Biodiversity and Conservation 9: 309–332, 2000.
© 2000 Kluwer Academic Publishers. Printed in the Netherlands.
Mangrove conservation in Singapore:
A physical or a psychological impossibility?
LIOW LEE HSIANG
The Swedish Biodiversity Centre, CBM, Box 7007, 750 07, Uppsala, Sweden and Department of
Biological Sciences, National University of Singapore, Kent Ridge, 119260, Singapore
(fax: +65-779-2486)
Received 7 January 1999; accepted in revised form 15 July 1999
Abstract. The coastal habitats in Singapore, in particular the mangrove and the adjacent wetland areas, are
rapidly being destroyed and degraded due to development and its side effects. For successful securing of the
future of the mangroves, public awareness of mangroves and politically and publicly supported, integrated
conservation programmes are needed. However, due to the lack of public awareness about the pressing
issue of nature conservation and the insufficiency in the understanding of the importance of mangroves by
decision-makers, plans and actions for the conservation of the remaining mangroves have been scarce and
inadequate. This manuscript will give a brief introduction to mangroves in Southeast Asia, and summarise
the history of the development of mangrove areas in Singapore and the current situation pertaining to
natural habitats and conservation in Singapore. It will point out the inadequacy of mangrove conservation
thus far in Singapore, highlight the paucity of baseline data pertaining to mangroves in Southeast Asia, discuss the problems stemming from the lack of public awareness, argue for the conservation of Singapore’s
remaining mangroves and propose conservation strategies and local and regional research directions.
Key words: alienation from nature, mangrove, nature conservation, public awareness, Singapore
Introduction
The mangroves are unique tropical inter-tidal habitats that have been rapidly destroyed in recent years due to the development of coastal zones throughout the tropical
world. This rapid destruction has also occurred in Singapore, a tiny island city which
has been vigorously reclaiming her coasts to increase her total land area for development. The mangroves have long been undervalued in Singapore for their utilitarian
and intrinsic values. Of the original 13% of the total land area which was mangrove
in character, only about 1% (6 km2 out of 647.8 km2) remains (Corlett 1987), much
of that scarred by adjacent developments.
Land-use changes have taken place very rapidly especially since Singapore’s independence in 1965 and thus she serves as an interesting case study of nature conservation versus economic development. Parallels can be drawn between Singapore and
countries with a similar history, for instance Hong Kong. The situation of nature conservation in Singapore can also be a forecast of what may happen in other Southeast
Asian countries in the near future as many Southeast Asian countries are mimicking
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their habitat conversion based on what is and what has been happening in the neighbouring Singapore. A review of the events pertaining to mangrove conservation in
Singapore is thus instructive for conservation managers and conservation biologists
in other countries. It is also hoped that the conservation strategies suggested will stimulate some positive responses from researchers, conservation managers and decisionmakers.
This manuscript first gives a brief introduction to the mangroves of Southeast
Asia, and summarises the history of the development of mangrove areas in Singapore
and the current situation pertaining to natural habitats and conservation in Singapore.
It then points out the inadequacy of mangrove conservation thus far in Singapore and
highlights the paucity of baseline data pertaining to mangroves. This will be followed
by a discussion of the problems stemming from the lack of public awareness and
alienation from nature, the arguments for the conservation of Singapore’s remaining
mangroves and finally proposals of conservation strategies and local and regional
research directions.
Introduction to the mangroves of Southeast Asia
Mangroves occur in sheltered coastal zones in tropical and subtropical areas, between
mid-tide level and the height of the highest tides within 25◦ north or south of the
Equator (Wong and Tam 1995). They are juxtaposed between the land and the sea,
forming important ecological and geographical links between the two (Tomlinson
1986). The extensive mangrove forests in Southeast Asia (SEA) account for the
greatest proportion of mangroves in the world (Gomez 1980). The area of mangroves in Indonesia, Philippines, Thailand, Brunei, Malaysia and Singapore combined has been roughly estimated to be 32,474 km2 (Ong 1994) or 40% of the world’s
remaining mangroves (Sasekumar et al. 1994). Southeast Asian mangroves are biologically richer than anywhere else in the world (Whitmore 1974; Ong 1994). For a
comparison, the Indo-West Pacific region harbours more than five times the number of
mangrove species in the Atlantic-East Pacific region (Duke in Osborn and Polsenberg
1996).
The destruction rate of the mangrove habitat is now at about 1% every year with
50% lost over the last 50 years (Ong 1994). Remote sensing techniques can easily
map the extent of mangroves (Aschbacher et al. 1995) but only one report from
Thailand is known (Ong 1994). This perhaps indicates a general lack of interest in
the protection of these areas.
History of the development of mangrove areas in Singapore
Singapore is an island city-state of 647.8 km2 with a population of 3.736 million
(Singapore Department of Statistics 1998). Wee and Corlett (1986) estimated that
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mangrove forests occupied about 13% of the total area of Singapore, including the
offshore islands during the period from 1819 (founding of Singapore by Sir Stamford
Raffles) to 1900 (Figure 1). During the period from 1901 to 1959, mangroves were
cleared for roads, housing, development projects, aerodromes and cultivation.
Since the 1960s, especially after 1965, the year Singapore obtained full independence, transformation of the Singapore landscape, accompanying development in
terms of housing, infrastructure and the economy has been even more dramatic (see
Figures 2–4, drawn with data from http://www.singstat.gov.sg, for population and
GDP increases). The Pandan Reserve, possibly the largest mangrove area when it was
gazetted as a Nature Reserve in 1951 (Hilton and Manning 1995) was de-gazetted for
the erection of the Jurong Industrial Estate (western coast) in 1962. Both the Jurong
and Sembawang industrial estates make use of the waterfront land for the ease of
movement of cargo internationally (Chia 1992). Kranji in the north was dammed
for the building of a reservoir and neighbouring mud-flat and mangrove areas were
converted for public housing and industries. In the eastern sector, mangroves have
also vanished to allow the development of Changi Village, Changi Beach, the Loyang
Industrial Area and the Changi International Airport. Off-shore islands previously
Figure 1. Mangroves in Singapore: past and present, modified from Chia (1992), Chou (1995) and Hilton
and Manning (1995). ( ), estimated mangrove extent from 1819 to the 1950s; ( ), estimated mangrove
extent in 1994; ( ), estimated land reclaimed up till 1994 other than reclaimed mangroves, Scale 1:
200,000. CBD (Central Business District); CV (Changi Village); JIE (Jurong Industrial Estate); KB (Khatib
Bongsu); KR (Kranji); LCK (Lim Chu Kang); LIA (Loyang Industrial Estate); M (Mandai); PAN (Pandan
Reserve in 1951); PR (Pasir Ris); PP (Pulau Pawai); PSM (Pulau Semakau); PSN (Pulau Senang); PSD
(Pulau Sudong); PU (Pulau Ubin); PT (Pulau Tekong); SS (Sembawang/Senoko); SBNP (Sungei Buloh
Nature Park); T (Tampines).
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Figure 2. Population increase in Singapore from 1960–1998.
harbouring mangroves were reclaimed for oil-based industries as well as recreation
(Lian 1988).
Now the mangrove forests in Singapore are estimated to be standing at about
1% (600 ha) of Singapore’s total land area (Corlett 1987) of which probably none is
pristine (Figure 4). The author’s attempt at obtaining updated information on currently
existing mangrove areas via the Urban Redevelopment Board (URA) and the
Figure 3. Population growth (%) in Singapore from 1960–1998.
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Figure 4. Singapore’s GDP from 1960–1998.
National Parks Board (NParks) has failed, the reason given by the authorities being
the unavailability of data. As far as the author is aware, there are small patches in the
north-eastern part of Singapore’s coast (e.g. Changi Creek, Pasir Ris Park, Loyang
and Khatib Bongsu) and in the north-western coast (Mandai, Sungei Buloh Nature
Park) (Chou 1994). Lim Chu Kang of the north-western coast have been degraded
and used as waste dumps but still harbour wild life. Mangroves still exist in small
patches on the southern and north-eastern islands, for instance Pulau Semakau, P.
Pawai, P. Senang, P. Tekong and P. Ubin. P. Tekong, P. Pawai and P. Senang are
presently used as army training areas and there are plans for P. Ubin to be developed
into a recreational area with chalets. With the reclamation of coastal areas, including mangroves and coral reefs, the total area of Singapore has increased from 581.5
(pre-independence) to 647.8 km2 today (Singapore Department of Statistics 1998).
The current situation pertaining to natural habitats and conservation
in Singapore
Issues pertaining to the loss of natural habitats, unsustainable development and the
rapid, man-induced extinction of species have increasingly gained importance in a
global context in recent years. Singapore has signed and ratified the Convention on
Biological Diversity (CBD, UNCED, Rio 1992) and has also published the Singapore
Green Plan (Ministry of the Environment 1992), a National Report for UNCED (InterMinistry Committee 1993) as well as a Red Data Book (Ng and Wee 1994) and a
general biodiversity report (Wee and Ng 1994) as responses to the CBD.
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The Singapore Green Plan (Ministry of the Environment 1992) proposed 5% of
Singapore’s land area to be set aside for protection as Nature Areas. Nature Areas as
defined by the Singapore Green plan are the 19 areas in Singapore (including primary,
secondary and mangrove forests) identified by the Ministry of the Environment (Ministry of the Environment 1992) which are largely untouched by large-scale development. However, the conservation status of the proposed Nature Areas is ambiguous,
as the designation ‘Nature Area’ is not defined by existing legislation’ (Hilton and
Manning 1995). Only Nature Areas designated as Nature Reserves and National Parks
are under the coverage of the National Parks Act (1990) which encompasses broad
protection of living organisms in their natural habitats (Lye 1991). In fact, some of
the designated areas are man-made parks and cultural sites (e.g. Mount Faber and the
Singapore Botanic Gardens). Some areas which do have real conservation value such
as Senoko (an important wetland feeding area for birds) have been ‘sacrificed’ for
urban development (e.g. Hesp 1995).
It is in the general mind-set of the government and the public that Singapore lacks
space since she has such a small land area. However, it should be brought to attention
as a counter example to the claim of ‘lack of space’ in Singapore, that the area of
golf courses increased from 90 to 1183 ha from 1922 to 1993 while that of natural
mangroves decreased from 7500 to 488 ha in the same period (Hilton and Manning
1995). Singapore now has 22 golf courses (Ho 1997) and more have been planned
in the wake of having to ‘sacrifice nature’ to create housing and infrastructure for
people since housing for people is more important than birds as bluntly put by one
of the spokesman for the Ministry of Environment. Are golf courses, catering to the
needs of a handful of well-to-do golfers, more important than housing and nature
areas for the Singaporean lower-middle and middle class majority?
Inadequacy of mangrove conservation in Singapore
It has been recently realised that there is a need to conserve wildlife, including those
found in the mangroves. Last ditch efforts have been made to conserve small fragments of mangroves, by incorporating fragments of mangroves into public parks (e.g.
Pasir Ris, see Figure 1) (Murphy and Sigurdsson 1990). However, conservation efforts are inadequate despite the possibilities of better conservation measures, largely
due to the lack of political commitment and the dearth of understanding of the importance of mangroves as a natural habitat and a national heritage. Some positive and
negative examples of conservation efforts will be given in the following paragraphs.
Sungei Buloh was proposed, gazetted (in 1990), developed (Murphy and Sigurdsson 1990) and finally opened to the public in 1993 as a Nature Area (See Figure 1
for the location of Sungei Buloh Nature Park, SBNP). A mature stand of mangroves
exists on the neighbouring islet P. Buloh, the only one of its kind in Singapore. There
is limited access to P. Buloh. About 130 bird species associated with mangroves
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have been recorded here, out of 2000 species of plants and animals (Murphy and
Sigurdsson 1990), though this is probably a serious under-estimate. Of the 130 birds
species, 103 have no particular affinity for Sungei Buloh Nature Park (SBNP) and
only three of the mangrove dependent birds have been sighted at there. The remaining
20 species largely feed in coastal zones (mud-flats and tidal creeks). These are the true
attractions at SBNP. The neighbouring Mandai mangrove area should be conserved
because the mud-flats supported by and adjacent to Mandai are feeding areas for the
birds that roost at Sungei Buloh. At present there are no plans to conserve Mandai, an
area with an immense potential to ‘become a major attraction with a higher level of
public use for recreation, education and tourism’ (Murphy and Sigurdsson 1990). The
bird community in Mandai is comparable with that at SBNP (Sodhi et al. 1997). The
emphasis on SBNP as a bird sanctuary was excellent for a start but future research
and education should also be directed toward other types of fauna to fully utilize the
scientific and educational value of this area. SBNP is not a total success story. It was
discovered by bird enthusiasts in 1986, who proposed to preserve the area as a 300 ha
protected zone. However, the Ministry of National Development allowed only about
85 ha (with 2 ha as buffer) to be used as a nature park. Since Sungei Buloh has been
designated only as a Nature Area (which is not a term defined legally or an area given
any formal protection) and not a Nature Reserve, there is no legislation to protect it
against future development.
There are supposed plans to convert Sungei Khatib Bongsu (See Figure 1) into
a park like SBNP (Chou 1995) and to set up a herony (Koh and Yuen 1996/1997).
However, the public is not at all well-informed on the conservation processes which
are supposedly currently underway. The plans, in fact, seem to have been stalled
indefinitely and there has been a proposal to build a road through the area.
Sungei Sembawang/Senoko, as recommended by the Nature Society (Singapore),
NSS, previously known as the Malayan Nature Society, Singapore Branch, to be set
aside as protected sites, has since been reclaimed and developed (Hilton and Manning
1995) into a industrial estate, under the jurisdiction of the Jurong Town Corporation,
as well as a public housing estate. At least 181 bird species have been recorded at
this site, including two of the world’s endangered species, the Chinese Egret (Egretta
eulophotes) and the Asian Dowitcher (Limnodromus semipalmatus) and many other
rare birds, which made it a very popular spot for bird-watchers in Singapore (Malayan
Nature Society, Singapore Branch, 1990). The development of Senoko went ahead
despite the protest staged by the Nature Society (Singapore), which argued for the
conservation of that area based on the vast number of bird sightings. Twenty-five
thousand signatures in the country were collected to lobby for the conservation of
Senoko but the Ministry of National Development adamantly refused this proposal
and even withdrew the bit of land that was initially set aside for conservation.
The Serangoon estuaries faced a similar fate. It was identified as the richest coastal
bird locality south of Thailand (Parish and Wells 1984). However, it was reclaimed
for the construction of the Serangoon Sewage Treatment Works.
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There are isolated positive examples of efforts in mangrove conservation. For
instance, a 5 ha plot of mangrove was protected as a Nature Area (S. Chan, pers.
comm.) at Pasir Ris when reclamation took place around it (in 1978) by the erection
of a tidal through channel to the plot for the supply of sea-water. This plot is now
accessible for the use of the public via a boardwalk (Chou 1995). A diversion drainage
tunnel was also built to drain out storm water instead of widening the Tampines River
in the same vicinity which would have destroyed the mangroves along the banks of
the river (Nathan 1992). Artificial mangrove regeneration programmes to facilitate
natural ecosystem restoration are taking place on P. Semakau (13 ha) and at Pasir Ris
where their growth is also being monitored (S.K. Lee, pers. comm.). Both the flora
and fauna are supposedly faring well and the initial results of restoration has been
published (Lee et al. 1996) and more updated data will be released soon (S.K. Lee,
pers. comm.). These are encouraging but they fall short of a well-conceived, general
plan to conserve remaining mangroves in Singapore.
Conservation has proceeded as a matter of convenience rather than realised necessity. This can only mean that the conserved areas are probably isolated and do not
have as high an intrinsic value and a long-term viability as they could have had with
better planning. At present, only Sungei Buloh Nature Park and the 5 ha plot at Pasir
Ris stand as mangrove Nature Areas and there are no mangrove Nature Reserves in
all of Singapore.
The puzzling matter is why ecologically valuable areas were sacrificed (e.g. Senoko) when less valuable sites (like artificial park land and golf courses) could have
been ‘swapped’ with them so that the total green area can remain the same, not at
the expense of housing development so needed in Singapore. In any case, it should
be noted that 90% of Singaporeans own a home (Ho 1997) and some even own more
than one home (pers. obs.) though statistics are not available, which does not quite
tally with the notion that Singapore is facing a lack of space for housing. There
are many misconceptions about natural resource management in Singapore (such as
the constraints of choice of development strategies, that environmental management
equals pollution control) which have contributed to failed conservation (Hilton and
Manning 1995). These should be clarified both with the general public as well as
with authorities who will make land-use decisions. It is highly possible that nature
conservation in Singapore is not a true physical impossibility due to the lack of space
as so many believe but rather a psychological refusal that has been imprinted on the
Singaporean mind.
Paucity of baseline data
The diversity of mangrove plants in Singapore was comparable to that on Peninsular
Malaysia, with 33 true and 36 transitional species (Wee and Corlett 1986), although
there are no endemic species since Singapore is essentially the tip of the Malaysian
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Table 1. List of extinct mangrove plant species (pers. com.
Hugh Tan TW).
Species
Family
Barringtonia conoidea Griff.
Ochthocharis borneensis Blume
Bruguiera sexangula (Lour.) Poir.
Brownlowia argentata Kurz
Lecythidaceae
Melastomataceae
Rhizophoraceae
Tiliaceae
peninsular. According to Murphy and Sigurdsson (1990) at least seven species of
mangrove trees have become locally extinct in Singapore in the last half-century
although only four mangrove species were listed as extinct by T.W. Hugh Tan (see
Table 1 for the list of extinct mangrove plant species and Table 2 for the statistics
on the conservation status of mangrove plant species), as have larger animals such
as the crocodile (Hesp 1995). But despite the shrinking habitats, new species are still
being discovered (Chou 1994). The invertebrate fauna is not well known in Singapore and new species are described from virtually every group being re-explored
in the mangroves (e.g. Ng and Nakasone 1994; Tan and Humphreys 1995; Tan and
Sigurdsson 1996; Liow 1997; Yeo and Ng 1997). It has been commented for instance
that ‘mangroves are one of the main brachyuran crab habitats in SEA with a species
diversity as high as if not higher than coral reefs’ (Tan and Ng 1994).
Not much is known about the impacts of development on the biodiversity in the
mangroves except that habitats have been lost and fragmented. Seven species of mangroves are locally extinct (Murphy and Sigurdsson 1990) while all 32 epiphytic orchid
species associated with old trees in mangroves have also disappeared from Singapore
(Turner et al. 1994). Other mangrove trees such as Aegiceras corniculatum, Sonneratia caseolaris and Dolichandrone spathacea are down to a few surviving individuals
(Turner et al. 1994). Two bird species which are mangrove specialists, the Lesser
Adjutant (Leptoptilos javanicus) and the Greater Goldenback (Reinwardtipicus lucidus) have already gone extinct from Singapore (Lim 1992) and more of them seem
to be becoming rarer (Sodhi et al. 1997). Almost nothing has been published about
the pre-development faunal components of the mangroves and not much is presently
Table 2. Statistics on the conservation status of mangrove
plant species (T.W. Hugh Tan, pers. comm.).
Status
No. of species
Extinct
Endangered
Vulnerable
Rare
Common
4
17
4
30
7
Total
62
% of total
6.5
27.5
6.5
48.0
11.5
100
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known about what are present in the mangroves and hence impact assessment for the
faunal component of the mangroves is difficult, to say the least.
There is a demand for land, including wetlands and mangroves, as solid waste
disposal sites. The use of coastal land for waste disposal is problematic due to the
proximity to coastal waters. Organic pollution (sewage) and oil pollution (from oil
spills, shipyards and petroleum-based industries) are also serious threats. However,
long-term pollution effects are not well studied in mangroves and the poverty of
information should be rectified by intensive research pertaining to pollution effects
and control, especially in a country like Singapore where oil-based industries are
important.
It is clear that baseline data, whether it is taxonomic, community, ecological or
biochemical are poor in the mangroves. This lack impedes proper management and
contingency plans.
Lack of public awareness and misconceptions about nature conservation
From a biological point of view, Southeast Asia is a gold-mine. Even Singapore, a
mere speck in Southeast Asia contains more species of flora or fauna compared with
say the whole of the UK. But how is nature perceived in the minds of the lay people
in Singapore? Is it really possible to create space for nature conservation, including
mangrove and wetland conservation, in the largely urban landscape of Singapore?
The new generation of Singaporeans who have been born since the independence
of Singapore have grown up in a society which is increasingly affluent. They are
pampered by the comforts of a modern society. Singapore is probably one of the Asian
cities with the highest standards of living and the rapid transformation of Singapore
from a mass of squatters and slums into a clean, neat and modern metropolis has been
outlined by Liu (1991). We have long since reached that state where we do have the
opportunity to slow down and contemplate about how we are affecting our environment. However, there is a serious lack of public awareness of brown and green issues,
especially matters concerning the destruction of natural habitats, many of which are
mangroves and wetlands found in the periphery of the country.
The lack of awareness is in part fuelled by certain misconceptions which have
been entrenched in the minds of Singaporeans during the period of our rapid development. There is the general view that ‘nature should be sacrificed if it obstructs
economic growth’ and that land is so hopelessly scarce that there is no place for
‘luxuries’ such as nature (Ho 1997). Also, there seems to be an association between
mangroves, mudflats, wetlands and filthy dumping grounds or wastelands (Lian 1988
and personal observation). In any case, there is a lot more hype about tropical rain
forests and coral reefs than mud-flats and mangroves.
A study which involved interviews with students ranging from the age of 13 to 24
was carried out by Savage and Lau (1993) and it revealed a clear deficiency in their
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knowledge of environmental issues, including those related to nature conservation.
Of the 23 questions posed (with multiple choice answers provided for aid), 90.6%
of the students could not provide more than nine correct answers. There was also a
tendency for students to know disproportionately more about local or regional issues
which have been emphasised by the local media as well as campaigns initiated by
the government. Singaporeans tend to be mainly concerned about keeping Singapore
clean (Clean and Green Week Post Campaign Evaluation 1991, 1992) but seem to
be unconcerned or unaware about environmental destruction in a more fundamental
context. This may be attributed to the fact that Singaporeans have little contact with
nature in Singapore and since Singapore has largely been urbanised, it seems to be
pointless to talk about nature conservation in a local context which most people are
tightly bound to.
In a recent study, it was found that in young people, nature conjured up an image of either manicured surroundings as we have in man-made parks and tree-lined
avenues, or one of distant, exotic and accessible places (Kong et al. 1999). However,
in a daily context, many fear nature because of the lack of understanding (e.g. the
unpredictable appearance of insects and perhaps the fear of sinking into the mangrove
mud). Kong et al. concluded that young Singaporeans have meagre interest in and
affinity for nature. This seems to be a result of young people growing up in a wholly
urban environment without substantial positive contact with nature, a condition which
can be summarised as alienation from nature.
Nature conservation and environmental issues other than pollution are probably
two of the last items on the Singaporean’s personal agenda which is saturated with
attaining modern comforts of life and more. The lack of awareness is a result of a
perception of non-necessity. However, this should not be the case as both local and
global environmental issues including species extinction, natural habitat destruction
and degradation can have and will have direct impact on their daily lives. For instance,
the forest fires in Kalimantan, aggravated by the domineering presence of logged and
cleared forests, have affected the lives of every Singaporean (e.g. health and visibility
problems). However, most Singaporeans have not made the association between the
issues of the conversion of nature areas and the loss of ecosystems functions and the
direct effects they can have on their daily lives.
Why we should conserve Singapore’s remaining mangroves
Singapore has, today, less than 600 ha of mangrove areas left. Is it then justifiable to
spend the effort in conserving this little bit of land? Here, I list seven reasons why
we should do so, though this list is by no means exhaustive. This list is applicable to
other countries in which forestry and aquaculture are not important undertakings as
they are in many countries which have larger tracts of mangroves left, like Malaysia
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and Indonesia. It is hoped that this has enough conviction powers for planners to
seriously consider the long-term fate of mangrove areas.
Ecological functions
Mangroves protect and stabilize coastlines and are land builders. They reduce sedimentation and are silt retainers. General reviews on multiple functions of mangroves
are given in Whitmore (1974), de la Cruz (1978), Paw and Chua (1991), Sasekumar
et al. (1994) and Singh (1994). A summary of the ecological functions of mangroves
is given in Table 3. In a nearly wholly urbanised Singapore, the general public should
be constantly reminded of the mangroves’ ecological functions as they do not come
into direct contact with the problems caused by the disappearance of mangroves.
Research
Despite the mangrove areas in Singapore not being as large as those found on her
neighbours, they can still be very valuable to science. This is exemplified by Bukit
Timah Nature Reserve (BTNR), a lowland Dipterocarp rain forest with an area of
81 ha only 8 km away from the city centre (Corlett 1995). A permanent plot has
been set up in BTNR by the Smithsonian Tropical Research Institute in collaboration
with the Nanyang Technological University in Singapore as part of a larger research
project (permanent forest demographic plots) involving tropical forests all over the
tropical world such as Barro Colorado Island (Panama) and the Pasoh Forest Reserve
(Malaysia) (CTFS 1995).
There is also an untapped value of the mangroves which may be utilized by bioprospecting. The Bioscience Centre located at the School of Biological Sciences at
the National University of Singapore is currently involved in screening coral reef
organisms collected from Singapore waters for an array of biologically active compounds. The Centre for Natural Products Research (CNPR) of the Institute of Cell and
Table 3. Summary of the ecological functions of mangroves.
Ecological functions
1
2
3
4
5
6
7
8
9
Buffer against storms and strong winds
Stabilizer of coastlines
Silt retainer and land builder
Protector of proximate sandy beaches and coral reefs (reduces sedimentation)
Filter for land runoff and remover of terrestrial organic matter
Producer of detritus which in turn contributes to near and offshore productivity
Waste assimilation (e.g. nitrogenous and phosphoric nutrients undergo microbial degradation
in mangrove mud)
Important contributor to global cycling of nitrogen and sulfur
Adult and juvenile habitats (spawning, nursery and feeding grounds) for many species of flora
and fauna, including commercially important species
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Molecular Biology are undertaking a similar task (Lam and Ng 1995). Arrangements
could be made for the scientists to screen mangrove organisms as well to expand the
possibilities for finding positive hits.
By engaging Singapore in result-oriented research (i.e. research which brings in
commercial profit for the country), Singapore could also become a centre of research
in SEA, complementing the image of her as a centre of other international activities
such as trade and commerce.
Education
Children in Singapore grow up in a wholly urbanised city without experiencing the
marvels of tropical nature that is supposed to be part of their natural heritage. A
Singaporean child learns a moderate amount about nature almost only if he or she
studies biology or geology at tertiary level. There is a general alienation of people
from nature due to their urban settings. This should not be the case since nature is part
of the environment human beings naturally have interactions with. Not only should
natural habitats and environmental concerns be taught in school at much lower levels,
children should also have the opportunity and the rights to visit forests, including
mangrove forests, in their own country. The appreciation of nature plays a substantial
part in creating a mature, socially and environmentally conscious society. In general,
there is a demise of both formal and informal public education on the importance
of and benefits we derive from mangroves. It is time now for this situation to be
rectified.
Responsibility
Singapore has signed the ASEAN Agreement on the Conservation of Nature and
Natural Resources on 9 July 1985, which includes an article that requires the conservation of natural forests, particularly mangroves, to maintain maximum forest species
diversity (Article 6) (Koh 1994). Singapore has also signed the Rio Convention (1992)
on Biodiversity in 1993 (Lam and Ng 1995) and recently ratified it. She thus has the
responsibility to carry out the agreements to the best of her abilities. At the present
moment, Singapore has more possibilities of carrying out conservation activities in
terms of manpower and training, as well as the economic and political situation than
many of her neighbours. It is not wise to depend on other countries to conserve their
mangrove habitats while tenaciously hanging onto the false belief that the mangroves
in Singapore are too small to be worth conserving. A responsible nation such as
Singapore should take it into her hands to contribute toward biological conservation
so vital for the future of mankind. Moreover, the government has the ambition to
make Singapore an ‘Environmental City’ (Kong and Yeoh 1996), so what better way
to do it than by contributing a little to nature conservation?
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Tourism
Tourism is the one of the greatest industries in the world. Mangroves have a great
touristic value as many people are simply fascinated by these forests growing in the
sea (Johnson 1973). Singapore is a city which is highly accessible to tourists and
her mangrove areas are well supported by infrastructure and visitor facilities such as
shopping malls, bus services and food centres. In fact, Singapore is marketed as one of
the rare cities in the world where urban convenience lies so close to pristine forests,
coastal charms and wildlife (Kong and Yeoh 1996). Although over-visitation may
pose a problem to the natural habitats in question, careful planning can override this
problem and draw huge amounts of eco-tourists and ordinary tourists to mangrove
and other nature areas in Singapore.
Recreation and aesthetics
In the concrete jungle of Singapore, people are always seeking out greenery for
relaxation and recreation. It would be very efficient to devise land use such that
conservation areas also seek to provide ecologically friendly recreation. As Sungei
Buloh Nature Park (SBNP) has shown, mangrove areas are visually interesting and
shade providing in the ever-hot Singapore. Bird-watching activities are popular in
SBNP as are walks through the boardwalks that provide easy access to parts of the
mangroves. Natural greenery can be a welcome change to the concrete jungle of
Singapore.
Biological diversity
Biological diversity or biodiversity is the ‘total variability of life on Earth’ and is
characterised by species richness, species diversity, taxic diversity and functional
diversity (UNEP 1995). The mangroves are a part of this diversity and have their own
unique set of biological and ecological functions. Although the diversity of mangrove
plants is not exceptionally high, the associated fauna is very diverse and hardly known
to science. Many terrestrial and marine organisms are also dependent on mangroves
for food, shelter and breeding grounds. One example closest to heart is the usage and
visitation of mangroves by bats which pollinate durian (Durio zibethinus) flowers to
provide economic input for companies and people who own durian plantations.
Conservation strategies: general
Singaporeans no longer have direct contact with nature, being so fully immersed in
urban living. A special approach has to be taken to convince the public about the
need for nature conservation because they have become detached from it in their
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daily living. It is clear that the arguments for conservation (e.g. establishment of
protected reserves for the maintenance of genetic diversity to ensure future timber
yield in production forests) such as those used in Malaysia (Ong 1982) cannot be used
in the same way in the Singaporean context. Ho (1997) suggested that the beauty of
nature, nature as a source of wonder and curiosity, a psychological safety valve and
nature as a sense of place should be emphasised to the general public to invoke a
responsive chord in the psyche of Singaporeans.
But first, the mind-set of the government has to be changed in order for campaigns to be supported by the government, the only way for the campaigns to be truly
successful. Clear examples of governmental support resulting in success stories are
reflected in programmes such as the Kallang Basin clean-up and the control of airpollution by having high taxes on cars and high fines on vehicles not fulfilling the
emission standards set by the Ministry of Environment (Inter-Ministry Committee
for the UNCED Preparatory Committee, Singapore 1993). In Singapore’s report to
UNCED (Inter-Ministry Committee 1993), it was stated that ‘..Singaporeans have
not had to sacrifice their quality of life, nor have they unduly damaged their environment in the process of industrialization, infrastructure-construction or the acquisition
of high-technology’. However, it is clear that more and more nature areas are silently disappearing without much public knowledge. For instance, the mangrove area
Khatib Bongsu which was to be converted into a nature park like the one existing
at Sungei Buloh has not received mention for a period of time and apparently, the
initial plans have been shelved and a road through the area is planned. There is,
unfortunately, a tendency for bureaucrats to treat nature reserves as land banks (Wee
1993) despite Singapore’s apparent commitment to the environmental cause. The loss
of natural areas is also the loss of a certain positive quality of life since the feelings of
freedom and openness experienced in nature are important ones especially in a city
of concrete and of frantic rat races.
It is not appropriate to be aggressive in the approach to environmental protection
and nature conservation as may be acceptable in many countries in the west (Ng
1991). The approach taken should be consultative and persuasive. The two major
NGOs concerned with conservation issues are the Nature Society (Singapore) and
the Singapore Environment Council (SEC). The NSS has published a Master Plan for
the Conservation of Nature in Singapore (Malayan Nature Society, Singapore branch
1990) and has since also given conservation recommendations to the government.
The SEC facilitates and co-ordinates environmental causes and groups in Singapore.
While both are sometimes active in pushing for environmental issues, they are sometimes not persistent enough. More strength can be demonstrated in their activities
especially in conjunction with the rising awareness of environmental problems on a
global scale and at a political level.
Singaporeans should be re-educated on environmental issues, especially pertaining to nature conservation. However, any education programme should have government support. Local, regional and global environmental issues should be taught as
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a compulsory subject in schools. Students should be encouraged to think about how
they can aid the global environmental cause and nature conservation even if Singapore
is one day urbanized beyond the possibility of nature conservation. Awareness is the
first and most important step for environmentally responsible acts. School education
should produce future generations of adults who are in tune with the largest issues in
the next millennium, i.e. environmental issues.
But the present generation of adults should not be forgotten. The easiest way
to educate the public is through mass media, especially television. The government
has been very successful with many campaigns run using mass media techniques
and these can be engaged in environmental campaigns too. At present, the Care-ForNature series (a nature program on radio) is only aired on the classical music radio
channel which is not tuned in to by many. The new nature program ‘Go Green’ (1999)
is aired during prime-time, however, it is only screened in English, thus foregoing the
many Singaporeans who do not watch English programmes. For campaigns to be
successful, airing has to be on popular radio channels and advertisements should be
run during prime-time television on all channels.
Creating an ‘ecologically friendly’ society in Singapore is not an easy task, but
it appears that some progress is being made (e.g. Ho 1997; Wee 1993). It is now the
ripe time for environmentalists, biologists and other people who are concerned about
nature conservation to put their heads together and come up with a feasible grand
plan to ingrain ecological thinking and awareness of global environmental and nature
conservation issues into the minds of pragmatic, ‘economy-first’ Singaporeans.
Conservation strategies: specific to mangroves in Singapore
There is no governmental or quasi-governmental body at present which has the responsibility to manage and conserve coastal habitats. The Urban Redevelopment
Authority (URA) has the responsibility to conserve historic sections of Singapore
including historical architecture while the National Parks Board (NParks) handles
existing terrestrial nature reserves and catchment areas (Chia 1992). The coast is
under the jurisdiction of URA, MPA (Maritime and Port Authority of Singapore),
PPD (Primary Production Department), HDB (Housing and Development Board) and
various other bodies depending on the zone or area in question. With so many parties
involved, diverse interests surely exist and conflicts often arise. What is required
is a central co-ordinating body which looks into the conflicting potential uses of
coastal zones yet fully developed, which can also make strategic proposals that will
satisfy all stakeholders. This body also needs to examine potential legislation and
re-examine existing legislation (anti-pollution measures, habitat protection laws etc.)
and guidelines for land usage, habitat restoration and monitoring activities, once wellbalanced decisions have been made. There is also a need to involve NGOs, research
institutes and educators to ensure a successful, public-supported, high awareness level
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programe. Singapore needs to plan for the rational use of coastal resources, taking into
serious consideration the future of mangrove habitats. It would be very short-sighted
to develop coastal lands without embracing the conservation ideology so permeating
in the present day philosophy. The best scenario of conservation is one in which
all parties at stake (including the public) form general agreements and in which the
central co-ordinating body can make an integrated effort to ensure that the needs of
all stakeholders have been carefully considered.
With the support of appropriate ministries, education can proceed in the following manner. Public education can take place in the form of campaigns for the
mangroves. These can involve a series of posters in shopping malls, movie theatres
and schools which summarise visually and graphically the importance and beauty of
mangroves. During the campaigning period, coffee-table books on mangroves or even
a short collectible education booklet series can be published to stimulate interest and
disseminate information.
Popular books and magazines are an excellent media for the transmitting of information at anytime, even though truths could be slightly distorted at times. However, some information is better than no information at all. In a recent minor survey
(Liow, unpublished results) done in Singapore, it was found that a group of Singaporeans from diverse walks of life have poor understanding of natural habitats found
in their own country. This should not be the case in a society where there is a high
literacy rate. Documentaries pertaining to the mangrove habitat and articles in the
newspapers and popular magazines can also surface in the same time period so that
national attention is brought to mangrove conservation.
The Internet can also be utilised to spread information since many Singaporeans
have the ease of access to Internet. There are encouraging global trends where groups
concerned about the mangrove habitat have begun to examine ways and means to protect and replenish the mangroves of the world. This is evident on the Internet where
the author located sites such as the Indonesian Mangrove Foundation
(http://www.mangrove-f·org/), the mangrove Replenishment Initiative based in Florida (http://mangrove.org/) and the Mangrove Action Project which has a membership of 40 nations and about 300 NGOs (http://www.earthisland.org/map/map.html/)
among others. The attention of Singaporeans could be brought to such sites so as
to increase awareness and connectivity with the rest of the world. A site featuring
mangroves in Singapore can also be established for the exchange of information and
to attract potential eco-tourists and collaborative research.
Important groups of people to be convinced are upper and middle-upper class
adult citizens belonging to clubs and country clubs. It would be excellent to bring
to their attention environmental and conservation issues within their recreational recesses by having seminars and presentations in the clubs. These will hopefully open
their eyes, which are accustomed to artificial landscapes, to natural habitats.
It is important to market the mangroves as a useful product since general views
on mangroves have so far not been very positive in the minds of the general public.
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Mis-conceptions need to be corrected to give the mangroves more public support.
Surveys before and after the campaigns would serve as a gauge as to whether the
dissemination of information in various forms has altered the mind-set of the public.
School children from all levels need to be taught about their natural heritage, including tropical rain forests, coral reefs and not least, mangrove forests and mud-flats.
The subject of conservation, biological diversity and environmental issues should be
incorporated in textbooks and class discussions. Children should be taught at a young
age and throughout their education to respect nature and to appreciate the diverse
habitats so close to their homes. Field excursions should be planned as widely as
possible so that students can have a first hand experience of nature. Such activities
are organised in some schools during the end of semesters but, as far as the author understands, are not widespread. Most students actually express surprise that
mangroves can be seen in Singapore and delight at seeing these ‘forests in water’
and their associated animal life, such as mudskippers (Periphthalmus spp.), monitor
lizards (Varanus sp.) and waders (personal observations).
Conservation activities at grass-root levels can also contribute to mangrove conservation as exemplified by the mangrove clean-up organised by NSS in 1997 (Foo
1997). More activities like this not only increases public awareness of environmental
issues but also introduces them to habitats only vaguely known to them, such as the
mangroves. Conservation can only be effective when the public understands what
policy and decision-makers are spending their tax money on.
Upon gaining the support of both the public and government, we need to consider
which mangroves should be conserved under the present circumstances. Based on
limited data and knowledge of governmental plans, I make the following proposals
here as a starting point for planning.
Sungei Buloh has already been designated as a Nature Park. It would be convenient to raise its status to one of a nature reserve so that it will be protected from future
development. Since the adjacent Mandai mud-flats are important to the waders which
roost at Sungei Buloh and also provide a supplementary source of genetic material (at
least for the flora and invertebrates), the incorporation of Mandai into Sungei Buloh
Nature Park should also be seriously considered. However, conservation in Singapore
cannot mean leaving nature to fend for itself because it is surrounded by too many
enemies. With all the injuries the mangroves have already suffered, they must be protected (i.e. selected coastal wetlands should be gazetted as nature reserves in order to
be protected by law) and then nursed back into their previous splendour. Hence restoration and re-introduction programs should be devised once a comprehensive plan for
the permanent gazetting of mangrove protected areas is decided upon. Locally extinct
species can be re-planted using seedlings from Malaysia after carefully considering
the ecology of the system and locality in question. Re-planting in Singapore is a
tricky question since the zonation seen commonly and normally in other mangrove
areas is compressed in Singapore (D.H. Murphy, pers. comm.) and studies need to be
undertaken to determine the best sites for re-introduction. Re-introductions must, of
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course, be followed by long-term monitoring and management so that regeneration
of the mangroves can be assured and long-term viability is possible. Studies on the
impacts of pollutants from adjacent developed areas and the sea should be pursued so
that pollution prevention methods can be devised if necessary and contingency plans
made for emergencies such as oil spills.
The Sungei Khatib Bongsu conservation plans have been dormant for quite a
while now. It is time to revive those plans and re-examine the feasibility of conservation. It should, at least for the moment, be raised to Nature Park status and be
promoted as a recreational site. This strategy can also be used for P. Ubin mangroves
since P. Ubin is being developed as an outdoor adventure area. Conserving the mangroves on P. Ubin can added to the exotic flavour of the island and can also increase
public awareness of mangroves as an important tropical habitat. It is known for instance that there are even day tours to P. Ubin for tourists stopping over in Singapore
for a day enroute somewhere else. Conserving the mangroves on P. Ubin can present
the natural side of Singapore for a stark contrast to all her high-rise buildings which
can surely fascinate tourists. However more publicity is required for tourism on P.
Ubin to be more lucrative.
It is hoped that development or further damage to mangroves in areas such as
Lim Chu Kang, Loyang and P. Semakau can be put on hold until more is know about
the values of those areas so that integrated management plans can be formulated.
Environmental Impact Assessments need to be carried out.
It is obvious that there is a lot to be done for the mangroves in Singapore. This
will take time, manpower and money. At present, little effort is going into biological
conservation due to the lack of funds. More funding should be reallocated to data procuring in mangroves so that weighed decisions can be made on land use. Support can
also be sought from concerned private donors and world-wide conservation programs.
But first, potential donors have to know how their contributions can benefit the natural
habitats before public campaigning for donations can be organised. It is only when a
larger proportion of people participate in one way or another to a specified cause that
conservation programs can be better supported both in monetary and spiritual senses.
Research directions
As in many other research areas pertaining to wildlife, more mangrove conservation
related research has been done on other geographical regions more readily accessible
to western scientists. In a recent search done by the author in the database Biological
Abstracts (1980 to 1997), the search words ‘mangrove + conservation’ yielded 110
records, of which 31 are specific to the Americas (mainly Florida) and 19 contained a
Southeast Asian element. The titles of the articles clearly articulated the fact that most
of what is published on Florida mangroves are narrow research questions while those
on SEA are broad management issues and basic taxonomic research. This contrast
328
puts across the implication that little baseline data exists in SEA for the mangroves
while enough data exists in Florida for narrower, more specific questions to be posed
and answered by research. Also, the number of papers published is disproportionate
since much more of the world’s mangroves are found in SEA rather than in Florida.
This Biological Abstracts search also revealed that the emphasis was very much
focused on the conservation and ecology of birds. This over-emphasis on only one
taxonomic group may not be healthy in the long run.
However, there is a pressing need for management-oriented research in SEA now.
There has been a lack of it due to (1) scientists being unwilling to consider applied
problems, (2) a lack of interdisciplinary research, (3) the dearth of communication
between policy makers and scientists, (4) intellectual and cultural arrogance and (5)
limited training at local levels (Chua 1997). This is a pity as scientific data are very
useful in aiding the process of wise decision-making. Dialogue between scientists and
representatives from decision-makers should be promoted so that natural resources
can be rationally and intelligently utilised.
Baseline data is needed on changes in land use and how that has affected tidal
patterns, soil chemistry, micro-fauna, flora, fauna and ecology in the coastal zones,
not least the mangroves. Experimental data from manipulative experiments would
also be useful. There is a long tradition of research in the coastal habitats of Singapore
(Lam and Ng 1995). However the results of this research has not been published in
a comprehensive form for utilisation. Few floral and faunal checklists for mangroves
are available in Asia. Comprehensive checklists and studies like the one done on
plant species richness, gastropod species richness, occurrence of rare species and site
representativeness done in Hong Kong for nine mangrove sites (Yip et al. 1995) are
urgently needed in Singapore. Important lessons for Singapore could be learned from
Hong Kong as urbanisation has severely affected the natural habitats in Hong Kong
too.
Ecological data from the mangroves is virtually absent, in part due to present
scientific efforts being focused on inventories. This focus is a result of the lack of
baseline data on what is actually found in the mangroves. However, the ecological
and evolutionary aspects of the mangroves should not be neglected because there is a
need to understand and conserve biological processes as well (Smith et al. 1993).
It is also vital to co-ordinate research with other Southeast Asian nations, especially Malaysia and Indonesia. Living organisms know no political boundaries,
thus the organisms found in Singapore may be a population belonging to a metapopulation in Johor or Bintan Island. For the best strategy to be formulated, metapopulation structures and genetic diversity must be known. But of course, before
that, we have to know what is actually present in the habitat. To obtain a fuller picture
of the biotic component of our environment, collaborative efforts need to be initiated
and maintained between neighbouring countries.
Massive mangrove restoration projects have taken place in Columbia, Pakistan,
Ecuador and Bangladesh (UNEP 1995). Useful experiences can be shared between
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countries which have attempted mangrove restoration and those about to consider
it. In Singapore, natural and artificial regeneration of mangroves have taken place
in some of the southern islands (Chou and Lee 1994), Pasir Ris (Lee et al. 1996)
and P. Semakau (S.Y. Lee, pers. comm.) where monitoring work on the growth and
succession of mangroves is still being carried out. It has been found for instance
that the correct tidal conditions and an adequate supply of propagules are essential
for natural mangrove regeneration (Lee et al. 1996). Floral restoration work will be
affected by both the invertebrate fauna and the microbial community (Alongi 1994).
It is thus necessary to study the mangrove ecosystem as a whole to have a fuller
understanding of mangrove regeneration.
There should also be more in-depth research on how human disturbances (such
as wastes deposits and soil changes) affect the mangrove forest and mud-flats as
a community and not just how these affect trees and shrubs because members of
a community cannot be subtracted from the picture as they are intricately linked.
Particularly important in the Singapore context is how the type of soil used in reclamation can affect mangrove establishment and growth. Some preliminary work
has been pursued by Kryger and Lee (1996). Contamination of coastal waters and the
impact of this in mangroves also need to be studied in the Singaporean context.
Nature conservation should not be an esoteric issue limited to biologists and
environmentalists. The social aspect of land use, use of nature in its natural state,
human psychology and its interaction with nature should also be explored in detail. It
may also be well worthwhile to conduct interviews with the public on specific nature
conservation issues to discover their impressions and biases so that campaigns and
education can be better designed to suit their needs. All the data and information generated should be viewed as a totality and not as fragments in order to yield accurate
over-views of the situations.
Conclusions
The present efforts put into mangrove conservation in Singapore is at best inadequate.
Many conservation and environmental issues have not been addressed by authorities
responsible for land-use. There is a lack of understanding of the importance of the
mangrove habitat, henceforth the lack of public attention. The general public is alienated from nature and hence have limited concern over green issues. The first step
in securing the future of the mangroves is to increase public awareness of conservation needs, followed by a politically and publicly supported, integrated approach to
conserve the remaining mangrove areas. It is clear that Singapore will stand to lose
in the, albeit somewhat abstract, future if she does not take into serious consideration
the conservation of the remaining vestiges of her natural habitats. We have come
this far in economic development and it is now time for us to pause to think about
conservation aesthetics, moral responsibility and the posterity. It is not a physical
330
but a psychological impossibility, which can be reversed, to conserve the remaining
mangroves in Singapore.
Acknowledgements
The author thanks Dr K.S. Tan, Dr T. Elmqvist and Dr N.S. Sodhi for their constructive criticisms on early drafts of the manuscript, Assoc. Prof. S.Y. Lee, Dr T.W. Hugh
Tan and Ms. S. Chan for providing information, Dr J.B. Sigurdsson and Assoc. Prof.
D.H. Murphy for their discussions with the author and an anonymous reviewer for
his/her comments. This study was funded by the Swedish Biodiversity Centre.
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