Chek Jawa (South) still alive

We do our annual low tide check up on the southern area of Chek Jawa near the Beacon, with kind permission and support from NParks.

We find healthy hard corals and soft corals, and sponges and sea fans. The seagrasses were particularly lush and green. I felt today that the southern sand bar had gotten wider, and that sand had built up on the landward side of the sand bar and in the area directly beneath the Beacon. The team make all the special finds: seahorse, stonefish, lots of Knobbly sea stars and more.

Other intertidal surveys: Mar 2026

Thanks to Marcus for visiting Cyrene in March so we could get an update on the mass injuries we saw to the Knobbly sea stars that we observed in Feb  2026.

Collage of photos by Marcus Ng.

Marcus photographed 14 Knobblies on his Mar 2026 visit. Although all of them appear healthy at first glance, a closer look at the top 5 knobs shows that 10 sea stars (or about 70%) show recovery from damage. Where the top 5 big knobs should be, there was a sheared flat surface - which were a dark colour and thus seem 'healed', not greyish-blue as we observed in Feb  2026. Others had dark patches at the top and the knobs were missing or seem a little 'limp'. One had knobs that look like they were starting to separate at the base from the main body. One pale sea star had three knobs instead of one large knob. Only 5 sea stars seem normal. Again, still not sure what is going on. But at least there isn't new damage?

Other intertidal surveys in Feb 2026

Between the low spring tides, the intrepid Rui Quan Oh relentlessly checked out more shores! As usual, I learn a lot about crabs, and also the pretty insects and spiders of our mangroves. So glad to know cute fiddlers and awesome Blue-spotted mudskippers still abound on Pulau Ubin. 

Collage of photos by Rui Quan Oh

Rui Quan checked out Sentosa, Coney Island, Admiralty Park. And also Ubin together with Zen Xuan He. Thanks also to Dr Clarence Sim for inviting Rui Quan to help in his intertidal work at Pulau Semakau.

Quiet at Chek Jawa North

For the first time in years, the rain fell somewhere else on our annual survey of Chek Jawa's vast northern sand bar! 

The sand bar is still alive! Seagrasses are still doing well on the seaward side facing Johor, we saw dugong feeding trails and carpet anemones are still there. But the shores seem a little quieter than previous years. Perhaps the pollution events at the Johor River last month had something to do with this? But our May 2025 survey of the Southern sand bar, we also noticed it was more subdued - so perhaps it's something else? Thanks to NParks for permission to survey.

Two unrelated pollution events at East Johor Straits (1 Nov 2025)

Two unrelated pollution events occurred on 31 Oct; one in the Johor River caused by sand mining activities, the other a palm oil spill that affected the coastal waters off Kampung Pasir Putih in Johor.

Photos of palm oil spill (above)
and sand mining operations (below)
from Bernama

Singapore agencies were closely monitoring and as at 1 Nov, NParks has not observed any impact at biodiversity-rich sites at Pulau Ubin, Coney Island Park, Pasir Ris Park and Changi Beach Park. Water quality in Singapore is normal and fish farms are unaffected. 

PUB’s Johor River Waterworks have been temporarily suspended, water supply in Singapore remains unaffected as it has stepped up production at local plants to meet demand. Operations will resume when water quality checks show that the Johor River quality is back to normal.

Update: Operations at PUB's Johor River Waterworks resumed on 2 Nov.

Media articles below

Quiet at Chek Jawa (South)

A small team does our annual low tide check up on the southern area of Chek Jawa with kind permission and support from NParks.

With flaring at Johor's petrochemical plants on the horizon, we find corals are doing well, sponges seem to be recovering. About 2 months ago, Changi and other shores in the East Johor Straits were impacted by an oil leak from Langsat, Johor. Today at Chek Jawa, we didn't see obvious signs of spill effects, but there were many 'missing' animals. Nevertheless, we saw many sea stars, 2 seahorses and many other marvelous marine creatures!

East Johor Straits oil patch from Langsat Terminal, Johor (3 Apr 2025)

An oil patch was sighted in the eastern Johor Strait off the northeastern coast of Pulau Ubin on 3 Apr 2025 at around 7pm. Johor Port Authority confirmed an oil spill incident within Langsat Terminal, located near the mouth of the Johor River.

The Malaysian Environment department said low sulfur fuel oil was being transferred to a vessel at the Tanjung Langsat Port Terminal’s jetty when the leak occurred. Approximately 1.6m³ of oil spilled into the sea". From Free Malaysia Today 04 Apr 2025, 05:57 PM

For the latest updates, visit https://go.gov.sg/nparksnoticeboard

For daily updates on facebook, see this album on wildsingapore FB

Chek Jawa North is alive!

It seems to rain every time we survey Chek Jawa! This year, it was just a drizzle as we surveyed the vast northern sand bar. 

Seagrasses are still doing well, carpet anemones are back on the seaward side. Kelvin spotted some dugong feeding trails, and we saw favourites like Button snails and Common sea stars. Thanks to NParks for permission to survey.

Chek Jawa closed 1 Jul - 31 Oct 2024

Chek Jawa Wetlands (circled in black) and the trail leading towards it (indicated in red) are closed from 1 July 2024.

This is to facilitate trail maintenance works. Expected completion date: 31 October 2024.

From NParks website.

Chek Jawa (South) with signs of dugong and rare sea stars

We do our annual low tide check up on the southern area of Chek Jawa with kind permission and support from NParks.

We see signs of dugong feeding in the lush seagrass meadows, and lots of juveniles of a rare sea star. The hard corals near the beacon are not mass bleaching, but some seem stressed. There is hardly any sponges and most of the sprinkling of small soft corals were bleaching. 

Chek Jawa in the rain - still alive!

In a constant downpour, we surveyed northern Chek Jawa, with permission from NParks. I worry every time there is a lot of rain. Heavy and prolonged rain was believed to have caused the mass deaths at Chek Jawa in 2007. 

It was a relief to see healthy specimens of animals that died in 2007. In fact, the team spotted special animals including Pentaceraster sea stars, our first sighting for our northern shores. We also saw signs of dugongs! 

Chek Jawa coral garden still thrives!

We do our annual super low tide check up on the southern area of Chek Jawa with kind permission and support from NParks.

The delicate garden here still thrives! With flowery soft corals, sea fans and colourful sponges. I also saw a few signs of dugong feeding trails while the rest of the team have some special finds.

Shorebird rescue and signs of dugong at Chek Jawa

A small team of volunteers did our annual health check on the northern shores of Chek Jawa with permission from NParks.

We are delighted to see many many dugong feeding trails. The team also rescued a trapped shorebird (our second encounter of this situation). However, there seems to be a lot less seagrass in the area.

Coral garden at Chek Jawa with sign of dugong

A small team does our annual super low tide check up on the southern area of Chek Jawa. As usual, this happens predawn, and today, under a full moon. Thanks to NParks for permission.

The delicate coral garden here still thrives! With flowery soft corals, sea fans and colourful sponges of all kinds. I also saw a few signs of dugong feeding trails, on the way back from the shore, James spotted a mousedeer!

Buttons return to Chek Jawa

A small team of volunteers did our annual health check on the northern shores of Chek Jawa with permission from NParks.

Button snails have returned to the northern sand bar! But we notice some common animals were 'missing' too.

Delicate coral garden at Chek Jawa still thrives!

The delicate coral garden at the Chek Jawa beacon still thrives! With flowery soft corals, sea fans and colourful sponges of all kinds.

Chek Jawa is looking more like it used to before the devastating mass deaths in 2007 which wiped out the sponges and many other animals here. Chek Jawa was also hit by the 300-tonne oil spill in the East Johor Strait in Jan 2017. So it was a relief to see such a magnificent array of marine life there this morning.

I was glad to see many sponges of various kinds all along the survey route from the House No. 1 Jetty to the Chek Jawa Front Beacon! I first noticed improved sponge diversity during our survey in Jul 2016, which improved further during our Jun 2017 survey and in our Jul 2018 survey.

Chek Jawa with signs of dugong

Once a year, we do a health check on the northern shores of Chek Jawa. This trip was particularly poignant for me as my last field trip with Subaraj was here.

Rain meant a shorter survey on the sand bar as we kept closer to shelter in case of lightning. But we managed a quick check and saw dugong feeding trails in the lush seagrass meadows and other interesting marine life. Thanks to NParks for permission to survey the shore.

Return of Common sea stars to Chek Jawa?

A small team completes our annual survey of Chek Jawa's southern shore. Unfortunately, the tide wasn't as low as we would have liked it, so we couldn't really confirm if the coral rubble area is as rich as it was at our last survey in Jul 2019.

But we were thrilled to see that the Common sea stars appear to be making a comeback to Chek Jawa. They were wiped out in the devastating mass deaths in 2007 which also wiped out the sponges and many other animals here. Chek Jawa was also hit by the 300-tonne oil spill in the East Johor Strait in Jan 2017.

White sediments on Chek Jawa - where is it coming from?

Today, at Chek Jawa off the boardwalk, there was a long stretch of white sediments on the high shore.

Opposite this stretch of white sediments, there was work on part of the boadwalk. Is this where the sediments came from?

Will Chek Jawa be impacted by the non-stop rain?

The non-stop rain and reports of flooding in Johor recently made me worry that there will be a repeat of the mass death at Chek Jawa in 2007. Fortunately, during our survey of Chek Jawa on 14 Dec, we didn't see mass death, although we came across some small sea stars that appear to be dying.

It was great to see lots of dugong feeding trails near the southern sand bar! As well as many other interesting marine life! Thanks to NParks for permission to do this survey of Chek Jawa.