Monday, January 11, 2016

Northern Chek Jawa survey

We are back at Chek Jawa for our intertidal survey, with permission from Nparks. We hardly have the energy and time to do the northern part of Chek Jawa as we usually get distracted by the coral rubble in the south.

Thus, it is good that we dedicated a not-so-low tide to properly look at the northern part. It was a bright sunny Sunday, perfect for taking landscape shots. And I'm glad to see the seagrasses expanding its territories.

The Haddon's carpet anemones (Stichodactyla haddoni) seem to have increased in numbers! Slow but recovery since the mass death event in 2007.

These anemones look pretty when submerged underwater, together with the seagrasses.

And they are also many of them found exposed on the sandbar during the low tide.

On the sandy stretches and parts of the sandbar, there still are many of the Cake sand dollars (Arachnoides placenta).

This is how they look like when one brushes off the sand that covers their surface. Chek Jawa is indeed rich as there are many sand dollars on its sand bank. :)

Something new that we observe on this trip would be the "explosion" of Pink warty sea cucumbers (Cercodemas anceps) and Thorny sea cucumbers (Colochirus quadrangularis) on the seagrass.

There seems to be more of the warty than the thorny sea cucumbers. The warty sea cucumbers are more brightly coloured.

The Garlic bread sea cucumbers (Holothuria scabra) are abundantly found on Chek Jawa even on a hot day. Though many of them were semi or fully buried underneath sand. I also found one black version of this sea cucumber.

The tip furthest from the shoreline allows one to observe the beautiful Lesser Crested Terns and Greater Crested Terns. One can also see Tekong at the background.

Here's how they look like when they fly off! These terns need to learn how to take turns before flying.

We are reminded that the seagrass meadows are important as they also support dugongs which exist in our waters!

Many of these "botak" or bare trails in seagrass beds are likely to be dugong feeding trails where these magnificent huge marine creatures would graze on the seagrass when the tide is higher.  

I only came across two of these Biscuit stars (Goniodiscaster scaber). They are usually more abundantly found at the coral rubble.

I have not seen the Common sea star (Archaster typicus) at Chek Jawa for a long while! Likely to be since 2012 but of course it is also due to the fact that I didn't look hard enough. Thus, I was thrilled to come across one!

And here's another one close to where I found the first one. Unfortunately, these common sea stars are no longer common after the 2007 mass mortality event. And it seems like the population is as small all along since the beginning of recovery. At least they are still around!

I noticed on this trip that these Cerianthids (Order Ceriantharia) are more commonly found nearer to the south than the north. I have no idea why.

Some cool-looking critters spotted include this Pygmy squid (Idiosepius sp.). They are usually actively swimming and that makes photographing these squids difficult. 

Another tough creature to photograph would be this Kite butterflyfish (Parachaetodon ocellatus) that seems to like being associated with the Haddon's carpet anemones.

Here's a close to this blog post with a half submerged photo of both the boardwalk and the carpet anemone. If possible, we will likely be back again at a much lower tide to do our annual survey at the coral rubble.

More photos of the survey here:

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