Chek Jawa: Death and Life in 2007

By Ria Tan

In early 2007, there was mass death on Chek Jawa. It was a sombre scene of dead sea anemones, sea cucumbers and other marine life. The smell of death hung heavy over Chek Jawa.

What happened? Did Chek Jawa recover?

Ria shares some personal encounters

I first heard of the mass deaths from the Chek Jawa guides, and later saw it for myself during the first TeamSeagrass field orientation at Chek Jawa on 20 Jan 07. Although the Team steeled ourselves, but still our hearts broke when we arrived.

The carpet anemones seem to be bloating up and then exploding. Those that are still intact have distorted tentacles. Many were in 'pieces', and often I came across only 'melted' remains. It was heartbreaking to see so many of these magnificent creatures in distress, death and decay.Sea cucumbers were among the many casualties. Ball sea cucumbers (Phyllophorus sp.) seemed to 'deflate' like bad ping pong balls. A similar fate suffered by what seemed to have been Sandfish sea cucumbers (Holothuria scabra). There were hundreds of these poor animals in various states of distress and death.I failed to find any living sea stars (Archaster typicus), and only saw two badly decomposed ones. The noble volutes (Cymbiola nobilis) also seem to be distressed, and many clean empty shells were seen, without hermit crabs. There were also many empty gong-gong snail shells (Strombus canius).The cause of death?

Possibly the huge influx of freshwater from the Johor River due to the recent massive flooding there, following the highest recorded rainfall in 100 years. Chek Jawa lies just at the mouth of the Johor River. Locally, Singapore has also experienced record rainfall. All that freshwater probably affected the osmotic pressure of these marine animals.

Adelle from Ubin NParks shared that the Ubin villagers say this sort of thing has happened before in the past. And Chek Jawa eventually recovers. So there's some hope yet.

Not everything died. Peacock anemones (Order Ceriantharia) were still seen in what appears to be good health. The sand dollars also seemed to have survived and the fiddler crabs and other crabs were busy as ever.Following the mass deaths, it was decided to suspend the guided public walks to give the shore a rest.

Is Chek Jawa recovering?

Fortunately, thanks to Loh Kok Sheng we will soon find out. Kok Sheng bravely took on the challenge of monitoring the recovery process. He and a 'garang' team of volunteers worked hard throughout 2007 to make regular and painstaking measurements and counts of all kinds of aspects.

I took part in some of the less arduous aspects of the study, and it seems that there is some recovery on Chek Jawa! Kok Sheng's Chek Jawa project blog has all the details.

Here is Kok Sheng (just behind the orange flag) with some of his dedicated volunteers, on Christmas Day, toasting to the speedy recovery of our favourite shore.
Indeed, to more good years for Chek Jawa!

You CAN make a difference
do your part to ease stress to our shores

Monitoring our shores' health helps obtain data to help manage impacts. TeamSeagrass relies on volunteers to monitor various sites around Singapore.

Be a good shore visitor and avoid stressing our shores. Don't litter, don't remove or harass marinelife, be a responsible diver.

Links to more about the deaths and recovery
No more Chek Jawa tours - for now Boon Chan Straits Times 25 Mar 07. With a long list of links to other blog entries about the mass deaths, how other nearby shores fared, and about signs of recovery.

Protecting nature's beauty By Liana Tang Straits Times 10 Sep 07
about Kok Sheng and other youths working for our shores.

Photos of mass deaths on Chek Jawa on flickr
including past years when the carpet anemones were stressed.

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