17 June 2018

Pulau Sekudu is alive!

This tiny island off Chek Jawa was lively during our annual survey! Colourful sponges are covering some parts of the rubbly shores, the seagrass meadows are lush - with dugong feeding trails, and all kinds of interesting animals were seen.
Living shores of Pulau Sekudu, Jun 2018
The team also took care of fish traps found on the island, and an abandoned net.

Lying next to a major shipping channel, and in the flight path of planes landing at Changi, the tiny island is rich with marine life.
Living shores of Pulau Sekudu, Jun 2018
Colourful sponges have returned to the rubbly eastern side of the island too. Our predawn survey started there and ended as the sun rose and tide started to turn. The lagoon and reefy arm around it is no longer very bare and sandy as we saw in Jul 2015. The area and the lagoon itself is thickly covered with seaweeds of various kinds.
Living shores of Pulau Sekudu, Jun 2018
Here's some of the colourful sponges I saw growing on the rubble.
Small clumps of Pink flowery soft coral and Spiky flowery soft corals were also growing on the rubble. I saw one small Ball flowery soft coral. There were many Flowery sea pens and some Sea pencils.
There were also many Cerianthids. I tried to video them in the dark...
Common cerianthid with Phoronid worms (Phoronis australis)
 I saw a Kanga nudibranch and one Reef octopus.
As well as this pretty nudibranch which Chay Hoon pointed out was laying eggs!
Nudibranch laying eggs, awaiting identification
There was also this large mama Noble volute who was laying a large egg capsule.
Noble volute (Cymbiola nobilis) laying egg mass
There were some sea fans of various kinds although most of them were heavily laden by the bloom of Ulva and other seaweeds. And some had lost a lot of tissue, leaving only bare 'wires'. But I couldn't find any commensals on them.
Maze sea fan (Echinogorgia sp.)
I saw some Gnarled sea fans and Candelabra sea fans, Skinny sea fans and one Maze sea fan. I sense we saw more sea fans in better condition during our last survey in Jun 2017.
We saw several Knobbly sea stars. They looked like big old grandmothers, and were rather dispersed. We didn't see any small ones. I saw a Biscuit sea star, a Cake sea star and a Crown sea star.
There were some Thorny and Pink warty sea cucumbers, but not as abundant as on Changi. Others seen included Orange sea cucumbers, Ball sea cucumbers and many small Garlic bread sea cucumbers in the calmer lagoons. There were also some White sea urchins.
It was nice to see a variety of small hard coral colonies. Some were growing suprisingly close to the shoreline.
Boulder pore coral (Porites sp.)
I came across a small Disk coral, which I have not seen since 2013. I also saw one Pock-marked coral and many small Boulder pore corals. This is somewhat similar to our last annual survey in Jun 2017, just after mass coral bleaching in 2016.
The rocks were coated in colourful animals such as sponges, ascidians, worm snails and more.
Various marine life on rocks of Pulau Sekudu, Jun 2018
The two Diadema sea urchins have moved to another nearby rock.
Various marine life on rocks of Pulau Sekudu, Jun 2018
Haddon's carpet anemones are super abundant everywhere on the shore. Other anemones seen in large numbers included Swimming anemones and Posy anemones.
Haddon's carpet anemone (Stichodactyla haddoni)
The seagrasses are lush and we saw some dugong feeding trails. The trails appear to avoid the carpet anemones. The seagrasses were mostly Spoon seagrass (both small and large leaf blades). There were many patches of Fern seagrass and Needle seagrass.
Dugong feeding trail in seagrass meadows, Pulau Sekudu Jun 2018
Here's a video clip of some of the animals I saw among the seagrasses.
Living seagrass meadows of Pulau Sekudu, Jun 2018
I saw two clumps of Tape seagrass. One had leaf blades about 30cm long, the other about 50cm long.
Tape seagrass (Enhalus acoroides)
The patch of Serrated ribbon seagrass appears to have grown larger, to about 10m from the low water mark.
Serrated ribbon seagrass (Cymodocea serrulata)
Adrianne took care of three fish trap found in the middle of the lagoon. And some of the team released a few crabs that were trapped in an abandoned net that was half buried in the sand.

This little island lies just off Chek Jawa on Pulau Ubin. It is part of the Chek Jawa Wetlands that is managed by NParks. Pulau Sekudu is off limits since 2007 and requires special permission from NParks. 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!

Chek Jawa and Pulau Sekudu may be affected by the 2030 landuse plan by the Ministry of National Development. The plan includes plans for 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 amount of shore at Changi Beach.

I feel it is thus important to update our understanding of what is going on in the field at these sites including Chek Jawa and Pulau Sekudu.

Posts by others on this trip

By Loh Kok Sheng

By Carol Phillips

By Chong Siew Men

By Jianlin Liu

By Toh Chay Hoon

By Dayna Cheah

By Russel Low

By Adriane Lee

By Richard Kuah

By Lisa Lim.

Lisa Lim also did a lovely video

Others on this trip: Jesselyn Chua.

Meanwhile, elsewhere on the same day

Doreen Foo was at Changi with the NParks intertidal survey

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