Under a full moon in clear skies, a small team does our annual predawn survey of Chek Jawa
During a very low spring tide, we have a glimpse of some of the more delicate parts of Chek Jawa. How are they doing?
We are always glad to see
Knobbly sea star! I saw these three large ones, but the team saw more. However, we didn't see any baby Knobblies.
Other sea stars I encountered included one
Cake sea star and one Spiny sea star. There were a lot of
Biscuit sea stars of all sizes from tiny to large. I also saw many medium sized
Garlic bread sea cucumbers. There were many
brittle stars which quickly retracted their arms into the crevices where they were hiding.
I came across about 10
white sea urchins on the coral rubble near the very low water mark. I didn't see any among the seagrasses. I have often wondered why there are a lot more white sea urchins among the seagrasses on Changi, but much fewer at Chek Jawa's seagrass meadows.
How nice to see the
Spotted orange hermit crab. The last time I saw it here was in 2001.
Ivan found this hermit crab that we have not encountered before.
It looks somewhat similar to this one I saw at Tanah Merah in 2012.
I saw three little
Reef octopuses. Two of them were stranded out of water. This one fortunately was still in a pool.
I saw a small
Estuarine moray eel. This is a fish and NOT a snake. It has tubular nostrils, tiny eyes and no pectoral fins.
There are two
Fan-bellied filefishes in this photo! I saw many of these fishes, mostly small.
This looks like a
Black-spot tuskfish. My first time seeing it on Chek Jawa and I seldom see it. This fish is currently being considered for listing on the IUCN Red List of internationally threatened fishes.
Stranded at low tide were these small
Black eeltail catfishes which were still alive although quite distressed. There were no nearby pools for me to transfer them to. Fortunately, the tide turns at sunrise and I'm sure they will be ok. I think Singapore's sea shores are so rich because our very low tides only occur in the dark. Otherwise, I can imagine many delicate marine animals will fry in the hot sun!
Here's some fishes I saw which I'm not sure of their identity. The rest of the team also found a live
shark, which Dr Zeehan says looks like a bamboo shark. While Chay Hoon found a tiny
Hollow-cheeked stonefish.
This
Red egg crab was hiding in a healthy looking colony of Pore coral. The last time I saw this crab on Chek Jawa was in 2005. Chay Hoon found a
Mosaic crab too, which I haven't seen since 2001. There were many colourful
Swimming crabs of various kinds. Tiny and small shrimps of all kinds were busy on the shore including:
Prawns (Family Penaeidae),
snapping shrimps (Family Alpheidae) and various kinds of tiny shrimps.
This yet-to-be-identified
Fine-lined flatworm seems particularly common on Chek Jawa. But today, only this one was found. Hopefully Rene will be able to sort out its identity.
There were a lot of
Haddon's carpet anemones, especially in the seagrass meadows, but also on the coral rubble area. I didn't see any that were bleaching.
I also saw a
Snaky sea anemone! My first time seeing this since we started the predawn surveys. The last time I saw this at Chek Jawa was in 2005.
I don't know what this pretty sea anemone is. I also saw one
Tiger anemone, and many
Swimming anemones.
I saw one small
Ball flowery coral, and many
Spiky flowery soft corals. One had
Tiny colourful brittle stars. But I couldn't find any Ovulid snails.
There are corals at Chek Jawa! Many tiny to small patches of
Zebra coral, but also small to medium-sized
Boulder pore corals. I saw about 15 colonies. Kok Sheng says he saw about the same number as on his last survey in
Jan 2014.
Some of the corals have a touch of coral bleaching, and one flowery soft coral was very pale pink.
There were many patches of these yet-to-be-indentified
Posy anemones, as well as many small mounds of
Button zoanthids.
There were some, but not a lot of seafans. I saw several
Candelabra sea fans, one small cluster of
Tree seafan, two clusters of
Skinny sea fans, and one
Gnarled sea fan. I couldn't find any of the usual commensals on the sea fans (like snails or clams).
Among the lush seagrasses, I saw many
Flowery sea pens. I also saw a few half-retracted
Spiky sea pens. I also saw one
Common cerianthid.
I saw one bunch of strange hydroids with flower-like polyps, and another bunch of
stinging hydroids.
We were rather disappointed to see few sponges. The largest sponge I saw was this dark rose pink one which I have yet to figure out, I saw several of them. There were also several
Yellow horn sponges and
Yellow bumpy sponges.
I saw one cluster of
Barrel sponge, a few clusters of
Purple branching sponge, some black sponges but very few and small patches of other colourful sponges.
But most of the coral rubble area looked like this today.
This is what the coral rubble looked like when I last visited
in Aug 2013.
Kok Sheng says the shores looked much better in
Jan 2014 when the team surveyed Chek Jawa for possible impact of the heavy rains at end 2013.
The photo below is of the Chek Jawa coral rubble area before the sponges were wiped out by the mass deaths in 2007. This incident is believed to have been caused by heavy rain and
Kok Sheng did a study of Chek Jawa's recovery.
 |
| Sponge garden at Chek Jawa in 2002 |
Sadly, I came across a trap under the House No. 1 jetty. There's also litter but not a lot. As well as large tyres. Although it was a relief not to come across a driftnet laid across Chek Jawa, like we did in
July 2013.
The team last surveyed Chek Jawa in Jan 2014, I couldn't join them because I was still in a wheelchair from a broken foot. I was really glad to be able to walk again, although I still can't walk well in soft mud and can't walk very far.
More about the Jan 2014 survey:
Thanks to NParks for permission and support to do these predawn low spring tide surveys of Chek Jawa. Thanks also to Chay Hoon for making all the transport arrangements. And the team for helping to cover as much ground as we can during the narrow low tide window. Thank you!
More about why I think
it's important to regularly survey Pulau Sekudu and Chek Jawa.
Posts by others on this trip
