15 January 2009

Languishing Labrador

Singapore's last mainland reef and natural rocky shore and cliffs are found at Labrador Nature Reserve. Unfortunately, it has recently come under lots of development pressures. I thought I should have a quick look to see how the shores there were doing.
This is a view of the massive reclamation just off the Labrador jetty (in the foreground), taken from the lookout point at the top of the hill at Labrador.

Here's a closer look at some of the large vessels and structures just off the shore. We had a ground view of these during an earlier visit.

Before heading off for the reef, I had a quick look at the mangroves at Berlayar Creek which is just next to Labrador Nature Reserve. There are plans to develop a new nature walkway along this Creek.This little stream was edged with lots of mangrove trees, mostly with common species such as Sonneratia alba, Avicennia alba and Rhizophora apiculata. There were also lots of Sea hibiscus.
At the mouth of the stream, which faces Sentosa and the works for the integrated resort, was soft silty sand and patches of Spoon seagrass (Halophila ovalis).
Mud of course means mudskippers! And there were lots of these little fidgetty fishes there. This one might be e a Silver-lined mudskipper (Periophthalmus argentilineatus) as it has fine silvery bars on the side of the body.I'm not too sure what kind of mudskipper this is. But nevertheless, it's fun to encounter these lively fishes. I notice while some of them skip away as I approach, others stay absolutely still. Probably hoping I will be distracted from the more frantic fishes and miss them, which is easy to do as they are so well camouflaged. Knowing this allowed me to get closer to the ones that freeze. But they will still flee if I get too close. Sigh.There were also lots of hermit crabs. But this particular one seemed different from the rest.It had bright blue on the tips of some legs, but no stripes on the legs or eye stalks like the Striped hermit crabs (Clibanarius sp.). It is a kind of Very hairy hermit crab (which I still have no ID for)?I came across a small half shell that looks like it was a small Giant clam (Family Tridacnidae). I remember Mei Lin saying we hardly see baby Giant clams. Sigh. Where was it before it died?Another sad sight was a long driftnet entangled in the roots of several mangrove trees.The Naked Hermit Crabs made a valiant effort with several trips to this shore in 2007 to remove massive amounts of driftnets. But new nets keep appearing.

I hurried over to the reef to catch the lowest tide as the sun set.The rocky shore was teeming with Nerites. And not just any Nerite, but the Polished nerites (Nerita polita). I've never seen so many of these special snails together! They sure are pretty and colourful, appearing in a wide range of patterns too.Here's a closer look at the upper side of a Polished nerite.To identify Nerites, however, it helps to look at the underside. The Polished nerite has a smooth operculum (the 'door' that shuts the hole in the shell). And a few 'teeth' in at the shell opening.

Here are some nerites that are more commonly seen on many of our shores.The Chameleon nerite (Nerita chamaeleon) has a pimply operculum and short parallel ridges at the shell opening. The Waved nerite (Nerita undata) has a pimply operculum, a few large 'teeth' with the corner tooth' often squarish. Also, the spire of the shell sticks out more than the other nerites.
The Scaled nerite (Nerita histrio) has a pimply operculum and really tiny 'teeth' at the shell opening.Earlier in the mangroves, I came across lots of Lined nerites (Nerita articulata, previously known as Nerita lineata) on tree trunks and branches. These look like they are in pin-striped suits and the underside has a pimply operculum with a yellowish stain at the shell opening.Among the coral rubble, there was one little Ovum cowrie (Cypraea ovum). It didn't have spots on the front or back ends of the shell. When I tried to have a look at the underside, it secreted copious amounts of very sticky, gooey mucus. Icky stuff. I had a hard time getting rid of the slime. I have never had this sort of experience with a cowrie before. In the rubble was this pair of snapping shrimps, probably the Orange clawed snapping shrimp (Alpheus lobidens). While one of them zoomed away among the rubble, the other remained at the burrow opening and started repairs on it. And there were many small Blue swimming crabs (Family Portunidae).
But I didn't see any living hard corals, and even the growths of Zoanthids (Order Zoanthidea) was sparse.

There was a bloom of Sargassum seaweeds as well as Hairy green seaweeds (Bryopsis sp.), with a sprinkling of other common seaweeds. The Spoon seagrasses (Halophila ovalis) on the midwater mark seemed alright, but I couldn't find much Sickle seagrass (Thalassia hemprichii).

The tide didn't really go down as low as it should have, so perhaps the seagrasses were out there in the very murky waters. This also meant that I couldn't check up on the situation with the abandoned pieces of concrete on this shore.

Massive reclamation is currently ongoing right next to Labrador shore.This is for the construction of new wharves at Pasir Panjang Container Terminal.This photo is from the table top model at the URA Master Plan exhibition shows the size of the project.In addition, Labrador's shores are near ongoing works at Sentosa for the integrated resort which involves reclamation and other coastal works.

Links to more

Info for visitors to Labrador with a map on what marinelife was seen on the shore in the past, on the wildsingapore website.

2 comments:

  1. Hi Ria!

    I believe the giant clam half valve looks like a burrowing giant clam (Tridacna crocea), which was listed by Lim et al. (1994) in Rhythms of the Sea: Labrador beach. It was said to be previously abundant! But this one might have been washed up too, since the location of the shell is a slity and muddy region of Labrador? Nonetheless, these poor creatures are rarely seen at Labrador anymore... :(

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  2. Thanks Mei Lin! That's interesting to know and yes, so very sad that these and other beautiful animals are no longer seen on our last mainland reef. Sigh.

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