Proceedings of the Jakarta Workshop on Coastal Resources [PDF]

Proceedings of the Jakarta Workshop on Coastal Resources Management (UNU, 1980, 106 pages) 3. Main papers and discussions Model development for integrated utilization of land-water interactive resource systems in the coastal part of the citarum watershed Environmental problems related to the coastal dynamics of humid tropical deltas Morphogenesis of the northern coastal plain of west Java between Cirebon and Jakarta: Its implications for coastal zone management The oceanographic features of the coastal region between Jakarta and Cirebon Socio-economic studies in Java in the context of a coastal resources evaluation The mangrove ecosystem of the northern coast of west Java The marine fishery resources of the north coast of west Java The interpretability of landsat colour composite images for a geographical study of the northern coastal zone of west Java Water-quality assessment of the cimanuk watershed

Model development for integrated utilization of land-water interactive resource systems in the coastal part of the citarum watershed Chairul Muluk, Ngadiono, Koesoebiono, and Soeratno Partoatmodjo Introduction A watershed is a natural ecosystem which is separated topographically from adjacent watersheds. As a system the watershed may be divided into three sub-systems, namely the upland, lowland, and coastal sub-systems which have the following major functions: 1. the upland sub-system as the main water catchment and flow regulator, 2. the lowland sub-system as the main water distributor and water consumer, and 3. the coastal sub-system as a water-based resource system. Being connected, the condition of the resources in the coastal sub-system is affected by the resource utilization decisions made in the two upper sub-systems of the watershed Furthermore, resource utilization in the coastal subsystem is affected not only by the influx of freshwater channelled through both natural and man-made channel systems into the area, but also by the marine system. The boundary between the upland and the lowland subsystems is the "reservoir belt," which is a line connecting the lowest location above sea-level potential for reservoir constructions. The boundary between the lower and the coastal sub-systems is difficult to identify and is assumed to be the line connecting the locations potentially affected by salt intrusion. Based on the land-use in the coastal part of the Citarum watershed, four agricultural production systems, namely food and cash crop agriculture, aquaculture, animal husbandry, and forestry, can be identified. These production systems can be termed the agro-ecosystem in which land-water interaction plays an important role. Response of the agro-ecosystem is affected by the state of interaction among these four components. The output of the agroecosystem in the coastal zone is a result of the interaction of the agro-ecosystem, human resources (social, cultural conditions", and the technological and economic conditions prevailing in the area. Therefore, determining strategies to optimize resource use aimed at providing the majority of the people with basic necessities beyond their minimal sustenance level involves manipulating the agro-ecosystem, human resources, and the technological and capital inputs. Theoretical Framework In developing the coastal part of the Citarum watershed it is imperative that integrated development of three components, i.e., the agro ecosystem, human resources, and capital and technological aspects, should be achieved. Agro-ecosystem The agro-ecosystem is the agricultural production system and comprises four components: food and cash agriculture, aquaculture, animal husbandry, and forestry. Among the components, the interaction through land is a matter of competition for space, while within each component the landwater interaction may affect, adversely or Positively, its production process. However, among the components water acts as an integrator due to its ability to flow from one to the other. Besides these interactions, the possibility exists for inter-component man induced interactions (Fig. 2). Figure 1 shows the theoretically derived interactions among components. Human resources Human resources are the part of a society which has the potential or actual capability to manage available natural resources within the system to provide sufficient products and conditions to sustain or improve the livelihood of that society. The efficiency or productivity of the human resources in achieving these objectives is determined by three major characteristics, namely, the quality and quantity of the human resources, and the social institutions. Improvements in quality may be achieved through training and education, nutrition, etc. Creation of better employment opportunities and wages will increase the productivity of available human resources, while the social institutions can promote the capability to innovate and to participate in supporting development programmes (Fig. 3). Ultimately, manipulation of these activities creates better chances of achieving improvement in the quality of life and the distribution of income per capita.

FIG.1. Theoretical land - water interactions in the agro - ecosystem ( - = transferred through water; * = man - induced)

FIG. 2. The agro - ecosystem

FIG. 3. Development strategies in human resources (Hidayat 1979, modified)

FIG. 4. Theoretical interactions between the agro-ecosystem, human resources, and technology and capital in the coastal part of the Citanum watershed Technology and capital Technology applied to and capital needed in resource utilization should be relevant to conditions of the existing human and natural resources, should increase the efficiency of the activities to obtain beneficial outputs, and should minimize the harmful or non-utilizable outputs of each process. Both technology and capital may already exist as a part of the human resources or may be introduced into the system. Interaction of the major components Interactions of the three major components related to integrated development of resource utilization in the coastal part of the Citarum watershed are shown in Figure 4. This figure describes the activities or decisions in resource (agroecosystem) utilization or exploitation in obtaining products and making them available directly or indirectly to the society. It also describes the decisions or activities needed to improve the productivity of the human resource and the capability to sustain or improve the resource base, which will provide not only the society's needs but also improved environmental conditions. These decisions or activities require a certain level of input of available or introduced technology and capital. The result of interactions occurring in the system forms the output of the systems and this will affect other systems Management strategies Based on the foregoing discussions it can be stated that development strategies are aimed at improving conditions of the coastal part of the Citarum watershed. Indicators of improved conditions of the coastal part of the Citarum watershed are among others increased production and minimized waste of the agro-ecosystem, and improved social and economic levels of the society. Therefore, the development strategies are decisions or activities which will simultaneously increase production and improve the social and ecological conditions. These decisions are among others exploitation, handling, processing and recycling, distribution, regeneration, rehabilitation, conservation, education, technology and capital, protection, and aesthetics (see Fig. 4). These expressions may be formulated as follows: maximize: St = St-1 + ft (St-1 , dt) subject to dt = decisions or activities,

(social development),

(ecological development), where St = production in period t ft = function in period t dt = (d1 , d2 ,...,dn ) = vector of decision variables Description of the Coastal Part of the Citarum Watershed Introduction The coastal part of the Citarum watershed covers an area around 351 km². It forms a relatively flat area, with slopes of less than 5 per cent, the highest elevation being 2 m above sea level. Ninety-five per cent of the area has poor drainage and low water-infiltration capability. The land capability for crop production is identified as good, and the prevailing soil type (96 per cent) is alluvial. The distribution for agriculture-related land-use amounts to: agriculture:

17.5 %

forest:

46.6 %

aquaculture:

15.5 %

swamps:

17.6 %

The remaining ±3 per cent is the area used for human settlements. Based on Oldeman's classification the agroclimatic type prevailing in the area is type E, with one to two wet months (rainfall greater than 200 mm) (Fig. 5). The average annual rainfall is 1,300 mm. The water available in the area is used not only for agricultural purposes (in the broadest sense of the word) but also for domestic purposes. Aside from rainfall, the water supply is provided through channel systems from the Citarum River (Fig. 6). Specifically in the case of coastal aquaculture, sea water is provided through natural and manmade channel systems using tides as a driving factor (Fig. 7). The population density in the area is 360 persons/km², and the population (1975) is 126,404, out of which 61 per cent forms the potential labour force, composed of 44 per cent males and 56 per cent females. The average annual population increase rate, estimated from 1971 to 1975, is 2.6 per cent. Formal education is offered through general and religious primary schools. The latter are involved not only with religious and general education but also with vocational education relevant to the conditions in the area. Children can enter school from age six, but only 15 per cent of those eligible receive primary education. Rural social institutions such as village cooperative units are involved in the capital raising and technology dissemination necessary for resource exploitation, processing, and distribution activities, and also for sustaining and improving the resource base and the environmental conditions. In general it can be stated that only in the field of agriculture, through government programmes, is the application of improved technology (e.g., the use of pesticides, fertilizers, and high-yielding and pest-resistant varieties) relatively intensive. This is also true in the case of making available the capital needed to obtain the technology. However, traditional technology and capital formation institutions are already rooted in the society of the area and should be considered in development. The agro-ecosystems 1. Agriculture Rice fields, of which 68 per cent are irrigated, constitute 80 per cent of the agricultural land of the area. The land capability of the area is identified to be good for the development of cash and food-crop agriculture. However, its topography, soil conditions, and elevation cause problems in its development. Sedimentation of drainage canals causes floods during the rainy season, and makes this area unsuitable for agriculture in the following season. The area is also potentially exposed to sodium hazards. However, improvement of channels, both irrigation and drainage channels, will increase the ricefield area. In addition, the use of fertilizers and pesticides increases the annual rice production per ha from 3.3 to 4.0 T. However, the poor infrastructure in the area limits the distribution of pesticides and fertilizers. Only 24 per cent of the farmers are exposed to these inputs. Co-operative units and other institutions involved in processing and distribution of products are also involved in providing capital, pesticides, and fertilizers to the farmers.

FIG. 5. Climatic types in the downstream part of the Citarum watershed

FIG. 6. Kabupaten (County) Karawang irrigation network (1977)

FIG. 7. Types of potential aquatic resource utilization in Kabupaten (County) Karawang (1977) 2. Aquaculture The condition of the area available for aquaculture only permits the development of brackish-water aquaculture, which is also termed tambak culture. The greater part (60 per cent) of the tambak culture is executed with the tumpangsari method in the mangrove forest. Areas exposed to floods which become unsuitable for agriculture and recently accreted areas are potential areas for tambak culture. However, where improvements of irrigation and drainage channels are made, increasing the rice-field area and also areas exposed to marine erosion, the area of the tambak tends to decrease. The average annual production of the tambak ranges from 130 kg/ha to 200 kg/ha. This low productivity reflects the simple, traditional technology used and the insufficiency of both capital for proper care and seeds for the production process. 3 Animal husbandry The animal husbandry in the area involves the raising of cattle, sheep, goats, pigs, and poultry (chickens and ducks). Large animals with a density of 0.3 head/ha are mainly used as draught animals in soil preparation. Piggeries are restricted to farmers of Chinese origin, and wastes from this activity are used in dry-land food-crop cultivation. Waste and by-products from the agriculture components form the principal feed for the animals raised. Water supplies available in the area may be unsuitable for this production process, especially during dry spells. Vaccination and improvement of breed are conducted to increase the productivity of poultry and cattle. 4. Forestry Mangrove forest forms the principal forest of the area, and it provides energy in the form of firewood for the inhabitants in the surrounding area. In mangrove areas land accretion is promoted and becomes an area of conflict of interest. The local inhabitants tend to transform this area into tambak, while the Forestry Service and the local government tend to preserve the area as a forest. However, there are concessions made to the local inhabitants to practice aquaculture using the tumpangsari method. Programmes to rehabilitate and create a green belt along the shore have been established. Difficulties in implementing these programmes are caused by conflict of interest and ecological conditions inherent in certain localities (e.g., marine erosion caused by strong sea currents and wave action). Alternative Decisions in Coastal Area Development At the present stage of the study, the data base constructed from primary and secondary sources is not large enough for the important decisions on integrated utilization of the area's resources that are aimed at increasing production and improving the social and ecological conditions of the area. Therefore, the existing conditions as stated in the foregoing section and the reasoning behind the qualitative models expressed in Figures 1, 2, 3, and 4 were taken as the basis for the formulation of hypothetical decisions leading to the stated objectives. These decisions are categorized as follows: 1. Decisions within the agro-ecosystem to increase production This category includes those decisions that are based on the interactions as shown in Figure 2. Thus, examples of decisions are maximize wafer enrichment minimize eutrophication, residual effects of pesticides, and aquatic-weed infestation maximize nutrient exchange between land and water 2. Decisions related to exploitation e.g. land-use allocation for agro-ecosystems optimization of exploitation level 3. Decisions related to handling e.g. improvement of harvest and post-harvest techniques to minimize losses 4. Decisions related to processing e.g. improvement of harvested products to increase the quality and marketability of the products 5. Decisions related to distribution e.g. improvement of distribution institutions improvement of accessibility to markets 6. Decisions within the society Within this category are decisions aimed at improvement of ideas, activity, and productivity of human resources through training and education programmes improvement of health and nutrition conditions creation of employment opportunities 7. Decisions related to regeneration, rehabilitation, and conservation of the agro-ecosystem e.g. laws and regulations related to rehabilitation and conservation of the agro-ecosystem 8. Decisions related to recycling of supplementary outputs e.g. maximize recycling processes and minimize effects of wastes 9. Decisions related to protection and aesthetics e.g. laws and regulations related to the protection of the agro-ecosystems and the improvement of the aesthetics of the environment 10. Decisions for the mobilization of technology, capital, and human resources from outside the coastal sub-system e.g. laws and regulations Additional field work and data collection are necessary to a. verify the present models as presented in Figures 1, 2, 3, and 4; b. verify the above-mentioned decision categories; c. verify the type and degree of interactions existing in the area, and existing constraints. Based on this information a set of decision alternatives can be formulated as a basis for developing a model for integrated resource utilization in the area. This model should become the guideline in resource utilization which minimizes wastes and maximizes production for each time span decided, and within existing constraints. References Adiramta, E. R.;Sunarto;Said Rusli; and E, Kusumah 1971 - 1972. Penggunaan teknologi baru oleh petani padi di Kabupaten Karawang. Laporan penelitian kerjasama Badan Pengendali Binas Nasional den Institut Pertanian Bogor. Adiramta, E. R.; A. Gafur; Sujadi; and Hatomi 1971-1972. Menuju kearah diversifikasi usaha dalam Usahatani, suatu pendekatan dalam model pembangunan pertanian Kabupaten Karawang. Kerjasama Direktorat Perentjanaan den Pengembangan Direktorat Djendral Pertanian den Institut Pertanian Bogor. Anwar, A., 1969. Wilayah potensi pertanian den sumber-sumber lain Daerah Kabupaten Karawang. Laporan Survey sebagai Landasan Penyusunan Pola Dasar Pembangunan Daerah Kabupaten Karawang. Kerjasama Karawang - Institut Pertanian Bogor. __________1971. Karawang potensi pertanian dalam pembangunan regional. Proyek Kerjasama Pemerintah Daerah Kabupaten Karawang- IPB. Azzaino, Z., and Soeharnis 1969. Wilayah potensi pertanian den sumber-sumber lain Daerah Kabupaten Karawang. Laporan Survey sebagai Landasan Penyusunan Pola Dasar Pembangunan Daerah Kabupaten Karawang. Kerjasama Karawang-Institut Pertanian Bogor. __________1970. Faktor-faktor strategic jang harus diperhatikan dalam mentjiptakan pembangunan pertanian jang progresif di Lokalita Wadas dalam hubungan dengan perentjanean pembangunan Kabupaten Karawang. Suatu pendekatan decision making process dalam Lokalita. Proyek kerjasama Pemerintah Daerah Kabapaten Karawang-IPB. Birowo, A.T., and A. Gafur 1973. Peranan pertanian dalam pembangunan ekonomi daerah di Kabapaten Karawang. Laporan penelitian kerjasama Direktorat Jendral Pertanian dengan Institut Pertanian Bogor. Muluk, C.; S. T. H. Wardayo; Koesoebiono; E. Manan; D. R. O. Monintja; M. l. Effendie; and S. Sosromarsono 1976. Studi Penentuan Kriteria kualitas lingkungan perairan den biotik. Panitia Perumus den Rencana Kerja Bagi Pemerintah di Bidang Pengembangan Lingkungan Hidup. Proyek Pengelolaan Sumber- Sumber Alam den Lingkungan Hidup, Ruddle,K., and T. B. Grandstaff 1978. The international potential of traditional resource systems in marginal areas. Technological Forecasting and Social Change 11: 119 - 131. Elsevier, New York. Soewardi, B.; S. Ngadiono; Partoatmodjo; and M. Soekandar 1978. Studi pembinaan model pengelolaan wilayah Daerah Aliran Sungai. Buku I den Buku II. Panitia Perumus den Rencana Kerja Bagi Pemerintah di Bidang Pengembangan Lingkungan Hidup. Proyek Pengelolaan Sumber-Sumber Alam den Lingkungan Hidup. Soewardi,B., and Ngadiono 1979. Watershed management: an analysis through modelling. Paper presented at the Programmatic Workshop on Agro-Ecosystems in the Framework of Watershed Management, 18 - 20 June 1979, Bogor, Indonesia. Center for Natural Resource Management and Environmental Studies Bogor Agricultural University. Sumawidjaja, K.; C. Muluk; T. H. Supomo; Wardoyo; Koesoebiono; Daniel R. O. Monintja; and G. W. Atmadja 1977. Survai ekologi perikanan Daerah Aliran Sungai: aspek-aspek penyelamatan perikanan di perairan umum. Bagian Il: Daerah Aliran Sungai Citarum. Proyek Penyelamatan Perairan Umum Direktorat Jendral Perikanan. Departemen Pertanian-Institut Pertanian Bogor. Discussion Burgers: Please explain the use and ownership of these resources. Muluk: The use of water for aquaculture purposes is regulated by water resources regulations issued since the Dutch colonial period. Although disposal of waste into the water system is prohibited, we actually have no law yet. Piggeries cannot be located near the water system area due to religious reasons. On the ownership system we have land reform, which stated that one person cannot own more than 2 ha of land, but the water is public property. As you know, the accretion rate of land is very fast, particularly in the north coast of Java. The question is who owns that new land, the government or the people? Hehuwat: Accretion is rapid, and no cadastral map exists, but strictly speaking, the new land up to a certain distance inland from the coastline is owned by the government. If we apply strictly the government law on the new area, then there will be a conflict with the local people. Bird: Please explain the tumpangsari method. Muluk: It is a system where the mangrove forest and aquaculture can be in the same area, so that two crops are cultivated from the same land; a kind of multiple cropping.

Environmental problems related to the coastal dynamics of humid tropical deltas Eric C. F. Bird Deltas are numerous and extensive on coasts with humid tropical (Koppen Am) climates, partly because the high runoff resulting from heavy rainfall supplies rivers with large quantities of sediment derived from the outcrops of deeply weathered rock formations that have developed under hot, wet conditions in the hinterlands, and partly because the prevalence of low to moderate wind energy, due to relatively weak wind action over coastal waters, has permitted the growth and persistence of these protruding depositional landforms. Studies have been made of the geomorphological, hydrological, and ecological features of a number of humid tropical-zone deltas (e.g., Unesco 1966), with Particular attention to the changes, both natural and man-induced, that take place on and around them (Verstappen 1964). The present paper reviews the coastal dynamics of humid tropical deltas in terms of environmental problems that have arisen in the course of man's development and utilization of these areas. It provides a basis for investigating these problems on the extensive deltaic coast east of Jakarta, where deposition from a number of rivers, including the Citarum, the Cipunegara, and the Cimanuk, with headwaters in the uplifted steep and high ranges to the south, has built up a broad deltaic lowland, with a seaward margin consisting mainly of swampy terrain fringed by narrow sandy beaches (Bird and Ongkosongo 1980). Such deltas attained their present form during and since the Holocene marine transgression, which began about 20,000 years ago, when the sea was at least 100 m below its present level, and came to an end about 6,000 years ago with the attainment of the present stillstand. On humid tropical coasts, rapid and abundant fluvial deposition has generally offset the effects of submergence which elsewhere persist in the form of drowned valley mouths and coastal embayments. Drilling has shown that deltas are deep wedges of sediment, largely of fluvial origin, but with intercalations of marine sediment, mainly fluvial deposits reworked by waves and currents in the nearshore zone. The stratigraphy of a delta usually indicates a history of gradual or intermittent subsidence, evidently a localized isostatic response of the earth's crust to the accumulation of a large sedimentary load. Continuing subsidence, perhaps augmented by a slight rise of the world sea level, explains why sectors of deltas that are not still receiving sediment, either of fluvial origin or after marine reworking, commonly show active shoreline erosion. The internal structure and stratigraphy of a delta is of much scientific interest, and of economic importance in terms of the disposition of water-bearing, oil-bearing, or mineral-bearing formations; but in terms of environmental problems an understanding of the processes that are changing the delta surface and its seaward margins is of more practical value. Delta Dynamics Deltas are low-lying terrain, with gentle transverse gradients (a few centimetres per kilometre). River channels often divide into distributaries as they approach the sea, and distributary channels are apt to be variable in form and dimensions, waxing and waning through time, and subject to diversion and closure, especially at their mouths. The rivers carry water and sediment to the deltaic shore and out into the adjacent sea, the flow being related partly to fluvial discharge and partly to the effects of tidal action entering the river mouth and of waves and currents in the nearshore zone. In addition, the delta shoreline may be interrupted by tidal creeks, which are often relics of earlier distributary mouths cut off by deposition upstream. These inlets are subject to the regular ebb and flow of tidal sea water, but receive fluvial runoff and sediment occasionally during episodes when the delta is inundated by major river flooding. Sediment delivered by rivers is usually a mixture of sand, silt, and clay; it is carried to the river mouths, especially during floods, and deposited in the form of channel shoals and offshore bars. The sand fraction is sorted out by wave action and distributed along the shore as beaches and spits by waves and associated currents. This longshore drifting is responsible for the deflection, and sometimes the closure, of tidal creeks along the delta margin. Nearshore waters are frequently discoloured by the discharged fluvial load of suspended silt and clay, which gradually settles in calm water environments offshore, or in inlets and embayments along the coast, where it builds up tidal mudflats colonized by mangroves. The pattern of sedimentation is influenced by the positions of river mouths. Distributaries carrying a substantial sediment load develop lobes at their mouths Changes in the position of river mouths occur both naturally, as the result of deflection along the shore or diversion upstream, and as the result of engineering works. New deltaic lobes are initiated at the diverted or deflected outlet, and earlier lobes may then start to erode away. The deltaic shoreline is thus dynamic, prograding on sectors that are directly or indirectly supplied with sediment, and being cut back on sectors where the sediment supply has diminished. Studies of historical maps and charts, and successions of air photographs, in comparison with existing outlines, show the patterns of gain and loss along deltaic shorelines in the past, and can be used as a means of predicting where future changes are likely to occur. The factors that influence delta dynamics may be summarized as follows: 1. Water discharge, related to the incidence and pattern of rainfall in the river catchment. During episodes of flooding, large quantities of sediment move downstream and the salinity of water at the mouths of rivers and in the adjacent sea is diminished, while in relatively dry periods the lower reaches of the rivers may become brackish. Finer sediment, especially clay, remains in suspension in fresh water, but is flocculated and precipitated as the water becomes brackish Reduction of fluvial discharge, due to dam construction or diversion of rivers upstream, results in a diminished incidence of flooding, a reduced sediment yield, and increased salinity at the mouths of rivers. 2. Fluvial currents, generated by river discharge, scour channels in estuaries and produce patterns of shoal deposition splaying outward through the nearshore zone. An outflowing current can act as a "breakwater," interrupting the longshore drifting of sediment by waves and currents, and resulting in accretion on the updrift side of a river mouth. 3. Fluvial sediment yield, the nature and abundance of which is determined by the surficial geology of the catchment region. In the humid tropics, rock formations generally show deep weathering, due mainly to intense chemical decomposition under the prevailing warm and wet conditions. Granitic rocks and sandstone outcrops yield predominantly sandy sediment, whereas slates, shales, and volcanic rocks weather to yield silts and clays. The rate of sediment yield is a function of runoff, slope gradients, and the density of vegetation cover within the catchment. It can be increased by tectonic uplift or volcanic activity in the hinterland, or by reduction of the vegetation cover, either as the result of natural changes (landslides, bushfires, desiccation), or as the outcome of man's activities, especially deforestation and the introduction of grazing or cultivation. On the other hand, sediment yield can be reduced by the construction of weirs or dams that impound river water and trap sediment, or by the diversion of rivers into canal systems which disperse the sediment load. An increase in sediment yield from rivers is followed by coastal accretion, shallowing the nearshore zone and prograding the deltaic shoreline, while a decrease results in nearshore deepening and shoreline erosion. It should be noted that the sediment accumulating on a deltaic shoreline may include material carried in by wave action from the sea floor (the bulk of which is reworked fluvial sediment derived from preceding episodes of floodwater discharge) and material brought along the coast by longshore drifting from adjacent sectors (such as cliffed headlands or eroding coastal plains). 4. Nearshore processes include the rise and fall of tides and currents associated with these movements, wave and current action generated by winds over coastal waters, and swell waves of distant origin which may reach the deltaic coast. Where the tide range is large on deltaic shores, broad inter tidal flats are exposed at low tide, and the associated strong tidal currents shape a complex shoal and-channel topography in estuaries and across the nearshore zone; wave effects are diminished, and shorelines develop an intricate, highly indented configuration, as on the shores of the Irrawaddy Delta, where the spring tide range attains 6 m. On most humid tropical deltas the tidal range is much smaller, and these features are less well developed. Wave action is important, first in sorting the sediment by dispersing silt and clay and concentrating the sand fraction in the nearshore zone, and then in carrying it shorewards and distributing it alongshore as beaches and spits. The outcome is a smoothing of the outline of the delta shore. Associated current action transports the finer sediment, silt and clay, until it reaches calm water, where it is deposited on shoals or in sheltered inlets and embayments. 5. Shore vegetation, especially mangroves, which colonize the upper inter tidal zone on sectors of shoreline that are sheltered from strong wave or current scour, promote sedimentation and the accumulation of organic materials to stabilize the backshore in the form of a depositional terrace. Mangroves also colonize intertidal shoals in estuaries, building them up as depositional islands that divide the channel into distributaries. They readily colonize muddy substrates, and can also grow on stable sandy terrain within the upper inter-tidal zone; they are adapted to tidal conditions, each species showing variations in tolerance of depth and duration of submergence, substrate mobility, and salinity. Where a sediment supply is sustained, mangrove encroachment advances the shoreline and reduces inlets and embayments until the residual tidal creeks become well defined, and often deeper. Such encroachment is usually marked by a successional zonation of mangrove species, followed by a fresh-water swamp forest to the rear as sedimentation builds up the substrate to the limits of tidal submergence. Where the sediment supply is reduced, mangroves cease to spread, and may die back or be eroded away as nearshore waters deepen and the shoreline begins to retreat. If the mangrove fringe is cleared away by man, either to obtain timber and associated products or to establish access for boat landings, erosion of the previously deposited sediment ensues. 6. Changes in kind or sea level may result from subsidence of the delta region due to isostasy or the compaction of sediments (especially peats) within the delta, to tectonic movements such as warping or tilting of the delta region, or to eustatic rise or fall of the world's ocean surface. Submergence impedes the growth of a delta, reducing the extent of depositional gains and initiating or accelerating shoreline erosion. Most deltas are subsiding, but if emergence occurred, as the result of localized tectonic uplift for example, shoreline progradation would be accelerated, and channels within the delta would become incised. Environmental Problems These geomorphological, hydrological, and ecological processes give rise to a number of problems for the people who develop and utilize land and water resources on deltaic coasts. In the humid tropics, most deltas have been intensively modified to sustain large human populations, and the problems of natural or man-induced coastal change are often severe. Some key problems are listed: 1. Coastal erosion results in the loss of important resources such as the mangrove fringe, used as a source of timber and fuel and as a habitat from which fish, birds, and crustaceans may be obtained. As erosion proceeds, productive systems such as brackish fish ponds and rice fields, developed where former swampy terrain has been reclaimed, are invaded by the sea and rendered useless. Villages built immediately behind the beach are damaged, and must be relocated as the coastal terrain is cut back. Eventually, continuing erosion intersects and destroys older beach ridges and cheniers on which settlements and areas of dry-land crop cultivation have developed. As has been noted, such erosion is usually either the outcome of a change in the position of a channel mouth, or a reduction of fluvial sediment yield following construction of dams and weirs, or canals upstream. Attempts to halt shoreline erosion by building sea walls along the shore, or by putting in groynes in the hope of retaining a protective beach, are of little value. Suitable stone or concrete materials are rarely available, and wooden structures are soon washed away. As shoreline recession is the outcome of a progressive deepening of nearshore waters, and consequently an increase in the size of breaking waves, only very massive and expensive structures could maintain such a shoreline once this erosion has started. It is important to avoid actions likely to initiate erosion, such as clearance of the seaward fringe of mangroves or the dredging of nearshore areas, and to be aware that such upstream activities as weir and dam construction, the dredging or diversion of river channels, the building of artificial river levees to restrict flooding, or the excavation of canals for transport, drainage, or irrigation purposes, may initiate or accelerate shoreline erosion and produce environmental problems on the delta coast. Some of these activities may lead to progradation elsewhere, forming new coastal land to offset the losses by erosion, but this is not always the case, and where it is, the transference of settlements and agricultural/ aquacultural systems from an eroding to an accreting area raises many practical as well as social problems. 2. Coastal deposition is a much less serious problem but it can have adverse effects for fishing communities based on the shoreline, and may impede navigation. It may be difficult to maintain sea-water inflow to brackish fish ponds where deposition shallows or seals the mouths of river channels and tidal inlets, and behind prograding sectors the fish ponds may have to be abandoned or converted to other uses as they become more remote from the sea water supply. 3. Channel changes on estuaries and tidal inlets include lateral migration, which poses problems for riverside communities whose villages and farmland are undermined, and shallowing by sedimentation, which may lead to bank erosion to maintain the cross-sectional area necessary to conduct downstream flow. Shallowing also impedes navigation, and may diminish fishery resources. 4. Salinity regimes are determined by the interaction of freshwater runoff and sea incursion, and have effects on sedimentation and the ecology of shore and nearshore organisms. Changes in the salinity regime occur when fluvial discharge is modified, or when the pattern of river mouths and tidal creeks alters. Such changes are followed by ecological responses in coastal vegetation and animal communities, including fisheries. An increase in salinity in the lower reaches of rivers can be damaging to rice fields, pastureland, and fresh-water vegetation; it can spoil the water supply available for domestic and irrigation purposes; and it may lead to the development of an excessive salt content in brackish fish ponds. A reduction in salinity is less harmful, since it results in a seaward migration of ecological zones, but it might raise problems in maintaining a sea-water supply to brackish fish ponds. 5. Coastal hazards are particularly severe on deltas, because it is difficult on low-lying terrain to escape the effects of storm surges, tsunamis, and river flooding, which frequently kill many people and animals and damage or destroy buildings and other structures, farmlands, and fish ponds. In addition, control of pest and disease organisms is often difficult on deltaic coasts, particularly where they occupy habitats (e.g., mangrove swamps) that should be conserved for shoreline protection or as a nursery for fish and crustaceans. Man-made hazards include water pollution, especially in the vicinity of ports and industrial areas, and the effects of toxic chemicals, which are introduced to farmed areas to control pests and diseases in crops and which become adverse if they pass into estuarine and nearshore fisheries and brackish fish ponds. The possibility of a sea-level rise due to the warming of the world's climate (e.g., by the melting of arctic ice as a consequence of large-scale river diversions in Siberia) would have drastic effects on all deltaic coasts. In northern Java a sea-level rise of 1 or 2 m would permanently submerge the brackish-water fish ponds and lead to salinization of ricefield areas to landward. The loss of habitable land and agricultural productivity would be severe in terms of living standards in this region. Conclusion There is thus a wide range of environmental problems related to the coastal dynamics of humid tropical deltas dynamics which, in turn, are the outcome of an interacting system of geomorphological, hydrological, and ecological processes. This system has been greatly modified by man's activities in these densely populated and intensively utilized deltaic regions. An understanding of the dynamics of humid tropical deltas is necessary as a basis for coastal management and land use strategies designed to maintain the productivity of these areas, and to provide the information needed to solve the environmental problems that have arisen. This Programmatic Workshop and Training Course aims to promote this understanding, and to initiate research on the dynamics of the coastal fringe of a Javanese delta. References Bird, E. C. P., and O. S. R. Ongkosongo Environmental changes on the coasts of Indonesia. UN University. (In preparation.) Unesco 1966. Scientific problems of humid tropical zone deltas and their implications. Proceedings of the Dacca Symposium, p. 422. Verstappen, H, T. 1964. Geomorphology in delta studies. 1. T. C. Publications, B 24, Delft, p. 24. Discussion Collier: On several ports of the Java deltas, tambaks are being constructed on the mudflats as soon as they accumulate, before they are colonized by vegetation. What effects could this have on delta dynamics? Bird: Unvegetated delta shores are less stable than those with a mangrove fringe. I would expect these tambaks to suffer storm damage, and to be readily eroded away if there is a change in river mouth positions.

Morphogenesis of the northern coastal plain of west Java between Cirebon and Jakarta: Its implications for coastal zone management P. E. Hehanussa and F. Hehuwat Introduction Geomorphologically, the province of West Java can be divided into three zones: the northern coastal plain, the volcanic backbone, and the southern coastal area. There is not much coastal plain on the south coast, the land-sea boundary usually being represented by cliffs or hilly to mountainous country rising directly from the sea. The area is sparsely populated. The volcanic backbone, forming the mountainous part of the island, represents the results of volcanic activity throughout the Quaternary, which was characterized by continuous shifting of the eruption centres. Consequently, a number of volcanic belts can be distinguished, active at different stages of Quaternary history. Interspaced with the volcanoes, a number of plains of different origin can be distinguished, the most conspicuous being those which represent former intramontane lakes (the plains of Bandung and Cianjur). Population density varies a great deal in the volcanic province, ranging from very dense in the intra-montane plains to sparse in the rugged mountainous parts. At least half of West Java's population occupies the northern coastal plain, which represents slightly less than one-third of the total land area of the province. In the discourse to follow, an analysis of the morphogenesis of the coastal plain is attempted and its implications for the development efforts of the area are discussed.

FIG. 1. Shallow groundwater distribution in West Java

FIG. 2. Coastal development in West Java (Arrows indicate accretion, dots indicate abrasion) The Northern West Java Coastal Plain Physiographically, the coastal plain can be divided into: 1. the alluvial plain, which also includes the upper deltaic plain, and 2. the coastal plain, in which we distinguish deltaic and inter-deltaic regions. The landward limit of salt water intrusion can be used as a division between the two units (Fig. 1), although they grade into each other. As the tidal range along the northern coast of Java is generally less than 1.0 m, the configuration of the coastal plain has been, for the larger part, determined by the main fluviatile systems in the area. Superimposed upon these alluvial processes were the effects of eustatic movements and the regional geological structure, which, for the most part, reflects the underlying Plio-Pleistocene structural grain, of which some elements continued to be active in Recent times (Hehuwai 1972). The main rivers debouching into the Java Sea in the area between Cirebon and Jakarta are from east to west: the Cimanok, Cipunegara, Citarum, Ciliwung, and Cisadane. The result of the interaction between the riverine and the marine systems has resulted in a coast which is generally prograding at rates varying from a mere 3.6 m per year for the Angke distributary of the Ciliwung, to an astonishing 204.0 m per year for the Cimanuk Delta (Fig. 2). The coastal types indude the deltaic areas which can be divided into distributary lobes or fans and inter-distributary bays, and the inter-deltaic areas, in which we can distinguish between straight barrierbeach stretches and the embayments. Stratigraphy of the Northern West Java Coastal Plain Detailed investigation of the Quaternary stratigraphy of the coastal plain is still lacking, but a preliminary stratigraphic subdivision based on water-well logs has been established for the Jakarta artesian basin (Soekardi and Koesmono 1973), in which nine lithologic units have been distinguished (Fig. 3). The division was made using key horizons (clay layers, quartzsand beds, etc.), marine fossil fragments, and groundwater characteristics as the distinguishing criteria. The thickness of the Quaternary in the Jakarta artesian basin generally exceeds 250 m and locally it exceeds 300 m. Attempts have been made to correlate the stratigraphic units with the eustatic rise and fall of the sea level during the Pleistocene, but in the absence of radiometric dates, these attempts are not too reliable. Three main sediment assemblages make up the Quaternary section of the coastal plain, namely: 1. marine sediments, consisting of greenish to bluish grey clay, quartz sand and black sands, and mica-rich sands, all frequently associated with fossil fragments; 2. fluviatile sediments, ranging from conglomerate to clay, whereby the finer sediments are sometimes carbonaceous; and 3. volcano-clastic sediments. Some of the marine intervals can be correlated over large distances, giving the impression that these intervals are associated with widespread transgressive events. Recent Sedimentation To get a better understanding of the mechanisms and processes involved in the formation of the coastal plain, studies in recent sedimentation have been carried out in the Cimanuk Delta area (Hehanussa etal. 1976) and in Jakarta Bay (Siregar and Hadiwisastra 1977). Cimanuk Delta Based on the Ethology and faunal content (mainly foraminifera and ostracods) a number of units can be distinguished, namely (Fig. 4): 1. 2. 3. 4. 5.

the "chenier-plain" sands, associated with the deltaic system, the "barrier-sands" of the interdeltaic region, the "mouth-bar" sands, the "inter distributary bay" and "delta-front" silts, and the "pro delta" clays.

The faunal assemblage does not reflect only the Ethology of the sub-stratum; it is also dependent on such factors as salinity, water depth, I;ght penetration, and temperature. The palaeontological and lithological data obtained from this study have been used to assign a facies interpretation to the sedimentary sequences encountered in water-well logs of the region,

FIG. 3. Stratigraphic division of Jakarta artesian basin

FIG. 3. Stratigraphic division of Jakarta artesian basin - continue

FIG. 4. Depositional environments in the Cimanuk Delta

FIG. 5. Biotope distribution in Jakarta Bay, January 1976 1. Embayment biotope 2. Transitional biotope 3. Open shelf biotope Jakarta Bay The study of Jakarta Bay proceeded along the same lines as the Cimanuk Delta study, but it was confined to the offshore area. This study also had an additional objective, which was to examine changes in the nearshore environment as a result of different climatic conditions (rainfall and wind direction). Two main biotopes have been distinguished in Jakarta Bay, the "open shelf" and the "embayment" biotopes (Fig. 5), and during the rainy season it is possible to distinguish between an "inner" and an "outer" embayment biotope (Hehuwat 1977). Environmental Implications From the foregoing discussions it can be seen that the coastal plain of northern West Java was formed by prograding sediments of deltaic and inter-deltaic facies. The spatial arrangement of the various facies is the resutt of a preexisting geologic structural grain, upon which there has been a delicate interplay between the river and the sea systems. Any man-made alteration such as the destruction of the mangrove forest, the dredging of sand from the river channel or from the beach, or the building of structures will disrupt the existing balance. This can result in a coastal plain in which different lithologies ( with different physico-chemical characteristics) are in juxtaposition in both the horizontal as well as the vertical sense. Development of such an area should take into account all these factors. We will here focus on two aspects, groundwater and soil/ sub soil characteristics. Groundwater The Jakarta artesian basin produces groundwater from aquifers at different depths. According to their depth of occurrence we can distinguish the following categories of aquifers (Soekardi and Purbo-Hadiwidjojo 1979): A-up to 60 m, B-between 60 - 150 m, C-between 150 - 225 m, D-exceeding 225 m.

FIG. 6. Salt water encroachment in the Jakarta artesian basin

FIG. 7. Piezometric surfaces of wells in the Jakarta artesian basin Groundwater is only produced from the aquifers A, B, and C, as the water of category D is usually mineralized. Each category furthermore has its own groundwater characteristics: Category A: salty north of a line that runs from Tanah Abang to Klender; south of this line the content of Fe and Mn is rather high, usually exceeding 0.3mg/l. Specific capacity varies between 50 - 100 I/minim drawdown. Category B: better quality groundwater, but with a high organic content, in excess of 10 mg/l. Specific capacity is small, and varies between 30 - 70 I/min/m drawdown. Category C: the most important water producer; quality in general is good and the specific capacity is between 50 - 100 I/minim drawdown. It has been estimated that the groundwater potential of the Jakarta artesian basin amounts to 39 million m³ per year, but there are indications that the actual production exceeds the sustainable yield. It has been estimated that the groundwater potential of the Jakarta artesian basin amounts to 39 million m³ per year, but there are indications that the actual production exceeds the sustainable yield. Excessive utilization of this resource results in salt-water encroachment and the lowering of the piezometric surface (Hehanussa 1979). Before the Second World War, salt water was only encountered in wells in the coastal zone at depths of less than 60 m, while today, aquifers of the B category are known to produce salt water (Fig. 6). A notable lowering of the piezometric surfaces can be observed from aquifers in the B and C categories (Fig. 7). In the foreseeable future this deterioration is bound to continue, because of the continuing decline of forest cover in the hinterland, the extension of the wet-rice-field acreage, and the spread of urbanization of Jakarta southward, all of which will result in diminished recharge of the aquifer system.

FlG. 8. Engineering geologoc man of Jakarta-Bogor area Engineering aspests The different mechanisms of sedimentation which created the coastal plain of northern West Java gave rise to different subsoil characteristics, as is shown on the engineering geological map of the Bogor-Jakarta area (Fig. 8). These varied characteristics, as well as the availability of building material, should be taken into consideration in the planning of the infrastructure development of the area. Summary The coastal plain of northern West Java was formed through the progradation of sediments carried by the rivers debouching into the Java Sea. The resulting patterns of sediment distribution are attributed to the interplay between the riverine and the marine systems. The whole process took place blanketing a Plio-Pleistocene unconformity surface, of which some of the structural elements continued to be active in Recent times. To understand the spatial relationships of the sediment assemblages in both horizontal and vertical senses, studies in Recent sedimentation have been carried out in the areas of the Cimanuk Delta and Jakarta Bay. The genetic history of the coastal plain has profound implications for the development of the area and the ,management of its resources. The repercussions on groundwater resources and civil engineering aspects have been discussed to serve as examples. References Hehanussa, P. E.,1979. Penyusupan air laut ke dalam cekungan artois Jakarta (Saltwater encroachment in the Jakarta artesian basin). Paper presented at 5th Ann. Conv. Indon. Geol. Assoc. ________; S. Hadiwisastra; and St. Djoehanah 1976. Sedimentasi delta baru Cimanuk (Sedimentation in the new Cimanuk Delta). Geol. Indon. 311):21 - 35. Hehuwat, F., 1972. The significance of zircon and rutile distribution pattern on the Sunda shelf. UN ESCAP Rept. 9th Session CCOP, pp.164 - 1 71. ________1977 Penyebaran biotop foraminifera Teluk Jakarta berdasarkan analisa "cluster" (The distribution of foraminiferal biotopes in the Bay of Jakarta based on cluster-analysis). Hiset Geol. Pertamb. 1 (1):1 - 3. Sireger, M. S., and S. Hadiwisastra 1977. Penyelidikan sedimen Teluk Jakarta (Investigations on the sediments of the Bay of Jakarta). in Teluk Jakarta: sumber daya, sifat-sifat oseanologi serta permasalahannya. Lembaga Oseanologi National-LIPI Jakarta, pp.107 - 137. Soekardi and M. Koesmono 1973. Pengamatan neotektonik den morfogenesa di daerah daratan Jakarta (Neotectonic and morphogenetic observations in the Jakarta area). Unp. Rept., Geol. Survey of Indonesie, no.1799. Soekardi,R., and M. M. Purbo-Hadiwidjojo 1979. Cekungan artois Jakarta (The Jakarta artesian basin). Geol. Indon. 2 (1): 25-28. Discussion Muluk: Are you suggesting that the plan for Cengkareng Airport is wrong? Hehuwat: No, but they have to consider the deeper geological structure of this area, in relation to other possible uses of the site. Koesoebiono: What factors increase the salinity of tambaks? Hehanussa: The problem of increased salinity in the tambaks may partly be due to the encroachment of saline water from below.

(introductory text...) Oceanography Geology Biology Introduction The present paper presents a description of the oceanographical features of the coastal zone between Jakarta and Cirebon. From the outset it has to be stated that the paper is not intended to be an exhaustive source of information concerning the oceanography of this region. Rather it is a brief report of the facts and figures of the physical, chemical, biological, and geological parameters that describe its oceanographical features. Research has been done on the coastal and land geology of the area, but not much has been done on its marine physics, chemistry, and biology. Therefore of necessity the present report contains mostly inferences and interpolations drawn from the oceanographical knowledge available on the adjacent areas, specifically the Java Sea and Jakarta Bay. The paper consists of three sections: "Oceanography" prepared by A. G. Ilahude, "Biology" prepared by D. P. Praseno, and "Geology" prepared by Otto S. R. Ongkosongo. It is hoped that the paper may serve as the basis for discussion of the oceanography of the region.

Oceanography A. G. Ilahude The Monsoons Situated between two continents and two oceans, and straddling the equator, the Indonesian archipelago is an ideal place for the development of the monsoon. The low atmospheric pressure of the equatorial trough crosses the equator twice a year in accordance with the shifting position of the sun in respect to the equator. During the northern summer a low atmospheric pressure area is formed over Asia as an extension of the equatorial trough while over Australia a high pressure area is formed as an extension of the subtropical high. Between the low and the high, the monsoon winds develop, in which the air flows from Australia to Asia. During the northern winter the reverse is the case (Wyrtki 1961). During the northern summer the direction of the winds is east and southeast south of the equator, south on the equator, and southwest north of the equator. The wind speed is generally 25 to 40 knots. This period is called the southeast season, and the monsoon is called the southeast monsoon in Indonesia. During the northern winter the wind reverses its direction to become north and northeast north of the equator, north on the equator, and northwest south of the equator. The speed is 30 to 45 knots. The period and the monsoon are called the northwest season and the northwest monsoon, respectively. Between the two seasons, transition periods develop in which the direction of the wind is variable and the speed is weak. In the Java Sea, to which the coastal region between Jakarta and Cirebon belongs, the northwest monsoon is usually accompanied by heavy rainfall, and is therefore called the rainy season, while the southeast monsoon is called the dry season. The terms "east monsoon" and "west monsoon" are sometimes used in place of "southeast monsoon" and "northwest monsoon." The monsoons are capable of creating and maintaining surface sea currents in the Indonesian archipelago. This is because of the following factors: (1 ) the wind is steady, and (2) the axis of the wind more or less coincides with the axis of the seas formed by the South China Sea, Karimata Strait, Java Sea, Flores Sea, and Banda Sea. Thus in the Java Sea the surface currents flow to the east during the northwest monsoon and to the west during the southeast monsoon. The velocity of the current is 25 - 38 cm/see during the northwest monsoon and 12 - 25 cm/see during the southeast monsoon (Wyrtki 1961). During the transition periods the currents are variable and relatively weak. In the coastal region between Jakarta and Cirebon the velocity of the currents generally varies from 5 - 40 cm/sec. Several observations in Jakarta Bay have indicated that the direction of the currents is basically in accordance with the directions of the monsoon. Apart from the monsoon, the current direction is also affected by the land and sea breezes, and its speed is influenced by the tides. The current direction tends to deviate away from the coast during the land breeze and toward the coast during the sea breeze. The current speed is usually stronger during the rise and ebb of tides, and weaker during the time of high and low water (Anonymous 1975). The coastal currents may also be affected by the coastline and the bottom topography, but so far no study in this area has been carried out. Tides and Waves Observation of tides in Jakarta Bay indicates that in this region they are diurnal, with one high water and one low water daily. The F (Form zahl) value is generally higher than 3; that is, around 4.9. The tidal range varies between 27 and 97 cm. The rate of occurrence of a tidal range greater than 50 cm is 86 per cent while that for a tidal range less than 50 cm is 14 per cent. The amplitude and phase of the major component of tides, standardized against the 0 hour (West Indonesia Time) are as follows (Anonymous 1975): Component

Amplitude (cm) Phase (degree)

M2

5.51

6.37

S2

2.68

-60.74

N2

1.18

32.90

K1

28.34

-21.75

O1

11.80

-86.98

M4

0.46

-41.06

The moon's influence on tides is observed mainly in tidal heights, the greatest range occurring during maximum lunar declination. Also in these regions the predominant diurnal tide may become mixed near minimum lunar declination (Anonymous 1972). The tidal currents are generally weak, and merely strengthen or reduce the speed of non-tidal currents. Therefore they are only perceptible during the transition periods between monsoons, when the prevailing current systems are not fully developed (Anonymous 1972). The velocity of tidal currents is believed to vary between 5 and 85 cm/see with the direction north and south in the Cirebon area, and west-northwest and east-southeast in the area between Tg. Krawang and Tg. Indramayu (Anonymous 1979). Observation of waves in Jakarta Bay shows that wave characteristics (wave height H, wave period T, and wave wave-length L) in both northwest and southeast monsoons are determined by the wind velocity. These characteristics increase with increasing wind velocity. The values observed for the Jakarta Bay area are 1 - 10 dm for wave height, 1 - 8 sec for wave period, and 1 - 21 m for wave wave-length. The direction of waves is dependent on the direction of the wind only for the offshore area. Close to the shore, the wave usually arrives perpendicular to the coastline due to refraction across the shallowing sea floor (Anonymous 1975). Temperature The water temperature in the coastal area between Jakarta and Cirebon is high, as it is in ail tropical regions. It ranges between 27.1° and 29.7°C, with two maxima and two minima annually. The primary maximum with a temperature of 29.1 29.7°C is generally found in April or May, the months of the first transition monsoon. The secondary maximum with a temperature of 28.6 - 29.2 C occurs in October or November, the period of the second transition monsoon. The primary minimum temperature of 27.4 - 28.2 C is usually found in December or January, during the northwest monsoon, while the secondary minimum of 27.5 28.3 C occurs in August, during the southeast monsoon. In exceptional cases the temperature may reach a highest value of 30.5°C or a lowest value of 26.5°C. The water temperature is about equal to the air temperature at sea level, which also has two maxima and two minima annually. The winds that flow during the monsoons influence the water temperature greatly. Similarly, rainfall during the northwest monsoon and evaporation during the southeast monsoon also reduce the temperature of the water. This is true not only of the coastal region between Jakarta and Cirebon, but also of the whole Java Sea (Whyrtki 1957). In the Jakarta Bay area, Arief (unpublished) found a similar annual course of surface water and air temperatures. In addition he also found the temperature in Jakarta Bay, which can be considered to be representative of the whole coastal zone between Jakarta and Cirebon, to be 0.8 C higher than in the open Java Sea. Thi's is believed to be due to the landmass effect of Java. Muluk et al. (1976) reported that the water temperature in the main river of Citarum is 26.0 - 28.0°C during the rainy season of the northwest monsoon and 27.0 - 30.0°C during the dry season of the southeast monsoon. In the tributary rivers of the Citarum, the temperature is 26.0- 27.0 C and 29.0 - 30.0°C, respectively. Salinity The salinity in the coastal area between Jakarta and Cirebon generally varies between 31.0‰ and 33.0‰. Due to the influence of the high salinity of the Pacific waters that come to the region through the South China Sea in the northeast monsoon and through the Flores Sea in the southeast monsoon, two maxima and two minima of salinity are usually observed in this region annually. This information is inferred from the papers of Soeriaatmadja (1956) and llabude et al. (1975). The primary maximum, with salinity value of 32.5 - 33.0 %o, is usually found in November, due to the mixing of the coastal water with Flores Sea water of around 34.2%o, brought to the region by the southeast monsoon current. This maximum is also strengthened by the dryness of the monsoon in this period. The secondary maximum usually occurs in May, with salinity 31.7 - 32.0 %o and is due to the mixing of the coastal water with the South China Sea water of around 32.5‰ salinity. The primary minimum, usually found in February with salinity value of 30.6 - 31.0%o, is caused by the heavy rains that occur during the northeast monsoon. The secondary minimum with value of 31.0 - 31.4%o is usually found in July and is due to the influence of the low-salinity water mass of 31.0 - 31.8%o formed by the mixing of sea water with the river water from South Kalimantan. The formation of this low salinity is discussed by Sjarif (1959). Apart from the seasonal factor, the salinity in the coastal region between Jakarta and Cirebon is also influenced by the river drainage, especially in Jakarta Bay. In front of the river mouths within this bay, the surface salinity can be as low as 15 %o ( llahude and Soepangat 1977). In the various depositional environments in the Cimanuk Delta, Hehanussa etal. found that salinity varies between 22.1 and 38.9 ‰. Most of the values lie between 30.0 and 33.7 ‰. In the rivers themselves the salinity is usually low. Muluk et al. (1976) found the salinity in the main flow of the Citarum River to be 0 to 0.5‰ during the rainy season and 0 to 31.0 ‰ during the dry season. A. J. van Bennekom and R. de Vries "Personal communication) found salinity values of 3.4 %o for the Ciujung River and 1.8 %o for the Cilontar River. Seston Measurements on seston (suspended particulate matter) have also been carried out in the coastal area and in the rivers of West Java. Nontji and Soepangat (1977) found the value of seston in Jakarta Bay to be 13.1 - 186.49 mg/l near the river mouths and 5.0 - 19.4 mg/l in the offshore areas. They found that the value of seston has a high negative correlation with the salinity of the water. The seasonal variation of rainfall on land may also cause variation of the seston concentration in Jakarta Bay. In the river water, Muluk et al. (1976) reported the values of 95 342 mg/l during the rainy season and 27 - 30 mg/l during the dry season in the Citarum River. A. J. van Bennekom and R. de Vries (personal communication) reported the value of 270 mg/l and 350 mg/l, respectively, for the Ciujung and Cilontar rivers, West Java, during the rainy season (December 1978). Dissolved Oxygen and pH Edi Legowo (unpublished) has reported the result of LONLlPl's observation on dissolved oxygen in Jakarta Bay. He found that the oxygen concentration during the northwest monsoon varied between 4.08 and 4.83 ml/l and in the southeast monsoon varied between 3.14 and 5.35 ml/l, the average values being 4.46 and 4.45 ml/l, respectively. The dissolved oxygen varied between 4.46 and 5.21 ml/l in the northwest monsoon and 4.42 and 4.58 ml/l in the southeast monsoon, with the average values of 4.62 and 4.51 ml/l, respectively. The percentage of oxygen saturation was 96.3 per cent for the northwest monsoon and 98.7 per cent for the southeast monsoon. Supersaturation values from 110 - 120 per cent were usually found during the southeast monsoon. Muluk et al. (1976) found dissolved oxygen in the Citarum River to vary between 1.4 and 4.8 ml/l with percentage saturation of 19.1 to 61.9 per cent. The pH in Jakarta Bay was found by Santoso et al. (1977) to be 7.5 - 8.2 near river mouths, and 7.9 - 8.2 in the offshore area, which is considered normal. In the Citarum River the pH value ranges between 6.2 and 7.7 (Muluk et al. 1976). Trace Elements Studies of water quality have also been carried out in the coastal region of West Java (Table 1). The results indicate that for certain elements, such as lead, copper, and mercury, the sea water has a larger concentration than the river water. Santoso et al.., using the criteria of the U.S. Federal Water Pollution Control Administration of 1968, decided that this concentration is larger than the standard set by the Administration. They believe that the high concentration of trace elements in Jakarta Bay is due to the outflow of industrial wastes and that such high concentration can have a deleterious effect on the marine organisms in the region. Table 1. Values of Trace Elements in the Coastal Region between Jakarta and Cirebon Elements

Author and Locality

Santosa et al. 1977

Jakarta Bay

Muluk et al. 1976

LON-LIPI*

Citarum River

Jakarta Bay

River mouths

Offshore

Pb mg/l

0.14 - 0.32

0.14 - 0.26

tr-0.03

-

Cu mg/l

0.02 - 0.10

0.02 - 0.08

tr-0.04

0.36 - 3.00

Fe mg/l

-

-

0.29 - 1.50



Zn mg/l

-

-

tr-0.25

0.24 - 0.65

Cd ug/l

tr** - 4.00

-

tr-6.00

-

Hg ug/l

0.15 - 0.75

0.25 - 4.25

tr -1.00

-

Co ug/l





5.40 - 17.10

-

* LON-LIPI = National Institute of Oceanology, LIPI (unpublished data) **tr= trace Table 2. Values of Nutrients in the Coastal Region of West Java Author and Locality Nutrients

Santoso et al. 1977 Jakarta Bay, mg/l

Muluk et al. 1976

van Bennekom & de Vries (personal communication)

LON-LIPI

Citarum River mg/l

Ciujung and Cisadane rivers, mg/l

Jakarta Bay mg/l

River mouths

Offshore

Phosphate

0 - 0.42

0 - 0.49

0.02 - 0.21

0.01 - 0.12

0 - 0.02

Nitrate

0-0.22

0 - 3.10

tr-0.08

0.10 - 0.23

0 - 0.03

Ammonia

0-tr

0-tr

tr-0.09

0.02 - 0.06

-

Silicate

-

-

0.40 - 46.25

15.8 - 21.00

0 - 0.42

The Nutrients The concentration of nutrients of the sea water, consisting of phosphate-phosphorus, nitrate-nitrogen, and silicate-silicon, has been studied by LON-LIPI in various Indonesian waters, including the Jakarta Bay area. The results of this study show that the nutrient values generally vary from 0-0.02 mg/l for phosphate, 0 - 0.03 mg/l for nitrate, and 0 - 0.42 mg/l for silicate (Table 2). The concentration of nutrients is very much affected by the fresh-water drainage from the land, and therefore it varies seasonally, the high concentration usually being found during the rainy season of the northwest monsoon. Measurements of nutrients in the river water indicate that the rivers have higher concentrations of nutrients than the sea. For example Santoso et al. (1977) reported values of 0 - 0.42 mg/l and 0 - 0.22 mg/l for phosphate and nitrate, respectively, for the river mouths in Jakarta Bay. Muluk et al. (1976) found the concentration of 0.02 - 0.21 mg/l, trace-0.08 mg/l, and 0.40 - 46.25 mg/l for phosphate, nitrate, and silicate, respectively in the Citarum River, while van Bennekom and de Vries (personal communication) found the values to be 0.01 0.12 mg/l, 0.10 - 0.23 mg/l, and 15.8 - 21.00 mg/l for phosphate, nitrate, and silicate, respectively, in the Ciujung and Cisadane rivers (Table 2). References Anonymous 1972. Kepanduan bahari untuk Djawa, Direktorat Hidrografi Angkatan Laut Rl. Djakarta. 537 p. _________1975. Laporan hasil penelitian terhadap arus, gelombang, sedimentasi den pasang surut di perairan pantai Marunda. Lembaga Oseanologi Nasional, 63 P. _________1979. Daftar arus pasang surut. Jawatan Hidro-Oseanografi Angkatan Laut Rl,Jakarta: 1 - 130. Arief, D., Keadaan suhu permukaan air laut den suhu udara di perairan Teluk Jakarta. Teluk Jakarta: pengajian fisika, kimia, biologi den geologi, 1975 - 1979. (In preparation for publication.| Ilahude, A. G.; D. P. Praseno; O. H. Arinardi; den A. Nontji 1975. Peta oseanografi hasil pelayaran selama Pelita I 11969 - 1974). In A. Soegiarto den S. Birowo (eds.), Atlas oseanologi perairan Indonesia den sekitarnya. Lembaga Oseanologi Nasional-LIPI Jakarta Buku No. 2:1 - 32,483 charts. Ilahude, A. G., and 1. Soepangat 1977. Pengamatan hidrologi di Teluk Jakarta, Januari 1977. Monitoring Teluk Jakarta, Laporan Pelayaran No. 6 Lembaga Oseanologi Nasional-LIPI, Jakarta 9 - 41. Ilahude, A.G.; I Soepangat; den P. Sianipar 1978. Pengamatan hidrologi Teluk Jakarta, Januari 1978. Monitoring Teluk Jakarta, Laporan Pelayaran No. 10. Lembaga Oseanologi Nasional-LIPI Jakarta: 6 - 43. Legowo, Edi, Oksigen di permakaan perairan Teluk Jakarta. Teluk Jakarta: pengajian fisika, kimia, biologi den geologi, 1975- 1 979. (In preparation for publication.) Muluk, C.; Koesoebiono; S. T. H. Wardojo; D. R. O. Monintja; M. I. Effendie; and S. Sosromarsono 1976. Study penentuan kriteria kualitas lingkungan perairan den biotis. Proyek Pend. Penel. Lingkungan IPB: 1 - 174. Nontji, A., and 1. Sopangat 1977. Seston di Teluk Jakarta. In Teluk Jakarta: sumber daya, sifat-sifat oseanologis serta permasalahannya. Lembaga Oseanologi Nasional-LIPI, Jakarta, pp. 219 - 231. Santoso; W. Aboejoewono; J. Bilal; and I. Bachtiar 1977. Inventarisasi kualitas air permukaan daerah Teluk Jakarta timur. In Teluk Jakarta: sumber daya, sifat-sifat oseanologis serta permasalahannya. Lembaga Oseanologi Nasional-LIPI, Jakarta, pp.197 - 217. Sjarif, S., 1959. Seasonal fluctuations in the surface salinity along the coast of the southern part of Kalimantan. Mar Res. Indonesia 4:1 25. Soerisatmadja, R. E., 1956. Seasonal fluctuations in the surface salinity off the north coast of Java. Mar. Res. Indonesia 1 :1 - 19. Wyrtki, K., 1957. Precipitation, evaporation and energy exchange at the surface of the Southeast Asian Waters. Mar. Res. Indonesia 3:7 - 26. _________1961. Physical oceanography of the Southeast Asian Waters. Scripps Institution of Oceanography, Naga Report 2:1 - 95.

Geology Otto S. R. Ongkosongo The northern part of West Java is formed by an alluvial lowland, which is usually called the coastal plain of Jakarta. The plain covers almost the whole coastal zone of West Java. On the most western tip it is almost absent, limited by the Gede (595 m) mountain, but to the east it spreads extensively north of Karawang, to about 43 km wide (Geological Survey of Indonesia 1977). It consists largely of alluvial river deposits and lahars from the volcanoes in the hinterland. From east to west the length of the alluvial lowland plain is about 290 km. The north coast of West Java contrasts with the south coast from the points of view of elevation, morphology, coastal development, Ethology, and wave characteristics. The north is low and relatively flat, with some bays and capes; the coast has a curved outline with rapid coastal accretion, consisting largely of alluvial river deposits, and with relatively weak waves. The south coast is mostly hilly and rocky, with sea cliff and notched coast; the sea bottom shelves steeply, the coastline is relatively straight, and the waves are strong. The northern coastline of West Java forms the southwest shore of the Java Sea, with general depths nowhere exceeding 60 m. The 5 m isobath lies generally about 2 km offshore, but in some places, for example off the cape of Ujung, it is more than 10 km. East of Tanjung Prick, Pasir Putih, Eretan Wetan, and Cirebon it lies at about 0.75 km, 2.7 km, 1 km, and 1.5 km offshore, respectively. The beach slopes of these four beaches are generally very gradual (less than 1 per cent) to low water line, while at high water line they are less gradual (1 - 3 per cent). The beach widths at low water are, respectively, 10 - 70 m, 50 m, more than 100 m, and possibly 40 m, in these areas. The currents in the open waters of the Java Sea and along the coast of West Java are mostly monsoon drift. In addition there is a slight current setting generally toward southsouthwest. The monsoon current sets westward from May to the end of October and eastward in January and February. In November a monsoon current of 2 knots in strength is sometimes encountered. There is little or no current during the transition periods (locally known as kentering) between the two monsoon seasons described above. In Jakarta, from July to September, the mean wind directions are as follows: at 0900 hours, 147 true; at 1400 hours, 33°; and at 1800 hours, 84 . In January and February, the mean directions at the same hours are 256, 331°, and 308°. In the vicinity of Cirebon, during the east monsoon, a dry wind from the south to southwest usually sets in between 1900 and 2100 hours, and continues strongly until sunrise; then it decreases in force and dies away by 0900 or 1000 hours. Two hours later a northeast to northerly wind starts, usually weak, but occasionally increasing to a stiff breeze in the afternoon. In the case of the latter, it usually shifts to the east. The south and southwest winds are strong and locally called kumbang. During the west monsoon the wind blows from west to west-northwest. Based on Koppen's classification, Schmidt and Ferguson (1951) mapped the climatic condition of West Java. The average rainfall over the Java Sea has been reported by Wyrtki (1956), and is presented in Table 3.

FIG.1. Comparison of the north coast of West Java between 1883 - 85 and 1976. The map shows the shallow bottom and silted area distribution, and the trend of probable coastline changes in the future.

FIG.1. Comparison of the north coast of West Java between 1883 - 85 and 1976. The map shows the shallow bottom and silted area distribution, and the trend of probable coastline changes in the future. continue The Growth of the Coastal Plain The evolution of the north coast of West Java has been studied by several authors such as t'Hoen (1929), Verstappen (1953a), Hollerwoger (1964), Tjia (1964,1965), Tjia et al. (1968), Hehanussa et al. (1975), and Pardjaman (1977). If we make a comparison between the 1883 - 85 maps (Stemfoort and Ten Siethoff 1883 - 85) and the 1976 LANDSAT photo, we may draw the area with rapid accretion during the intervening period (Fig. 1). Rapid changes occur along the big river mouths, especially the Ciujung, Cidurian, Cisadane, Ciasem, Cipunegara, Rambatan, and Cimanok deltas. The formation of bays on the north coast is due to the big river mouths forming capes, leaving the bays with relatively small rivers far behind (Umbgrove 1929). Verstappen (1953a, 1954a) mentioned that the whole alluvial plain has been formed in the last 5,000 years and is therefore of Holocene age. Although this figure was primarily based on his extrapolation from data on coastline progression, this is probably the oldest datum in the geomorphic history of the West Java coastal plain. Marks (1956) reported the analysis of sediments from a bore hole in Kebayoran Baru, Jakarta. The sediments from up to 253 m depth chronologically comprise four marine zones indicative of the glacial period. The marine sediments are rich in fossils of inter-tidal to shallow-water environments, but the only age indication is a jaw fragment of Sus brachygrathus, a mammal, from a depth of 51 - 52 m, which possibly indicates a Middle Pleistocene age. The former coastline is indicated by lines of beach ridges. Verstappen (1953a), the Geological Survey of Indonesia (1975), and Sandy (1976) have described ancient beach ridges around Jakarta Bay, some of which lie more than 10 km inland, for example at Pulogadung. Furthermore, Ongkosongo (1979) has studied the strandline advance in the Jakarta area from 1625 to 1978. Verstappen reported changes between 1873 and 1938, and Pardjaman (1977), the advance from 1951 to 1975. Verstappen drew an abrasion and accretion map of the coast, including the coastal advance from the cape of Kait in the west as far as Ciasem Bay in the east. To the east, coastal development around Ciasem Bay has been investigated by Tjia et al. (1968), who recognized the development of the coastline from 1725 to 1946 by assuming an annual rate of accretion of 50 m. Here the beach ridges can be recognized up to 9 km inland. Hollerwöger (1964) discussed the evolution of the Cipunegara Delta from the 1865 and 1934 topographic maps and the 1946 aerial photographs. Further to the east, the evolution of the Cimanuk Delta complex has been investigated by t'Hoen (1929), including changes from the bay north of Kandanghaur to north of Indramayu, from 1877 to 1914 - 15. Hollerwöger (1964) discussed the outlines of the Cimanuk Delta in 1857, 1917, 1935, and 1946, and Tjia (1965) examined delta development up to 1946. Tjia et al. (1968) described the Cimanuk Delta in 1857,1917,1935,1940, and 1946, and finally Hehanussa et al. (1975) extended the works of Tjia (1964,1965), and emphasized the new birth of the Comanuk Delta in 1947 and discussed its evolution until 1975. Purbo-Hadiwidjojo (1964) suggested that the cape of Ujung, north of Cirebon, was a former river mouth or delta of the ancient Cimanuk, which was a tributary of the large Pleistocene drowned river system in the Java Sea. This river system was mentioned by several authors, for example, by Tuyn (1932) and Bemmelen (1949). This suggestion should be indicated by the existence of an ancient river course off Ujung Cape. Relatively older soils are found on Ujung Cape in comparison with the Indramayu area, as shown by the 1961 soil map compiled by the Soil Research Institute in Bogor. Tjia (1965) made field observations as well as an aerialphotograph study, and came to the conclusion that Ujung Cape was not once part of a delta but was related to the presence of some resistant substratum, probably a buried patch of coral reef. The old map of West Java (Fig. 1) shows that from 1883 to 1885 the cape was as protuberant as the present time, which corresponds with Tjia's extrapolation. The rate of accretion of the north coastal plain of West Java, from the Ciujung River in the west to Ciwaringin, north of Cirebon, has been reported by Tjia et. al. (1968) and extended by Ongkosongo (1979a). The coastal changes are of the order of +416.6 m/year to-333.3 m/year. Figure 1 shows the trend of coastline changes in the north coast of West Java from the period 1883 - 85 to 1976. It also presents the 1976 siltation distribution from some important rivers that debouch into the southwestern coastal waters of the Java Sea. In the offshore areas of Northwest Java, coral reefs occur, especially to northwest of Jakarta. Many of these form coral the islands and are located near the mainland of Java. Due to the rapid of the north coast, some of the islands or reefs advance were buried by sediments. A buried coral reef was found in Harbour (Verstappen 1953a, 1977b), and a Tanjung Priok fossil tombolo formed by corals in Kramatpanjang, Jakarta, serial photographs, was checked by field clearly shown on investigation (Verstappen 1954, 1977a). Some smaller coral Sedari Cape and Ciasem Bay are known as islands between Sedari and Sedulang reefs. North-northeast of Jakarta Bay are the Thousand Islands, a group of 108 coral reefs. The reefs lie on a west-northwest to south-southeast trending ridge about 30 m below sea level. Deep east-to-west gullies cut across this ridge, and one of them, near Payung Island, reaches a depth of 93 m. Umbgrove (1947) suggested that the ridge might represent an anticline in the basement strata,and that the gullies are probably the result of the strong sea currents between the Java Sea and the Strait of Sunda. The seismic section across the ridge shows that it is due to the high basement beneath the Seribu Islands, commonly called the Seribu Platform. The existence of the ridge is supported by the north-south block fault system west and east of the platform, and a gentle anticline in the strata above the basement (Koesoemadinata and Pulunggono 1975). Factors Governing the Coastline Changes Ongkosongo (1979a, b) has mentioned the natural and human factors which influence the Indonesian coastline directly or indirectly. Some of the factors, probably ail of them, exist in this region. However, investigations should be carried out to obtain accurate figures. Some of the existing and important factors influencing the coasts are discussed below. 1. Sea waves and currents River mouths have a tendency to form capes jutting far out into the sea. Obviously this cannot continue for any length of time since the surf will attack these projecting parts of the coasts from three sides, one from offshore and two alongshore. Only in relatively calm water can this development freely continue, forming a bird's-foot delta, for example the new Cimanuk Delta. Normally, however, there is a certain balance between silt supply on the one hand and surf action on the other, with the bird's-foot delta and the arcuate as extreme formations (Verstappen 1953a). The lack of delta formation on the south coast of Java is because of the heavy breakers of the Indonesian ocean, where the currents remove all the mud, sand, and other sediments brought to the sea by the rivers. On the north coast, the surf is weaker,the tides and currents are relatively small, the sea bottom is shallow, and so deltas may be formed. The tides here are generally less than 1 m (Janhidros 1978). Delta formation is a land augmentation, but many deltas are being reduced by the action of the sea (Hollerwöger 1964), for example the Cidurian and Rambatan deltas. With a powerful surf, the coastline will develop a regular course. In Jakarta Bay, Verstappen (1953a) concluded that the regularly curving coastline exists in the western half of the bay (which is in contrast with the coastline of the eastern half, with its river deltas projecting far into the sea) because waves and currents produced by north, northeast, and easterly winds are generally stronger than those generated by westerly winds. The difference between the tapering form of Bekasi Delta and the broad Angke Delta can only have been caused by the difference in the force of the surf. 2. Sedimentation In most cases sedimentation promotes land advance because it can exceed coastal subsidence. Rapid sedimentation usually occurs at the mouths of rivers. When the conditions of waves and currents and the sea floor are not suitable for delta formation, the deposition is usually distributed along the coast, sometimes in one direction, generally with the prevailing wind. According to van Galen (1947) the tendency of big rivers on the north coast of Java, e.g., the Citarum, Cimanuk, and Cipunegara, to curve west is due to the prevailing east monsoon. The sedimentation, however, mostly occurs during the western monsoon because the river floods then bring 80 - 90 per cent of the annual sediment yield to the sea. The formation of beach ridges therefore occurs mostly east of the river mouth (Verstappen 1953a). Umbgrove (1929a, b) proposed that the lack of coral islands in the eastern part of Jakarta Bay was because of siltation by the Citarum River in the west monsoon. Verstappen (1953a) proved however that siltation was not the main cause. Water transparencies showed that silt content was limited mostly to the nearshore areas, and some of the coral islands in the western part of Jakarta Bay are located in front of river mouths. Measurements of water transparencies by the National Institute of Oceanology (LON) in 1975 - 79 in Jakarta Bay also gave the same trend, although wider in distribution than the measurements made by Verstappen 24 years before. Sediment grain size measurements offshore in Jakarta Bay by LON show that most of the bottom sediments are mud and sand. The latter also occur on and near the coast, for instance on the beaches of Muara Karang, Ancol, Tanjung Priok, and Marunda. Off the Cimanuk Delta, Hehanussa etal. (1975) found that clay exists only 1.5 - 3 km from the river mouth. Interpretation of the LANDSAT 1976 picture also proved that turbid or very shallow water is limited to within 4 km, and generally less than 2km, from the coastline. However, the picture was taken in the eastern monsoon in June, when there is more probability that the turbid water area will extend offshore from river mouths in the rainy western monsoon season. The photos also show the pattern of sedimentation and the probable direction of evolution of the coast. Tables 4 and 5 present data from some selected rivers debouching from the north coast of West Java (Census and Statistical Office 1978). 3. Wind Umbgrove (1928, 1929a, b) and later Verstappen (1953a, b,1954b, 1968) and Verstappen and Zaneveld (1952) demonstrated the effects of wind on the geomorphology of the Seribu Islands. Cays consisting of fine coral sand occur on the lee side and shingle ramparts built of coarse material are found on the windward side of the reefs. The orientation of the sand cays on the southwest side of the reefs in the period from 1917 - 26 to 1925 - 44 demonstrates that the northeast wind has the strongest influence on these islands. The effects of the monsoon on the changes along the north coast of West Java mentioned by van Galen (1947), but Verstappen (1953a, 1954b, 1968) investigated in more detail the processes at work on the coastline, and concluded that winds produce the currents that cause sedimentation on the beach. 4. Human impact Ongkosongo (1979a, b) mentioned the impacts of man on the coast of Indonesia, some of them on the north coast of West Java. Change in a river mouth due to the making of new irrigation canals usually results in abrasion around the old river mouth and accretion around the new river mouth. Some examples are the Ciujung River, Cidurian River (Verstappen 1953a), and Cimanuk River (Hollwerwöger 1964). Due to the cutting of an irrigation canal in 1927, in a period of 18 years the new Cidurian Delta, 4.5 km west of the old mouth, grew 2.5 km, while the shoreline 2 km east of the former mouth was abraded. In the period from 1873 to 1938, the Citarum River in its Tanjung Gembong estuary accreted about 45 m/year and the Pecah, 46 m/year (Verstappen 1953). After the Jatiluhur Dam was constructed upstream, the accretion from 1950 - 75 was decreased to 40 m/year and 44 m/year, respectively (Pardjaman 1977). The silting of the dammed water in Jatiluhur Reservoir . is clearly seen on the LANDSAT photograph of 1976. In contrast, in the neighbouring Bekasi and Cikarang rivers, catchments with no dam constructions upstream, the annual accretion rate increased from 15 to 50 m during the same period (Pardjaman 1977). During the period 1873 - 1938, Cilincing Beach in Jakarta retreated about 50 m, or at a rate of only 0.76 m/year. From 1951 to 1975, the retreat of the strandline increased to 600 m, or an average of 24 m/year. The changes were especially obvious in the period 1972 - 75, with a retreat of about 260 m or an annual recession of about 87 m. This was because of sand mining by the local population, which amounted to about 200 to 300 trucks of sand per day. This is the main cause of shoreline recession, because sedimentation from the rivers was not sufficient to balance this loss. The rapid retreat of the coast was also due to some extent to mangrove deforestation (Pardjaman 1977). In contrast to the effect of beach mining, land reclamation will prograde the land seaward. In Jakarta, land has been reclaimed in the Pluit and Muara Karang area for housing, recreation, and the power station project. Sea walls and other types of beach protections, such as jetties, groins, and breakwaters, will stabilize the shoreline, which in Jakarta, for example, extends from Muara Angke in the west to around Kalibaru in the east, about 20 km (Ongkosongo 1979c). The higher rate of sedimentation on the coast west of the Sunda Kelapa Canal ("Oude Haven Kannal") than to the east was largely due to the construction of two breakwaters, as shown in the coastline evolution map made by Ongkosongo (1979c). Hehanussa (1975) showed that construction of breakwaters for an oil terminal at Balongan (northwest of Cirebon) led to the abrasion of the adjacent coast. Table 3. Amount of Rainfall in mm over the Java Sea Averaged from 7 Coastal and Island Stations (including Labuhan and Edam Islands) according to Wyrtki in 1956 (Average Number of Observations in Year: 33) Jan.

Feb.

March

April

May

June

July

Aug.

Sept.

Oct.

Nov.

Dec.

Total Year

288

219

202

166

177

127

93

58

46

96

151

257

1880

Table 4. Lengths and Catchment Areas of the Rivers Flowing to the North Coast of West Java (Census and Statistical Office 1978) No.

River

Length

Catchment Area (km²)

1.

Cibanten

34

279.0

2.

Ciujung

110

2045.4

3.

Cidurian

100

924.4

4.

Cimanceuri

55

519.3

5.

Cisadane

112

1479.1

6.

Ciliwung

82

611.4

7.

Bekasi

45

1451.9

8.

Citarum

250

5969.0

9

Pegadungan

58

628.8

10.

Cilamaya

65

322.4

11.

Ciasem

68

690.9

12.

Cipunegara

98

1492.9

13.

Cimanuk

182

9650.2

14.

Ciwaringin

53

485.4

15

Cikabuyutan

80

1265. 0

Table 5. Data from Selected Rivers Debouching to the North Coast of West Java (Census and Statistical Office 1978)



Location

Volume (km2 )

Flow km2 Flow Average Flow Depth (l/sec) (m3 /sec)

Average Volume (m)

Water Volume (x103 m3 )











Catchment Area

Year

River





0

‘

0

‘











1971-

Ciujung-Rangkasbitung

6

21

106

15

1364

-

-

-

-

1972



78.7

57.7

1825

2486

1971-

Cidurian Kapomaja

21

69.3

2166

658

1972



22

72.3

2353

697

1971-

Cidurian Parigi

27.4

-

1122

727

1972



27

41.5

1317

853

1971-

Cisadane Batubeulah

66.1

78.9

2477

2083

1972



70.9

84.2

2666

2242

1971-

Citarum Saguling

129

56.4

1815

4051

1972



77.1

33.9

1070

2438

1971-

Citarum Palumbon

195

47.9

1507

6120

1972



148

36.4

1150

4673

1971-

Citarum Tanjung Pura

-

-

-

-

1972



7.14

-

283

1688

1971-

Cipunegara Sumurbarang

27.4

39.8

1252

728

1972



23.0

33.4

1059

728

1971-

Cimanuk Leuwidaun

18.8

-

1233

541

1972



14

31.9

1010

443

1971-

Cimanuk Leuwigoong

36.6

48.2

1516

1152

1972



23.6

31

980

746

1971-

Cimanuk Cipaos

42.3

-

1516

1220

1972



24.1

30

951

763

1971-

Cimanuk Tomo

84.9

43.9

1387

2680

1972



52.3

-

640

1235

1971-

Cimanuk Wado

40.1

-

832

1053

1972



139.8

31.5

997

1262

Latitude(S)

6

Longitude(E)

20

6

106

13

6

106

29

6

6

6

7

7

7

6

6

760

2

108

57

439

54

108

46

687.5

54

107

3

5970

20

107

6

4061

19

107

14

2283

20

107

35

841

25

107

19

649

41

107

51

304

22

106

55

6

24

803

8

108

1931

5

1264



References Bemmelen, R. W. van, 1949. The geology of Indonesia. Martinus Nijhoff, Vol. I A, the Hague. Census and Statistical Office 1978. Statistical year book of Jakarta. Census and Statistical Office, Jakarta. Galen, J. van, 1947. Morfologische kenmerken van West Java. Tijdschr. Kon. Net. Aardr. Gen. 64:448. Geological Survey of Indonesia 1975. Peta geologi teknik daerah JakartaBogor. Dep. Pertambangan Indonesia. Geol. Surv. Indon., Bandung. ———, 1977. Geological map of Java and Madura. Geol. Surv. Indon., Bandung. Hehanursa, P. E.; S. Hadiwisastra; and S. Djoehanah 1975. Sedimentasi delta baru Cimanuk. Geol. Indon. 3 (1):21 - 35. Hollerwöger, F.,1964. The progress of the river deltas in Java. In "Scientific problem of the humid tropic zone deltas and their implications." UNESCO Dacca Simp. Proc.: 347 - 355. Janhidros 1978. Tide tables, Indonesia archipelago 1978. Jawatan Hidrooseanografi (JANHIDROS), Markas Besar TNI-AL, Jakarta. Koesoemadinata, R. P., and A. Pulunggono 1975. Geology of the southern Sunda Shelf in reference to the tectonic framework of tertiary sedimentary basins of Western Indonesia. Geol. Indon. 2(2): 1 - 11. Marks, P., 1956. Foraminifera-kecil dari Sumur No. 1 (Sumur 1 ) di Kebayoran, Jakarta. Publ. Keilm. 30, Seri paleontologi, Djaw Geol. Bandung. Ongkosongo, O. S. R., 1979a. The nature of coastline changes in Indonesia. Workshop on Coastal Geomorphology, UNESCO, Singapore-Malaysia. ———, 1979b. Perubahan garis pantai di Indonesia. (In preparation for publication.) ———, 1979c. Perubahan den keadaan lingkungan pantai Jakarta. (In preparation for publication.) Pardjaman, D., 1977. Akresi den abrasi pantai Teluk Jakarta disebabkan oleh kondisi fisik den sosial, In M. Hutomo; K. Romimohtarto; Burhanuddin (eds.), Teluk Jakarta. Lembaga Oseanologi Nasional-LIPI, Jakarta. pp. 83 106. Purbo-Hadiwidjojo, M. M., 1964. On the Cimanuk river delta, West Java. Bull. Geol. Survey Indon. 1(2): 35 - 38. Sandy, 1. M., 1976. Klasifikasi pesisir den penggunean tanah. Simp. Dep. Biol. ITB. Bandung. Schmidt, F. D., and J, H. A. Ferguson 1951. Rainfall types based on wet and dry period rations for Indonesia with Western New Guinea. Kement. Perhub. Djaw. Meteor. and Geofisik, Djakarta. Stemfoort, J. W., and J. J. Ten Siethoff 1883 - 85. Derer Nederlandsche bezittingen in Oost Indie. Departement van Kolonien, Topographishe inrichting, Gravenhage. t'Hoen, C. W. A. P., 1929. Geologische overzichtskaart van den 12 Nederlandsch Indischen Archipel. 1: 1.000.000 Toelichting bij Blad XVI (Midden Java). Jaarb, Mijnb. Ned. India Verh. Tjia, H. D., 1964. On the Cimanuk river delta ( West Java). Bull. Geol. Surv. Indon. 1 ( 1 ) :1 7 - 1 9. ———, 1965. Course changes in the lower Tjimanuk river, West Java. Inst Tekn. Bandunk. Contrib. Dept. Geol. 62:77 - 82. ———, S. Asikin; and R. Soriaatmadja 1968. Coastal accretion in western Indonesia. Bull. Nat. Inst. Geol. Min. (11):15 - 46. Tuyn, J. van, 1932. Over de rangschikking der Duizend eilanden. De Mijningenieur 13(7 ) :132 - 134. Umbgrove, J. H. F,, 1928. De koralriffen in de base van Batavia. Dienst van Mijnbouw in Ned. Indie. Wetensch. Meded. 7. ———, 1929a. The coral reefs in the bay of Batavia. Fourth Pacific Science Congress, Java, Bandung. ———, 1929b. De koraalriffen der Duizend-Eilanden (Java Zee) Dienst van Mijnbouw in Nederlandsch-lndie Wetensch. Meded. 12. ———, 1947. Coral reef in the East Indies, Bull. Geol. Soc. Amer. 58:729 - 777. Verstappen, H. Th., 1953a. Djakarta Bay, a geomorphological study on shore line development. Doctoral dissertation, Rijkuniversitet, Utrescht s-Gravennage Trio. ———, 1953b. Oude en nieuwe onderzoekingen over de koraal- eilanden in de bead van Djakarta. Tijdschr. Kon. Ned. Aardr. Gen. 71 :472 - 478. ———, 1954a. Het kustgabied van Noordelijk West Java op de luchtfoto. Tijdschr. Kon. Net. Aardr. Gen. 71:146 - 152. ———, 1954b. The influence of climatic changes on the formation of coral islands. Amer. Journ. Sci. 252:428 - 435. ———, 1968. Coral reefs, wind and currant growth control. In R.w. Fairbridge (ed,), Encyclorpedia of earth sciences. Reinhold Publ. Corp., New York, pp.197 - 202. ———, 1977a. Remote sensing in geomorphology. Elseviers Publ. Corp., Amsterdam. ———, 1977b. Applied geomorphology. Lecture note', ITC, Enschede. ———, and J. S. Zaneveld 1952. A recent investigation on the geomorphology and the flora of some coral islands, in the bay of Djakarta. Kementerian Pertahanan Djawatan Topografi A.D. Inst. Geogr. Publ. 4, Djakarta. Wyrtki, K., 1956. The rainfall over the Indonesian waters. Kementerian Perhubungan Lembaga Meteorologi den Geofisik, Jakarta.

Biology D. P. Praseno The living organisms of the sea can be divided into three major groups: benthic, necton, and planktonic organisms. Benthic organisms usually live on the bottom of the sea, or attached to various substrates. They may crawl on the bottom of the sea, or live buried in holes. Necton are free swimming organisms, like most of the fishes, while plankton are suspended or floating organisms, and are not able to withstand water currents. This chapter will discuss only the third group, the planktonic organisms, and what is known so far about them in Indonesia, with special reference to the waters between Jakarta and Cirebon. Plankton Primary Productivity The most common method for studying primary productivity is the method introduced by Steeman-Nielsen (1952) using C14, Using this method, or modifications of it, measurements have been made on several cruises in Indonesian waters by Indonesian and foreign scientists (Birowo et al. 1975). As was expected, high productivity values were obtained from shallow waters, especially those influenced by river water discharge. Malacca Strait nearly always shows high values (more than 1 mg C/m³/hour). Usuaily primary productivity in the surface layers has a value ranging from 0.1 - 1 mg C/m³/hour. Doty et al. (1963) measured primary productivity of the waters around the Seribu Islands, and obtained values ranging from 0.23 - 0.52 mg C/m³ /hour but Nontji (personal communication) also obtained high values from waters around the coral reefs of the Pari Islands, where values ranging from 1.86 to 8.96 mg C/m³/hour were recorded. Similar values have been measured around several coral islands in the Pacific (Sargent and Austin 1949; Odum and Odum 1955; Kohn and Helfrich 1957). High values may also be found in estuarine waters or areas of marine upwelIing (Soegiarto and Nontji 1966). Another method of measuring primary productivity is by determining the chlorophyll content of phytoplankters. This method is commonly used by LON-LIPI. Nontji (1974a) compiled all chlorophyll data of the Indonesian waters and calculated an average value of 0.19 mg/m³. A higher average (0.24 mg/m³) was obtained in the east monsoon, while during the west monsoon the average value was 0.16 mg/m³. Depths of maximum chlorophyll concentration are variable. In the South China Sea (Hung and Tsai 1972) the depth was between 50 and 125 m, while in the Banda Sea it was 25 m (Nontji 1974a, 1975), and in the Halmahera Sea 50 m (Nontji 1974b). Periodical observations in Jakarta Bay revealed that the bay water is very productive. Observations were made during 1975 - 78. Sampling was carried out during both the rainy and dry seasons (January and August), and during the two transition periods (May and November). The average chlorophyll concentration ranged from 0.90 to 5.41 mg/m³ with a maximum value of 17.96 mg/m³. The highest concentrations were found in samples taken in front of river mouths. Tests were also made to detect and measure chlorophyll in sea water by remote sensing techniques. A chlorophyll detector was designed and constructed by the Deutsche Forschungs und Versuchtanstalt fur Luft und Raumfahrt (DFVLR) in co-operation with the Indonesian National Institute of Aeronautics and Space (LAPAN). The radiometer was tested in Jakarta Bay, and gave higher values than those recorded by surface sampling (Praseno et al. 1978a). Phytoplankton Diatoms and dinoflagellates are the main phytoplankters in the sea. The diatoms have wide distribution, while dinoflagellates are mostly concentrated in estuarine waters. Some dinoflagellates, e.g., Noctiluca, are holozoic types. These organisms do not possess photosynthetic capacity, and depend on consuming organic material from their surroundings. However, they are still grouped as phytoplankters in order not to separate them from the rest of the dinoflagellates and other planktonic algae that are holophytic types. Another member of the phytoplankters is Trichodesmium (Cyanophyceae). This appears only occasionally, but is then found in great numbers floating on the surface like sawdust. Delsman (1939) has observed the blooming of these organisms forming very long patches on the surface of the Java Sea. Trichodesmium spp. avoid less brackish water and are nearly always found some distance out from the coast. Delsman (1939) also found that in the Java Sea phytoplankton are concentrated in coastal waters and diminish towards the open sea. In coastal waters the diatoms are mostly represented by the genera Rhizosolenia, Chaetoceros, and Coscinodiscus, while dinoflagellates are mainly represented by the genera Noctiluca and Ceratium (Allen and Cupp 1935). During the last decade a number of observations have been carried out, mostly by staff members of LON-LIPI. Nontji and Arinardi (1975) studied phytoplankton distribution in relation to some ecological factors, and found that the rivers of Java and Kalimantan have important influences on phytoplankton. Nontji (1973) described distribution patterns of prominent phytoplankton genera in relation to ecological factors, and Hutomo (1977) studied seasonal variations in phytoplankton in the waters of the southern part of Pulau-Pulau Seribu, where three peaks occurred, during the months of October, January-February, and May Periodical observations in Jakarta Bay and its vicinity showed that besides the genera mentioned by Delsman (1939), other genera may also be important, like Skeletonema, Bacteriastrum, and Thalassionema/ Thalassiothrix of the diatoms, and Dinophysis of the dinoflagellates. Phytoplankters are mostly concentrated in the estuarine waters of Muara Angke-Muara Karang and Marunda. Phytoplankton growth is influenced by the presence of nutrients, derived either from river-water discharge or from marine upwelling processes. If sufficient nutrients are available, blooming of phytoplankton may occur, either of a single species, or of many species at the same time. Blooming of a single species was observed in Jakarta Bay by Praseno and Adnan (1978a, b, c). The plankton Noctiluca was often found blooming in waters influenced by river discharge, appearing in great numbers after heavy rainfall. Another phytoplankton that usually blooms independently is the diatom Skeletonema sp. While other diatoms do not grow because of the drop in salinity, Skeletonema can tolerate low salinity. This may be important for the mixed culture of the diatom without applying specie! techniques to produce a monoculture. Skeletonema 5p. is one of the diatoms used as food by many larvae. Zooplankton Zooplankton studies in the Java Sea were first made by Delsman (1921) when he made an inventory of fish eggs and larvae. His important work continued for 17 years (Delsman 1921,1922,1924, 1925,1926a, 1926b, 1926c, 1929a, 1929b, 1930, 1931a, 1931b, 1931c, 1932, 1933, and 1938). Other zooplankters were investigated in relation to ecological factors like salinity and phosphate (Delsman 1939). After that, little was done until 1964. In 1964 the Baruna Expedition I was carried out, with some stations located in the Java Sea. Results showed that zooplankters are mostly concentrated near the coasts of Java and Kalimantan. Plankton volumes reached an average of 0.04 ml/m³, and individual counts had an average of 226 plankters/m³. Copepods were predominant, and usually consisted of the genera Acrocalanus, Candacia, Corycaeus, Eucalanus, Oithona, and Pleuromamma (Arinardi 1970). Prawoto and Tjee (1966) made quantitative investigations of plankton of the waters around Java. They found that plankton volumes in the Java Sea are higher than those in the Indian Ocean. Thaliacea (mostly Salpidae) were found in abundance in the western part of the Java Sea. Zooplankton of the waters around Pulau-Pulau Seribu were investigated in more detail after 1969. The influence of seasons upon plankton concentrations was studied by Praseno and Arinardi (1974), who found that the volume of zooplankton during the rainy season was less than that during the dry season. The average zooplankton volume during the rainy season was 0.10 ml/m³, while during the dry season it was 0.20 ml/m³. The low value in the rainy season was due to the small amount of Thaliacea, which then had a frequency of occurrence of 23 per cent and a relative abundance of 0.17 per cent, while during the dry season the values were 63 per cent and 4.29 per cent, respectively. Further analysis showed that the average number of plankters during the rainy season was 695 organisms/m³ and during the dry season 689 organisms/m³. During the rainy season the distribution was more or less homogeneous, while during the dry season the plankters were concentrated near the coast (Arinardi et al. 1977). The influence of rain can be detected in the sea. After heavy rainfall certain zooplankers appear in great numbers, like the Calanoid copepods, Decapod larvae, and Oikopleura in the waters around Pulau Panggang, PulauPulau Seribu (Arinardi 1978a). Other plankters may appear at the approach of the dry season, e.g., Ostracoda, or during the dry season, e.g., Thaliacea. Arinardi (1978b) also studied the relationship between phytoplankton and zooplankton of the area, and found that a reverse relationship occurred during the dry season. Due to the fact that Jakarta Bay is located near a centre of marine research, it is natural that its waters have received much attention. Periodical surveys were carried out in the area to monitor changes of water condition. Thus Sutomo (1978) found that the distribution of zooplankters in the bay is influenced by water masses, rainfall, and the presence of Noctiluca sp. A maximum number of zooplankters was obtained in the month of November 1975, the transition period from the dry to the rainy season, when 1,689 organisms/m³ were counted. A minimum number of organisms was obtained in May 1976, the transition period from the rainy to the dry season, when the average was 1,309 organisms/m³. Copepoda, Luciferidae, and Larvacea were found mainly during the rainy season, while Ostracoda were found mainly during the dry season. Sutomo etal. (1977) made monthly observations of zooplankton in the waters in front of Angke River. Low zooplankton concentrations in this water were caused by blooming of Noctiluca and Thaliacea, or by the turbidity of sea water, which in turn was caused by heavy rainfall. High plankton concentration was observed in April (4,451 organisms/m³), and low concentration in October (366 organisms/m³). Plankton observations were also carried out in connection with fouling organisms, e.g., barnacles. In the waters seaward of the Karang River, in Jakarta Bay, barnacle larvae were found throughout the year, with a peak in September. Minimum numbers of Cirripid larvae were found in March (Hutomo etal. 1977; Romimohtarto and Arinardi 1977), their greatest concentration being some distance out from the coast. Micro-organisms Micro-organisms are sometimes included in the plankton community. These organisms cannot be captured by nets because of their size. Plankton that pass through the finest net are called nannoplankton, their size ranging from 5 to 60 microns, and they are usually collected by centrifuging water samples. Organisms smaller than 5 microns are called ultraplankton, and include bacteria and smaller flagellate forms. Nannoplankters have only been studied in regard to their chlorophyll content, together with the rest of the phytoplankters. Samples are obtained by dipping the surface water, or by using a van Dorn sampler to obtain water samples from certain depths. Ultraplankton may play an important role in the marine environment. In 1951 for the first time food poisoning due to the bacteria Pasteurella parahaemolyticus was reported by Fujino et al. (1951). Takikawa (1958, 1960) named the bacteria Pseudomonas enteritis,and it was later called Vibrio parahaemolyticus by Sakazaki et al. (1963), who divided it into three biotypes, according to morphological, cultural, and biochemical properties. The three biotypes are now referred to as Vibrio parahaemolyticus (Biotype I), V. alginolyticus (Biotype II), and V. anguillarum (Biotype III). In Japan V. parahaemolyticus is known to cause food poisoning, which can develop into an epidemic in the summer (Aiiso et al. 1963; Miyamoto et al. 1962). V. parahaemolyticus is a typical bacteria belonging to the marine environment (Horde et al. 1963; Asakawa 1966), and in the United States it has been isolated from sea water and mud as well as from several crustaceans, molluscs, and fishes (Baross and Liston 1968, 1970; Ward 1968). In Indonesia the extent of food poisoning due to V. Parahaemolyticus is not fully known. Observations in Jakarta Bay were carried out by LON (Thayib and Suhadi 1974), when V. parahaemolyticus was isolated from mud, molluscs, and fishes. Results showed that 15 per cent of the mud samples, 13.4 per cent of the molluscs, and 9.7 per cent of the fish samples were contaminated by the three biotypes. For V. parahaemolyticus the percentages were 5 per cent of the mud samples, 2.7 per cent of the molluscs, and 1 per cent of the fish samples. Investigations were also made to detect the presence of coliform bacteria (Thayib and Listiawati 1977, 1978). High concentrations were obtained from water samples of the estuarine area and waters surrounding the islands. The MPN of Coliform bacteria varied from 930 per 100 ml to 1,100,000 per 100 ml of sea water in Jakarta Bay. Further investigations of the bacteria in Jakarta Bay were carried out by Thayib et al. (1977). Other micro-organisms were also detected in clams (Anadara spp.) and in oysters (Crassostrea spp.). Salmonella was found to contaminate 52.3 per cent of the 300 clam samples, and 46 per cent of the 250 oyster samples. The bacteria Shigella contaminated 6.3 per cent of the clams, and 1.2 per cent of the oysters. Escherichia cold was found in 8.3 per cent of the clams, and 16.0 per cent of the oysters, while the bacteria Staphylococcus was detected in 1 per cent of the clams, and 37.1 per cent of the oysters. Further investigations showed that V. parahaemolyticus has contaminated 3 per cent of the clams, and 5.5 per cent of the oysters. These results showed that the clams and oysters of Jakarta Bay are contaminated to such a degree as to endanger the consumers. Besides pathogenic micro-organisms Thayib [1878) made an inventory of hydrocarbonoclastic micro-organisms in Jakarta Bay. Halophylic, halotolerant, and terrestrial bacteria were recorded. Of all the microorganisms Pseudomonas was found to predominate. Other bacteria were Arthorbacter, Nocardia, Micrococcus, and Corynebacterium. Investigations of plankton, chlorophylls, and micro-organisms have been concentrated mainly in Jakarta Bay. As a result it can be concluded that the waters of Jakarta Bay are very much influenced by the rivers which enter the area. Inputs of nutrients have made the bay water very productive, but it is also affected by many pathogenic bacteria, which contaminate marine products. If these marine products are not treated correctly, they may endanger their consumers. The bay water is also polluted by oil, especially in the Tanjung Priok and the Sunda Kelapa areas, and this can be detected indirectly from the MPN of hydrocarbonoclastic micro-organisms. The Jakarta Bay area has to be monitored periodically in order to trace possible changes. Only in this way can unfavourable developments be detected, and steps taken to prevent further damage of the environment. Little information is available on other coastal and estuarine waters between Jakarta and Cirebon. More attention should be paid to these areas since they are very important for fisheries. References Aiiso, K.; U. Somitzu; H. Katoh; K. Tatsumi; F. Sawada; and S. Kafoh 1963. Pseudomonas enteritis and related bacteria isolated from the sea-water at the area of Pacific coast. Am. Rep. Inst. Microbiol., Chaika Univ. 15:12. Allen, W. E., and E. E. Cupp 1935. Plankton diatoms of the Java Sea. Ann. Jard. Sot Buitenzorg 44:1 - 174. Arinardi, O. H., 1970. Preliminary investigation on zooplankton communities of the Java Sea, Banda Sea, and Arafuru Sea. M.S. thesis IPA Bagian Biologi, ITB (in Indonesian). ____________1978a. Seasonal variations of certain major zooplankton groups around Panggang Island, northwest of Jakarta. Mar. Res.. Indon. 21 :61 - 80. ____________1978b. Relationship between the quantitions of phytoplankton and zooplankton in the waters north of Pari Island Group. Oseanologi di Indonesia 11 :73 - 85 (in Indonesian). ____________; D. P. Praseno; and A. B. Sutomo 1977. Zooplankton concentration and distribution in the waters of Pulau-Pulau Seribu during the east monsoon and the west monsoon 1971. In M. Hutomo; K. Romimohtarto; and Burhanuddin (eds.l), Teluk Jakarta: sumber daya, sifat-sifat oseanologis, serta permasalahannya. Lembaga Oseanologi Nasional-LIPI, Jakarta, pp. 263 - 291 (in Indonesian). Asakawa, S.,1966. A study on the vertical distribution of Vibrio parahaemolyticus in sea bottom. J. Fac. Fish. Anim. I-lusb. 6:447. Baross, J., and J. Liston 1968. Isolation of V;brio parahaemolyticus from the Northwest Pacific. Nature 217:1263 - 1264. ____________1970. Occurrence of Vibrio parahaemolyticus and related homolytic vibrios in marine environments Washington State. Appl. Microbiol. 20:179 - 186. Birowo, S.; A. G. Ilahude; and A. Nontji 1975. Oceanological atlas of the Indonesian waters and its vicinity. Lembaga Oseanologi Nasional-LIPI, Jakarta, Book I. Delsman, H. C.,1921. Fish eggs and larvae of the Java Sea. 1. Fistularia serrate Cuv. Treubia 2:91 - 108. ____________1922. Fish eggs and larvae of the Java Sea. 2. Chirocentrus dorab (Forsk). Treubia 3:38 - 46. ____________1924. Fishreggs and larvae of the Java Sea. 3. Pelagic scombrescoid eggs. Treubia 5:408 - 418. ____________1925. Fish eggs and larvae of the Java Sea. 4. Dussumieria hasseltii Blkr. Treubia 6:297 - 307. ____________1926a. Fish eggs and larvae of the Java Sea. 5. Caranx kurra, C. marosoma and C. cromenophthalmus. 6. On a few other carangid eggs and larvae. 7. The genus Clupea. Treubia 8:199 - 239. ____________1926b. Fish eggs and larvae of the Java Sea. 8. Dorosoma chacunda (H.B.). 9. Scomber kanagurta C.V. and 10. On a few larvae of empang fishes. Treubia 8:389 - 412. ____________1926c. Fish eggs and larvae of the Java Sea. 11. The genus Trichiurus. Treubia 9:338 - 351. ____________1929a. Fish eggs and larvae of the Java Sea. 12. The genus Engraulis and 13. Chanos chanos Treubia 11 :275 - 286. ____________1929b. The study of pelagic eggs. 4th Pacific Science Congress, Batavia-Bandung (Java), pp.1 - 7. ____________1930. Fish eggs and larvae of the Java Sea. 14. The genus Pellona and 15. On Chirocentrus hipaelosoma and C. dorab. Treubia 12:37 - 50. ____________1931a. Fish eggs and larvae of the Java Sea.16. Amphiprion percula C. V. Treubia 12:367 - 370. ____________1931b. Fish eggs and larvae of the Java Sea. 17. The genus Stolephorus Treubia 13:217 - 243. ____________1931c. Fish eggs and larvae of the Java Sea. 18. The genus Cybium. Treubia 13:401 - 410. ____________1932. Fish eggs and larvae of the Java Sea. 19. The genus Setipinne and 20. Coilia. Treubia 14: 109 - 110. ____________1933. Fish eggs and larvae of the Java Sea. 21. Eel eggs, 22. Clupeoids lile and 23. A few more Clupea eggs. Treubia 14 :237254. ____________1938. Fish eggs and larvae of the Java Sea. 24. Myctophoidae. Treubia 16:415 - 420. ____________1939. Preliminary plankton investigation in the Java Sea. Treubia 17:139 - 141. Doty, M. S.; R. E. Soeriaatmadja; and A. Soegiarto 1963. Observations on the primary marine productivity of northwestern Indonesian waters. Mar. Res. Indon 5:1 - 25. Fujino, T.; J. Okino; D. Nakada; A. Aoyama; K. Fukai; T. Mukai; and T. Ueno 1951. On the bacteriological examination of Shirozu food poisoning. Med. J. Osaka Univ. 4:299 - 304. Horie, S.; K. Sakeki; M. Nara; T. Kozima; Y. Sekine; and T. Takayanagi 1963. Distribution of Takikawa's so-called pathogenic halophile bacteria in the coastal sea area. Bull. Jap. Coc. Fish 29:785. Hung, T. S., and C. C. H. Tsai 1972. Study on photosynthetic pigments and chemical nutrients in South China Sea. Acta Oceanographica 2:83 - 92. Hutomo, M.; O. H. Arinardi; M. K. Moosa; and K. Romimohtarto 1977. Biological observation in the Muara Karang waters with notes on fisheries in the area. In M. Hutomo; K. Romimohtarto; and Burhanuddin (eds.), Teluk Jakarta: sumber daya, sifat-sifat oseanologis, serta permasalahannya. Lembaga Oseanologi Nasional-LIPI, Jakarta, pp. 351 - 396 (in Indonesian). Kohn, A. J., and P. Helfrich 1957. Primary organic productivity of a Hawaiian coral reef. L;mnol Oceanogr. 2:241 - 251. Miyamoto, Y.; K. Nakamura; and K. Takizawa 1962. Seasonal distribution of Oceanomonas spp., halophilic bacteria, in the coastal area, its significance in epidemiology and marine industry. J. Med Sci. Vol. 6:141 - 158. Nontji, A. 1973. Phytoplankton of the waters around Pulau-Pulau Seribu (Java Sea) and some ecological factors. M.S. thesis, Biological Faculty Universitas Nasional (in Indonesian). ____________1974a. Chlorophyll content in the phytoplankton of the Banda and Seram Seas. Osoanologi d; Indonosia 2:1 - 16 (in Indonesian ). ____________1974b. Oceanological observations around Gag Island with reference to hydrology and phytoplankton chlorophyll. Oseanologi di Indonosia 3:11 - 27. ____________1975. Distribution of chlorophyll-a in the Banda Sea by the end of upwelling season. Mar. Res. Indon. 14:49 - 59. ____________and O. H. Arinardi 1975. Hydrology and diatoms of the Java Sea. Oseanologi di Indonosia 4:21 - 36 (in Indonesian ). Odum, H. T., and E. P. Odum 1955. Trophic structure and productivity of a windward coral reef community on Eniwitok atoll. Ecol. Monogr. 25:291 - 320. Praseno, D. P., and O. H. Arinardi 1974. Plankton volumes and their distribution in "perairan Pulau-Pulau Seribu" during the west and east monsoons 1971. Oseanologi di Indonosia 2:27 - 40 (in Indonesian). ____________and C. Adnan 1978a. Possibility study on the culture of Skeletonema spp. for food of marina larvae. Paper presented in the "Seminar Microbiologi I I ," Jogyakarta, 5 - 7 April 1978 (in Indonasian), ____________and Q. Adnan 1978b. Diatoms for supporting marine aquaculture. Paper presented in the "Simposium Modernisasi Perikanan Rakyat," Jakarta, 27 - 30 June 1978 (in Indonesian). ____________and Q. Adnan 1978c. Noctiluca miliaris SURIRAY in Jakarta Bay. Oseanologi di Indonesia 11:1 - 25. (in Indonesian), ____________; Z. Soejoeti; and Dijardjana 1978. The application of remote sensing in marine research in Indonesia. Proc. 12th Intern. Symp. Rem.. Son. Environ. 3:2071 - 2079. Prawato, D., and O. H. Tjee 1966. A quantitative study on the zooplankton of the waters around Java. Paper submitted to the 11th Pacific Science Congress, Tokyo, 22 August-3 Sept. 1966. Romimohtarto, K., and O. H. Arinardi 1977. Studies on the distribution of barnacle larvae and the barnacle fouling in the estuarine area of Muara Karang. Mar. figs. Indon. 20:19 - 36. Sakazaki, R.; S. Iwanami; and H. Fukumi 1963. Studies on the enteropathogenic facultatively halophilic bacteria, Vibrio parahaemolyticus. L Morphological, cultural, and biochemical properties and its taxonomical position. Jap. J. Mod. Sci. Biol.. 16:161 - 188. Sargent, F. D., and T. S. Austin 1949. Organic productivity of an atoll. Trans. Am. Geophys. Union 30(2):245 - 249, Soegiarto, A., and A. Nontji 1966. A seasonal study of the primary marine productivity in Indonesian waters. Paper presented in the 11th Pacific Congress, Tokyo, 22 August-3 Sept.1966. Steeman-Nielsen, E,, 1952. The use of radio-active carbon for measuring organic production in the Sea. J. Cons. Expl. Mer. 18:117 - 140. Sutomo, A. B., 1978. Zooplankton observations in the Jakarta Bay 1975 1976. Paper presented in the "Seminar Mikrobiologi l I," Jogyakarta, 5 - 7 April 1978. ____________; O. H. Arinardi; and D. P. Praseno 1977. Zooplankton observations in the western part of the Jakarta Bay 1974 - 1975 with notes on the ecology. In M. Hutomo; K. Romimohtarto; and Burhanuddin (eds.), Teluk Jakarta: sumber daya, sifat-sifat oseanologis, serta parmasalahannya. Lembaga Oseanologi Nasional-LiPI, Jakarta, pp. 245-253 (in Indonesian). Takikawa, 1.,1958. Studies on pathogenic halophilic bacteria. Yokohama Med. Bull. 2:313 - 322 (in Japanese). ____________1960. Pathogenic halophilic bacteria, Pseudomonas enteritis. J. Japan Ass. Infec. Dis. 33:1087. Thayib, S. H., 1978. Notes on hydrocarbonoclastic microorganisms from inshore and offshore waters in Jakarta Bay. Oseanologi di Indonesia 10:1 - 7 (in Indonesian). ____________and F. Suhadi 1974. An attempt to isolate Vibrio parahaomolyticus from mud and sea products around Jakarta Bay area. Oseanologi di lndonosia 2:41 - 55 (in Indonesian). ____________and J. T. D. Listiawati 1977. The Jakarta Bay and its pathogenic microorganisms. In M. Hutomo; K. Romimohtarto; and Burhanuddin (eds.), Teluk Jakarta: sumber daya, sifat-sifat oseanologis, serta permasalahannya. Lembaga Oseanologi Nasional-LIPI, Jakarta, pp. 233-244 (in Indonesian). ____________and J. T. D. Listiawati 1978. Bacteriological condition of the waters of Jakarta Bay. Oseanologi di Indonesia 10:15 - 23 (in Indonesian). ____________; W. Martoyudi; and F. Suhadi 1977. Some enteropathogenic bacteria in clams (Anadara) and oysters (Crassostrea). Oseanologi di Indonosia 7 :49 - 55, Ward, B. Q., 1968. Isolation of organisms related to Vibrio parahaemolyticus from American estuarine sediments. Appl. Microbiol. 16:543 - 546. Discussion Burgers: How do the micro-organisms contaminate fish and molluscs in the area? Praseno: They are probably not harmful to the consumers because sea foods are mostly cooked. There are blooms of other organisms but they do not cause substantial fish mortality. Sutamihardja: Would you comment on the high values of cadmium and mercury in Jakarta Bay and on the causes of high micro-organism populations? Praseno: Heavy-metal concentrations are due to industrial activity. Almost all the industrial waste water from the region enters the rivers and thus passes into Jakarta Bay, carrying high concentrations of heavy metals. Microorganisms also enter Jakarta Bay in river discharge, and the MPN of coliform bacteria is very high indeed.

Socio-economic studies in Java in the context of a coastal resources evaluation Geoff Missen The technological solution would appear to be particularly appealing both to researchers in the developed countries and to policy-makers in the developing countries, because, on the face of it, it does not violate vested interests and therefore seems to escape political opposition [and] . . . to lie beyond ideology. It . . . seems to tackle problems in a scientific, practical and workmanlike manner. Technology has been called the opium of the intellectual. But technology is both result and cause of income, asset, and powers of distribution. As the "Green Revolution" has shown . . . technology specifically invented to overcome food shortages for the growing number of poor people has reinforced and aggravated rural inequalities. Frances Stewart and Paul Streeten My purpose is to present a generalized case for scientific or technological-oriented research being seen within the social and economic context of the region in which this research might be applied. I use technology and science here in the broadest sense of those terms. An underlying assumption is that such research has value if it leads directly or indirectly to welfare improvement. I shall proceed from the general to the particular. A Preamble on Development and Technology As Figure 1 illustrates, scientific knowledge accumulates from essentially external sources (the general body of scientific knowledge in literature and institutions) and from specific research in a particular area (in our case the Cimanuk Delta). Such research potentially has welfare value in two senses: (11 to expand resource use by introducing new products of value and/or by introducing better inputs into production and (21 to consolidate the natural resource base, i.e., to prevent ecological, and hence economic, deterioration. This scientific knowledge tends to centralize. We may therefore speak of a technocratic centre. The ideas accumulated in the centre then need to be transferred through some information flow to be applied in the local region for value to be realized.

FIG. 1. Links between scientific knowledge and local resource use These points and Figure 1 are straightforward, simple, and seem common sense. They do, however, raise questions of how we see the world of technology, and the process of change and development. How we see these things will affect how we,.as technocrats, estimate the welfare value of our research efforts. Let me expand on this by looking at development very broadly. In a broad sense, Figure 1 represents a neo-classical, modernization view of development (e.g., Rostow 1961; Hoselitz 1960). The flow line represents "capital" to be diffused to regions; this diffusion, which for planning needs to be efficient (Ibrahim and Fisher 1979), may have to penetrate obstacles in the local area (e.g., the conservatism of values). In this argument the centralization of capital is first necessary because it is "scarce"; concentration of capital will lead to faster national growth than if it were not concentrated, and the results of this concentration (growth) will eventually be spread or redistributed to wider regions (Hirschman 1972). This view of development is still very much in vogue, even though within it new arguments have been developed about redistribution with growth (Chenery 1974). It is a view which rests on the work of modernization theorists of the 1950s and 1960s, typified in the American journal Economic Development and Cultural Change (for an excellent criticism, see Frank 1969). It is a view which is held by Indonesia's development planners. Another view of Figure 1 in the broad context of development (a view which sometimes has to do with dependency theory and neo-Marxist thought but which may generally and more properly be called an unequal relations view) focuses on the inequality that capital and technology may introduce in certain socio-political contexts (e.g., Amin 1976; Emmanuel 1972; Logan and Missen 1979). This view is concerned as much with what might be called production relations as it is with technology's potential to raise "resource horizons"; technological inputs may alter the institutional fabric of old societies whereby only certain groups come to control both the ownership of the technologically advanced means of production, and, also, the way higher production is distributed. In both views, technology and skills are seen as crucial in raising the general level of production (Emmanuel 1974); they differ in their understanding of the social, economic, and political context in which technology is applied. Within an essentially capitalist, free-market system, the first view (modernization) sees the technocratic centre as ultimately beneficial to the local region; the second view would argue that in such a system the centre is more concerned with its own values and its own growth (really in the city) within a programme of national growth, in which local regions are obliged to adjust to macro-forces. I raise these two broad views of development simply to suggest that the way we, as technocrats, eventually assess our work in a place like the Cimanuk Delta will depend on whether we see the broader issue of development as one of modernization to be diffused, or rather as a more complex process in which technocracy, inter alia, may work to shift production processes and socio-economic institutions in favour of the rich and against the poor. In any event, we are in a sense obliged to adopt the first of these views because that is the stance adopted by Indonesia (as reflected in Repelita). Assuming that technology or scientific knowledge aims at improving local welfare, it faces two problems. First, science, or at least the advice that flows from science, must be suitable to local social and economic conditions. The responsibility of scientific advice is not simply to stretch the resource horizons, but to predict the social and institutional changes technological inputs may bring, and to judge whether these are worthwhile. I might add that social and economic forecasting is not easy. The second problem is that once we have a set of ideas we assume to be good these ideas have to be communicated. Logically, the first of these tasks should precede the second. It is not always so, of course. Let me give one example from Java. In the early 1960s, on scientific advice, legislation was enacted to outlaw certain rent arrangements (e.g. iron, sewa, gade) in Java's rural villages and also to make the sale of village land easier (Collier et al. 1977; Hesti Wijaya and Sturgess 1979) . The general intent was to modernize agrarian laws. The advice behind this legislation was assumed good; the advice was "communicated" by way of government enactment. The part of this legislation having to do with rent showed, in retrospect, a lack of awareness of the value of "traditional" or local rent arrangements to local people. While there are some tani in Java's villages who are wealthy, there are more who do not have enough land or other assets and many who have none, the buruh or labouring class. Established systems of rent, flexible and risk-spreading, were designed to apportion a mass of general labour to rather small resources, and to do so with some social justice, if not perfect equity. The fact that the new rent laws have not been generally adopted in nearly 20 years (where old rent systems persist they are really lapsed laws) indicates that they were laws inappropriate to local circumstances (Hesti Wijaya and Sturgess 1979). On the other hand, the Agrarian Law of 1960 has made the sale of village land easier, and it seems that selling land is now a more widespread practice (see, e.g., the case outlined in collier at al. 1977, of a shift from communal land ownership in Desa Rowosari). This is understandable if one realizes that selling land in dire circumstances is one way a poor household can obtain some respite. One effect of the legislation has been very important in some areas: it allows outsiders to purchase land in local communities. This tendency has been in keeping with, and partly sponsored by, the capitalization forces generally operating in Javanese agriculture over the last 15 years or so. The entry of outsiders into village land ownership-and some villages have as much as three-quarters of their land owned in such a way (Collier et al. 1977) - has meant, among other things, a disruption of local institutional arrangements which allowed, with some equity, the landless and the poor access to work and income. The complex changes that may result from technology, in its broadest sense, are perhaps best illustrated in Java with reference to the sawah, the irrigated rice field that forms the backbone of the island's village economy. Before coming to this, let me make some generalizations about the possible detrimental effects of technology and secondly put the sawah in the socio-economic context of a coastal village. Some Possible Effects of Technology As I said at the beginning, technology and scientific research can, in two broad ways, increase the resource horizon and also work toward conserving resources (which is, of course, not unimportant in Java, where population pressure on resources is great indeed). But along with these truly developmental possibilities may come changes in the society and the economy that arouse more concern. These changes are: 1. An increase in production costs (e.g., seeds, fertilizers). 2. An increase in the sea/e of operation to make the adoption of new technologies worthwhile. 3. An increase in management needs (e.g., managing the high-yielding varieties of rice [HYVs] with their shorter growing period is much more difficult than managing the traditional varieties, which had more time to adjust to the shocks of drought, transplanting, pests, weeding, etc.). These increased management needs produce an increase in risk costs. 4. A combination of (a) more potential value to be derived from more scientific production and (b) increased costs and scale may produce forces which concentrate production in certain hands, i.e., the wealthy; changes in asset ownership patterns result and may be associated with an increase in outside urban owners of village land. Further, mechanization is often one way the wealthy can reduce costs, so this is also a likely accompaniment. 5. Institutional changes plus mechanization can displace labour, increase unemployment and underemployment, contribute to circular migration (whereby labour use from the household divides between the local area and the city [Hugo 1951] ), and increase inequality. These of course are all-important in Java where labour is abundant, the masses are poor, and inequities are already considerable. These generalized possibilities may be illustrated with reference to a particular case, the changes in village rice production. Before doing so, let me generalize still further to see the sawah within the broader horizons of a Javanese village. A Socio-economic Schema of a Village Figure 2 attempts to depict the important socio-economic elements we may need to consider in understanding a coastal village. Here I shall concentrate on the "village" side of the diagram. 1. The production and income sources are represented in the boxes in the middle of the Figure. I assume that sawah and tambak are the primary sources, both dependent in a fundamental sense on water control. 2. The main economic unit is the nuclear household (represented by a circle) whose main resource is its labour (for production) and whose main concern is for labour (for consumption). Both subsistence and commercial production employ household labour. 3. Labour (thick lines) applied to the production units is derived from two sources: from the village households and from outside the village. External labour is often production- and task-specific, competing with local labour for employment in certain types of production or for particular jobs in the production cycle. 4. The allocations of labour to productive assets, capital and income opportunities (or if you like, production relationsl, are represented by the thin lines that link households with administration, households with outside owners of productive assets (especially land), and one household with another. The specific ways labour is allocated rest on answers to the following questions: Who owns the land, the tambak, the boats, etc., and in what amounts? What are the instituted arrangements which apportion labour to these assets? What are the rewards for labour in the apportionment, A fundamental concern in examining village society and economy is to understand how these relations are changing and why, for they are central to our appreciation of growth, distribution, and employment. In the past, the Javanese village has had institutional arrangements which some have called "poverty sharing" mechanisms (Geertz 1963). These are undergoing change (related partly to technology) and there seem to be incipient class formations developing (Storer 1977). In general, we may note (from Hart, quoted in Collier et al.. 1977) three broad groups: ( 1 ) those with sufficient assets to support the family (some of whom will have enough assets to hire labour); (2) those with some, but insufficient, assets to support the family, so that some family labour will be hired out to (1), often at certain times of the year according to production cycles; and (3) those with no assets and who are solely dependent on hiring out their labour. We should make two notes in connection with the allocation of labour and assets. First, households may own assets or send labour outside the local area just as outsiders may have assets or work in the village. In general, as technological and institutional change has taken place in Java, the spatial dimension of production relations has broadened and the village has become less of a production "community." Secondly, advanced technology tends to concentrate in class (1), and tends to expand the number in class (3) which, in turn, may lower the price of labour in class (3). 5. The "learning" lines in Figure 5 are of three types: research which is centralized and diffused; values and ideology which are part of the habits of local culture; and finally the experience of people involved in the "day to day" business of both producing and relating with owners and/or workers. Value and experience may to some extent affect how things are produced and whether new technologies are adopted; modernization theorists would, for example, see traditional values as obstacles to be overcome before new technologies are adopted. They are also related to production relations; for example, one value system may stress communal activity, another independence. Too much can be made of these matters, however. To suggest for example that a low level of production and technology within a village is the result of a learning environment unsuited to capitalism or advanced technology suggests villagers are slow learners, tradition bound, value ridden, unentrepreneurial, even lazy. None of these things may be true. Such a view of things, moreover, tends to see a value system as a constant, whereas values change as the wider social and economic environment changes. One needs to appreciate that in conditions of poverty, and particularly when men and women have little more than their labour to "sell," an individual's economic behaviour is not so much a matter of his values as it is of what he can afford, or is allowed to do.

FIG. 2 Village-coastal ecology links Institutional and Technology Changes in Sawah In recent years a number of institutional changes have appeared in Java's villages which have altered the ways labour has traditionally been apportioned. These changes, as we shall see, are partly related to the technological advances in high-yielding varieties of rice (HYVs) brought by the Indonesian BIMAS packages since 1968. The changes appear so far at the harvesting, hulling, and distribution-toharvester stages of rice production. The old bawon system which absorbed large numbers of villagers into rice harvesting is giving way to something far less labourabsorptive. A number of studies (for example, Collier et al. 1973; Collier et al. 1977; Palmer 1977; Sinaga 1978) have noted these changes. The following summary is drawn from Collier etal. 1977. One aspect of the old system was the use of large numbers of villagers often mostly women, harvesting the rice essentially stalk by stalk using the ani-ani, a small razor-like instrument. Harvesters were entitled to one-fifth to one-fourth share of what they gathered, an entitlement that stemmed from their status in the production and social system. One or two days after the harvest, gleaners (women and children) would come to the field to pick up what was left on the ground after the harvest; again, the system entitled them to free gatherings. At the hulling stage labour (again often female) was intensively used. At the sharing stage of the harvest, women would, at the owner's house, select the biggest stalks in their claims to, say, a fifth share; this specific and personal way of allocating shares -allowed by social pressures in the village-often meant that a fifth share became a quarter. This system may raise some queries in the minds of traditional economists, but what it did provide was the use of much village labour in the production process, plus sharing, even if this may have been at times "sharing poverty." A number of things are altering this system. The ani-ani was once a useful instrument to maximize yields via its stalk-bystalk cultivation. With the increase in harvesters brought on by population growth (a demographic cause) and also by an increase in people who need to harvest for income purposes (an economic cause sponsored by a change in production relations), harvesting under the,oawon system has increased the costs of production by raising the risks of harvest (e.g., loss through stamping, dropping, and theft). To reduce these sorts of risks, the land owner has often called in a middleman (penebas) to control the harvest; he is often an outsider. Under this tebasan system, social pressures to conform to the old bawon system are less and the normal result is a reduction in the number of harvesters; indeed, the middleman sometimes brings in his own harvesters. Another change has been the introduction of the sickle in place of the ani-ani. This was a result of the general concern for reducing costs, and has halved the number of harvesters needed under the old system; it also tends to reduce what is left for gleaners; indeed, it may be argued that this was part of the reason for introducing the sickle, for recently gleaners were entering the field on the same day as the harvest, creating a general melee of people and making harvesting difficult to control. In addition, mechanized rice hullers have been widely adopted, with obvious effects on labour use. Collier et al. ( 1974) have estimated, for example, that hullers have lost some 125 million women-days of labour in Java (equal to a loss of $US 50 million to labourers). Further, the use of weighing scales, often by the penebas, has meant that the distribution of the harvest has become quite specific, at a cost to the harvester and at a saving to the owner or middleman. Now it may be argued that these changes have been brought on by Java's population growth, although, as I have said, this growth, in the paddy field as it were, is a function not only of natural demographic increase but of economic forces releasing labour. But these changes are also part of the introduction of HYVs of rice. Theoretically, this new technology of the 1960s (HYVs) promised a four- or five-fold increase in rice production. What it has tended to do is replace labour and concentrate wealth. It is not simply that the promise of higher yields is attractive to those better placed to increase their sawah assets; it is also a matter of costs of production being greater with HYVs-for seeds, fertilizers, and the like. Greater risk costs are involved in the management needs we have already mentioned. There is, thus, generally a greater impulse to reduce costs-and this has tended to take the form of labour-saving devices at the harvesting and hulling stages. We might note, here, that there is further room for labour displacement through mechanization of the ploughing and transporting stages of the production process, as is occurring in Kedah in Malaysia, but which appears to be less evident so far in Java. Despite these quite considerable changes in the economic and social systems related to rice, the HYVs may not yield very much more than traditional varieties; what appeared promising in the laboratory often appears disappointing to the tani in the field (Collier etal. 1977). It can be argued, of course, that the changes outlined for sawah are inevitable if rice production is to increase (accepting the promised potential of HYVs). Given the impact these changes have upon the poor, this is an argument I find trouble in accepting. But this is not the point I wish to make. Rather, the point is that these sorts of changes were not predicted at the time the new technology was introduced. They perhaps should have been. And perhaps they would have been had there been more awareness that technology cannot be divorced from social and economic realities. Now what I have said concerning the "technological impact" on rice does not mean to say that technology will, in the Javanese village situation, necessarily have the result of increasing unemployment and inequality, and upsetting established institutional arrangements. Small-scale, cheap technologies that raise production may have little such impact yet improve welfare. Larger and more costly technologies will, I would argue, mean a shift of assets to larger producers and an increase in the proportion of village labour that is hired, but such changes in the production relations may still mean that employment levels can be maintained in total. Let me give an example of what I mean by referring to the tambak-the brackish-water fish pond. The tambak may be small (about 1.5 ha) or large (about 3.5 ha or more). It is used on the north coast for the cultivation of shrimp or fish (milkfish) or both. Shrimp cultivation is a day-byday operation dependent upon the entry of the tide, and milkfish cultivation is more complex and costly with cyclical operations involving repair and pest cleaning of ponds, the purchase of fry for the nursery and eventual transfer to the pond, and raising the fish (four to six months). Polyculture (fish and shrimp) is more complex and obviously difficult if one depends on tides (entry and exit) for shrimp stocking. The main labour involved in this system is for pond digging, cleaning, etc., a periodic task (Collier et al.. 1977). There is little doubt that greater productivity can be achieved from these ponds through better operations, knowledge, and the application of better technologies (e.g., a better knowledge of tides, better sluice control, insecticides to control pests, fertilizers to increase food stock). Some of these are more costly than others, and each may have intricate repercussions on the ecological system. Fish offers the best chance of increasing incomes, but fish is more capital intensive (and dependent on the techniques of fry supply and transport-matters outside the area in the wider economy). Two other facts are needed before we comment. The construction of a tambak is costly (about 1/4 million Rp per ha). Secondly, labour employed per ha is less in the large ponds than in the small ponds and the large ponds depend relatively more on hired labour than family labour (Collier etal. 1977). For purposes of illustration, let me describe three possible employment impacts that may stem from improved technologies. First, small-scale improvements may be made to lift the shrimp cultivators' production with no lowering of labour employed (and perhaps with some marginal increase). Second, a technology-resources package which favours fish is likely to concentrate in the hands of the big operators (for various reasons, the principles of which are similar to what happened with rice); if this occurs by big ponds taking over established small ponds with no increase in total pond area, some labour is likely to be displaced and will have to be absorbed into other parts of the economy. Third, if a higher fish-technology package is developed but for new large ponds (i.e., an increase in total pond area), increases in employment opportunities may arise. I need to add that these examples are simplified; the impacts on the socio-economic system are likely to be more intricate than this. Let me end by saying something about the problem of communicating the ideas of science to the local population, again with reference to tambak and drawing some lessons from the sawah experience. Again, my comments are to serve as an illustration of complexity. Assume that technology offers ideas to improve tambak operations and production. There is, it seems, likely to be resistance to these ideas on the part of some operators and labourers, especially if the ideas involve a high level of risk and require experimentation. Part of this resistance will stem from the experience with the technological impact of sawah-which has not been uniformly beneficial. One way of overcoming this resistance, perhaps, is to experiment with new tambak technology on a village scale-i.e., through co-operative or higher taxed effort through the village administration. One thing that may constrain this, however, is the fact that the village administration may no longer be strong and the amount of tax collected may be less because of the entry of outsiders into the ownership pattern of the village assets. Even if the administration is socially a cohesive part of the village and amenable to co-operative effort to experiment with a better tambak, the results of this experiment may be skewed to the larger scale, wealthier operators. If only these operators adopt the results of the experiment, it will be a case of the village labour contributing to the experiment for the ultimate benefit of the few. To conclude, I have not been arguing that technology is irrelevant or useless. Rather I have been arguing for its relevance. But it requires an understanding of society and economy, not in a simple descriptive or static sense, not of "what is there," but an understanding of what has happened, is happening, and may happen. Until that understanding touches technocracy I suggest that priorities are misplaced and that technology runs the risk of being institutionally disruptive and irrelevant, or worse, to the poor. References Amin, Samir,1976. Unequal development: an essay on the social formations of peripheral capitalism. Hassocks, Sussex. Chenery, H. et al. 1974. Redistribution with growth. London. Collier, W. i.; Gunawan Wiradi; and Soentoro (1973). Recent changes in rice harvesting methods. Bulletin of Indonesian Economic Studies 9:36 - 45. Collier. W. L.,; Jusuf Colter; Sinarhadi; and Robert d'A Shaw 1974. Choice of technique in rice milling-a comment. Bulletin of Indonesian Economic Studios 10:106 - 121. Collier, W. L.; Harjadi Hadikoesworo; and Suwardi Saropie 1977. Income employment, and food systems in Javanese coastal villages. Ohio University Center for International Studies Southeast Asia Program, Athens, Ohio. Emmanuel, A.1972. Unequal exchange; a study of the imperialism of trade. New York. __________1974. Myths of development and myths of underdevelopment. New Left Review 85:61 - 82. Frank, A. G.,1969. Sociology of development and underdevelopment of sociology. In his book, Latin America: underdevelopment or revolution. New York and London. Geertz, C., 1963. Agricultural involution: the process of ecological change in Indonesia. Berkeley and Los Angeles. Hesti Wijaya and N. H. Sturgess 1979. Land leasing in East Java: some observations from around Malang. Unpublished paper presented to the 23rd Annual Conference of the Australian Agricultural Economics Society, 6 - 8 February, Canberra. Hirschman, A. O., 1972. The strategy of economic development. New Haven and London. Hoselitz, B. F.,1960. Sociological factors in economic development. Glencoe. Hugo, G., 1975. Population mobility in West Java. Unpublished Ph.D. thesis. Department of Demography, Australian National University, Canberra. Ibrahim, A. M., and H. B. Fisher 1979. Regional development studies and planning in Indonesia. Bulletin of Indonesian Economic Studies 15:113 - 125. Logan, M. l., and G. J. Missen 1979. Unequal relations and unequal development. Unpublished paper presented to the Seminar on National Development and Regional Policy, United Nations Centre for Regional Development, November, Nagoya. Palmer. I., 1977. The new rice in Indonesia. United Nations Research Institute for Social Development, Geneva. Rostow, W. W.,1961. The stages of economic growth: a noncommunist manifesto. Cambridge, Mass. Sinaga, R. S., 1978. Implications of agricultural mechanisation for employment and income distribution: a case study from Indramayu, West Java. Bulletin of Indonesian Economic Studios 14:102 - 111. Stewart F., and P. Streeten 1976. New strategies for development: poverty, income distribution and growth. Oxford Economic Papers 28. Stoler, A., 1977. Rice harvesting in Kali Loro: a study of class and labour relations in rural Java. American Ethnologist 4:678 - 698. Discussion Hehuwat: The figures are very suggestive, but why have you left out land resources and external influences? Missen: The box labelled production also represents land assets. Labour is applied to these in various ways; the labour allocation is represented by the lines between the household circles. As for external influences, yes, I agree they should be included. Vayda: In the diagram of the UNU programme, the cultural and socio-economic factors are noted only as obstacles. Is this your view? Missen: Cultural and socio-economic factors should not be regarded simply as obstacles.

The mangrove ecosystem of the northern coast of west Java Sukristijono Sukardjo Introduction The role of the mangrove ecosystem as a natural resource in Indonesia is increasing in importance. In Java, this is reflected in the rapid depletion of the mangrove forest through its conversion into agricultural land, tambak (fish ponds), and other uses which have been reviewed by Sukardjo (1978). Unfortunately, the natural regeneration of desired species such as Rhizopbora spp. and Bruguiera spp. in the mangrove forest in Java is generally poor. It is sad, however, to note that the remaining virgin mangrove forests of the northern coast of West Java e.g., Ujung Karawang, are now subject to exploitation for firewood and other uses. This eventually paves the way for their further conversion into tambak as seen in the areas around Sukamandi, Bolongan, and Marunda. Owing to the importance of mangrove resources on the northern coast of West Java it is urgent to record more accurately the extent of mangrove forests, which are one of the primary features on the coastal zone. The main objective of this paper is to provide information on the present status of the mangrove ecosystem of the northern coast of West Java which can be used as basic data for its development, especially in connection with the coastal resources management programme. Environment of the Northern Coast of West Java The whole area is mostly flat with an elevation of less than 10 m. It is extensively dissected by rivers running to the Java Sea. The main rivers are the Cimanuk, Cipunegara, Citarum, Bekasi, Ciliwung, Cisadane, and Cilontar (Fig.1). The soil consists of alluvial material, a complex of yellow-red prodsolic soil, latosol, and lithosol that originated from igneous rocks and sedimentary materials (Soepraptohardjo 1972). Few studies concerning the properties of mangrove soils on the northern coast of West Java have been made, except on the Ujung Karawang area, which was investigated by Soerianagara (1971). Alrasjid (1971b) and Sukardjo (1979a) reported data on soils up to 20 cm deep from both mangrove forests in Ujung Karawang and the Cimanuk Delta (Table 1). The mangrove forest on the northern coast of West Java has developed under the over-wet to (mid-year) dry climate (Kartawinata 1977). According to Schmidt and Ferguson (1951) the area belongs to the D (Mauk, Indramayu, and Ujung Karawang) and the C (Jakarta and Pamanukan) types, with the mean number of dry months (less than 60 mm) from 4.0 to 4.7 and the mean number of wet months (more than 100 mm) from 4.8 to 6.7; the ratio between dry and wet months is 0 - 79.9 per cent. The area has an annual rainfall of about 1,446 to 1,793 mm (Berlage 1949). The rainy season occurs mostly from November to March or April. During this period the rainfall is plentiful and regular, with very small variability, although the maximum rainfall occurs in January. Throughout the coastal area the duration of the dry season is less than 7 months. The seasonal temperature variations are very small, i.e., 0.9°C. The mean monthly temperature during the dry season rarely exceeds 27.5°C, and during the rainy season rarely drops below 25.1°C, mostly remaining at 26.8°C. The average relative humidity also remains fairly constant at about 65 per cent and rarely drops below 50 per cent. The climate diagrams for the meteorological stations at Indramayu, Pamanukan Cabang Bungin and Batujaya (Ujung Karawang), Jakarta, and Mauk are presented in Figure 1. Extent and Distribution of Mangroves Occurrence The mangrove forest of West Java covers an area of approximately 21,642 ha, of which about 200 ha are designated as nature reserve (e.g, Ujung Kulon, Muara Angke, Rambut Island, and Dua Island). Mangroves are found mainly in Jakarta Bay and from Ujung Karawang to Indramayu (Table 2, Fig. 1). The forest is concentrated along the coastline and estuaries of the Citarum and Bekasi rivers. The mangrove forest is confined to certain coastal stretches. The coastal region including the estuaries, backwaters, and creeks is fringed with mangrove vegetation. Some of the areas like Rambut Island and Dua Island, and the Ujung Karawang region show a luxuriant growth of mangrove forests, while other areas, such as the Cimanuk Delta and Sukamandi regions have been degraded because of destruction by human activities. Human pressure in the mangrove area is strong everywhere. Table 1. The Chemical and Physical Properties of the Soil in Some Areas of the Northern Coast of West Java (After Alrasjid 1971b and Sukardjo 1979b) Locations Soil Properties

Ujung Karawang

Cimanuk-lndramayu



1

2

3

4

5

6

Tiris

PS 1

PS 2

PS 3

PS 4

PB 1

PB 2

PB 3

PB 4

Soil depth (Cm)

1 - 20

1 - 20

1 - 20

1 - 20

1 - 20

1 - 20

1 - 20

1 - 20

1 - 20

1 - 20

1 - 20

1 - 20

1 - 20

1 - 20

1 20

-Sand

0.4

14.2

1.9

5.6

0.8

0.3

9

13

1

4

83

5.6

9.3

11.2

10.5

-Silt

33.9

34.6

58.2

27.6

27.6

27.6

29

38

53

25

13

30.30

39.80

27.90

33.50

-Clay

65.70

51.20

39.90

66.80

72.10

72.10

62

49

46

71

4

64.10

50.90

60.90

56.00

-H 2 0

7.50

6.80

7.15

7.25

6.50

5.25

5.10

7.60

7.80

7.00

8.40

7.50

7.50

7.00

7.00

-KCI

7.00

6.40

6.85

6.85

6.20

4.35

4.60

7.10

7.00

6.50

7.30

7.00

7.00

6.50

6.50

Organic Matter(%)

11

18

8

15

16

11

19

12

15

12

7

10

11

11

11

-P2 O 5

52

53

52

62

53

95

53

61

60

74

89

72

76

71

74

-K 2 O

265

316

68

274

2192

21

184

152

147

145

86

158

158

135

152

-CaO

570

400

500

600

310

80

388

390

571

366

482

378

378

521

413

-MgO

-

-

-

-

-

-

1041

1044

921

968

1169

957

957

900

909

Texture (%)

pH

Nutrient (Mg)

Exchangeable cation (M.E)

-Ca

10.90

8.00

14.50

10.90

10.10

8.80

-

-

-

-

-

-

-

-

-

-Mg

4.50

4.40

4.10

4.20

4.20

6.20

-

-

-

-

-

-

-

-

-

-K

3.10

3.10

0.50

5.20

3.40

1.10

-

-

-

-

-

-

-

-

-

-Ma

36.00

35.40

7.30

26.60

29.00

8.50

-

-

-

-

-

-

-

-

-

Adsorption capacity

77.50

69.90

77.70

46.90

46.70

35.20

-

-

-

-

-

-

-

-

-

Key to table: PS = Pancar Song PB = Pancar Balok

FIG.1. A map showing the locations and the climate diagrams of the mangrove forest areas on the northern coast of West Java However, much variation exists in estimates of the extent of the mangrove, and it is not clear whether this is because of the fast rate of reclamation, the result of natural destruction, or due to errors in the surveys. It is also not clear whether the estimated area includes only the wooded area or the total mangrove environment including salt marshes. Therefore, there is a need to have more accurate surveys. Structure and species composition The mangrove communities on the northern coast of West Java are structurally and floristically varied, from the relative simple community (e.g., Muara Angke) to the more complex and luxuriant community (e.g., Rambut Island and Ujung Karawang). However, in some areas, such as Sukamandi, Indramayu, and Pamanukan, the mangrove is declining (Sukardjo 1979a, b). Few studies on the ecology of the mangrove community of this area have as yet been carried out. The forest on the Cimanok Delta has been recently investigated by Sukardjo (1979a), that on Rambut Island by Kartawinata and Waluyo (1977), and that on Dua Island by Buadi (1978). The silvicultural investigation in the Ujung Karawang mangrove was undertaken by Alrasjid (1969). The study of flora and fauna found in the mangrove forests of various places on the northern coast of West Java has received greater attention (Burhanuddin and Martosewojo 1978; De la Cruz 1978; Hutomo and Djamali 1978; Munaf 1978; Soemodihardjo and Kastoro 1977; Sukardjo 1978; Toro 1978). Table 2. Mangrove Forests in West Java

Area in hectares Productive

Unproductive

Nature Reserve Total

Ujung Kulon

-

-

125

125

Dua Island

-

-

8

8

Rambut Island

-

-

25

25

Bokor Island

-

-

18

18

Muara Angke

-

-

15

15

Ujung Karawang

-

10,035.15

-

10,035.15

- KPH Bogor

2,196.00

-

-

2,196.00

Pamanukan









- KPH Purwakarta

1,283.90

-

-

1,283.90

Indramayu









- KPH Indramayu

3,586.79

-

-

3,586.79

Indramayu and Pamanukan

-

4,349.41

-

4,349.41

Total West Java

7,066.65

14,384.56

191

21,642.25

Source: Direktorat Bina Program and PPA (Directorate General of Forestry, Bogor) The species composition of the mangrove forest on the northern coast of West Java differs from one area to another. The forest consists of up to 29 species of mangrove trees, along with various shrubs and herbs. The most common and typical mangrove species occurring in the area are shown in Table 3. It is evident that Avicennia marina and A. alba are dominant and have a large number of individuals in all sites. Human Impact on the Mangrove Ecosystem Very little work has been done on human aspects of West Java mangrove resources (Arwati 1977; Kunstadter 1978; Kunstadter and Tiwari 1977). A survey of the mangrove ecosystems on the northern coast of West Java has been done by Soemodihardjo et al. (1977), particularly those found in Jakarta Bay and adjacent areas. Sukardjo (1978, 1979b) and De la Cruz (1978) studied the human uses of the mangrove environment and the traditional use of mangrove species, and the Direktorat Bina Program (Directorate of Forest Planning) study (1977) was concerned with the stand density. Effect of mangrove modification on human populations On the northern coast of West Java, many mangrove forests have been cleared for various purposes such as tambak and agricultural land (Schuster 1949, 1952; Sukardjo 1979b). Poor coastal zone management has induced land erosion. Large-scale agricultural land reformation is resulting in stress to the mangrove ecosystem. The erosion of coastal areas seems to occur at several places annually. Further cutting of the mangrove forests and development of the tambak accelerate the erosion process, although these aspects have so far not been studied in detail (Hehanussa, personal communication). Because of pollution, the productivity of the mangrove environment decreases constantly. The mangrove ecosystem, which is also considered the best nursery grounds for fish species, is adversely affected by pollutants. Quantitative and qualitative appraisal of humaninduced stresses Natural and human-induced stresses disturb the mangrove in various ways. There are different types of humaninduced stresses on mangrove environment, such as indiscriminate cutting, reclamation of mangrove areas, pollution of the wetland, and grazing on dryland. These stresses should be investigated further. Table 3. The Distribution of Typical Mangrove Species in Terms of Their Relative Dominance in the Northern Coast of West Java

Bokor Island

TREES



Apocy naceae:

Dua Island

Lancang Island

Pari Groups Island

Rambut Island

Muara Gembong

Ujung Karawang

Marunda

Sukamandi region

Pamanukan region

Indramayu region

























1. Cerbera manghas L.













o











Combretaceae:

























2. Lumnitzera littorea (Jack.) Voilt.



o

o

o

o

o













3. L. racemosa L.



o





o



o













o





o

o

o



o









o

o



o















6.Xylocarpusgranatum Koen





o



o



o



o







7.X.maluccensis (Lamk.) Roem.





o



o



o



o







o

o

o

o

o

o

o





o

o

o













o



o









o





o



o











11. Bruguiera cylindrica (L.) Lamk.

o

o





















12. B. gymnorrhiza Lamk.

o



o

o

o

o

o



o



o

o

13. Criops decandra (Griff.) Ding Hou. o



o



o

o













14. C. tagal (Perr.) C. B. Robins





o



o

o













15. Rhizophore apiculata B1



o

o

o

o

o

o



o

o

o

o

16. R. mucronata Lmk.





o



o

o

o

o

o

o

o

o

17. R. stylosa Griff.

o

o

o

o

o















18. Sonneratia alba J. E. Smith





o

o

o

o

o



o

o

o

o

19. S. caseo/aris (L.) Engl.

















o







20. S. ovata Back.



o















o





21. Avicennia alba B1









o

o

o

o

o

o

o

o

22. A. marina (Forsh.) Vierh.



o

o

o

o

o

o

o

o

o

o

o

23. A. officinalis L.









o

o

o

o

o

o

o

o



o

o

o





o

o

o

o

o

o





o







o



o







Mauk to Mura Angke

Euphorbiaceae: 4. Excoecaria agllocha L. Lythraceae: 5. Pemphis acidula J. R. & G. Forst. Meliaceae:

Myrsinaceae: 8. Aegiceras corniculatum (L.) Blanco Palmae: 9. Nypa fruticans Wurmb. Rubiaceae: 10. Scyphyphora hydrophyllacea Gaertn. Phizophoraceae:

Sonneratiaceae:

Verbenaceae:

TERNA Acanthaceae: 24. Acanthus ilicifolius L. Polypodiaceae: 25. Acrostichum aureum L.

Key to table: Rare : o 0.1% Very common: o 5 - 50% Less common: o 0.1 - 0.5% Dominant : o 50% Common : o 0 5 - 5% Data collected by Mr. Buadi (Dua Island), Mr. Aliasrid (Ujung Karawang), and Mr. Victor Toro (Part Groups Isdand). 1. Pollution Pollution on the northern coast of West Java is constantly increasing due to the lack of regulations dealing with the disposal of industrial and other wastes from various cities. For different types of pollution, such as industrial, oil, sediment, and sewage (Hehanussa, personal communication; Soegiarto 1973,1975a, 1975b; Wisaksono 1974), the common outlet of pollutants is the estuary, where mangroves are invariably present (e.g., Ujung Karawang, Marunda, and Cimanuk). Although a considerable amount of work has been done on different aspects of pollution, none of it has been concerned with the toxic effects of pollutants on the mangrove flora and fauna or on the mangrove ecosystem. There is no doubt that some pollutants are capable of destroying the mangrove ecosystem on the northern coast of West Java. Recently, l observed that industrial wastes and petroleum products appear to be harmful to the growth and the survival of the mangrove seedlings. A one-year observation of the remaining mangrove forest at Sukamandi through Tegal and of the virgin forest on Rambut Island indicates that the mortality of Rhizophora mucronata seedlings is 10 to 15 per cent. Sewage and industrial wastes from the cities, as well as miscellaneous household wastes, accumulate a great amount of organic materials and have an influence on the mangrove. My preliminary observations on the establishment of mangroves in polluted areas indicate that a remarkable change in the faunal communities on the mud surface is taking place. A heavily polluted area does not support as great a variety of animals. 2. Indiscriminate cutting Mangrove forests on the northern coast of West Java have been adversely affected by illegal cutting at the Cimanak Delta, Sukamandi, Muara Gembong, and Marunda. During one year of observation, especially on the dry period, it was found that about two pikul (+ 40 kg) of wood/day/ha were removed from these areas. This includes trees and saplings. The illegal cutting is mostly attributed to the difficulties in obtaining firewood in the village and to the poverty of the villagers, 3. Reclamation of mangrove areas According to the Direktorat Bina Program, the total area of forest in West Java is estimated to be 991,340.32 ha (22.23 per cent of the total land area). This includes 476,474 ha of protected forest (including nature and game reserves) and 514,867 ha of production forest (Direktorat Bina Program 1977; Haeruman et al. 1977; Wiroatmodjo and Judi 1978). Table 2 indicates that most mangrove in West Java is classified as unproductive, consisting mainly of abandoned cut-over forest. Due to this situation, the destruction of mangrove areas by the villagers and other local inhabitants is still going on. Unfortunately, the mangrove forests of the northern coast of West Java show many examples of areas where reclamation of the forests or marshy areas has been undertaken on a small scale by local inhabitants. In the last decade, the illegal destruction of mangrove areas by local people has become a great problem in terms of coastal resources management. Studies to find remedies have not yet been undertaken. In the Cimanuk and Sukamandi regions, for example, approximately 500 ha have been converted into agricultural land and tambak by local inhabitants since 1950. A few years ago there was a continuous belt of mangrove vegetation from Mauk to Muara Angke. Today, due to the population pressure, all of these areas have become tambak areas (e.g., Marunda). Based on field observations from 1977 to 1979, I estimate that more than 1,500 ha of the mangrove forest land on the northern coast of West Java have been converted into tambak and agricultural land. There is no data available on the total loss and decline of mangrove areas in Indonesia as a whole. However, from the information given above, some estimate can be made. Economic Importance of the Mangroves of the Northern Coast of West Java Sound management leads to the optimal use of the mangrove ecosystem for long-term benefits to human communities. This ecosystem is viewed as a valuable natural resource that provides free services and goods for human needs, and it functions without subsidies. People have the option to manage this ecosystem in its natural state or to subject it to limited or complete modification for other uses. Management must be in such a form that yields direct benefit to the local community (Soemodihardjo and Nontji 1978). The scope of the management scheme must be based on regional ,features of geomorphology, hydrology, labour, skills, and the social and economic structure of the community. Rational management schemes require decision-making criteria based on calculating the net value (total cost and benefits) of the existing mangrove ecosystem, and of the alternative uses for it. It is well known that the mangrove ecosystem on the northern coast of West Java provides fishermen and inhabitants with valuable raw materials like firewood and tannin, although on a small scale (Alrasjid 1971b; De la Cruz 1978; Sukardjo 1978, 1979b). Also, a number of mangrove areas provide a good breeding ground for fish (e.g., Ujung Karawang, Muara Angke). It should be emphasized that the mangrove is little exploited industrially. The principal product is firewood. The forests are quite often used as grazing grounds for buffalo, cattle, goats, and sheep, and as an important source of forage, for which the sprouts and young leaves of Avicennia spp. are preferred (e.g., Cimanuk Delta, Tiris-lndramayu, Sukamandi [Sukardjo 1979b] ). Exploitation of the mangrove forest it was mentioned earlier that remaining mangrove forests on the northern coast of West Java are now subject to exploitation for firewood (e.g., Indramayu, Purwakarta, and Bogor) and other local uses, and later are clear-cut to make tambak. Some areas are already leased for the latter purpose#, e.g., Sukamandi, Balongan, and Cirebon. In West Java the productive mangrove forest covers an area of about 7,066.69 ha (see Table 2). The Rhizophoraceae are now so small in number that they cannot be exploited for tannin. Most of the trees are used only as firewood. The average production is about 19.8 m³/ha/year, consisting of trees of cutting-age classes IV through Vll. They mostly come from Indramayu (Haeruman et al. 1977). The acreage of mangroves in West Java according to age class is presented in Table 4. In the remaining mangrove areas, Sukardjo (1979a) estimated that Avicennia alba and A. marina make up nearly 90 per cent of the saplings (diameter: 2 - 9.99 cm), especially those in the Cimanuk Delta. Both species occur gregariously throughout the Indramayu and Sukamandi areas. Their natural regeneration rate is good, and seed is efficiently dispersed by tidal waters. For full growth the young plants need direct sunlight. In the case of Sonneratia alba and S. caseolaris, which occur together in the Avicennia belt, seedling regeneration is very poor. Unfortunately, firewood is in great demand, especially in coastal districts where mangroves are easily accessible. The villagers prefer firewood collected from the mangrove trees for home consumption. As yet there is no data available on the exploitation of mangrove trees by villagers. Some local uses of the principal mangrove species This is based on field work conducted from 1977 to 1979. The villagers possess the art of effectively utilizing the mangrove forest products, including those of herbaceous plants and halophytes. The use of each species is much the same from one region to another. It is generally the fishermen who make the best use of the plants. Avicennia spp. All species of Avicennia are heavily exploited for their wood, which is considered to make the best firewood for home consumption, especially at Marunda, Muara Gembong, Sukamandi, the Cimanak Delta, and Pamanukan. The sprouts and young leaves are used as fodder and vegetables in Sukamandi and the Cimanuk region. Avicennia is good for reforestation. It produces large quantities of fertile seed that is able to withstand transport by sea water for several weeks. It also coppices well (Alrasjid 1971a). Sometimes Avicennia is used as green manure, especially in the tambak region which is managed through the tumpangsari (multiple crop) system (e.g., Sukamandi and Pamanukan). Nypa fruticans This plant is not very common on the northern coast of West Java, except in Marunda, Ujung Karawang, Tiris, and Balongan. The leaves of Nypa are quite costly since they are highly valued as a roofing material. Planting of Nypa fruticans in some areas in Ujung Karawang or Pamanukan is recommended to supply local needs. Ceriops Spp. There are two species of Ceriops which are collected by local people for firewood. Ceriops decandra is the most important species and it is also used for the construction of small houses and huts. The fishermen also extract a reddish liquid from the bark and use it to protect fishing nets. Table 4. The Hectarage of the Productive Forest by Age Classes in West Java (after Haeruman 1977)

Age Classes (Year)

Area (ha)

1.

0 - 5

4,579.67

2.

5 - 10

824.27

3.

10 - 15

217.00

4.

15 - 20

100.00

5.

20 - 25

52.10

6.

25-30

5.25

7.

30-35

4.50

Total



5,782.79

Lumnitzera racemosa This is a small tree with a dense, hard, and resistant wood. It is used mostly for construction of small buildings and also for firewood. Sonneratia alba This species has been over-exploited for firewood. In the Cimanuk Delta and on the eastern coast of Jakarta it has almost completely disappeared. Aegiceras corniculatum This is a bushy or shrubby species found on all parts of the northern coast of West Java. The wood is used as firewood and for the framework of huts. The fishermen, e.g., in Tiris-Indramayu, use the bark as a fish poison. Excoecaria agallocha This species, along with Avicennia, is one of the common species in Ujung Karawang. It offers a very good plant cover because of its rapid growth. Its wood is soft and light, and is used for making fishing floats, crates, and boxes, and as firewood. Preparations of the latex from the leaves and bark are used in the treatment of many ailments in the countryside. Conclusions and Recommendations The economic importance of the mangrove forest both as an ecological niche and a source of firewood cannot be ignored. Every effort should be made to try to maintain it in perpetuity. Even if a large-scale regeneration of this forest fails, the smaller areas that can regenerate successfully should be maintained as a habitat for marine life and as a perpetual source of firewood for domestic consumption. I believe that we must underscore the urgency of two factors. First, the physical destruction of estuarine mangrove (e.g., Cimanuk areas-Indramayu, Muara Angke areas-Jakarta) must be halted and their biological fitness restored through pollution abatement. Second, it must be widely recognized that estuarine farming is based on entirely different principles than dryland farming. Consideration must always be given to other uses, too. The mangrove forests on the northern coast of West Java are rapidly diminishing. Measures must now be taken before we totally lose the mangrove forests, and the many tangible and intangible benefits derived therefrom that play a vital role in stabilizing the socio-economic life of fishermen (e.g., Ujung Karawang, Cimanuk Delta, Muara Angke). Regarding tambak development in Java and Bali, I recommend detailed studies on the carrying capacity of the mangrove areas before permitting them to be used for tambak culture and other aquaculture projects. The Directorate General of Fishery, in cooperation with the Directorate General of Forestry, is seeking conservation of the mangrove forests in Jakarta Bay at Ujung Karawang. Encouragement should be given also to increase the yield per hectare through the introduction of new technology to improve the production of fish, instead of increasing the acreage (extensification system). In coastal resource management cases involving the structural, dynamic, and economic values of the mangrove system on the northern coast of West Java, while taking into consideration the importance of the mangrove forest and the surrounding environment, I suggest that: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.

Mangrove areas should be surveyed using aerial photographs supplemented with ground data. Critical areas, e.g. Marunda, Muara Gembong, Ujung Karawang, the Cimanuk Delta, where immediate attention is required, should be given priority in future studies. Inventory and distribution of mangrove flora and fauna should be studied in detail, with particular reference to economically important species. Forest law should be clearly defined and published separately for wide circulation. If possible, local languages (Sundanese and Cirebonese) should be used so that laws are easily understood by the villagers and the poachers. Sufficient funds should be released for research and development work on mangroves. Rules and regulations framed by the Directorate General of Forestry should be implemented properly. Also, better working plans should be prepared. Rehabilitation of mangrove areas should be done judiciously. Utilization of mangrove trees or areas should be undertaken without disturbing the ecological balance of nature. Strict measures should be taken against polluting the mangrove environment. More studies on the effect of external factors on mangrove ecosystems, including the input of fresh water, nutrients, and silt from upstream, and tidal input from the Java Sea, should be undertaken. Future studies should include the determination of the net primary production of the plant community in the mangrove ecosystem in relation to the environmental variables within a single area and between different areas. Studies should also cover such aspects as the effects of aeration and drainage of the soil by mud burrowers, the magnitude of litter decomposition, and the transport of debris to nearby waters. It is desirable to study the waters within and adjacent to the mangrove ecosystems along the following three lines of research: a. Geomorphology, bathymetry, water volume, and sedimentation dynamics. b. Hydrology, including water budgets and water turnover rates. c. Seasonal shifts in the physiochemical and biological dynamics including budgets of organic constituents and patterns of population movements. Budget studies should include inputs, outputs, and internal accounting of recycling. Ail studies should consider the horizontal, vertical, and seasonal variations of physical and biological parameters.

13. Studies to determine the significance of litter production, particulate detritus, and soluble organic compounds to consumers within mangrove forests, to consumers downstream, and to the fauna of nearby marine areas should be encouraged. 14. Identification and quantitative analysis of the eggs and larvae of commercially important fishes, prawns, crabs, and shellfish within mangrove areas and determination of the nature and availability of their food requirements and their seasonal succession should be undertaken. 15. The direct values of mangroves and the products derived from them, and an estimate of the extent and value of the coastal fisheries (shellfish, prawns, crabs, and fish) that are dependent on mangroves at some stage of their existence should be determined. 16. Studies should also include the determination of the indirect values of mangroves through their contributions to neighbouring ecosystems and coastal stability. Sukardjo (1979b) also suggested that the plans concerning management and research, especially in Java and Bali, should be laid down as follows: 1. 2. 3. 4.

Effectively assess the exploitation of mangrove by dividing the mangrove forest into a reservation zone and an exploitation zone. Fishery-study the relationship between the mangrove ecosystem and coastal fishing, and investigate ways to increase the yield of coastal aquaculture in order to fix a suitable area for coastal culture. Forest-study forest management, including reforestation and methods for increasing productivity. Mining-studY the ecological impact resulting from mining in the mangrove area.

In order to achieve these goals, the First National Symposium on the Mangrove Ecosystem held in Jakarta in 1978 strongly recommended that research in various fields be accelerated and that the government promote this research and intensify enforcement of existing laws and regulations. Acknowledgement I wish very much to thank Prof. Dr. Purukawa Hisao (The Centre for Southeast Asian Studies, Kyoto University, Japan) for his financial support for my field work in Java and Bali in 1979, and the Director of Lembaga Biologi Nasional-LIPI, for allowing me to leave my duties during the trip. References Alrasjid, H., 1969. The choice of tree species to increase the productivity of mangrove forest, with special reference to the mangrove forest at Ujung Karawang. M.S.F. thesis (Tropical Silviculture). Faculty of Forestry, Bogor Agricultural University, Bogor, 79 pp. (in Indonesian). ____________1971a. Pemakaian sistem hutan tambak dalam rangka reboisasi den konversi hutan payau. Laporan No.122. Lembaga Penelitian Hutan, Bogor. ____________1971b. Pemilihan jenis tanaman dalam rangka meningkatkan produksi hutan payau Ujung Karawang. Laporan No. 134. Lembaga Penelitian Hutan, Bogor. Arwati 1977. Cross-sectoral background paper based on malaria control technical study. Jakarta, Kasubdit Malaria (Malaria control), Ministry of Health. Berlage, H.P., 1949. Regenval in Indonesie. Ray. Magnest. Meteor. Observ. Batavia, Verhandelingen No. 37. Buadi 1978. Hutan cager alam Pulau Dual Paper presented at the Symposium on Mangrove Ecosystem, Jakarta, 27 February- 1 March 1978, 8 pp. Burhanuddin and S. Martosewojo 1978. Pengamatan terhadap ikan gelodok, Periopthalmus koelreuteri (Pallas) di pulau Pari. Paper presented at the Symposium on Mangrove Ecosystem, Jakarta,27 February-1 March,1978,8 pp. De la Cruz. A. A., 1978. The functions of mangroves. Paper presented at the SYmposium on Mangrove and Estuarine Vegetation in Southeast Asia, Serdang,Selangor, Malaysia, 25 28 April 1978,24 pp. Direktorat Bina Program 1977. Tegakan hutan di Indonesia. Buku Vll, Jawa Barat den DKI. Pengumuman No. 16. Direktorat Bina Program-Dirjen Kehutanan Bogor. Haeruman Js. H.; S. N. Hamamah; Y. Mulyana; E. Z. Abidin; and Suparno 1977. Potensi sumber-sumber seam kehutanan den pengembangannya di Jawa Barat. Departemen Management Hutan. Hutomo, M., and A. Djamali 1978. Penelitian pendahuluan tentang komunitas ikan di daerah mangrove Pulau Pari, Pulau-pulau Seribu. Paper presented at the Symposium on Mangrove Ecosystem, Jakarta,27 February-1 March 1978, 25 pp. Kartawinata, K., 1977. The ecological zones of Indonesia. Paper presented at the 13th Pacific Science Congress, Vancouver, Canada 18 - 20 August, 1979, 6 pp. ____________and E. B. Waluyo 1977. A preliminary study of the mangrove forest on Pulau Rambut, Jakarta Bay. Mar. Res. Indon. 18:119- 129. Kunstadter, Peter, 1978. Human settlements, demography and health in Asia and Pacific mangrove forest areas. Paper presented at the Symposium on Human Uses of Mangrove Environment and Management Implications, Dacca, Bangladesh, 4 - 10 December 1 978, 18 Pp. ____________and Krishna Kant Tiwari 1977. Consultant's report on human uses and management of the mangrove environment in South and Southeast Asia. September-October 1977. New Delhi. Unesco Regional Office for Sciences and Technology for South and Central Asia, 26 October 1977. Munaf, Hasan Basri 1978. Fauna caplak di hutan mangrove Pulau Dual Paper presented at the Symposium on Mangrove Ecosystem, Jakarta. 27 February-1 March 1978,9 PP. Schmidt, F. H., and F. H. A. Ferguson 1951. Rainfall types based on wet and dry period ration for Indonesia with Western New Guinea. Djawatan Meteorologi Geofisika, Jakarta. Verhandelingen No. 24. Schuster,W. H., 1949. De viscultuur in de kustvijvers op Java. Department van Landbouw on Visserij. Publicatie No. 2. 227 pp. ____________1952. Fishculture in brackish water ponds of Java. Spec. Publ. Indo-Pasific Fish Counc. No.1.143 pp. Soegiarto, Aprilani, 1973. Impact of human activities upon coastal environment in Indonesia. In B. Marton (ed.). Pacific Science Association Special Symposium in Marine Science, Hongkong, 8 14 December 1973,Symposium paper:111 - 113. ____________1975a. The state of pollution in the water environment of Indonesia. Paper presented at the 13th Pacific Science Congress, Vancouver, Canada, 18 - 28 August 1975,16 pp. ____________1975b. The need for developing a marine park system in Indonesia. Paper presented at the 13th Pacific Science Congress, Vancouver, Canada, 18 - 28 August 1975,8 pp. Soemodihardjo, S., and W. Kastoro 1977. Notes on the Telebralia polustris (Gastropoda) from the coral island in the Jakarta Bay area. Mar. Res. Indon. 18:131 - 148. Soemodihardjo, S; K. Kartawinata; and S. Prawiroatmodjo 1977, Kondisi hutan payau di taluk Jakarta den pulau-pulau sekitarnya. Oseanologi di Indonesia 7:1 - 23. Soemodihardjo, S., and Anugerah Nontji (eds9 1978. The proceedings of the symposium on mangrove ecosystem. MAB Indonesia, LON-LIPI (In press), Soepraptohardjo, M. 1972. Generalized soil map Indonesia. scale 1 :2,500,000. Soils Research Institute, Bogor. Soerianagara. I., 1971. Characteristics of mangrove soils of Java. Rimba Indonesia 16:1 4 1 - 1 50. Sukardjo, Sukristijono, 1978. The utilization of mangrove forest in Indonesia with special reference to charcoal and firewood production. Paper presented at the Symposium on Human Uses of Mangrove Environment and Management Implications, Dacca, Bangladesh,4 - 10 December 1978, 24 pp. ____________1979a. The preliminary report of the mangrove ecology and deltaic desedimentation in Ci Manuk West Java, Indonesia. Unpublished report, 8 pp. ____________1979b. The present status of mangrove forest in Java and Bali with special reference to the "tambak" development. Paper to be presented at the Second International Symposium on the Biology and Management of Mangrove. Toro, Victor, 1978. Beberapa catatan komposisi fauna Crustacea mangrove gugus pulau Pari, pulau-pulau Seribu. Jakarta. Paper presented at the Symposium on Mangrove Ecosystem, Jakarta, 27 February-1 March 1979, 11 pp. Wiroatmobjo, P., and D. M. Judi 1978. Pengelolaan hutan payau di Indonesia. Paper presented at the Symposium on Mangrove Ecosystem, Jakarta, 27 February-1 March 1978, 7 pp. Wisaksono, W., 1974. Beberapa aspek pencemaran minyak di perairan Indonesia. Paper presented in the Environmental Week, Jakarta, 21 26 January 1974,25 pp. + 4 maps. Discussion Hehanussa: What about the effects of pollutants on the mortality of Rhizophora? Sukardjo: The effect is not known, except that there is mortality at some polluted areas, such as Tegal, Cirebon, and Indramayu. Hehanussa: The mortality of mangrove at some areas has been pointed out; in this case, what is the cause of the mortality, the oil pollution or any other factor? What species are mostly affected? Sukardjo: Oil is one of the factors, but the species disturbed have not been studied extensively. Bird: Do you have any control area for comparison? Sukardjo: We do have, at Ujung Krawang. Koesoebiono: I suggest that not only carrying capacities but also economic feasibility has to be considered in doing research. Sukardjo: I mentioned the connection between "destruction" of mangrove forests and the depletion of fishery problem; to produce fish from the area without mangrove forests seems to be impossible, because of the imbalance of nature. Bird: About eight mangrove species have economic value. Is it possible to develop artificial cultivation of these mangroves? Sukardjo: Many species belonging to Rhizophora have been destroyed widely. To use only certain kinds of mangrove is difficult, and not easily accepted by the local people. Bird: Are the reserve areas adequate to maintain the species? Sukardjo: Rhizophora species are not being maintained. Siregar: Can the mortality of the seedlings (10 - 15 per cent) be used as an indication of the existence of any pollutant? Other methods should be applied for monitoring pollutants. Sukardjo: I agree with your suggestion. Siregar: Do you observe the mortality of other species? Sukardjo: Yes,Avicennia sp. and Rhizophora sp. Ongkosongo: Is Bruguiera sp. a pollutant indicator? Sukardjo: It prefers to grow on sites with low salinity and hard soil, usually on land, and is less useful as an indicator. Muluk: Mangrove seedlings can die naturally without any pollutant. Sutamihardja: What is the dominant cause of pollutant? Sukardjo: I think oil is dominant. Soegiarto: Some of the previous questions were not completely answered. 1. 2. 3. 4.

Is there any proof that 10 - 15 per cent of mortalities of mangrove seedlings were caused by oil or is this conclusion not yet proven? What is the origin of the oil, is it from oil wells, harbours, or ships? Is it possible to use Rhizophora seedlings as a species indicator for pollution, especially oil pollution? One of the reasons is that they are very sensitive to pollutants. is the present system adequate for conservation purposes of economically important species? Or for ecologically important species?

Sukardjo: 1. It is important to determine the pollutant. My observation is limited to the knowledge that the pollutant has negative effects on the growth and existence of Rhizophora mucronata seedlings, but from observations, it seems that the oil originates from oil discharge. 2. The origin of the pollutant might be discharged from harbours and ships. 3. At the moment I am not able to state that Rhizophora seedling is an indicator species for pollution. First I want to know whether there is negative affect for the growth and existence of Rhizophora mucrata. After that I want to know the growth rate of the seedling in a polluted area. Finally, lethal doses I LD) can be determined, and this is my final goal. 4. Traditionally the fishermen and people living near the coast know the basic principles of conservation of several species which have economic values. The system in management which is presently used by the Directorate General of Forestry is adequate, but the execution is not good and is not based on ecological data on the mangrove forest. As we all know, much of the mangrove forest of the northern coast of West Java has been destroyed, and reforestation is badly needed. For certain sensitive areas the conservation of ecologically important species is useless.

The marine fishery resources of the north coast of west Java Tatang Sujastani Introduction The Indonesian archipelago covers an area of 3.2 million km² of which 70 per cent is water. The coastline is 61,000 km, and the shelf area is 775,000 km². The north coast of West Java is a part of the Sunda shelf that stretches to the east and borders the Strait of Macassar and the Bali Sea. The present marine fish catch exceeds 1 million tonnes, of which 157.4 thousand tonnes come from the north coast of Java and 55.3 thousand tonnes from the north coast of West Java (1977). The catches mostly come from small-scale fishing activities, which are estimated to produce 90 per cent of the nation's total catch. The waters north of Java have been exploited traditionally for a long time. The fishing is mostly indigenous and static, which causes low efficiency. Better technology has been introduced, inclusing trawl fishing for demersal and purse seining for pelagic resources. Both of these, introduced in late 1970, can be considered as small-scale fishery modernization. The development of trawl and purse-seine fisheries in this area was very fast. The trawlers operating in the coastal waters increased rapidly, concentrating especially on shrimp that fetch a high price for export. This caused a fully demersal resource exploitation level in the coastal zone, whereas the offshore zone is still under-exploited. The North Coast of West Java Area For the purpose of this Workshop the term "north coast of West Java waters" refers to the sea area of the coastal zone down to 20 m depth (isobath 20 m) for demersal resource grounds and up to 30 miles (48 km) offshore for pelagic resource grounds. These limitations are related to the operational fishing capabilities of existing fishing units, especially those of trawlers and purse seiners. The surface area of the north coast of Java waters is estimated to be 3,400 square miles (8,840 km² ); thus, the north coast of West Java is approximately one third of the total, or 1,100 square miles (2,860 km²). It belongs to the Provinces of West Java and the Jakarta Metropolitan Administration. Depth and type of bottom The area under consideration is limited by the 20 m isobath. The oceanographical conditions are those of the Java Sea as a whole, the bottom sediment consisting partly of thick grey mud, and partly of sand, with gravel, coral, and rocks in island areas (Emery et al. 1972). Meteorological and oceanographical conditions Coastal waters are under the direct influence of the east and west monsoons. The first lasts from June to September and the second from December to March. The east monsoon produces a current which flows westward, but during the west monsoon the current runs from the South China Sea with a speed of approximately 1.5 knots along the north coast of Java eastward, and through Sunda Strait to the southwest (Emery et al. 1972). The results of the R. V. Mutiara-4 surveys show that the temperature of the surface layer ranged from 21 to over 30 C. There is no thermocline in shallow waters, and salinity goes down to 20‰ in the nearshore zone due to river discharge ( Emery et al. 1972) . The Fishery Resources Demersal The data available on trawl catches of the R. V. Mutiara-4 show that the demersal fishes comprise a large number of species. Preliminary analyses of the catches indicate that in some communities, such as those of ponyfishes, Lelognatbus splendens occurs inshore while L. elongatus is found mainly offshore. The demersal fishes here are defined as fish species caught by demersal gear (Table 1). Table 1. List of Demersal Fishes No.

Species

Scientific Name

1.

Pomfret

Pampus spp., Formio niger

2.

Red snapper

Lutianus spp.

3.

Threadfin

Polynemus spp.

4.

Baramundi

Lates calcarifer

5.

Threadfin bream

Nemipterus spp.

6.

Fusilier

Caesio spp.

7.

Mullet

Mugil dussumieri, Valamugil seheli

8.

Pelona

Pelona ditchoa

9.

Catfish

Arius spp.

10.

Canine catfish

Plotosus spp.

11.

Croakers

Sciaenidae

12.

Sharks

Carcharinus spp.

13.

Halibut sole

Psettodes erumei, Cynoglossidae

14.

Ponyfishes gerres

Leiognathus spp., Gerres spp.

15.

Lizardfish

Saurida spp.

16.

Grunts

Pomadasys spp.

17.

Grouper

Epinephelus spp.

18.

Hairtail

Trichiurus spp.

19.

Chinese herring

Hilsa spp.

20.

Trevally

Crangoides

21.

Others

-

Source: Report of the Workshop on Demersal and Pelagic Fish Resources of the Java Sea. 5 - 9 December 1978, Semarang, Indonesia. South China Sea Fisheries Development and Coordinating Programme, Manila, Philippines, SCS/GEN/79/20 (Revised). The exploitation of demersal resources has developed rapidly in the last six years through the use of trawlers, but the majority of the fishermen are still using traditional gear, such as traps, bottom gill-nets, handlines, lift nets (began), danish seines (dogol), and beach seines. Trawlers are of small size (20 GT) with an average of five days' fishing per trip, operating in waters less than 30 m deep. The total catch of demersal fishes by demersal gear in 1977 was more than 20,000 tonnes. There has been an increase of 67 per cent in the demersal fish landings in recent years, due to the increased number of trawlers entering the fishery concentrated mainly in Cirebon. Extensive demersal-resource surveys in the Java Sea were conducted by the Indonesian-German demersal fisheries project using the R. V. Mutiara4 in the period 1974 - 78. The vessel is a wooden stern trawler of 100 GT. Due to the vast area covered the data are still far from complete, but they provide useful information for the demersal fishery development programme and necessary management measures. The catch rate is considered to be an index of abundance; therefore changes in the catch rate indicate changes in fish abundance. There are two sources of data available to study changes in the fish stock, the catch-rate data collected by the research vessel R. V. Mutiara-4 and data of fish caught on the north coast of Java. The results of the R. V. Mutiara-4 survey gave a catch rate in 1976 of 189 kg/hour with stock density of 2.8t/km²; in 1977 it was 133 kg/hr and 2.0 t/km², and in 1978 102 kg/hr and 1.5t/km². Estimation of abundance based on fishery data analyses recently made by Sujastani (1978) and Dwiponggo (1978) on demersal resources gave the values of maximum sustainable Yields (MSY) as 63,000 tonnes and 57,000 tonnes, respectively. It should be mentioned that these data refer only to the areas off the north coast of Java. For the area off West Java, the MSY figures could be roughly one third of these. The latest catch data will be important for evaluating the state of exploitation, since the last recorded catch (1977) is slightly under the MSY level. Shrimp species in the catch from this area consisted of: 1. 2. 3. 4. 5. 6.

Udang jerbung (banana prawn, Penaeus merguiensis) Udang dogol (endeavour shrimp, Metapenaeus ensis) Udang cendana (Yellow-white shrimp, M. brevicornis) Udang putih (white shrimp, P. indicus) Udang windu (jumbo tiger prawn, P. monodon) Udang windu (Bago) (tiger prawn, P. semisulcatus)

There were also other species of endeavour shrimp (Metapenaeus spp. and Parapenaeopsis spp.). Table 2. Pelagic Catches off the North Coast of West Java [tonnes) 1973 - 77 Year

Layang

Tembang

Kembung

Tongkol

Tenggiri

1977

3,195

2,528

2,659

3,191

2,716

1976

2,324

1,323

1,986

2,567

2,208

1975

2,053

1,038

5,263

3,300

1,657

1974

2,106

727

1,822

1,250

412

1973

2,009

677

1,795

1,246

595

Source: Report of the Workshop on Demersal and Pelagic Fish Resources of the Java Sea, Semarang, 1978. Sujastani (1978) calculated the MSY of shrimp from the waters of the north coast of Java as 3,200 tonnes, whereas the actual catch is around 2,500 tonnes. However, in view ol the natural fluctuations of shrimp stocks, this level of exploitation could be considered high. Pelagic The number of species of pelagic fishes is great. However, only the so-called economically important species in the landings have been identified to the genus level. There is some information at species level on the chub mackerel or kembung (Rastrelliger brachysoma and B. kanagurta).. Information on stocks in the area is not Yet available. The fish stocks in the Java Sea have not been well studied except for kembung, and a hypothesis concerning west and east monsoon stocks of round scad or layang (Decapterus spp.). The pelagic species that are commercially important belong to the Clupeids, the Carangids, and the Scombrids. Owing to present circumstances the following group of species could be considered as separate stocks: 1. 2. 3. 4. 5. 6. 7. 8. 9.

Layang (round scad, Decapterus spp.) Kembung (chub mackerel, Rastrelliger spp.) Tenggiri (spanish mackerel, Scomberomorus spp.) Tongkol (little tuna, Euthynnus spp.) Selar (trevallies, Caranx spp.) Tembang (sardine-like fishes, Sardinella spp.) Teri (anchovies, Stolephorus spp.) Japuh (sprats, Dussumiera acute) Other Clupeids

The inshore fishery catches are dominated by Clupeids and sardine-like fishes such as Sardinella fimbriate and S. sirm, caught mainly by gill nets and surface danish seines (locally called payang). In light fishing with lift nets, which is being discouraged by the government, the dominant catch is anchovies and mysides (reborn). The catches offshore are round scads, chub mackerels, and little tuna with purseseine, and lampara using fish lures (rumpon) and gill nets. The development of pelagic fishery has significantly increased in the last five years due to the use of more effective gear, mainly purse seines (introduced in 1970) and the improvement of payang performance ( payang-ampera) and lampara. The purse-seine fishery started to develop in Central Java in 1971 and spread out into the Java Sea. The vessels in use are wooden boats of around 20 GT with 80 - 120 HP. The pelagic fish catch of the north coast of Java in 1977 was 157,000 tonnes (from the north coast of West Java it was 55,300 tonnes) with a 7 per cent increase per year since 1975. An analysis of the relationship between catch and effort to calculate maximum sustainable yields (MSY) is possible for the north coast of Java waters (30 miles [48 km] offshore). It shows that the level of exploitation is in a developing stage with an estimated MSY of 190,000 tonnes (Report 1979). Therefore, for the north coast of West Java proper the MSY level should be around 63,000 tonnes. Table 3. Percentage of Total Catch by Type of Gear off the North Coast of West Java Type of gear

%

Remarks

Purse seine

2

Total pelagic fish catch in

Payang

17

1977 was 55,300 tonnes

Lift net

38



Drift gill-net

12



Encircling gill-net

2



Traps

1



Trawl

22



Lines

6



Source: Report of the Workshop on Demersal and Pelagic Fish Resources of the Java Sea, Semarang, 1978. The general conclusion is that the potential catch of pelagic resources is now higher than it was in 1977. Management Demersal fishes of the north coast of West Java are being taken by trawlers and traditional indigenous fishing gear Trawl fishery is not based only on finfish; its economic viability depends to a greater extent on shrimp. The shrimp grounds are in the nearshore areas, where the local fishermen using traditional fishing gear have been exploiting these coastal resources for years. Conflict of interests, therefore, has emerged in some regions due to this overlapping of fishing operations. In order to avoid serious problems of social friction in the fishing community, the government is enforcing the Ministry of Agriculture Decree of 1975, which limits the operation of trawlers bigger than 25 GT to an area 7 miles (11 km) out and seaward. The effective implementation of this regulation requires time to allow the information to spread, and understanding by the fishermen involved. The fishing community need to be convinced that the measures are necessary to sustain their resources. The management measures in the Ministry of Agriculture Decree of 1975 are generally closures of fishing grounds, such as exclusion from certain coastal strips of fishing vessels exceeding particular sizes and horsepowers. These were introduced to protect the small-scale fishermen using traditional gear and sailing boats, but it is unlikely that they will serve to protect the juveniles and small fishes in the nursery grounds since some of the traditional gear, such as scoop nets, traps, and push nets, is capable of destroying large numbers of small individuals Any increase in the number of traditional gear that takes juveniles should be discouraged and further extension of its use should be prevented (Report 1979). A mesh-size limitation exists to regulate the fishing of some pelagic as well as demersal resources (e.g., trawl cod-end mesh-size regulation). The mash size of purse seine for chub mackerel, round scad, trevally, sardines, and other pelagic species should be not less than 55 mm for the wing side and not less than 25 mm for the bunt (Ministry of Agriculture Decree No. 607, 1976). There have been complaints by fishermen that the implementation of this regulation led to difficulty in using larger mesh size by taking off gilled specimens. Because of the wide range of species involved, differing in size, shape, and value, difficulties arise in determining the optimum size for mesh-size limitation measures. The implementation of management measures should therefore be carefully monitored in order to adjust the existing regulations when required. Further investigation, by means of selectivity experiments, should be carried out. References Dwiponggo. A. 1978. Status of demersal fisheries on coastal areas of the Java Sea-potential and stage of effort. Paper presented at the Symposium on Modernization of Small Scale Fisheries. Jakarta, June 1978. Emery, K. 0.; Uchup; J. Sunderland; H. L. Uktolseja; and E. M. Young 1972. Geological structure and some water characteristics of the Java Sea and adjacent continental shelf. United Nations ECAFE, CCOP Techn. Bull. vol. 6. Report of the Workshop on Demersal and Pelagic Resources of the Java Sea (Semarang, Indonesia, 5 - 9 December 1978) 1979. Prepared by R. B. Buzeta, A. Dwiponggo, and T. Sujastani, SCS/GEN/79/20, South China Sea Fisheries Development and Coordinating Programme, Manila, 1979. Sujastani, T. 1978. Calculating stock size of fishery resources of the Java Sea based on statistical data of the regional fisheries. Paper presented at the Symposium on Modernization of Small Scale Fisheries,Jakarta, June 1978. Discussion Soegiarto: Does the amount of MSY (55,000 tonnes) denote the catch or the quantity landed? Sujastani: The figure was the official figure after making some corrections (by adding 10 - 15 per cent) to evaluate the catch, because the above-mentioned figure is the landing data. Soegiatro: How about the activities in developing aquaculture such as tambak? Sujastani: The development of aquaculture in North Java should have first priority. We are asking the Japanese to develop mariculture of oysters and cockles. MacDonald: Your data on MSY of pelagic fishes suggest there should be anxiety about over-fishing. Sujastani: Pelagic fishes are migrating species, and so the catch is unlikely to reach the MSY. Regarding the demersal fish, the government is going to limit the activities of fishing, with some limitation on the number of trawlers and fishing areas, and suggest that people develop aquaculture. Siregar: What about the source of protein for West Java? Sujastani: According to the statistics the population of West Java obtains its protein from Bagan Siapi-Api. How to overcome this problem is one of the main tasks of the government. Ilahude: I suggest the speaker make some corrections in using the term MSY, using Optimal Sustainable Yield instead of the MSY. Sujastani: To meet Indonesian socio-economic conditions it is better to use MSY than OSY for various reasons. If we use OSY there is a tendency that the only people who get the benefits are the owners, but this is not so for MSY. Thayib: Aquaculture programmes (oysters for example) are welcome, but water conditions have to be checked beforehand for the purpose because of the pollution problem. Do you have any data? Sujastani: We do not have complete data, but based on experience, the Pamanukan area is better than Banten Bay for mariculture.

The interpretability of landsat colour composite images for a geographical study of the northern coastal zone of west Java Kardono Damojuwono and P. J. Wisnusudibyo (paper presented by Aziz Poniman and Mimi Munami) Introduction The north coast of West Java is interesting because it has shown rapid changes during the last few decades. The coastal zone consists mostly of recent fluvial and marine deposits, with some volcanic rock in the northwestern part. Satellite remote sensing has become more and more important as a technique for regional studies, especially for less accessible large areas where previously information was very scarce. Most of the Indonesian coastal zone belongs to this category. Many features of the coastal zone, especially the geographical elements, can be identified through LANDSAT colour composite images. This paper discusses the geographical interpretation of the 1976 LANDSAT photos. The interpretation was based on: physical characteristics; features developed by human influence; features representing the interaction between physical and man-made processes; and identifiable features and processes which are useful for coastal zone management. A similar study has been published by Suwahyowono (1979) on the north coast of East Java, around the mouth of Bengawan Solo River. The aim of his study was to determine the extent to which a rural Land Use Classification could be made using the images of LANDSAT colour composite MSS bands 4,5, and 7 for multistage and multispectral analysis. Hadisumarno (1977) describes the use of LANDSAT images for geomorphological mapping in the Palu area. Materials and Methods The quality of the images used was very good: clear, clean, and relatively free of cloud cover. Using the normal enlarger, the contrasts of tone, colour, texture, and resolution were easily delineated. The colour composites consisted of band 4 (green), band 5 (red), and band 7 (near infrared). The methods used in this study were photomorphic analysis and field observation. The results are presented on a map; geographical features are identified by image interpretation and field observations are indicated by letters keyed to the discussion in this text. The main geomorphological units as represented on the map using the ITC system of geomorphological survey are scarp zones, barren lands, fluvial terraces, flood plains, deression deposits, and alluvial coastal plains. The photos are made in mosaic, scale 1 :250,000, as a colour composite image, processed directly from a Computer Compatible Tape (CCT) with double-edge enhancement by the Earth Satellite Corporation, USA. This mosaic represents frames as follows: Frame

Path/Row

Date

Number

1. Pamanukan

130/064

6.20.76

E.2515-02082

2. Bandung

130/065

6.20.76

E.2513-02082

3. Jakarta

131/064

6.21.76

E.2516-02151

4. Sukabumi

131/065

6.21.76

E.2516-2143

In a colour composite, the objects in the image can be differentiated by using a colour indicator. Vegetation generally gives a red colour reflection, and water appears as light blue, dark blue, and black, depending on the depth. Unvegetated dry land gives a white colour reflection, whereas wet land gives a bluish colour. A mixture of vegetation, water, and land gives transitions from red to blue to white (Purwadhi 1978). To support the interpretation, the following maps were used: 1. Vegetation map of Java and Madura, 1950, scale 1 :1 ,000,000 2. Geological map of Indonesia, 1965, scale 1 :2,000,000 3. Soil observation map of West Java, 1963, scale 1 :250,000. There are six distinctive units of soil in the study area (see Table 1). Results and Discussion From the LANDSAT photo and the existing maps, some of the following geographical features, important for coastal zone management, were interpreted (Fig.1). TABLE. 1. Units of Soil in the North Coast of West Java Soil Number

Unit of Soil

Parent Material

Physiography

Land Form

2

grey alluvial

river sediment

alluvial plain

flat

7

dark grey alluvial and low clay sediment grey humic

coastal plain

flat

5

dark grey alluvial

clay sediment

coastal plain and

flat

12

brownish grey regosol

sandy sediment (volcanic)

coastal sand

flat to undulate

34

reddish brown latosol and intermediary igneous lithosol rocks

volcanic cone

hilly to mountainous

13

brown regosol

coastal sand

flat to undulate

sandy sediment

Source: Soil Observation Map of West Java, 1963, scale 1:250,000. 1. Physical Features 1.1 Boundary between land and sea The boundary between land and sea is clear on the LANDSAT imagery because of the colour reflection difference. Sea water gives a dark blue colour reflection while land gives variable colour reflection, from red, blue, green, to white. 1.2 Water bodies, rivers, river mouths, and beaches These features can be traced from the colour difference, colour gradation, texture, site, pattern, and association of each one. 1.2.1 The sea On the LANDSAT colour composite, the sea is dark blue in colour. 1.2.2 Lagoons Lagoons are water bodies within an atoll or behind barrier reefs or islands (Desannetes 1977). They show blue colour reflection because the water here is relatively shallow. Although small, a lagoon is easily detected from the LANDSAT colour composite on a scale of 1:250,000 because of its association with reefs and islands, for example, the lagoons at Kepulauan Seribu. 1.2.3 River mouths River mouths are easily detected because of the distinctive light blue colour of the turbid water where they meet the sea. Some examples are the mouths of the Cimanuk, Citarum, Cilamaya, and Cipunegara rivers. 1.2.4 Beach ridges Beach ridges of sand, gravel, or cobbles are built up by storm waves on the backshore (Desannetes 1977). Beach ridges are seen as lines parallel to the shoreline, with a whitish colour reflection. An example is the beach ridge at Tanjung Bangkaderes near Cirebon. 1.2.5 Deltas A delta is a deposit of sediments formed at the mouth of a river either in the ocean or lake (Desannetes 1977). Deltas are identified not by their colour reflection (because this depends on their land cover or land use) but rather by their site near the shore and its form. There are three types of deltas: bird-foot, cuspate, and arcuate. The bird-foot delta of the new Cimanuk River and the arcuate delta of the Citarum River are examples. 1.2.6 Alluvial fans These are cone-shaped deposits of alluvium made by a stream where it runs out from high ground onto a level plain. A fan is generally formed where a stream flows from a mountain to the low land (Desannetes 1977). Therefore, alluvial fans, among others, can be detected from their site, with a river branching from a mountain front. In general, alluvial fans are fertile land and are therefore used for agriculture, such as rice fields or dry farming. In a LANDSAT colour composite such alluvial fans look like a triangle, violet to blue or pale blue, sometimes mixed with reddish colour. An example is the alluvial fans at the foot of Mt. Batur at the western end of the north coast of West Java. 2. Features Developed by Human Influence 2.1 Settlements and built-up areas (K) An administrative criterion (population) is generally used to distinguish a town from a village (Malingreau, 1977). Such areas are blue and pale in colour reflection, associated with some linear patterns which contrast with the surounding colour. Some examples are the urban zones of Jakarta, Indramayu, Cirebon, Jatibarang, and Pamanukan. 2.2 Road network The road network is a very clear linear pattern, in contrast to the surrounding colour features. Examples are the Jakarta-Cirebon and Jagorawi highways. 2.3 Irrigation network This is characterized by its patterns of bluish lines and its association with rivers, river branches, or rice field areas, as in the irrigation networks around the Cimanuk, Cipunegara, and Citarum rivers. 2.4 Present land use and land cover Land use is any type of permanent or cyclic human intervention to satisfy human needs, either material or spiritual or both, from the complex of natural and artificial resources. Present land use is by no means static (Malingreau 1 978). Data can be collected by ground survey (field observations, questionnaires) or by the interpretation of air photos and other remote imagery. When the latter method is adapted, land use is inferred from the study of the image characteristics, which are directly related to the land cover present at the time of the flight (Malingresu 1977). In this interpretation, land use when the LANDSAT photos were taken can be deduced from present land cover features. Existing land use and land cover along the north coast of West Java that can be identified from LANDSAT Image colour composites on a scale of 1 :250,000 are as follows: 2.4.1 Irrigated rice fields or sawah (Si) A sawah is a rice field which is artificially supplied with water (Malingreau 1977). Irrigated sawah features, whether in ploughing or in planting periods, give greenish blue or pale blue colour reflection due to the water cover. As the rice ripens it gives a bluish pink colour reflection. In the harvest period, or immediately after harvesting, the colour reflection is yellow. The greenish blue or pale colour reflection depends largely on the physical properties of each soil type. Irrigated sawah occur along the Cimanuk, Cipunegara, and Citarum rivers, and also to the southeast of Cirebon. 2.4.2 Rainfed sawah (St) Rainfed sawah are sawah which are watered only by impounded rain water, sometimes supplemented by a very localized runoff collection system (Malingreau 1977). Rainfed sawah, whether in the ploughed period or the planting period, give greenish or pale colour reflection, depending on the physical properties of the soil type. They do not give a blue colour reflection like the irrigated sawah because the soil is not always water-covered. As the rice ripens it gives a pink colour reflection, and in or after the harvest period it gives a yellow colour reflection. An example of a rainfed sawah feature is seen to the west of Jatibarang (Losarang area). 2.4.3 Field crops (Tg) Field crops show greenish or pale colouration with red spots which represent the soils and green vegetation. Such features are seen south of Jakarta as far as Bogor. 2.4.4 Tidal swamps Tidal swamps are influenced by regular incursions of salty water and are usually covered with mangrove (Desannete 1977). A tidal swamp is seen as greenish blue with dark brown spots. Generally, it is located near a seashore or associated with river mouths, such as Muara Gembong, Muara Mati, Muara Pondok Tengah, and Muara Bekasi, which are located on the coast of Jakarta Bay. 2.4.5 Brackish fish ponds (T) Brackish fish ponds are bodies of water managed for fish production (Malingreau 1977). They appear as bluish green with many dark brown spots. They are generally located near the coast, for example along Banten Bay to Pontang Cape, and in several places along the north coast. 2.4.6 Tidal forests (Hp) These are brackish-water coastal forests which include mangrove (Avicennia, Rhizophora, etc.) and nipah (Malingreau 1977). A tidal forest gives a red to bluish colour reflection. Generally it is located on the coastal fringe, near the mouths of rivers as on Krawang Cape (in the area of the Citarum River mouth) and at Pamanukan Cape (in the area of the Cipunegara River mouth). 2.4.7 Teak forests (Hj) In LANDSAT colour composites teak forest give a red colour reflection, sometimes mixed with brown and paler colours during the leaf-fall period in autumn. An example is the teak forest southwest of Jatibarang. 3. Features Representing Interaction Between Physical and Man-made Processes 3.1 Harbours A harbour appears as a short inlet with blue colour, located on the coast near a city. Tanjung Priok harbour in Jakarta is an example. 3.2. Drainage canals Artificial drainage systems can be traced on LANDSAT colour composite images. They are relatively more linear than the mother river, generally flow through rice fields or wet land agriculture areas, and originate from a reservoir. There are examples of canal systems along the Citarum, Cipunegara, and Cimanuk rivers. 3.3 Dams and reservoirs (L) Dams and reservoirs can be detected by their blue colour reflection. If the water bodies are turbid or shallow they become light blue, while clear and deep water becomes dark blue. Dam and reservoir building is usually associated with irrigation networks or with management of rivers. An example is the Jatiluhur reservoir. 3.4 Settlement patterns The pattern of linear settlement along a river looks like red spots, sometimes mixed with white and following the river. The red spots represent the reflection of karangkitri (garden) vegetation. A linear settlement pattern appears along the banks of the Ciujung, Citarum, and Cimanuk rivers. 3.5 Erosion ( Lk) Areas where erosion is very active are usually associated with barren land. These areas appear as brownish yellow reflections and usually are located in rough topography as around the Gede and Salak volcanoes in the west of the north coast of West Java. 4. Identifiable Features and Processes Useful for Coastal Zone Management 4.1 Water pollution or sea-water turbidity Pollution or turbidity in sea water can be identified in a LANDSAT photo. Generally, water gives blue colour reflection with a variation from dark blue to light blue, and the cleaner and deeper water bodies tend to give dark blue. Pollution caused by sediments, hot water, petroleum, synthethic chemicals such as detergents and fertilizers, and organic wastes such as domestic and industrial wastes brought down by the rivers will influence the transparency of sea water and cause a difference in spectrum characteristics, e.g., from violet blue to greenish blue. Examples are the turbid coastal sea water in Jakarta Bay and in several places along the north coast of West Java, such as northeast of Cirebon. 4.2 Sedimentation in the waters around a river mouth Sedimentation can be identified by its light blue to greenish blue reflection around the mouths of rivers and in coastal waters. This sedimentation is from the suspended load produced by erosion upstream and brought by the river and flood canals down to the coast. Sedimentation occurs in coastal waters from the mouth of the Citarum River to the mouth of the Cipunegara River and also from the mouth of the Cimanuk River to the coastal waters off Cirebon. 4.3 Excavation of clay for roof-tile and brick making (P1 ) The excavation of clay for roof-tile and brick making shows as pale brown in a speckled pattern around sawah areas, for instance in the Cikarang area. 4.4 Identification and monitoring of the extent of forest area and detection of illegal forest clearings Primary forest areas are characterized by a dark red colour reflection, and different textures depend upon the type and age of vegetation and the pattern of growth. Other land use or land cover types will also give different colours and textures. Thus a LANDSAT colour composite can be used for controlling illegal forest clearing or shifting cultivation in forest areas. Illegal forest cutting will be shown by the change from dark red to pale pink, while shifting cultivation will be seen as greenish or pale, and sometimes red, speckled with rough texture and located in the inner part of a forest. 4.5 Study of the accessibility of settlements along the coast An estimation of the accessibility of a settlement along the coast can be obtained from the density of the transportation network in the area. An assumption can be made that the more roads leading to the settlement area, the more accessible the settlement, and vice versa. Settlements along the north coast of West Java based on the above assumption are considered less accessible, including those from the mouth of the Cimanuk River to Indramayu Cape, from the Anyar River to Cimanuk Cape, and from the mouth of the Cipunegara River to Pamanukan Cape. 4.6 Evaluation of the suitability of existing settlements on the coastal zone for future development The suitability of existing or proposed settlements can be evaluated by studying the environmental features in these areas. On the north coast of West Java, for example, the settlements around the north part of the Citarum River, around Pamanukan Cape, and around Cimanuk and Indramayu capes are in areas unsuitable for settlement, due in part to the many swamps and tidal forests. Conclusions Conclusions that can be drawn from this paper are: 1. 2. 3. 4. 5. 6.

Remote sensing techniques such as LANDSAT are adequate for studying large areas. The colour reflection of the earth's surface in LANDSAT colour composite images depends on the enhancement processing and the colour composition of the bands used. Field observation is necessary to confirm the interpretation results. Even small objects can in some cases be identified from LANDSAT imagery, using a multistage surveying system and field observation. The accuracy and speed of identifying objects depend largely on the image quality and the experience and capability of the interpreter. LANDSAT colour composite images on a scale of 1:250,000 are very interpretable for a geographical study in the coastal area of West Java and are useful to guide coastal zone management.

References Darmoyuwono, Kardono, 1975. Penerapan penginderean jauh di Indonesia, Lokakarya Evaluasi Pandidikan Penginderaan Jauh den Penerapannya di dalam Menunjang Pembangunan, Fak. Geograpi UGM, Jogyakarta. _____________1976. Penerapan Penginderean Jauh dalam Mendetekti den rnemonitor Pencemaran Lingkungan Laut di Indonesia, Preceding Seminar Pencemaran Laut. LON-LIPI, Jakarta. Desannetes V. R.1977. Catalogue of landforms for Indonesia. Soil Research Institute Bogor, Bogor. Estes, J. E. oral. 1975. Fundamental. of image interpetation. In: Manual of remote sensing, R. G. Reeves, ed. American Society of Photogrammetry. Hadisumarno, Surastopo, 1977. The geomorphology of Palu area Sulawesi from LANDSAT-I. The Indonesian Journal of Geography 7:34. _____________1978. Metode penulisan laporan. PUSPICS UGMBAKOSURTANAL, Jogyakarta. Malingresu, J. P., 1977. A proposed land cover/land use classfication and its use with remote sensing data in Indonesia. The Indonesian Journal of Geography 7 :33. _____________1978. Rural land use image interpretation for its inventory and analysis. PUSPICS UGM-BAKOSURTANAL, Jogyakarta. Purwadhi, Hardiyanti, 1978. Datar-dasar Interpretasi data data remote sensing. PUSPICS UGM-BAKOSURTANAL, Jogyakarte. Sutanto 1978. Dasar-dasar interpretasi citra. PUSPICS UGMBAKOSURTANAL, Jogyakarta. Suwahyuwono 1979. Klasifikasi penggunaan lahan pedesaan melalui citra Landsat komposit berwarna den foto udara merah infra di Kecamatan Bungah den sekitarnya, Laporan Akhir PUSPICSUGMBAKOSURTANAL Angkatan ke IV, Jogyakarta. Discussion Hehanussa: Do you have information on colour composites of LANDSAT I imagery of West Java other than those made in June 19767 Poniman: No composite was made of imageries obtained before and after June 1976, because the necessary imageries were not available, due to cloud cover. Birowo: Why are certain area of Indonesia uncovered? Poniman: They were covered by clouds of more than 60 per cent. Siregar: Is it possible to detect enceng gondok (Eichornia crassipes)? Poniman: It is possible to detect this plant by aerial photography, but not from satellite imageries. (Dr. Hehuwat explained that these plants were nevertheless detected at Rawa Pening using LANDSAT data.) Siregar: How do you analyze erosion of riverbanks using LANDSAT data? Poniman: It is possible to see undercut banks. Sutamihardja: What is the percentage of dense forest in the Cimanuk area from analysis of LANDSAT imageries; Poniman: It can be determined, but has not been done yet. From aerial photography it is about 40 per cent. Ongkosongo: The US Topographic Army Map of 1972 might not be correct, because it was based on earlier data. According to available data at that time changes had occurred. Poniman: I fully agree with that statement. Ongkosongo: Is it possible to determine abrasion and accretion from turbid water patterns? Poniman: To determine the occurrence of abrasion and accretion, you would have to compare the LANDSAT imagery with old maps.

Water-quality assessment of the cimanuk watershed R. T. M. Sutamihardja and Herman Haeruman Js. Data on water quality [physical' chemical, and biological) of the Cimanuk watershed were collected directly from the field on two occasions, namely in January and September 1978. To support this primary data, secondary data were also collected, including the geological, topographical, climatological data, and also data on demography and land use (including industrial use). Determination of sampling sites was based on the following criteria: a. b. c. d.

altitude land condition main stream and sub-stream distance from transportation facilities

The parameters of water quality were analyzed in the field laboratory in situ, and the rest of the data were analyzed in the laboratories of Bogor Agricultural University and DPMA Bandung. The Cimanuk watershed covers an area of more than 400,000 ha and is situated between 107°25' and 108 25' east longitude, and between 6 10' and 7° 30' south latitude. The Cimanuk watershed area could physiographically and topographically be divided into three regions: a. the upper region (consisting of the upper Cimanuk sub watershed, Cipeles sub-watershed, and Cilutung subwatershed) b. the central region (central Cimanuk sub-watershed) c. the lower region (lower Cimanuk watershed) The upper region has a type A climate, the central region type B, and the lower region type C. In 1977 the population density in the upper region was 450.13 persons/km², whereas for the central region and lower region the figure was 1109.05 and 323.78 persons/km², respectively. With regard to year the total population of the Cimanuk watershed was 2,296,254 (in 1971) and 2,359,345 (in 1977) with an average population density of 551.36 persons/km² in 1971, and 556.51 persons/km² in 1977, resulting in a population rate of increase of around 2.75 per cent during the six-year period. The water debit of the upper region during the rainy season was one to three times as high as the levels during the dry season, whereas in the lower region the same parameter during the rainy season was six to ten times that in the dry season. The temperature of water in the upper region ranged between 15° and 19°C, and in the lower region between 20° and 29°C. Flooding is still a serious problem in the Cimanuk watershed during the rainy season, in contrast to the problem of water deficiency during the dry season. Water temperature of the Cimanuk streams was found to be naturally normal, and no signs of thermal pollution were detected which could endanger the lives of aquatic organisms. Suspended solids were the main physical pollutant, especially during the rainy season. The suspended solid content of the Cimanuk River during the rainy season was 20 to 60 times as high as the level during the dry season. The suspended solid content of the Cipeles River during the rainy season was found to be 35 to 180 times the level during the dry season. The same parameter for the Cikamiri and Cikeruh rivers during the rainy season was 60 times the level during the dry season. The suspended solid contents of 2055.4 - 3907.4 g/l during the rainy season and of 36.2 - 173.1 g/l during the dry season were an indication of a quite high level of soil erosion in the Cimanuk watershed. The dissolved salt (indicated as salinity and conductivity) content and its SAR level showed that water from the streams of the Cimanuk watershed was still suitable for fishery, agricultural, and domestic use. This was also true of the pH level. From the standpoint of alkalinity, the hardness and the calcium content, the water of the Cimanuk watershed may be classified as having a hardness of medium to high grade. The levels of these parameters, however, were still below the critical threshold for domestic, agricultural, fishery, and industrial use. The dissolved oxygen content of the observed streams was found to be still within the feasibility range for aquatic organisms, especially fish. This was due to the lotic type of the observed water with its turbulency current, which made it possible for the oxygen from the air to diffuse into the water easily. At the observation stations of Ciseureupan and Limbangan during the rainy season, the ammonia-N content of the streams of the Cimanuk watershed was found to be still within the feasibility range for fish. For drinking water and as a raw-water supply, however, the water should first be treated, e.g., by boiling. The chlorine content of the observed water was found to be below the threshold level for fish, except at the observation stations of Samarang and Tolengas during the rainy season. This was possibly due to the chlorinecontaining pesticides frequently used in agricultural areas, which were carried by the run-off during the rainy season. This presumption was based on the fact that the areas in the vicinity above the observation stations were used for dry-land agriculture and for intensive sawah culture as well. The organic substance (BOD and TOM) content showed that the streams of the Cimanuk watershed already carried low to medium levels of organic pollutants. The MPN-Coliform level showed that the streams of the Cimanuk watershed were already polluted by human and animal excrement and also by home domestic wastes. The MPN-Coliform density (TPC/ml = 1.1 x 105 and MPN-Coliform = 1.1 x 105 per 100 ml) far exceeded the level recommended for water for public use (MPN-Coliform = 103 per 100ml). From the data obtained from the brief survey on water quality of the Cimanuk watershed, it could be concluded that the streams of the watershed: 1. 2. 3. 4. 5.

were already polluted by suspended solids of medium to severe levels; were already polluted by organic matter (including excement of human and animal origin) of low to medium levels; had Fe and Zn contents, at some places also a Ci content, which exceeded the maximum limit for drinking water; could no longer be used for drinking water or drinking water sources without certain treatments; this is also true of water used for industrial purposes, for cooling, or for water processing; and had a water quality which was found feasible enough for agricultural and fishery uses.

References APHA 1975. Standard methods for the examination of water and waste water. 14th ed. APHA Inc., New York. Dent et al. 1977. Detailed reconnaisance land resource survey Cimanuk watershed area. Pescop, M. B., 1973. Investigation of rational effluent and stream standards for tropical countries. AIT, Bangkok. Team Kualitas Air Pusdi PSL-IPB and Proyek Pengelolaan Sumbersumber Alam Lingkungan Hidup Panitia Perumus den Rencana Kerja Bagi Pemerintah Di bidang Lingkungan Hidup 1978. A Study on the Determination of Criteria for the Quality of Water and Biotic Environment of the Cimanuk Watershed. World Health Organization 1963. International standard for water supplies. WHO Monograph, Geneva, 2nd ed. Discussion Thayib: Surely the standard required for drinking water should follow WHO standards. Sutamihardja: True, but the people have to drink whatever water is available. Punjanan: Is it possible to determine the distance of penetration of sea water into the Cimanuk River by using salinity data? Sutamihardja: Sampling was only in fresh water, so salinity was not analyzed.