm and 0.5cm square of the tentacles. Then poor Kok Sheng will later count and extrapolate total number of tentacles. He shares more about how he did this on his wonderful creations blog. OK. That's doable at 6am when we're still half asleep. By the way, you can tell this anemone is a Haddon's carpet anemone (Stichodactyla haddoni) because it has the typical long-short tentacles at the edge.

After all that is done, YC whacks a marker near, but not too near. This is so that we can find it again and repeat the whole thing another day. In this way, we hope to find out whether the carpet anemones are growing.

Well, you'd think this was quite an idiot-proof thing to do. Alas, we realised lots of things could go wrong.

Some carpet anemones were very sticky and tried to 'eat up' the square markers.
Such a sticky one tended to cringe up and shrink, which made Yuan Ting's job of measuring the diameter more difficult if not impossible.

Sometimes, an oops, foot-in-the-mud situation results in a disastrous photo.And poor YC, after whacking in all those stakes, develops a wrist problem that he says he can't sue Hustler magazine for.

Anyway, we managed to locate and mark 30 carpet anemones all throughout Chek Jawa. And of course, saw lots more than 30 of them. It's good to know they are still there. Although not as numerous yet, as they were before the flood.

Along the way, we spotted lots of other interesting animals.

Besides the carpet anemones, Captain Anemone and I were secretly on the lookout for other 'nems too. And behold, we find 'Bob the Blob'.This is an affectionate name for a rather boring and unremarkable sea anemone, aside from its size and rather rare occurrence.

Other blobs in the sand included this Moon snail.You can see its pair of banded tentacles sticking out of its oversized body. The white blob next to the tentacles is a little tube or siphon that it uses to breathe with. There were lots of sand collars too on the shore. Some of them were HUGE! They must have been created by really Big Mamas.

Kok Sheng again spotted the 8-armed sea star (Luidia maculata). Only this one seemed to have lost and is regrowing several of its arms.
Gwyn also showed an orange sea star that she found. Wow! I have no idea what it is.There were also lots of Sand stars (Astropecten sp.) and it was Ron's job to find and measure them. He shares his Star Search and other tribulations to do with rapidly vanishing stars on the tidechaser blog.

The other 'Bambi' we are waiting for, are the Common sea stars. Alas, we didn't see a single one today. But we hope they will return soon. Before the flood, they were truly common on Chek Jawa. Elsewhere in Singapore, they are no longer common.

We came across many large and active brittle stars too.And what a huge surprise, the team came across many feather stars on the North sand bar! I think 5 of them altogether. I only managed to photograph this blue-and-black one, that we commonly see on Beting Bronok.And Dickson shared this bright red one, which I've never seen before.It's really strange to see so many of these animals on a sand bar. They are usually found near reefs.

Were they washed away from some other reef? Oh dear. Still so much we have yet to learn about our shores.

Links to more about this trip
The Big Picture on Kok Sheng's wonderful creations blog
Sand star search and other surprises on Ron's tidechaser blog


YC said...

har.har. its carpal tunnel syndrome. bleaugh. wrist guards are definitely a must i say

Yours truly said...
This comment has been removed by the author.
Yours truly said...

haha we didn't get to see the waterspout in the end. aww. looks like the number 13 AND the 7th month is not a lethal enough combination
-yuan ting

Sivasothi said...

Bob was delivered to Swee Hee in the midst of a meeting at the museum by some insistent delivery girls.

YC said...

hahaha that'd be gwynne and huijia i suppose!

Fatham @ Yale said...

yes that would be us...the funny thing is gwynne was in front saying something like "This creature needs to be put down immediately" and I limp out from behind her and I saw the aghast look on some of the "What, her?"