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Official Magazine of the Nature Society (Singapore)
colour paintings of some fishes
Looking out from the mangrove
onto the sandy mud flat across
the Straits to mainland Singapore
Pulau Ubin's Tanjung Chek Jawa
A Treasure to Behold

main article | sponges galore | nature as model teacher

Text by Chua Sek Chuan and Shawn Lum
Photos by Leong Kwok Peng

Pulau Ubin remains one of Singapore's few areas of natural and cultural heritage. Not for much longer as there are plans to develop the island for residential and light industrial use. Unfortunately, there are plans for part of the its coastline to be extended by land reclamation. The natural environment is yet again forsaken, its hidden potential ignored and case by the wayside in the relentless pursuit of progress.

The south-east coast of Pulau Ubin harbours a unique ecosystem no longer found elsewhere in Singapore. Tanjong Chek Jawa used to be home to a Malay kampong until the inhabitants vacated it earlier this year. This is a rich, fertile area, the result of synergy between many coexisting habitats.

Along the coast of Chek Jawa lies an expanse of mud and sand flats with a mangrove forest on the landward side. These sand and mud flats are home to a variety of fauna and flora, providing for a high biodiversity habitat.

This area has at least five species of seagrasses, including two Enhalus species, the type of grass that the Sea Cow or Dugong (Dugong dugong) feeds on. All seagrasses are listed as "Rare" or "Endangered" in the Singapore Red Data Book. Extensive seagrass beds are an extremely rare sight in Singapore and in other areas. The sandflats at Chek Jawa are possibly the last of their kind anywhere in Singapore, which speaks volumes for their conservation value.

Due to the nature of the substrate, burrowing animals abound such as tube worms and nemerteans (a burrowing worm). Horseshoe crabs (F. Merostomata), an ancient form of animal that can rightly be called a living fossil, creep along the bottom. Mantis shrimps can be found stalking prey. Other marine organisms include tunicates or sea squirts, sea cucumbers, sand dollars, nudibranchs and anemones.

The mangroves at Chek Jawa feature a magnificent stand of bakau (Rhizophora species), a patch of nipah or attap palms (Nipah fruticans), and a back mangrove that includes a number of majestic dungun trees (Heritiera littoralis). Mangrove species such as api-api puteh (Avicennia alba) will no doubt re-colonise the future reclaimed land, but mature mangroves such as those found at Chek Jawa will neither regenerate rapidly nor lend themselves to simple restoration.

Highlights of this wonderful flora include the seashore nutmeg (Knema globularia) so rare that it was once thought to have gone extinct locally; a coastal relative of the mangosteen (Garcinia hombroniana), listed as locally 'Endangered" in the Singapore Red Data Book; the sea olive (Olea brachiata), listed as "Vulnerable"; the coastal shrub Memecylon edule ("Rare"), and a good number of other rarities.

Chek Jawa is slated for reclamation at the end of this year. Another part of Singapore's natural heritage will disappear forever as will any research potential to benefit our emerging biomedical and life sciences industry. Horseshoe crabs have been the subject of medical research that has been conducted for more than 10 years. Sponges, one of the familiar marine organisms at Chek Jawa, have the potential to provide derivatives that would offer medical benefits.

Gone too will be the chance for Singaporeans to experience a recreational nature area that they might not be able to see elsewhere. Sand and mud flats of this type are no longer found in other parts of Singapore. The loss of this valuable ecosystem outweighs the gains from expensive land reclamation. Like Labrador Park, Chek Jawa can also be considered an extended classroom offering a different experience for students as well as a chance to observe a part of Singapore rarely glimpsed.

more on sponges>>

Sand Dollar
(F. Laganidae)

It is an unusual species of
sea urchin with a starfish marking on its upper side.
It has a large amount of tiny spines and tube feet.
They are found mainly in the more sandy parts of mudflats.

Intsia bijuga
Belonging to the bean family, this plant is known in Malay
as Ipil. It is a rare, native tree found by coasts and riverbanks. Its flowers have one white
petal which turns pink
and then to purple.

Flower Crab
(F. Portunidae)

The males have blue marking
on their shells and pincers.
They are also known as swimming crabs as their last
pair of legs are like paddles.

When the tide comes in, anemones on beds of seagrass unfurl to trap food particles.

Horseshoe Crab
(F. Merostomata)

It is not exactly a crab, but something more ancient.
It used to be very common on the beaches of Singapore.

Fiddler Crabs
(Uca spp.)

They are found in abundance along Chek Jawa's sandy shoreline. The male has an enlarged claw which he uses
to attract the female or
to fend off rival males.

(F. Chromodorididae)

This is just one of the many kinds of sea slug, which
include the sea hare,
to be found at Chek Jawa.
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