Human Impacts & Conservations
Singapore in the Past
—150 inhabitants residing along the coasts
—Human impacts were minimal
—Many researchers named a lot of new plants and animals
• Sun bear/Helarctos malayanus
• Long-tailed macaque/Macaca fascicularis
• Cream-coloured giant squirrel/Ratufa affinis affinis
Land Use Change
—Has led to the loss of old forests, swamps and mangroves. As SG became a trading hub, the forest was replaced by
spice plantations. Gambier, Pepper are widely planted while the price was high
(Spices were valuable!)
Cash crops
• Gambier/Uncaria gambir – planted for tannin (need to be boiled)
After tannin is extracted what left of gambier is used as a fertilizer for pepper
• Pepper/Capsicum spp. (Climbers that grow on wooden sticks and climbs at regular intervals; it will produce
peppercorns (fruits). If it was plucked when raw (unripe) and dried under the Sun, it will be black pepper. If it is ripe,
then soaked in water and the skin is removed, then you will get white pepper.)
green pepper corn To get black pepper corn – harvest the corn before the corn mature (more spicy)
White pepper: Let the green pepper ripen on tree, harvest, soak, remove skin to get white pepper (generally more
expensive)
So what development has occurred?
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2
3
4
5
6
7
8
9
After the price of spices fell due to too many spice plantations, rubber was planted (from South America, went
through Europe and to Singapore)
Rubber seeds that went through this path, pathogen will be killed due to the weather conditions in Europe
The original forest was lost to agriculture
More immigrants came for manpower in agricultural work
Need more housing
More land was converted to housing for the immigrants
To meet the needs of much more people, rivers were converted to reservoirs (to meet water demands)
Hills were leveled, vegetation cleared, and then the soil is used for land reclamation
—military installations, naval base and camps (due to more people in Singapore)
—3 airports; now in SG there’s only 2 airports
Islands have been amalgamated; (different islands joint together)
A lot of sand needed to be dumped for this process to occur
Semakau landfill (dump rubbish) = Pulau Sakeng + Pulau Semakau
Jurong islands = reclamation and merger of 13 islands
Causeway between Johor and SG was built [Northern side] in 1923. However, the causeway split the ocean into
2
Second link was built near Tuas, this time a bridge was built and ensured water flow across it
Development has led to habitat loss
Natural habitats were lost to make way for
- Airports
- Harbours
- Buildings
- Reclaimed sites
- Reservoirs
—Others; development along Johor coastline affects migratory birds’ feeding ground as they travel from Russia to
Australia
—Others; building reclaimed land/islands can decline the fishermen catch as these lands reduce variety and number of
catch available
Disturbed Habitats
Disturbed Habitat
Slightly Disturbed Habitat
Reconstituted/Recreated
Habitat
- Highly disturbed: secondary forest, agricultural land growing wild
- Can slowly recover on its own but…
- Process can be hastened by man
Primary forest with past shelling;
Shelling as in those ww2 shelling (due to bombs coming out from planes creating
disturbances in the forests)
-Reclaimed land
-Managed areas: parks, gardens, streetscapes
eg. Pang Sua Park Connector
• Atlas moth/Attacus atlas
Singapore have migratory birds as far as Russia coming to areas such as Sungei Buloh. As such birds fly long distance,
consume a lot of energy. If there more development in Johor, Johor may no longer be a feeding ground for such birds.
Thus, they may not have the energy to travel as far of as a place like Singapore
forest town(Singapore)
forest city(Johor)
Conservation
• Conservation in 1900s
• British established nature reserves: Bukit Timah, parts of Changi, Pandan, Seletar and Kranji
• Nature Reserves Ordinance was formally established in 1951 (law that was established from long time ago)
Under developmental pressure
• Degazetted (no longer nature reserves)
- Pandan Reserve - 1962
- Kranji Reserve - 1973
- Labrador reserve - 1973
• Central Catchment utilized by MINDEF
Wildlife Protection
• Wild Animals and Bird Act protects most vertebrates (animals with backbone) drafted late 1800s, enacted in 1965 and
revised in 2000
• National Parks Act, established in 1990, protects all plants and animals in reserves
• Today 4.7% of land are nature reserves
• Sungei Buloh Wetland Reserve and Labrador Nature Reserve gazetted – 2002
* New nature park to be open beside Sungei Buloh (Mandai Mangrove & Mudflat)
to be opened in 2022
-73 hectare park
-3km
-Announcement was made on October 7th 2019
-Ecologically linked to the Sungei Buloh Wetland Reserve, the new nature park will be situated along two future major
recreational routes - the Round-Island Route and the Rail Corridor.
Throughout the years, recorded species of known flora and fauna in SG keeps on changing, and they can be classified as
the following:
—Increase in number [introduced]; Vascular Plant taxa has the greatest increase at 54
—New species [new to Science!]; Dipteran taxa has the greatest increase at 32
—New records [recorded for the first time in SG; not new to Science]
—Rediscoveries [though lost, but found again]; Vascular Plant taxa has the greatest increase at 33
—Extirpations [locally extinct in SG]
Plants & Others
Taxonomic
Group
Vascular
Plants
No. of
Species
3604
Changes
in
Number
54
Source
Comments
Baseline:
Chong et al. (2009)
Baseline of 3550 is
based on Chong
21 new records:
Ang et al (2010,2011), Neo et al (2013,2014), Rodda &
Ang (2012a), Tan et al. (2011), Tan (2013), Yeo et. Al.
(2012,2012a), NParks Pulau Ubin Branch (2013), pers,
comm. 11 Dec, NParks Plants information Unit (2013),
pers. Comm 13 Dec
33 Rediscoveries:
Ang(2010), Ang, Lok & Ching et al. (2010), Ang, Lok &
Yeo et al. (2010,2011), Ang, Lok, Yeo & Angkasa et.
Al.(2012), Ang & Yeo et al (2012), Hassan Ibrahim et al.
(2011), Lim et al. (2014), Lok et
(2010,2011,2011a,2012), Loo (2011), Rodda et al
(2012) , Tan & Yeo (2012), Yam et al (2012), Leong &
Yam (2013), Yeo et al. (2013,2013a,2013b),Yeo, Ang &
Lok (2012a,b), Nparks Pulau Ubin Branch (2013), pers,
comm. 11 Dec , NParks Plant Information Unit (2013)
pers. Comm 13 Dec
Baseline : Pham et al. (2010)
Baseline: Wee & Ng (1994)
Baseline: Ng et al. (2011)
(2009). Only extant
species were
counted. Chong et al.
(2009) had a total of
4192 plants
recorded.
Subtracting the 642
presumed extinct
species gave a total
of 3550 extant
vascular plant
Algae
Fungi
Lichen
1054
950
376
0
0
0
Bryophytes
232
1
1 New Record:
Ho (2013)
Baseline:
Ho. B. C. (2013) pers, comm, 30 April, Pippo et al.
(2002a,2002b), Tan & Ho (2008), Yong et al (2013)
Source
Comment
Baseline:
Baker & Lim (2008), Nature Society (Singapore) (2014),
Includes species of indeterminate status
1 New Record:
Lim & Leong (2014)
1 Rediscovery:
Cai (2010)
Baseline: Wang & Hails (2007)
18 New Records, 3 Rediscovery, 1 Extirpation
Nature Society (Singapore) Bird Group Records
Committee (2013)
Baseline: Baker & Lim (2008), Nature Society
(Singapore) (2014) Includes species of indeterminate
status
4 New Records:
Lim (2009), Lim & Cheong (2011), Tan & Lim (2012),
Thomas et al. (2014)
Baseline: Baker & Lim (2008)
Baseline: Baker & Lim (2008), Nature Society
(Singapore) (2014) Includes species of indeterminate
status
2 New Records:
Tan et al. (2013)
Baseline: Froese & Pauly (2014), Ng (2012a,b)
12 New records:
Low (2013), Jaafar & Ng (2012), Ng (2013), Jaafar et al.
(2012)
Baseline changed as
transient animals
are counted
80 are unknown
species. 296 species
are known species
Vertebrates
Taxonomic
Group
No. of
Species
Mammals
99
Changes
in
number
2
Birds
384
20
Reptiles
152
4
Amphibians
Freshwater
fishes
29
106
0
2
Marine
fishes
585
13
Baseline changes as
5NR includes
marine turtles and
marine snakes but
4NR did not
1 Rediscovery :
Ng (2012a)
Insects & Arachnids
Taxonomic
Group
No. of
Species
Butterflies
Beetles
317
10000+
Changes
in
number
22
10
Dipterans
910
42
Hymenopterans
540
1
Myriapods
Odonates
55
127
0
15
Orthopterans
200+
18
Other Invertibrates
Taxonomic
No. of
Group
Species
Spiders
425
Changes
in
number
26
Crustaceans
1000+
8
Source
Comment
Baseline: Khew (2014)
Estimate based on Ng et al. (2011)
5 New speciesL
Jach et al. (2013)
3 New RecordsL
Jach et al. (2013)
1 Rediscovery:
Ong et al. (2013)
Baseline: Ng et al. (2011)
42 New Species:
Ng et al. (2011), Grrotaert (2013), Grootaert &
Shamshev (2012)
Baseline: Ng et al. (2011)
1 New Species:
Pauly (2012)
1 New record:
Lee.J. X. Q. pers. Comm. 28 Oct 2013
1 possible Extirpation
John X. Q. Lee. Pers. Comm 28 Oct 2013
Baseline: Decker (2013)
BaselineL Norma- Rashid et al. (2008)
15 New Records:
Tang et al. (2010), Ngiam, W.J. (2014), pers.comm 6
Feb
Baseline estimate based on Ng et al. (2011)
16 New Species:
Gorochov & Tan (2011,2012), Ingrisch & Tan (2012),
Robillard & Tan (2013)
1 New Record :
Tan & Wang (2012)
1 Rediscovery:
Tan (2011)
Source
Baseline: Courtm D,J (2009) pers comm 6 Oct
1 New Species:
Wang & Li (2010)
25 New Records:
Baehr et al (2012), Bayer (2011), Dankittipakul et al.
(2012), Eichenberger et al. (2012), Huber (2011), Koh &
Leong (2013), Platnick et al. (2012), Yoshida & Koh
(2011), Zabka & Waldock (2012)
Baseline: Ng et al. (2011)
3 New species:
Naruse & Ng (2010), Mendoza & Ng (2011), Cai & Teo
(2012)
4 New records:
Low & Tan (2012), Lee & Ng (2012), Cai & Teo (2012)
1 Rediscovery
Tan (2012)
Comment
Molluscs
1291
6
Octocorallia
(Soft Corals
+
Gorgonians)
63
32
Hard Corals
Ascidians
255
32
0
14
Sponges
228
3
Echinoderms
120
1
Marine
Mites
39
0
Baseline: Tan & Woo (2010), Wong (2011)
1 New species:
Tan & Chan et al. (2011)
5 New RecordsL
Ang & Tan (2013), Tan & Low (2013a,b), Ng et al. (2014)
1 Rediscovery:
Tan & Tan et al (2011)
1 Extirpation :
Neo & Todd (2013)
Baseline: Goh & Chou (1996)
2 New species:
Benayahu & Chou (2010), Benayahu & Ofwegen (2011)
30 New records:
Benayahu & Chou (2010), Benayahu & Ofwegen (2011)
Baseline: Huang et al. (2009)
Baseline: Ng et al. (2011)
14 new recordsL
Lee et. Al. (2013), Su et al.(2013)
Baseline: Lim, De Voogd & Tan (2012), Lim et al. (2009),
De Voogd & Cleary (2009)
1 New species:
Lim, De Voogd & Tan (2012)
1 New record:
Lim & Tan (2013)
1 Rediscovery:
Lim, Tun & Goh (2012)
Baseline: Ng et al (2011)
1 new record:
Teo et. al (2010)
Baseline: Bartsch (2009)
c
New found species
• 150 new species of long-legged flies found in catchment areas and mangroves
• New worms
• Dwarf snakehead/Channa gachua (thought to be extirpated, rediscovered in some streams in the CCNR in late 1980s)
can find in Chinatown, cook it and supposedly help in accelerating wound healing
• Malayan porcupine/Hystrix brachyura (thought to be extirpated)
• Dumeril’s monitor/Varanus dumerili (SG’s 3rd monitor lizard. It is a carrion eater [eats decaying flesh of carcasses]
and are carnivores)
• Greater mousedeer/Tragulus napu (slender skinny legs and a very shy creature. Nocturnal; active at night and has 5
white lines below its chin) *can be found in Pulau Ubin
• Lesser mousedeer/Tragulus kanchil (slender skinny legs and a very shy creature. Crepuscular; active during dawn or
dusk period where light is low and has 3 white lines below its chin)*Can be found in Central Catchment Nature Reserves
• Vrydagzynea lancifolia orchid (lance-like leaves)
Habitats need management
Roads & Highways
• Bukit Timah Expressway isolated Bukit Timah Nature Reserve (BTNR) from Central Catchment Nature Reserve (CCNR)
since 1983
—Building of roads, highways has disrupted habitats(separate species from the different areas as they will be roadkill if
they cross the road) ; Bukit Timah Expressway isolated BTNR from CCNR since 1983
—BTNR is surrounded by PIE, BKE, Hindhede Drive, Dairy Farm Road, Upper Bukit Timah Road, Condominiums, and
granite quarries. As habitats need management, the Eco-link @ BKE was built to connect BTNR and CCNR, at a cost of
$17 million.
—Good news on the Eco-link is that new species have been discovered as well
• 5 new species of orthopterans (grassshoppers and crickets) were discovered
• Asiophlugis thaumasia grasshopper (presumed extinct in SG/extirpated, and was rediscovered recently)
• Singapuriola separata cricket
• Tremellia timah cricket
Under intense pressure
• Thousands of walkers use BTNR to exercise
• Practice for climbing Mt Kinabalu and other mountains
• Mountain bikers use the place during the day as well as night
• Recreation
* The North face 100 run 4-5 Oct 2013 at CCNR has disrupted animals who hunt via vibrations, such as spiders
• BTNR closed for urgent repairs
*Even though some soil paths face excess soil erosion, and BTNR is closed for urgent repair, illegal trespassers are
present
• Illegal trespassers
Mangroves
—Chek Jawa; Pulau Ubin, has been designated as a nature area so Check Jawa is safe for the moment. With the
presence of boardwalk, it is also more permanent as a status of a Nature Reserve. There are a total of 6 habitats in Chek
Jawa:
1. Coastal forest
2. Mangroves
3. Rocky shore
4. Sandy shore and banks
5. Seagrass lagoon
6. Coral rubble
Alien Flora & Fauna
Aliens
• Not native to Singapore
• Do well in manmade habitats, seriously affect native fauna
• Direct competition with local resources
• Introduce dangerous diseases (vectors of diseases)
• act as reservoirs for disease, including insects, rodents, and birds, which carry diseases such as yellow fever
and
malaria.
• E.g West Nile Virus that spread across North America was carried by non-native mosquitoes
•Out of 2145 native vascular plants, 1826 exotic.
•Close to 46% of total flora are exotic. Eg. Kolster’s Curse
• Some can potentially become alien invasives
Direct Effects of Aliens
• compete for space, nutrients, water and light with natives because no natural
herbivores and pathogens
• crowd out and displace native species, causing local extinctions
Indirect Effects of Aliens
• alter soil water content
• nutrient cycling
• light conditions
• disturbance regimes (disturbing natural succession of certain plants)
• affect animal habitats
—Our native Green crested lizard now has limited areas with more forest as it is being outcompeted by the Changeable
lizard (originates from Northern Malaysia and Thailand, introduced in early 1980s, larger and more aggressive)
• Green crested lizard/Bronchocela cristatella (native)
• Changeable lizard/Calotes versicolor (exotic)
Originate from northern Malaysia and Thailand Came in early 1980s Larger, more aggressive
—The populace is licensed to kill these 3 birds: Myna, House crow, Eurasian tree sparrow
Mynas
Javan Myna
• Javan or white-vented Myna originates from Java
• introduced in Singapore via the cage bird trade
• established in Singapore since 1925 and is now the most abundant bird locally.
• It has grey plumage. Two distinct white patches can be clearly seen on the underside of the wings during flight.
Common Myna
• Common Myna is readily identified by the brown body, black hooded head and the bare yellow patch behind the eye.
• Droppings, noise
• Spreading zoonoses like histoplasmosis (fungal disease of the respiratory system, avian flu
-Symptoms very similar to cold (histoplasmosis)
-Found in Changi and Pulau Ubin
-Not so common
Fish Alien
—Aquatic aliens are present as well. Alien fishes prefer alkaline water, while native species prefer acidic water due to
the humic acid from rotting of abundant vegetation.
• Tilapia/Oreochromis mossambicus
• Where do you think the fish originate from?
Originated from Mozambique. It was introduced to supplement food supply by Japanese in the World War 2
-Luohan fish is a type of Tilapia
• Common molly/Poecilia sphenops (Originated from South America, prefers open water and have not penetrated the
more acidic water of SG’s catchment area. Alien fishes prefer alkaline water, while native species prefer acidic water
due to the humic acid from rotting of abundant vegetation)
• Guppy/Poecilia reticulata (Originated from South America, prefers open water and have not penetrated the more
acidic water of SG’s catchment area. Alien fishes prefer alkaline water, while native species prefer acidic water due to
the humic acid from rotting of abundant vegetation)
—Aliens can be introduced due to food demands as well.
-The Chinese softshell turtle competes with the Asian softshell turtle, which has become very rare today.
-The American bullfrog competes with local native frogs for resources as well.
• Large, voracious, threat to local native frogs and to animals that it preys on (eat small animals and even small frogs)
• Normally found in temperate regions and has not been able to breed naturally here
Aliens can be introduced as a result of pet trade
• Red-eared slider/Trachemys scripta elegans (Introduced from the US. Bought and released by local owners when
they get too big and competes with native species for resources. It is also released during religious festivals as well, such
as Vesak Day. A $10,000 fine can be issued for illegally releasing animals into nature areas. It has a lifespan of roughly 30
years.)
—Sometimes, we did not even know that we have alien species in places such as canals, until certain incidents happen.
At Sungei Ulu Pandan in 1994, there was the overflow of sewage pipe, causing fishes (and surprisingly alien species) to
die and float on the water surface.
• Koi/Cyprinus carpio (informal group of the coloured variants of Carp)
• Carp/Cyprinus carpio
• South American armoured catfishes/Loricariidae
*13 November 2012 Surfactant spill into drain
When alien predators are introduced into SG, they have no competitors and they dominate the habitats (foreign fish)
• Snakeheads/Channidae (edible)
• Jaguar guapote/Parachromis managuensis
• Mayan cichlid/Mayaheros urophthalmus
• Knife fish (edible)
*could potentially eat up non-aggressive fishes
• South American apple snail/Pomacea canaliculata (introduced during aquarium trade in the 1980s, it displaced the
native apple snail Pila scutata. The alien species produces pink eggs. The shell looks similar to the Pila scutata’s as well,
except that it is more light-brown in colour.)
• Pila scutata (Native species that is currently being outcompeted by the South American apple snail. It produces white
eggs. The shell looks similar to the South American apple snail’s as well, except that it is more dark-brown in colour. It is
very rare to find nowadays.)
• African land snail/Lissachatina fulica
• Yellow crazy ants/Anoplolepis gracilipes (Found in SG, unknown impacts to the local flora and fauna. It impacts Red
land crabs or Christmas Island red crabs/Gecarcoidea natalis and other endemic animals. It does not have a fixed
direction of movement, wonders haphazardly [but they know where they are going, just difficult to track their
movement]. It Originates from Africa, and some of the worker ants can switch from being a worker to a reproductive
ant.)
—Other alien species can be introduced just because of their looks. Some of them may be poisonous and lethal, they
will wreak havoc in our local ecosystem.
• Ferret/Mustela putorius furo (Predators, they were introduced because they look cute)
• Blue-arrowed frog/Dendrobates tinctorius "azureus" (Poisonous and lethal)
• Piranha/Characidae (Predator fish)
—Marine aliens are present in SG as a result of accidental introduction by the ship’s hulls and/or ballast water of ships.
Previously ballast was done by soil, the modern ballast is done by seawater, which introduces these marine aliens.
• Black striped mussel/Mytlopsis sallei (Originated from Carribean, now found in Japan, Taiwan, Hong Kong, Singapore,
Malaysia, Fiji and India. It arrived via the ships full and/or ballast water of ships.)
—As Singapore is the busiest port in the world, marine organisms are stucked onto the ship [fouling/sticking]. To
counteract, anti-fouling paint, Tributyltin was installed. However, this causes female marine snails to develop a pseudopenis. This disorder is called imposex. Furthermore, this causes Pearl oysters to have stunted growth, shell thickening,
and reproductive failure.
• Pearl oysters/Pinctada
Public Education
• Need more environmental consciousness
• Educate through nature publications and nature programmes by LKCNHM or NGOs
• Bank sponsored many green activities e.g. President’s award for the environment
• Conservation of Nature areas, minimize disturbance, stop poaching, introducing exotic organisms by releasing them
during festivals
• Prolong the lifespan of Semakau landfill
—World’s first offshore landfill made from the seascrape
—Cost $610 million
—Reclamation between 2 islands: Pulau Sakeng and Pulau Semakau
—Evicted residents on both islands to the mainland
—Started operation since 1 Apr 1999, supposed to last till 2035 or beyond (Initially supposed to last 2045)
—2189 tonnes of non-incinerable waste and incineration ash dumped here every day
—Divided into 2 phases: phase 1 is expected to be filled by 2016. Corals were translocated to Sister’s island in 2014 and
phase 2 has started to be developed. There was no translocation of marine life when phase 1 was being constructed,
although sediment screen was set up to reduce sedimentation on the corals. The destroyed mangroves were replanted
using 400,000 saplings. This is the first occurrence for a government organisation attempting to minimised the impact
of development on the marine environment. There is no way a habitat can be moved; only certain important coral
species were moved.
• Avicennia marina
—4.5 million square feet of XR-5, a geomembrane designed to withstand both the long-term effects of the tropical
environment and the rigours of the installation process; prevents toxic ash/waste from leaking out into the marine
environment.
—Furthermore, mangroves were used as a bioindicator for leakage of pollutants from the landfill itself.
—Seagrass meadows are present as well.
-Knobbly Sea Star
-Funeral Nudibranch
-Sunflower Mushroom Coral
*All this found in Pulau Semakau
Semakau Landfill
• World’s first offshore landfill made from the seascape
• Cost $610 million
• Reclamation between two islands: Pulau Sakeng and Pulau Semakau
• Evicted residents on both islands to the mainland • Started operation since 1 Apr, 1999, supposed to last till 2035 or
beyond
• 2189 tonnes of non-incinerable waste and incineration ash dumped here every day
• Divided into 2 phases:
• Phase 1 is completely filled with incineration ash and non-incinerable waste
• Corals were translocated to Sister’s island in 2014 and Phase 2 has started to be utilised, there will be one big cell
instead of multiple small cells
• 4.5 million square feet of XR-5, a geomembrane designed to withstand both the long-term effects of the tropical
environment and the rigors of the installation process
• There was no translocation of marine life when phase 1 was being constructed
• Although sediment screen was set up to reduce sedimentation on the corals
• The destroyed mangroves were replanted
• using 400,000 saplings
• First time government organisations try to minimize impact of development on the marine environment
• There is no way a habitat can be moved, only certain important coral species were moved
Activities at Semakau Landfill
• Sport fishing
• Bird watching
• Star-gazing