24 September 2009

Labrador sunset walk with NParks

With a glorious sunset as a backdrop, a small team heads out to Labrador.
While Bian and Marcus help Mei Lin check out the shore for her Giant Clam project, I had the pleasure of sharing about Labrador with some new friends from NParks.

First stop, we have a look at the seagrasses! Labrador has the last good meadow of Sickle seagrass (Thalassia hemprichii) on the mainland. This seagrass is only common also on offshore islands. There are also some clumps of long Tape seagrass (Enhalus acoroides), and lots of little Spoon seagrasses (Halophila ovalis).
Seagrasses are an important habitat for young animals, small animals and part of a natural continuum of marine habitats: from rocky shore, sandy shore to coral reefs.

There are lots of intriguing holes on the shore. Many of them are dug out by tiny snapping shrimps (Family Alpheidae) which create the incessant clicks we hear on the shore. But the big smooth-sided burrows are created by the elusive Coral ghost shrimp (Glypturus sp.). Often, all we get is a glimpse of the bright orange pincers before the shy creature slides back into its burrow.
As it gets dark, more crabs come out to play. Like this pretty round brown crab. It is the Brown or Floral egg crab (Atergatis floridus) which among the most poisonous crabs in Singapore. It contains toxins that are not destroyed by cooking and should never be eaten.
Another common egg crab is the Red egg crab (Atergatis integerrimus) which is also highly poisonous. Also very common on Labrador are the swimming crabs (Family Portunidae) which come in various colours and patterns. They also hide themselves under sand, which is why we must watch our step. We also saw a hairy crab (Family Pilumnidae) but it refused to come out of its hiding place.
A most exciting find was this large prawn (Family Penaeidae) by one of the NParks team. These prawns are quite commonly seen on our shores with seagrasses.
Labrador was also full of fishes. Marcus finds a scorpionfish!
This is the Painted scorpionfish (Parascorpaena picta) which can be quite large but is very well camouflaged.
Bian and Mei Lin also found lots of fishes! Like this pretty yellow filefish (Family Monacanthidae).
And an elegant Frilly filefish (Chaetodermis penicilligerus). It's quite well camouflaged among the many seaweeds growing on the shore.
In a pool, we suddenly saw a large Copperband butterflyfish (Chelmon rostratus)! We also saw some tiny butterflyfishes.
There were also lots of silvery blue Tropical silversides (Atherinomorus duodecimalis), little spotted glass perchlets, a small halfbeak (Family Hemiramphidae). Marcus found a beautiful Fringe-eyed flathead (Cymbacephalus nematophthalmus), see his blog for the photo of it. Read more on his Signs of Recovery.

On the wish list: octopus. And Bian found us one! Octopuses are quite common on most of our shores where there's hiding places and food for them. But they are hard to spot as they can change colours and even the texture of the body to match their surroundings!
And Bian finds another special mollusc: the Spider conch (Lambis lambis)! This snail is listed as 'Vulnerable' on our Red List and is "no longer as abundant as in the 1960's". Earlier on, we also had a closer look at the Dwarf turban snails (Turbo brunneus) to see the thick 'door' (operculum) that they have to seal the shell opening. In the conch snails, the operculum is knife-like and attached to a muscular foot. The conch doesn't creep, but instead hops like a pole-vaulter.
We also came across a cute little Ovum cowrie (Cypraea ovum). Bian also found a very tiny Pink moon snail on the sargassum seaweed! While Marcus saw a Pencil squid (Family Loliginidae) in deeper water.
But how are the corals doing? Today, we saw some small colonies. A hard coral is a colony of tiny animals called polyps. Here's the small flower-like polyps of a Goniopora coral (Goniopora sp.).
Some species have larger, fleshier polyps. Like this one which is possibly a Favid coral (Family Faviidae).
Others have tiny polyps, like these Pore corals (Porites sp.). Each tiny hexagonal depression is the skeleton created by a tiny polyp. Polyps can retract into their skeleton when out of water. But there remains a thin tissue over the skeleton. So we should not touch hard corals as we might damage this tissue, and most certainly shouldn't step on them.
Corals come in different colours! The colours are often due to the tiny symbiotic algae that live inside the polyp. The algae make food through photosynthesis which it shares with the polyp. The polyp in return provide shelter and minerals. When polyps are stressed, they may lose their algae which makes them colourless and reveals the white skeleton beneath. This is called coral bleaching.
The arrangement of the tiny skeletons results in the different colony shapes. Some colonies may have branches.
There are also other colonial animals that do not create a hard skeleton. These flowery soft corals (Family Nephtheidae) have tiny polyps embedded in a common tissue.
This is another colonial animal with feathery polyps. I still don't know its identity although it is commonly encountered on many of our reefy shores.
A very pretty animal are the colonial anemones or zoanthids (Order Zoanthidea). These look like small flowers on the sand and come in a wide variety of colours. When exposed at low tide, they tuck their tentacles into the body column and look like blobs.
There were also several Frilly anemones (Phymanthus sp.). This pink one that Bian found reminds me of strawberry cake.
There were also some sponges on the shores. The most common one seen where the blue Spatula sponges (Lamellodysidea herbacea). There were also many Chocolate sponges (Spheciospongia cf. vagabunda), little patches of orange ones (Mycale sp.) and this patch of yellow Prickly sponge (Pseudoceratina purpurea). Sponges are food for interesting animals such as flatworms and nudibranchs. But we didn't see any on this trip.
Other animals seen included a fan worm (Family Sabellidae).

All too soon, the tide turned. As we headed back, Bian noticed a scuttling among the leaves near the high shore. It was a little mouse! It clambered up the bushes.
And I only got this partial shot of its whiskery face.
Other scavengers on the high shore were Land hermit crabs (Coenobita sp.)! Marcus spotted lots of these brownish ones. I just couldn't see them as they moved slowly and blended right in with the leaves.
But later on, I spotted this beautiful lilac Land hermit crab. Land hermit crabs are no longer common on our shores. They are listed as 'Vulnerable' on our Red List. Ironically, this is because many of our public beaches are kept too clean. Natural leaves and flotsam are efficiently removed with other litter. So there is no place for these hermit crabs to hide or find food.
Alas, we didn't see any Giant clams today. It was hard to check with the lush growths of Sargassum seaweed (Sargassum sp.). We should probably come back again after the seasonal bloom of this seaweed is over. There were also lots of other kinds of seaweeds on the shore.

See also Mei Lin's Psychedelic Nature blog for MORE about what we saw at Labrador.

Labrador seems to be improving a little since our last trip. It's good that the shore is being given a reprieve from the public. Access to the beach has been restricted since Jun 09.

It was also good to see that the seacil on the seagrass meadow has finally been removed, although there were still a few smaller blocks of concrete in the vicinity.

This shore used to have rich marine life. It has recently been affected by major coastal developments including
As we stopped by at the washing point, I noticed this lovely mural on the restroom wall.
Yes, indeed. We should appreciate and conserve our marine heritage at this precious shore on the mainland.

Thanks to Yuet Hsin and the team from NParks for a great evening out exploring one of our favourite mainland shores!

See also Float like a butterflyfish by Marcus on his the annotated budak blog.

MORE LINKS

About Labrador on the wildsingapore website.

Media articles on impacts on Labrador
Other impacts
Previous trips to this shore
Other related posts

2 comments:

  1. i've been to labrador so many times, and all ive seen are hairy crabs and bristleworms! didnt know there were so many other beautiful crabs there....... and i wouldnt have guessed that was an octopus. would have walked right past one, if it didnt move...

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  2. We were lucky to be able to go after dark and with a team of sharp eyed people!

    I'm glad to see Labrador is recovering somewhat. Once the major construction nearby is completed, we can hope for a full recovery over time.

    Then, hopefully, Labrador can once again be open to the public and perhaps we can do public walks there to share with everyone our marvelous marine heritage!

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