01 December 2012

Seagrassy with nudi at Tanah Merah

How nice to come across this tiny nudibranch (Gymnodoris sp.) at Tanah Merah, which was hit by a massive oil spill in May 2010. It's been four months since we last checked up on this shore.
We saw other slugs, the seagrasses are doing very well, corals seem good and there were lots of fishes too.

We also found super tiny Strawberry slugs (Costasiella sp.) that live on Fan green seaweeds (Avrainvillea sp.).
Another very surprising find was lots and lots of Ornate leaf slugs (Elysia ornata). They were all over the shore, often moving around on bare sand. I've never come across such a situation before here or on any other shore.
Nicole was the first to spot the Ornate leaf slugs. When I went over to have a look, we noticed a huge pile of poop, probably made by an Acorn worm (Class Enteropneusta).
Marcus spotted this Garlic bread sea cucumber (Holothuria scabra)! They seem to be coming back as I spotted one too this year.
I looked hard for seahorses, which used to be seen here among seaweeds and seagrasses. Although I didn't spot any, I did see this cute little Variable fang-blenny (Petroscirtes variabilis) perched on a clump of Tape seagrass growing in deeper water.
While we didn't come across any Hollow-cheeked stonefish (Synanceia horrida) on this trip, we did come across the False stonefish (Scorpaenopsis diabolus).
After sunset, it was much easier to photograph the fishes as they came out of hiding. I saw a wide variety of them from tiny gobies and damselfishes to larger ones.
I saw two of the pretty Spotted orange hermit crabs (Dardanus megistos), as well as several Striped hermit crabs. There were lots of little shrimps on the rocks and when it got dark, the bigger shrimps came out to feed.
For the first time, I came across a hermit crab that was wandering around without a shell. It turned out that it was moulting! A great opportunity to show how this animal has a soft abdomen that is coiled to fit perfectly into an empty shell!
There were lots of crabs on the shore. Many small and medium sized Flower crabs, many with algae growing on them. Also other kinds of Swimming crabs (Family Portunidae). And quite a large number of Stone crabs (Myomenippe hardwickii) which I had not observed before on this shore. The Ghost crabs (Ocypode cerathophthalmus) came out after sunset to forage.
I did a quick check on the corals here and I didn't come across any that were bleaching. There were many small to medium-sized colonies of Pore corals (Porites sp.).
There were, as usual, many Favid corals (Family Faviidae), many small colonies and some medium-sized.
Some special corals I came across include a nice 'fluffy' colony of Anemone coral (Goniopora sp.), a row of tiny mushroom corals still stuck to a hard surface, as well as a larger Circular mushroom coral (Family Fungiidae) that was already free living on the bottom. As well as a few small Flowery disk corals (Turbinaria sp.) and one small Brain coral (Family Mussidae).
I saw several patches of Button zoanthids or colonial anemones (Zoanthus sp.) in various colours. They seem to be doing very well.
I saw four rather large Frilly sea anemone (Phymanthus sp.).
Delicate fanworms dot the seawall here and there. Also many Thumbs up sea squirts (Polycarpa sp.), most of them completely covered in fluffy epiphytes. Although I didn't see any myself, Marcus and Nicole saw a colony of Common sea stars (Archaster typicus). I saw some Pink moon snails (Natica zonalis) and some sand collars. I also came across a Reef murex (Chicoreus sp.).
We enjoyed a surprising rain-free evening and were pleasantly surprised by a shore that was quite clean of rubbish. And the two large patches of Smooth ribbon seagrass (Cymodocea rotundata) (yellow arrows) were doing very well.
The Ribbon seagrass patches were doing very well. Both seemed to have grown sideways and towards the seawall. The leaf blades were nice and long and I didn't see any burnt or bleaching blades.
There's lots of life among the Ribbon seagrasses. From tiny crabs to tiny fishes. There were many Haddon's carpet anemones (Stichodactyla haddoni) although I didn't see anemoneshrimps in any of them. And Fan clams (Family Pinnidae) and Window-pane shells (Placuna sp.) are coming back too.
The patch of  Tape seagrass (Enhalus acoroides) in the middle of the lagoon is doing nicely, with long fresh green blades.
I came across another large clump of Tape seagrass. The Sickle seagrass (Thalassia hemprichii) patch is also looking lush with long green blades. The last time I saw them, the blades were 'chomped' short. But the nicest surprise was to see large areas covered with Spoon seagrass (Halophila ovalis) , in some places these seagrasses were quite dense. Hurray!
There were nice clumps of various kinds of seaweeds too, here and there and among the seagrasses.
There were lots of signs of little crabs in the sand, possibly Sand bubbler crabs (Scopimera sp.). Lots of Dubious nerite (Clithon oualaniensis) and Bazillion snails (Batillaria zonalis) still cover large parts of the sandy lagoon.
The sand level seems to be rising in the lagoon, burying some of the corals.
There were also those odd patches of white stuff that look like fungus that I've been seeing here since the oil spill. Greenish stuff is growing on the edges and these seem to attract the Bazillion snails.
There were still areas with dark sand, often just beneath a thin layer of clean sand, with a slight sheen in the water when I dug into the dark sand.
In some parts of the lagoon, there was still a scummy layer on the water.
Although there were some large debris on the high shore, there was very little plastic rubbish. We didn't come across any abandoned driftnets. But we did see two people foraging on the shore. They left at sunset.
The Siemens project on the shore is still there. But hoarding has been put up at the fence.
The pipes from the Siemens project are still discharging onto the shore. More about my correspondence with Siemens about this project.
Although we enjoyed good weather, it was raining in the south.
Although this stretch of Tanah Merah is entirely artificial, all kinds of interesting marine life have settled here and persisted despite the oil spill. There are not many good low spring tides towards the end of the year, so this is the last trip in November.

Posts by others on this trip
  • Marcus shared about the awesome huge cuttlefish and tiny squids he saw.

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