Friday, January 31, 2014

Any Impact on Chek Jawa from Dec flood at Johor?

Every year towards December and January, it is likely to come across news on floods in Johor and other parts of Malaysia. It was the flood of Dec 2006 and Jan 2007 that lead to a mass mortality of marine invertebrates in Chek Jawa. To find out more on what happened back then, you may read my blog post on What caused the mass death here.

On Dec 2013, we read news of yet more flood in Johor and therefore it is imperative for us to do a check on whether the outflow of freshwater into the Johor Straits have any impact on Chek Jawa.

With special permission from National Parks Board, a small team of us were able to survey the intertidal shore of Chek Jawa on an evening. And we were relieved to not experience any sight of mass mortality on the shore.

The Haddon's carpet anemones (Stichodactyla haddoni) are still doing well. Most of them that I saw on the trip were healthy, not showing any signs of distress. I only came across one or two of them that does not look good.

I went up to the northern shore to have a look at how it is doing. The seagrasses are growing very abundantly and there were evidently more carpet anemones! A good sign. Also, there are several of these Pink warty sea cucumbers (Cercodemas anceps).

Another sign of the northern shore doing well would be having to see a wider variety of sea stars at this stretch ranging from Biscuit stars (Goniodiscaster scaber), Sand stars (Astropecten sp.) and Cake sea stars (Anthenea aspera)! What a delight to see them.

A tiny sea star was spotted by the gals and we suspect it could very well be a juvenile version of the Cake sea star.

From the quick survey, we can see that the marine invertebrates are thriving- ranging from sea cucumbers, cerianthids and sand sollars.

I came across this yellow sea cucumber that I don't think I have seen before at Chek Jawa.

The size, shape and features of this sea cucumber looks very similar to the Garlic bread sea cucumber (Holothuria scabra). It could be a different morph of the same species or yet another species altogether.

As the sun sets, we quickly checked out the coral rubble when the tide receded to its lowest. This is the richest part of Chek Jawa.

The coral rubble is very different from the sandy and seagrass habitats and is home to lots of colourful marine life such as sponges, anemones, zoanthids and ascidians.

Here's another look of the crowded coral rubble with anemones, sponges, zoanthids, fan worm and even a sea cucumber wedged amongst the encrustations.

Though the tide was not supposed to be very low, we could still see a good variety and mosaic of sponges in different colours and forms exposed. During the mass death in Jan 2007, many of these sponges literally melted due to the drastic drop in salinity.

The ladies of the survey team are superb. With them around (especially Chay Hoon), there is no lack of nudibranch and sea slug finds. One of the many finds include this Purple foot nudibranch (Atagema spongiosa).

I have not seen this Actinocyclus nudibranch (Actinocyclus sp.) since 2009 and was elated to see it at Chek Jawa. This slug is usually seen at Tuas.

Chay Hoon found a new slug sighting! And this well camouflaged slug was found through the egg ribbons laid on the sponge. This is probably a Jorunna sp.

My first time seeing this Paper bubble snail (Hydatina sp.)! This is such an elegant creature!

Here's a collage of more slugs that we saw on the trip ranging from the purplish Denison's nudibranch (Dendrodoris denisoni), Black prickly nudibranch (Atagema intecta), Hypselodoris nudibranch (Hypselodoris sp.) and the Beaded nudibranch (Hoplodoris nodulosa).

And even MORE sea stars were sighted at the coral rubble! This collage shows the Spiny sea stars (Gymnanthenea laevis), Scaly sea stars (Nepanthia belcheri), Eight-armed sand star (Luidia maculata), Biscuit star (Goniodiscaster scaber) and Cake sea stars (Anthenea aspera). 

I was searching high and low for the Knobbly sea star (Protoreaster nodosus) and was relieved to find one adult individual.

More echinoderms can be found even on the Spiky flowery soft corals (Stereonephthya sp.)! Where are they?

If you take a closer look, you would spot many of these really tiny orange brittle stars! Amazing isn't it?

Here's more commensals on soft corals. These photos show the Tiny colourful brittle stars (Ophiothela danae) that live on the Pink flowery soft corals (Family Nephtheidae).

Ending off the post, here's a feature on the flatworms at the coral rubble. Just at the foot of the pillar of the boardwalk are plenty of these Little ruby flatworms (Phrikoceros baibaiye)! There was an explosion of these flatworms and we found them in great numbers on this trip. Looks like they are in season.

There is actually another flatworm in this photo found on the pillar. Can you spot it?

Here's a closeup on the flatworm found on the pillar. This brown flatworm with white edge has not been sighted before! Probably another first sighting!

And here's a collage of the different flatworms found on the trip. They are the Blue-spotted flatworm (Pseudoceros indicus), Brown striped flatworm (Pseudobiceros gratus), Fine-lined flatworm and the Blue-lined flatworm (Pseudoceros sp.).

From this survey, it looks like Chek Jawa is doing fine and is not affected by the recent floods in the north. Let's hope the shore will continue to thrive like this blooming Delek air (Memecylon edule), an endangered tree found near the cliff of Chek Jawa.

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