01 August 2015

Missing sponge gardens at Pulau Ubin

Besides Chek Jawa, there are other Ubin shores that are just as beautiful. A small team explored one such shore this morning well before dawn.
Alas, the sponges and other colourful marine life we saw on the rocks in the past are missing. We saw a similar decline recently at Chek Jawa and Pulau Sekudu, as well as Changi opposite.


Kok Sheng first brought us here in Dec 2009, and we returned in May 2010Dec 2010 and Dec 2012. During those surveys, the rocks were coated in colourful sponges, ascidians, soft corals and sea fans. This morning, they were quite bare. But we did see some interesting marine life.

There were some small sea fans growing on the rocks in deeper water. I saw Candelabra sea fans amd Gnarled sea fans.
Many of the large sea fans that I saw appear to be succumbing to fouling organisms growing on them.
I saw one long Asparagus sea fan which I usually only see at Beting Bronok. Fouling organisms appear to be starting to grow on it.
There were many patches of Zebra coral on the rocks in deeper water. As well as tiny clumps or scattered polyps of Cave corals. I saw only a few clumps of Candy hydroids and zoanthids. There were also some clumps of Ball-tip corallimorphs.
It was lovely to see four feather stars: three Blue feather stars and one Black-and-white feather star.
I saw a few medium to large Biscuit stars and one medium Cake star. But no other kinds of sea stars. I only saw one thorny sea cucumber.
There were very few clumps of sponges. I saw a few clumps of Prickly ball sponge, a small patch of Elegant branching sponge, some clumps of Rainbow sponge. There were many patches of Melted chocolate sponge. Chay Hoon of course managed to spot some interesting nudibranchs.
There were a variety of ascidians on the shores, the most abundant being the Thumbs up ascidians and Yellow clustered ascidians. The patch of ascidians below seems to be getting coated with a green scum.
There were a lot of these Blue spotted flatworms. Flatworms eat immobile animals such as ascidians. This one is well wrapped around a Yellow clustered ascidian and is probably eating it.
There were many Onyx cowries as well as the more commonly seen Ovum cowries. Still abundant on the rocky shores are Banded bead anemones and onch slugs. As well as many Drills laying yellow egg capsules. There were also many Haddon's carpet anemones.
This boring looking lump is an Armoured sea cucumber. The first one I've seen outside of Changi.
This is not a little dead leaf. It is a fish! The Brown sweetlips.
Jose spotted this large octopus which slowly disappeared into its burrow.
There was a small Noble volute which was clutching something in its foot.
There were Spoon seagrasses on the softer parts of the shore as well as a lot of pink fluffy stuff which might be some kind of seaweed or cyanobacteria. The stick-like thing is a Slender sea pen!
Lisa found a Spiky sea pen. It had a tiny porcelain crab in it that looks different from the ones I usually see in this sea pen.
I came across a bundle of abandoned fishing nets. It has been abandoned for so long that marine life has started to grow on it including one sea fan.
I came across one fish trap that appears to be active.
At first I thought it was a jellyfish. But it turned out to be a spotted balloon. Sea turtles love to eat jellyfish and if they mistakenly eat balloons, they can die a slow death. Please do not release balloons!
The loss of sponges on our northern shores is disturbing. Is this a reflection of water quality? There's so much more we still don't know.

Photos by others on this trip

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