Sabah shoreline management plan (Borneo, Malaysia): Ecosystems and pollution

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Ocean & Coastal Management 50 (2007) 84–102 www.elsevier.com/locate/ocecoaman

Sabah shoreline management plan (Borneo, Malaysia): Ecosystems and pollution Flemming Jakobsen, Neil Hartstein, Julien Frachisse, Tania Golingi DHI Water & Environment (M) Sdn. Bhd., 11th Floor, Hill-View Side, Wisma Perindustrian, Jalan Istiadat, Likas, 88400 Kota Kinabalu, Sabah, Malaysia Available online 13 November 2006

Abstract The management of the coastline around Sabah (Borneo, Malaysia) faces numerous conflicting interests from the public, private and industry groups. The public demands socio-economic growth, sustainable development and preservation of natural resources while the private sector and industry demand local coastal protection and often reckless development. Subsequently, there are numerous multi-disciplinary conflicts across user groups, over the use of coastal resources. To resolve these issues the creation of a management plan for Sabah’s coastline has been initiated. A baseline was established from historical investigations, data collection and using a combination of visual inspections and photos. Understanding of the physical, chemical and biological processes involved as well as the dynamics of the integrated processes and a holistic impact assessment is also required. To do so numerical models were used to integrate available information and knowledge and to hind-cast and now-cast conditions and predict the consequences of different development scenarios. In some cases the models results needed further detailed analysis in combination with specific knowledge on local habitats to determine the impacts. The focus of the paper is on the integration of information, but some details are also given on the important conflicts and habitat threats. r 2006 Elsevier Ltd. All rights reserved.

1. Introduction Major population centres and socio-economic growth in Sabah (Borneo, Malaysia) is concentrated in the coastal area. With Sabah’s 4328 km coastline (inclusive of islands and lagoons), the management of the shoreline is therefore of critical importance. There are Corresponding author.

E-mail address: fl[email protected] (F. Jakobsen). 0964-5691/$ - see front matter r 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.ocecoaman.2006.03.013

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four major growth centres: the state capital Kota Kinabalu, Sandakan, Tawau and Kudat; and more than 300 villages along the Sabah coastline (Fig. 1). The majority of coastal villages depend upon fisheries as their main source of income, but agriculture and tourism are becoming more important. Economic growth in Sabah is driven mainly by agricultural development, however, the tourism industry is also growing at 420 percent per year and has strong potential development [1]. Sabah’s coastal environment is dominated by three ecosystems. The first is a wetland ecosystem consisting of peat swamp, mangrove forest, mudflats and a wide range of animal species. This ecosystem is predominantly found in turbid environments and dominates the coastline in eastern Sabah. The second is a coral reef ecosystem which comprises various marine micro and macro faunal species. The third is a seagrass ecosystem which often plays a role as a link between the wetland and coral ecosystems; however, seagrass beds are generally not widely distributed along the coastline of Sabah. Both coral and seagrass ecosystems are usually found in low-turbidity, non-polluted waters in front of sandy

Fig. 1. Map of Sabah (Borneo, Malaysia) showing main centres and major rivers.

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beaches and for the latter, in sheltered lagoons in East and West Sabah, Darvel Bay and around islands. These ecosystems are important for the physical protection of coastal habitat, economically in supporting fishing, aquaculture, forestry and tourism industries and finally to protect and preserve natural resources for future generations. Increasing population and resulting urbanisation have altered environmental conditions in coastal areas (e.g. [2,3]). In urban areas, untreated and improperly treated sewage and solid waste is discharged directly into coastal waters while illegal fishing techniques destroy or stress coastal ecosystems. Deforestation for agricultural and aquaculture development has increased soil erosion [4] leading to increased sedimentation of coastal ecosystems. Furthermore agricultural development (oil palm plantations, pig/chicken farms) and industrial development, mainly palm oil and saw-mills, also leads to pollution of the coastal environment through inputs of fertilizers, pesticides, organic matter and bacteria. Tourism, while potentially able to assist in the conservation of the environment, has in some cases through improper management caused stress or destruction of natural resources [5]. The deterioration of the coastal environment is visible to everybody residing in or visiting Sabah and is of general growing concern. Development in catchment areas can potentially influence coastal environmental conditions. Overland runoff can transport sediment into rivers which is eventually deposited downstream in coastal waters. For that reason the coastal area cannot be seen in isolation. Planning, zoning and controlling coastal areas can optimize coastal development while preserving natural resources, but can do little about the development in the upstream catchment. Socio-economic growth in Sabah is needed and demanded. Still, if the present unsustainable development continues, natural resources will deteriorate further and several industries will be harmed in the long run. On the other hand, it is also possible to maintain both socio-economic growth and preserve targeted natural resources. To do so, appropriate management, legislation and effective enforcement is crucial. The ultimate aim of the Shoreline Management Plan study is to produce a development plan for Sabah shoreline which is sensitive to the particular conditions of the coast Abdullah [6] and is consistent with the general development policies of Sabah State (e.g. Moktar and Aziz [7]). In the present paper we limit our focus on the present environmental situation and the application of numerical models, but relate the findings to future work on the plan. As sediment and pollution is transported from Sabah’s many sub-catchments to the coastal area, where it mixes with sea water, effort is put into resolving catchment hydrology, land use, etc. to provide integrated and holistic results. The methodology applied to develop a shoreline management plan for Sabah is considered as an example to be followed along many coastal areas in Southeast Asia, and around the world, in resolving the impact of inland development on the coastal environment. 2. Measurements and methods The central themes covered in the study are outlined in Table 1. To establish a baseline a combination of earlier investigations, measurements and photos were collected and analysed. Numerical models served to integrate the available information to hind-cast and now-cast physical conditions and predict the consequences of different development scenarios. Details on model systems, calibration, validation, etc. can be found in the project reports [8].

Coastal morphology Sediment transport

Hydrography Tides Currents

Coast

Sea

Comments

Data processes numerical modeling

Fine sediment

Salinity Water quality

Catchment hydrology Sediment load Pollution load

Land

All

Physical

Place

Table 1 Overview of topics covered in the study to-date

Data processes numerical modeling

Pollution

Water quality

Coral reef ecosystem Fish seagrass ecosystem

Wetland ecosystem Peat swamp Mudflat Mangrove Animal

Terrestrial vegetation

Biology

Sustainable dev. economical dev.

Solid waste disposal sewage Tourism

Fisheries New techniques Illegal methods

Sand mining

Agriculture Palm plantations Animal farms forestry Aquaculture infrastructure/ utilities industry

Use

Perception feasible

Legislation and administration Selected issues

Socio-economy socio-cultural Surveys

Other

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On the basis of the model system named MIKE 11 a numerical rainfall-runoff model was set-up, calibrated and validated. Sabah was divided into 79 sub-catchments of which 18 were calibrated and validated. Some details on the model system and how to set-up a similar model can be found in [9]. It should be noted that runoff was imposed in the coastal models to simulate the salinity distribution. A sediment load model was also setup, calibrated and validated. It is based on the model named SEAGIS. Source erosion was assessed according to the universal soil loss equation (USLE). Sediment loads were imposed in the coastal models to simulate the sediment plumes. Similarly a pollution load model was setup, calibrated and validated based on the model system named LOAD. The pollution loads were imposed in the coastal models to simulate the spreading of pollution in the coastal area. On the basis of the model system named MIKE 21 numerical models of depth averaged hydrodynamics, salinity, cohesive sediment and pollution around Sabah were set-up, calibrated and validated. The impact of pollution loads from the entire drainage area on the water quality conditions along the Sabah coastline was studied by considering the following components: dissolved oxygen (DO); BOD5 (up to three fractions: dissolved, suspended, settled); ammonia; nitrate/nitrite; phosphate; and coliform bacteria (E. coli). Some details on the model systems and how to set-up the models can be found in for example, [10,11]. Year 2003 was chosen as ‘design period’ for ‘production runs’ as analysis showed it was an average year for rainfall, catchment runoff etc. 3. Coastal ecology results A detailed understanding of the coastal ecology and the distribution of the dominant ecological systems along Sabah’s coastline guides a sound sustainable management of the coastal environment. For example, the environmental tolerance limits of a coral reef ecosystem are different from the tolerance limits of a wetland ecosystem which would therefore have implications on the management strategies for adjacent shoreline and inland areas. 3.1. Mangroves Mangrove forest occurs in the inter-tidal zone along sheltered, generally muddy shores. Mangrove swamps have economic importance as a fishery source (prawns, crabs, molluscs and fish), forestry and eco-tourism. Wood products from mangrove forests are presently not exploited on a commercial scale in Sabah, although small-scale extraction by local villagers does occur in most mangrove areas. In addition, it is now becoming recognised that the ability of mangroves to filter water and trap sediment and pollutants is important as it improves downstream water quality, an essential requirement for seagrass and coral growth and stabilises estuarine banks, protecting property from erosion [12]. In 1999–2002 the total area of Sabah mangroves was 341,377 ha (ref. Sabah Forestry Department). Of this 317,423 ha has been gazetted as permanent forest reserves of which 316,024 ha are ‘‘Class V Mangrove Forest Reserves’’ set aside to supply mangrove timber and other produce, and 1,399 ha are ‘‘Class VI Virgin Jungle Reserves’’ reserved primarily for the purpose of conservation and research. Based on analysis of recent satellite images, mangroves presently cover an area of 327,678 ha (Fig. 2).

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Although there are still vast mangrove forests in Sabah, they are under increased pressure from socio-economic activities, such as aquaculture and urbanisation, in addition to the emerging possibility of large-scale commercial exploitation. Threatened areas include Kota Kinabalu and its increasingly extensive suburbia, Sandakan, Tawau and Semporna where the need for land for both commercial and housing development is high. Overall, in Sabah, as elsewhere in Malaysia, the main threats to mangroves arise from wholesale clearing and destruction of mangrove habitats, rather than indirect impacts such as changes in water quality, sedimentation, etc (e.g. [13]). In general mangroves are resilient to environmental changes and are tolerant to changes in inundation frequency, salinity and sedimentation as long as they are not too steep or sudden and unless the mangroves occur in areas where they are already at the limits of their tolerance range (e.g. [14–16]). Owing to the importance of mangrove forests for instance as spawning and feeding areas for many marine and inter-tidal species, it is considered that the primary management objective under the SMP for mangrove areas is protection and conservation. Economic objectives, such as aquaculture or other mangrove conversion for development, should only be considered in specific areas with clear limits and guidelines. 3.2. Coral reefs The waters around Sabah support over 75% of all Malaysian coral reefs ([17]). Three types of reefs occur along the west coast of Sabah: fringing reefs, patch reefs and bank reefs, with fringing reefs being the most common. Fringing reefs are found parallel to the

Fig. 2. Mangrove, coastal classification, coral reef data and fishing information.

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coast and around islands. The most extensive and well-preserved areas of reef in Sabah occur on Sabah’s southeast, including the reefs of Darvel Bay, which support a number of rare and endemic coral reef species, and the reefs around Semporna and the worldreknown Sipadan Island. Coral reefs in Sabah (and around the world) have been rapidly and adversely impacted by human activities in past decades [2]. The main causes of reef habitat loss in Sabah is the use of destructive fishing methods (dynamite and cyanide fishing, and illegal trawling), and sediment erosion from improper development along the coast and in the hinterland leading to coral mortality from high turbidity and/or burial [18]. There has been a dramatic rise in sediment and nutrient loads of rivers in Sabah over the past two decades with adverse effects on the coral reef ecosystem. Less commonly, outbreaks of corallivorous consumers like crown of thorns starfish have affected some areas of reef, such as at Tunku Abdul Rahman Park. Reef fish surveys show a decline in commercial reef fish in most areas since the 1980s, providing strong evidence that the majority of reefs are over-fished [18]. This is believed to reflect the impacts of fish bombing. To avert the continued destruction of Sabah’s reefs, one strategy currently being implemented is the creation of marine protected areas which provide special protection for valuable areas. These statutory objectives shall be preserved and enhanced under the SMP. Further, all good quality coral reef areas shall be considered ‘critical environmental capital’, the preservation of which is essential to achieve environmental sustainability. Buffer zones around good quality coral reef areas shall be established under the SMP based on knowledge of water flow and existing suspended sediment and pollution loadings to appropriately restrict adjacent and nearby shoreline area development. 3.3. Seagrasses Seagrass beds intermix with coral reefs or cover shallow areas that fringe mangrove swamps. Seagrass beds are important nursery grounds for fish and other fauna [19]. The seagrass beds also provide shelter for mature fish and invertebrates such as crabs, shrimps, clams, sea cucumbers and sometimes corals. Seagrasses and epiphytic algae provide grazing for dugongs, sea turtles, and certain species of fish. Extensive seagrass beds are found in the larger estuaries on the West Coast of Sabah, such in the Tuaran district, while many other areas have smaller, patchy seagrass areas. On the east coast, scattered distribution of seagrass beds is found in many areas along the coast, such as in Darvel Bay and the Semporna Islands, Paitan Bay, Labuk Bay and at Tambisan. Seagrass beds in many areas around Sabah are at risk due to siltation that both reduces light availability and changes sediment characteristics [3]. Another threat, particularly along the East coast of Sabah, is eutrophication caused by excessive loads with nutrients, which similarly to suspended sediments, reduces light availability for the seagrass plant due to shading from planktonic or epiphytic algae. In addition to shading effects of suspended sediments, sedimentation of fines can also affect seagrass beds. Most seagrasses are intolerant of smothering. They typically bend over if laden with sediment and can be buried in only a few centimetres of sediment before they die [20]. This has been observed in a number of seagrass meadows around the Kota Kinabalu area, where extensive land clearing and filling has caused increased

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sedimentation in the sheltered bays and estuaries where the seagrasses are found. Under the SMP all remaining coastal areas containing seagrass are to be protected as either wildlife or marine reserves. Under the SMP, the seagrass ecosystem is also considered ‘critical environmental capital’, given its importance in supporting the fisheries resource through its role as a shelter and nursery area for fish, which in many areas provides a link between mangrove and coral reefs habitats. In addition, the seagrass ecosystem provides habitat for endangered marine fauna, in particular believed to be the sole food source for the dugong, Dugon dugon. 3.4. Marine megafauna Historically, there have been numerous reports of marine mammals and other mega fauna sighted around Sabah. Those that inhabited the shallow coastal waters were frequently hunted and were considered a delicacy. This has probably led to the decline in numbers of some of these marine species, especially dugong [21]. The use of gillnets and kelongs are found to be the main causes of incidental catches of dugongs and inshore cetaceans, particularly the Irrawaddy dolphins and finless porpoises; trawlers are involved to a lesser extent [21,22]). Dynamite bombing has also been claimed to be another cause of marine faunal mortality. In terms of the SMP, the distribution of rare and endangered marine fauna must be taken into consideration in terms of habitat connectivity in establishing the location of protected areas. In addition the SMP must consider the siting of industrial or other development areas to avoid heavy marine traffic conflicting with marine faunal habitats and any known migration routes. 3.5. Water quality standards Four water quality standards for selected parameters are outlined in Table 2. These are mostly defined as fixed limits that should not be exceeded, while in some cases limits have not been defined. In many other countries, comparison to water quality standards considers the percentage of time the particular criteria is exceeded. In some administrative systems (such as the European Union) the goal is to meet the standard 490% of the time. From the preceeding descriptions of the wetland and coral reef ecosystems it would seem reasonable to use different standards for areas dominated by wetland and coral reef ecosystems, but no differentiation is offered in the current Malaysian standards, which are primarily developed from the point of view of human water usage, such as safety for drinking, bathing, aesthetics, etc. Within this study we do not apply these standards, but treat the different ecosystems according to known tolerances from previous investigations on seagrass [3,20] and corals [23,24]. 4. Results of simulated salinity distribution At river mouths and in the coastal environment, fresh water runoff from Sabah’s catchments mix with salt water masses in the marine environment. The extent of lowsalinity water masses relates directly to marine habitat niches; for example mangrove forests are found in brackish water. In any given area, high river discharge and long

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Table 2 Comparison of selected parameters from different water quality standards Parameter

ASEAN marine water quality criteria

Malaysian interim sea water quality standards

Malaysian interim water quality standards

MSJCE water quality guidelines for straits of Johor

Nitrate (mg/l) Phosphate (mg/l)

0.060 0.045 (estuaries) 0.015 (coastal) 0.070 NA 4 100

NA NA

NA NA

NA NA

NA NA NA 100

0.3 3 5–7 400

0.9 NA 5 1000

See

50

50

NA

Ammonia (mg/l) BOD (mg/l) DO (mg/l) faecal coliform (MPN/100 ml) TSS (mg/l)

(NA: Not available).  Permissible 10% maximum increase over seasonal average concentration.

flushing times results in low salinity conditions, while small river discharge and short flushing times results in high salinity conditions. Areas with the lowest salinity concentrations can also potentially have the worst water quality (although sediment and pollution loads do not only depend on the amount of discharge water). Sabah faces the South China, Sulu and Celebes Sea and is part of South Asian Waters [25]. The NE monsoon wind (at its peak in January, February and March) creates wind set-up in the South China Sea and an anti-clockwise circulation tendency [25,26]. In comparison the SW monsoon (peaks in July, August and September) creates a clockwise circulation tendency. The coastal currents close to land are significantly influenced by local winds (e.g. [26]). The horizontal salinity distribution was modelled (extent of freshwater plumes in coastal waters) for 2003. Representative examples of horizontal salinity distribution from NE and SW monsoons are shown (Fig. 3). The distribution changes during the year and one major reason for the change is the advection of salinity along with the wind-driven currents. The simulation results indicate that during the NE monsoon, conditions at Kota Kinabalu are significantly influenced by river outflow in the Sulu Sea. In contrast during the SW monsoon it is significantly influenced by the river outflow into Brunei Bay. This indicates that terrestrial point source pollution loads are not always just a local problem and can have regional influences. The lowest salinities are found along the coastline towards the Sulu Sea, especially in Marudu, Labuk and Sandakan Bay. Low salinities are also found in Brunei Bay and sometimes in Tawau Bay. These are the locations where the biggest potential for water quality problems exists. Along the open coastline in front of Kota Kinabalu and in Darvel Bay, salinity concentrations are higher. In the first case, this is due to higher water exchange. In the second case, this is due to limited river inflow. 5. Results of simulated sediment load and sediment plumes Sediment (soil) is eroded from the land catchments of Sabah, during rainfall events, and is transported by rivers to the coastline. Upon reaching the coast, sediment plumes are

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Fig. 3. Map of simulated salinity distribution around Sabah (Borneo, Malaysia) on 1 March 2003 and on 1 September 2003.

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advected by currents and dispersed. Sediment settles through the water column and is deposited onto the bed where it can be re-suspended depending on bed shear stress. The soil erosion at a given location is governed by soil type, land use, terrain and rainfall-runoff, while the amount transported to the coastline is governed by the river systems. Based on the model results some general comments can be made regarding our findings on sediment erosion and sediment load along the Sabah coastline (Fig. 4). Erosion depends mostly on terrain and land use. Areas with source erosion rate less than 5 ton/ha represent more than 80% of the total area, and the average source erosion is in the order of 3.5 ton/ha. In terms of land use, the main generators of soil erosion are croplands, cleared land (including logging) and palm oil plantations. In the numerical modelling as well as in the collected measurement and observations the major sources of sediment to coastal waters are found along the northeast coast of Sabah (including Kinabatangan River). The actual sediment concentration at a location depends on the sediment load and water exchange. The areas most influenced by high suspended sediment concentrations are Tawau and Indonesian bays (Figs. 1 and 5). Darvel Bay is influenced in areas immediately adjacent to the source, in contrast Labuk Bay and the Sulu Sea have high concentrations most of the year (Fig. 5). It is highly likely that the concentrations in these embayments have increased due to land-based activities. Along the coastline towards the South China Sea and towards the Sulu Sea, an area 5–10 km in width is influenced. Most river systems in Sabah transport sediment to the coastal environment during and just after periods of rainfall (Fig. 6). Outside these periods there are at least 10 orders of magnitude lower sediment concentrations in and around coastal river systems. This has

Fig. 4. Annual averaged (2003) suspended sediment load at the coastline.

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Fig. 5. Suspended sediment concentrations on 19 May 2003 at 18:00.

Fig. 6. Time-series of suspended load at the coastline at three selected locations.

important implications for effects on coastal ecosystems where it is perhaps the length of these high sedimentation events rather than the mean values which need to be determined when examining environmental impacts.

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Comparing the sediment concentration and the coral reef distribution (Fig. 2), it is found that in areas with high concentrations, either no coral reefs or only poor quality reefs were found. Likewise a correlation between high sediment concentrations, mangrove forest and prawn trawling grounds was found (Fig. 2). 6. Pollution loads and coastal distribution Pollution loads from land depend on the nature and extent of industry, population and agriculture present in each catchment, and also on the distance from the coastline and runoff quantity. Concentrations in the coastal waters are influenced by the same physical processes, advection and mixing, as salinity and cohesive sediment. In addition, biological processes also affect the concentrations. The average pollution loads include both a constant and a temporally varying component (Figs. 7–10). Some general comments can be made regarding pollution load along the coastlines: On the West Coast, heavy industrial polluters are located in Kota Kinabalu, Penampang and Papar areas. On the east coast, heavy industrial polluters exist in the Sandakan and Tawau areas. Industrial pollution is a long-term concern. Population concentrations in urban areas generate significant amounts of BOD, TN, TP and in particular E coli. The most heavily populated areas are Penampang, Kota Kinabalu, Kudat, Sandakan, Lahad Datu, Semporna and Tawau. Agricultural or cultivated areas such as oil palm plantations are a significant source of nitrogen and phosphorus. This can be seen in the lower part of the Kinabatangan

Fig. 7. Annual average BOD loads reaching the coastline.

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Fig. 8. Annual average TN loads reaching the coastline.

Fig. 9. Annual average TP loads reaching the coastline.

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Fig. 10. Annual average E. coli loads reaching the coastline.

catchment. Significant sources of BOD can be found in Labuk, Tuaran and Papar catchments. Effluents from palm oil refineries into the aquatic environment are also a major concern. The impact of present pollution loads from the entire drainage area on the water quality conditions along the Sabah coastline was studied by considering the following components: dissolved oxygen (DO); BOD5 (up to three fractions: dissolved, suspended, settled); ammonia; nitrate/nitrite; phosphate; and (E. coli) bacteria. Pollutants tend to accumulate in semi-enclosed areas, such as Brunei Bay, Tawau and Marudu. In general, calculated concentrations meet water quality standards, but the assessment needs to be made in greater detail. Phosphate and BOD concentrations for example meet water quality standards during the period considered. 7. Scenario assessment The model scenarios provide insight into the relevant issues and major concerns relating to pollution generation in Sabah and provide indicators and guidance to management options. The following scenarios have been considered: Existing condition (see earlier sections). Scenario 1: Future condition if current trends continue. Scenario 2: Existing condition with full compliance to existing guidelines. Scenario 3: Pristine condition, no humans.

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Scenarios 1 and 2 are compared to the existing situation to assess the effectiveness of each scenario, while Scenario 3 is primarily for reference. Scenario 1 represents likely catchment pollution loads in 2020 if no changes to the existing procedures of management, treatment and enforcement are made. It is an extrapolation of the base (existing) condition, with a ‘‘status quo’’ approach to management. The following assumptions have been made: (1) all the suitable soils for agriculture in Sabah are used for agriculture practices; (2) a constant population growth rate of 3.8%. Areas with a density higher than 100 inhabitants/km2 are connected to a sewage system, and 15% of the sewered population are connected to a treatment plant; (3) existing land-use distribution remains basically the same; and (4) a linear trend has been applied to derive employment growth factor per industrial sector for 2020. Scenario 2 considers the existing condition with pollution loads in full compliance with existing water quality standards and guidelines. This gives an indication of whether the existing guidelines and recommendations are sufficient to create a sustainable and environmentally friendly solution. Assumptions are: (1) all residential and commercial properties are sewered; (2) all wastewater discharge is treated in accordance with rules. This corresponds to a reduction of approximately 90% from existing loads; (3) a buffer zone is maintained along the rivers of Sabah. The self-purification is assumed to reduce water quality loads by 10%; and (4) a decrease in suspended sediment loading as a result of a buffer zone between utilised land and waterways. The reduction in loads is estimated to be 75%. Scenario 3 represents the natural situation, with no people, industry or agriculture. This is not suggested as a solution, but represents the best water quality conditions achievable. In this ideal situation, the entire catchment area is natural forest and there are no domestic pollution sources: (1) the leaching of BOD, total-N, total-P, faecal coliforms from the catchment area follows literature values for forest; (2) domestic and industrial point sources (COD, BOD, total-N, total-P, faecal coliforms) are excluded; and (3) suspended sediment loads are representative of complete coverage of natural forest. A summary of each scenario in provided in Table 3. By comparing the total pollution loads entering coastal waters for each scenario, the following observations can be made: if the current practice of pollution management is left unchecked, pollution loads will increase by approximately 100% over the next 20 years (Scenario 1). This will have disastrous consequences upon the coastal environment. If existing guidelines and legislation are implemented and enforced, pollution loads will reduce by approximately 10–50% (Scenario 2). This is an achievable solution, which would eliminate most of the coastal water quality issues faced in Sabah. Table 3 Total loads entering coastal waters around Sabah (Borneo, Malaysia) for all scenarios; values in brackets represent percentage increase/decrease compared to existing conditions Scenario

SS (106 ton/year)

BOD (ton/year)

TN (ton/year)

TP (ton/year)

E-Coli (1012 counts/year)

Existing 1 Future 2 Guidelines 3 Pristine

19 39 (105%) 13 ( 33%) 11 ( 42%)

118 331 (180%) 56 ( 53%) 53 ( 55%)

46 68 (47%) 41 ( 10%) 24 ( 49%)

3 4 (72%) 2 ( 12%) 1 ( 49%)

871 1629 (87%) 586 ( 33%) 0 ( 100%)

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Going further, if Sabah wants to become the ‘‘world’s leading eco-tourist destination’’, pollution loads would need to be reduced by approximately 40–60% to be close to the pristine condition (Scenario 3). 8. Discussion and conclusion Through the baseline data collection and analyses as described in the above sections, a detailed understanding of the issues relating to Sabah’s coastline has been established, allowing management objectives to be set. For example, threats to mangrove forests have been identified in terms of clearing and reclamation, thus protection of mangroves can be considered a management objective. The management objectives are general in that they represent a set of alternatives for the overall study area from which specific strategies for specific areas or coastal reaches can be applied. Following the development of a list of broad management objectives, the coastline is then divided into management units whereby primary and secondary objectives are selected from this list for each unit based upon the particular characteristics of that unit. In carrying this out, extensive use of suitability mapping, threat mapping, etc. will be undertaken using GIS. For the purposes of the SMP, the preferred management objectives for each management unit will be chosen on the basis of the issue or sector given the most weighting. For example, where excellent quality coral reefs may be found near the shoreline, these will be given preferential weighting in terms of environmental protection objectives over economic objectives. Clearly there is a considerable degree of subjectivity and potential conflicts in this process, thus necessitating extensive input and feedback of the relevant government authorities, NGO’s, local community leaders and where possible, the local community. In considering management strategies for each unit, an appraisal of alternative strategies will be considered and tested against the objectives for the management unit and the preferred sustainable option selected. Testing of the management strategies will involve an appraisal of the extent to which they fulfil the primary and secondary objectives. The zoning and management strategies to be developed as part of the SMP can be regarded as an overall planning tool for sustainable development of the shoreline on a regional scale. However, many of the varying problems or issues observed during the coastline assessment arise from disregard of established laws and regulations, of which the SMP as a policy and planning tool has little control. A fairly comprehensive body of legislation to protect the environment exists [6]. But due to resource and logistical constraints the enforcement of the well-intended legislation is not preventing illegal exploitation of the natural resources. With 4328 km of coastline monitoring of the coastal waters of Sabah is both logistically difficult and economically demanding. Alternative approaches and/or increased funding and resources for the relevant authorities are required. An example of an alternative approach to monitoring and enforcement could be the local reef ownership concept proposed by Pilcher and Cabanban [18] to control blast and cyanide fishing. In this case, each village would be allowed to manage its own coastal area, including the coral reefs, to the exclusion of other villages. With such a scenario, a village that is awarded custody of nearby reefs, and understands that neighbouring villages have their own reefs and can be denied access to their reefs, enforcement of sustainability will be introduced through peer pressure. State enforcement could then be focused on monitoring

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