20 February 2023

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.
Dugong feeding trails, Chek Jawa north, Feb 2023
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.

There were lots and lots of trails on the seaward side of the northern sand bar.
Dugong feeding trails, Chek Jawa north, Feb 2023
Also many trails on the seagrasses growing on the lagoon side of the northern sand bar.
Dugong feeding trails, Chek Jawa north, Feb 2023
Dugong feeding trails are formed when dugongs chomp up seagrasses including their roots, leaving a shallow meandering furrow of about equal width and depth. Here's a closer look at the furrow in the seagrass meadow that I saw today.
Dugong feeding trails, Chek Jawa north, Feb 2023
Today, the team rescued yet another shorebird that was trapped in the sand! Here's Kelvin's video of the bird. The team dug its legs out of the sand and it flew away. They tried to dig (carefully) down to see why it was trapped in the sand and couldn't find anything. Joleen Chan saw a similar situation during our survey on Dec 2019. Which she submitted to Singapore Biodiversity Records at the Lee Kong Chian Natural History Museum. Here's her report.

As usual, there were many shorebirds feeding on the shore, and also pooping. Studies have shown that shorebird poop helps seagrasses to grow, and in the process heal damaged seagrass meadows. This photo of shorebirds with the Changi Airport tower is perfect for the story of how Singapore is central to international shorebird travel - While Changi Airport is well known as an international travel hub, Singapore has long been an important stopover for shorebirds that travel thousands of kilometers every year.
As on our last survey in Dec 2021, we saw lots of moon snails of various kinds. The most abundant were Ball moon snailsTiger moon snails and many sand collars, which are the egg mass created by mama moon snails. I also saw the Naked moon snail. Sadly, we didn't come across Button snails - we saw these in large numbers on our last survey. We didn't come across other predatory snails common in our other sandy shores: like olive snails, bonnet snails or fig snails. These snails have not been commonly seen on our previous surveys either.  But there were lots of Noble volutes - I saw one eating a clam. Also lots of Cake sand dollars and Straw tube worms.
A dead moon snail is being 'cleaned out' by whelks while hermit crabs are getting ready for a big 'shell exchange'. Like many people, hermit crabs are always keen to upgrade their home. Thus, the availability of an empty shell often results in a hilarious queue. Because when one hermit crab chooses to take the new shell, its old shell becomes available to the rest. And when this discarded shell is taken by another hermit, another old shell is empty and available for exchange. And so on in a musical shell manner.
Tidal hermit crab (Diogenes sp.)
As on our last survey in Dec 2021, we still didn't see any Haddon's carpet anemones on the seaward facing part of the northern sand bar. They used to be quite common here. But we were relieved to see a few on the inner lagoon. We saw only a few Cerianthids, also some Pink warty sea cucumbers and large Garlic bread sea cucumbers.
There seems to be a lot less seagrass in the northern area compared to our last survey in Dec 2021. So the northern sand bar appears even more enormous than in the past.
Northern Chek Jawa, Feb 2023
There is usually lush seagrasses around this stream that winds out in the middle of Chek Jawa lagoon. Today, it was mostly bare sand.
Northern Chek Jawa, Feb 2023
The southern sand bar has moved further east, and the lack of seagrass makes it appear to have joined the northern sand bar.
Southern Chek Jawa, Feb 2023
There is, however, still lush seagrasses near the boardwalk area.
Southern Chek Jawa, Feb 2023
Indeed, a comparison of Google Earth screenshots from Jan 2008 and Feb 2023, shows how the northern sand bar has widened into the lagoon and lengthened southward. While the southern sand bar has grow larger and moved very far east so it is much closer to the northern sand bar. 
On the northern sand bar, there was mostly Spoon seagrass (small and large leaves) and Needle seagrass with narrow leaves. I only saw some Fern seagrass in near the sourthern sand bar. Smooth ribbon seagrass continues to flourish and have taken over the southern sand bar and large parts of the southern area.
Unfortunately, the trash build up on the northern shore still remains. We have seen this going on for years. But today, we didn't come across any fish traps or nets.

What is the fate of Chek Jawa?

Chek Jawa and Pulau Sekudu is slated for reclamation in the Long-Term Plan Review. The plan includes a road link (black line) from the mainland jumping off at Punggol, crossing to Pulau Ubin through Chek Jawa to jump off to Pulau Tekong before circling back to the mainland on Changi East. Proposed reclamation (in yellow) will bury Pasir Ris shores, Pulau Sekudu and Chek Jawa as well as a large stretches of Changi Beach.

The Singapore Blue Plan 2018

Among the Proposed Areas for Immediate Conservation Priority, the Singapore Blue Plan 2018 proposes that the intertidal and subtidal marine areas of Pulau Ubin to be designated Marine Reserve.
Southern Chek Jawa, Feb 2023
The proposed area would include Tanjung Chek Jawa, the largest known intertidal area in northern Singapore. Considered one of the richest in Singapore, Chek Jawa comprises many adjacent ecosystems: coastal hill forest, mangrove areas, rocky shores, seagrass meadows, coral communities, and sandy areas. Chek Jawa remains an icon of celebration and hope for many Singaporeans since its reprieve from reclamation in 2001.

DOWNLOAD the Plan, SUPPORT the Plan! More on the Singapore Blue Plan 2018 site.

Posts by others on the survey

Liz Lim

Kelvin Yong

Richard Kuah

Che Cheng Neo


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