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SSA2215 BIOPHYSICAL CHANGES OF SINGAPORE

Fieldwork Essay Fieldtrip to Pasir Ris Picture sources shared with: Tan Kim Chwee (U074492U)

Lim Fang Jeng (U076372R) Lab group: Tuesday 3/24/2008

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SSA2215

Fieldwork Project (Lab Group: Tuesday)

Lim Fang Jeng (U076372R)

Investigation of Mangroves toward Environment in Singapore using the case study in Pasir Ris Park Fieldtrip location: Pasir Ris Park (N 1o22' 52.8", E 103o57' 7.2") Interested site: Mangrove forest (N 1O22’41.7”, E 103O 57’4.5”) Date of fieldwork: 23 February 2008 (Saturday) Objective of study: Will the mangrove forest bring any interactive influence to its surrounding environments? Hypothesis: Mangrove forest will bring tremendous biophysical effect to its surroundings and the forests are affected greatly by their surrounding environments and activities such as tides and various human activities. Mangroves are a special type of trees which exist in the Mother Nature, these trees differs from other trees in terms of their natural habitat and biological characteristics. In order to further investigate and discuss the objective of this fieldwork, a trip to Pasir Ris Park was carried out. The purpose of this trip is to carry on investigation of the behavior of the mangrove forests and their interactive influences to and from their surroundings. Prior to the commencing of the fieldwork investigation, two colored region maps of Singapore are attached in the attachment section to show the comparisons of the areas of Mangrove in Singapore in the year of 1819 and 1990. It can be seen clearly that the region of mangroves are greatly reduced. It is shocking that the change of mangroves in Singapore has been reduced from 10-12% since 1822 to less than 1% of the mainland today (Chua, 2007). With this observation of the tremendous change in mangrove areas, investigation was carried out to study the effect of these remaining areas to the surroundings. Pasir Ris Park is one of the natural parks in Singapore, though it has been addressed as a natural park, it still contains plenty of so called ‘artificial’ works found in the areas of these parks such as park rebuilding, reconstruction, replanting, etc. Back then, most of the primary mangrove forest in this region has been removed and being reduced from 60 hectares to 7 hectares after 1978. Nevertheless, the species of the mangroves in a particular viewing area (Figure 1) is still wholly

23 species of mangrove trees in Singapore. Some of the species found here are Rhizophora mucronata, Sonneratia alba, etc.

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Figure 1 - Diversity of Mangroves in Pasir Ris Park

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diverse. In this particular area, there are roughly 8 out of the

SSA2215

Fieldwork Project (Lab Group: Tuesday)

Lim Fang Jeng (U076372R)

By observing around the mangrove areas, the population of mangroves is different in different areas of the shoreline. Different classes of species of mangroves can be found according to the region of the coastline. According to Pernetta (1993, p. 15), 5 different classes of coastline zones can be seen according to the degree of salt water inundation and different type of mangroves grows in different types of zones: (1) High tides area (2) Medium high tides area (3) Normal high tides area (4) Spring tides area (5) Exceptional high tides area Mangroves which have more salt-water resistant properties and more toleration to high tides of sea water such as consisting of stronger root system such as Avicennia and Sonneratia are being distributed in the area at which have high tides and medium high tides. Areas of normal high tides are mainly consist of Rhizophora whereas Bruguiera, which has lower tolerance to high tides are mainly found in region consists of spring tides. The mangroves which are specially found in the area of exceptional high tides are Bruguiera gymnorrhiza and Rhizophora apiculata (Pernetta, 1993). Along the route, pencil-like structures are being observed on the soil ground around the mangroves (Figure 2). Those structures are the seeds of mangrove, the reason for the structure of their seeds to be so is to ensure the maximum possibility to stay firmly on the unstable soil ground instead of being washed away by the tides. Moreover, if the seeds are being Figure 2 - Viviparous seed

washed away by the tides, they can also grow on the new environment as long as

the place is under the condition of their growth. With this special property, they can really make a great impact to their environments. At the shoreline region of Pasir Ris Park, mangroves can be found near the shorelines, the reason for the mangrove to be existed in that particular area is due to the properties of their viviparous seeds. Their seeds got washed by the waves and being brought to the shorelines, since the seawater has high salinity, which is the ideal condition for

mangroves does bring down a significant effect for the Figure 3 – Sediments near shoreline

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their growth and nurture. As a result, the growth of these

SSA2215

Fieldwork Project (Lab Group: Tuesday)

Lim Fang Jeng (U076372R)

shorelines. One of the significant changes observed by the existence of the mangrove near the shoreline is the encouragement of sedimentations (Figure 3). As we knew that the roots of the mangroves contain the property of encouraging sediments, it plays a role in causing natural land reclamation by trapping the eroded particles from the land and preventing it from being washed away by the waves. Besides encouraging sedimentations, mangroves around the shores also serve as a natural protector for the shores by greatly absorbing the wave energy which propagated to the shores. One of the proofs of the sedimentation is that a breakwater (Figure 4) is surprisingly found approximately 14 paces from the beach, which makes an abnormally great distance. This giant structure was served to protect the land from the propagating of ocean waves. However, since the mangroves were grown in front of the shores, sedimentation occurs before the breakwater perform any function in protecting the land and causes a large region of land was formed in

Figure 4 – Breakwater found near the shoreline

front of the breakwater this made the breakwater has no effect in protecting the shore from waves anymore. Some organisms are also found in the mangrove forest, small fishes which are supposed to be in the ocean are found along with musketeers, crabs, etc. Under the relative calm environment from outside, in addition to the environment which suits best to the saltwater fishes, mangroves in Pasir Ris Park also serve as a nurturing ground for the marine organisms before they are matured to go out to the open sea. Apart from the influence of the mangroves to the environments, the environments do play a major role in affecting the ecosystem mangroves forest nowadays. In this particular park, the influence of human activities influencing the bionetwork of mangroves can be easily examined. The problem of solid wastes and water pollution caused by residential wastes and industrial wastes has greatly impinges on the mangrove systems in Pasir Ris Mangrove. A large amount of solid wastes can be found on the soil ground of mangrove due to the Figure 5 - Water pollution

trapping of them by the roots of the mangroves. Furthermore, the water pollutions in a particular area

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unknown substance can be seen and the mangroves on the region start dying, which greatly causes a great

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have caused the mangrove tree to start withering and dying. In this particular area (Figure 5), effervesce of

SSA2215

Fieldwork Project (Lab Group: Tuesday)

Lim Fang Jeng (U076372R)

drop in the aesthetic value of the mangroves. On the other hand, foreign substances such as metal ions will disrupt the metabolism of mangroves, hence causing the plant to die. More importantly, the tides will carry some of the wastes accumulated in the mangrove areas will also be washed to the coastal areas and finally causes a great impact on the pollution of the coastal areas. Fortunately, the problem of extensive oil coating in the mangroves of Pasir Ris does not exist, the presence of oil contamination will threat the respiratory system of mangrove pneumatophors and hence causing the lack of oxygen which will soon causing them to arrive in the stage of death( Chan, 1977, as cited in Lacerda, 2001). Management should be done extensively to ensure that the remaining 7 hectares of mangrove in Pasir Ris Park to be kept natural and healthy. Actions such as exercising more people to participate in the activity of cleaning mangrove forests can greatly help reducing the solid wastes in the mangroves. Moreover, management of the waste disposal in the urbanized areas should be taken care as well. In conclusion, the mangrove forest in Pasir Ris Park is conserved and maintained well. However, there are still a lot of hazards and threats which are affecting their living. To reiterate, mangroves do really bring in a lot of effects towards their environments such as regulating the waves near the coasts by absorbing high wave energy and encouraging sedimentations. In addition, the environments and activities such as changes of tides causing the different diversity of mangroves, urbanization, existence of solid waste products and water pollution due to human activities do really affect the mangroves to a great extent.

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END

SSA2215

Fieldwork Project (Lab Group: Tuesday)

Lim Fang Jeng (U076372R)

References Chua E.K. (2007). Singapore’s splendor: Life on the edge: Along the shoreline. Simply Green: Singapore. Debby. (2005, April 29). Mangroves of Singapore waters, past and present. Retrieved March 8, 2008, from http://habitatnews.nus.edu.sg/news/pulauhantu/archive/2005_04_01_archive.html Lacerda, L.D.. (2001). Mangrove ecosystems: function and management (1st ed.). Berlin; Heidelberg; New York; Barcelona; Hong Kong; London; Milan; Paris; Tokyo: Springer. Pernetta, J. (1993). Mangrove forests, climate change and sea level rise: Present mangrove distribution and diversity. International Union for Conservation of Nature and Natural Resources: Switzerland. Peter K. L. Ng and N. Sivasothi. (n.d.). Guide to the mangroves of Singapore: Mangrove forests in Singapore.

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Retrieved March 8, 2008, from http://mangrove.nus.edu.sg/guidebooks/text/1004.htm