|Environment and development
in coastal regions and in small islands
|Paper from:||"Science &
Technology in Asia and the Pacific
Co-operation for Development"
|This Collection, conceived, compiled and edited by Penelope Gobel, Office of the ADG/SC, is based on the contributions of many staff members of UNESCO, both active and retired, at Headquarters and in the field|
Development of the UNESCO Coral Reef Programme Over the Last Decade
Coral Reef Assessment and Status Evaluation in South-East Asia
At the 5th International Coral Reef Congress (1985) in Tahiti at the opening session, on the basis of work done by the UNESCO Coastal Marine Programme in Jakarta Bay, Indonesia, UNESCO made a call for more systematic data sets describing natural reef responses to commonly occurring physical gradients so that man induced pressures can be readily recognized and quantified. Since that time, a considerable amount of data has been collected showing degradation and simplification of reef structures throughout the world.
Along with the effects of pollutants and exploitation patterns, it may be anticipated that global warning, due to the greenhouse effect, will also result in structural adjustments to coral reef communities. Provided that the effects of the various factors can be distinguished one from another, coral reefs may thus serve as sensitive indicators of heat-stress induced by global warming, the "canary" in the coal-mine. Although the calcium carbonate skeletons that form coral reefs provide modest carbon storage (sinks) overall they are none-the-less true sinks unlike trees which, although they are the primary sources of fixed carbon, are merely temporary storage structures unless the vegetative material becomes buried or otherwise immobilized. Additionally, because coral reefs provide dynamic protective structures to islands, it is important that their health and responses to conditions governing their well-being be monitored. Coral reefs also provide the basis for direct and indirect support of human communities in the form of fish and invertebrate protein, as well as building materials and decorative products derived from a number of organisms. Lastly, coral reefs are an important source of revenue in the growing field of eco-tourism.
As far as coral reefs are concerned, the problem in environmental analysis involves the elaboration of monitoring strategies capable of:
One of the main purposes of an assessment programme is to provide a knowledge-base that can be used to carry out deductive reasoning with respect to the environment by monitoring the major active factors. A competent monitoring programme is an essential adjunct to any attempt to manage a coral reef in an ecologically sound and sustainable manner. This is particularly true of biological factors. In general one must look first at economically important species (commercial and recreational), nationally protected or internationally endangered species, and finally at the structure of the food web supporting such "important" species. Any species or group of species through which a major energy flux takes place (coral reefs, mangrove ecosystems, seagrass beds etc.) should likely also be considered.
Sampling Coral Reefs
Natural coral reef communities are sampled and examined for a number of reasons, the most common being to satisfy the requirements of quantitative description so that one situation may be compared with another. The requirement for such comparisons may arise in response to a variety of circumstances some of which are listed:
In the case of a monitoring programme, the first priority is the detection of change in existing patterns or trends. However, once this has been accomplished attempts should be made to determine the causes of such changes through experimental analysis and associated manipulation, where this is possible.
|Research scientist measuring coral growth. Photo: R. Harger|
|Assertion 1:||There are No
Locations Free from
Immediate Anthropogenic Effects
High population density situation, Jakarta Bay, Indonesia
The negative impact of industrial development both on the land and in the marine environment has long been understood by various coastal communities. The deliberate introduction of pollutants in many regions of the world's coastal waters, such as heavy metals, hydrocarbons, and pesticides, by factories has increased the burden of pollutants in these waters to such an extent that many communities have been warned to take special care in using the waters and their biological resources. This is particularly true for areas where large-scale industrial projects have been and are being developed, where broad expanses of agricultural land drain into the sea, and near large cities.
A survey of the reef structure associated with islands in the Pulau Seribu (Thousand Islands) chain (Indonesia) extending north-west into the Java Sea from Jakarta Bay on the north coast of Java was made in 1985 by a UNESCO training course looking at the effects of man-made influences. Data on coral reef structure were obtained at two depths (roughly 1 metre and 3 metres, below the mean tidal level) from the north face of approximately 28 islands. Additional measurements of physical environmental factors were also made. The city of Jakarta through its extensive discharge of pollutants was found to be responsible for the dominant pattern of degraded reefs in Jakarta Bay with progressive improvement out to a distance of 45 km. Perhaps not surprisingly, it was also found that reefs associated with resort developments were usually healthier (higher coral cover, more species) than nearby islands without resorts. Thus eco-tourism may be said to offer some degree of protection to coral reefs. A further assessment over the same islands was made 10 years later in 1995 and the results indicated that the outer islands had suffered yet further reductions in diversity.
Explaining variance in coral reef population structure
The dominant influences on the coral reefs in the Pulau Seribu region can be split into two categories:
The fact that great changes have been induced in the reef within recent times is clearly demonstrated by comparing the present day structure of inshore reefs within Jakarta Bay with the situation as described by J. H. F. Umbgrove in the 1920s. The obvious conclusion to be drawn from this comparison is that the inshore Jakarta Bay reefs have been largely destroyed in recent times since very few if any scleractinian (hard coral) species can now be found on the islands affected to the greatest extent (within 10-20 km of Jakarta) as opposed to the situation described by Umbgrove where previously extensive reefs are noted. In fact, it is now necessary to move 40-50 km beyond the islands Umbgrove described in order to find reef structures which match his original accounts.
The next point that may be made is that many of the islands further from the mainland show considerable coral reef development at the present time so that a trend exists between degraded reefs close to Jakarta and those further from the mainland along the island chain. Although the dominant influence on the reef systems appears to arise as the result of pollution discharges from the city of Jakarta, the nature of the trend is not straightforward. One reason for this is that islands further out tend to be more disturbed by various activities such as "blast fishing" than those closer to Java.
The most degraded reefs in the Jakarta Bay area have completely lost the large "massive" boulder-like Porites colonies which were mapped by Umbgrove in 1929 and in addition now support virtually no coral. Pulau Nyamuk Besar, 6.6 km from Jakarta and a former resort in Dutch colonial times is now almost deviod of hard corals (2.3%-4% cover) and has been abandoned as a recreation spot.
The above considerations suggest that the first indication of degradation in reef systems might be associated with the loss of the "interstitial short-lived" elements (including secondary species such as butterfly fish which generally eat coral polyps in a species-specif manner). When this progresses to the long-lived structural species, the reef has been "lost" to all intents and purposes as far as current monitoring is concerned although some forms of "secondary invasion" by otherwise resistant long-lived forms can take place.
Since the initial survey of 1985 (and even before that time), a minimum of one and often two assessment exercises per year have been carried out by senior high school students from the Jakarta International School as part of the field studies required by the International Baccalaureate programme. These exercises were first initiated in 1983 using transects placed at right angles to the reef face but were changed after 1985 to favour the use of transects placed parallel to the reef face in order to obtain better statistical control of variance associated with depth. Data have been gathered from three of the islands surveyed during the 1985 UNESCO training course (Pulau Tikus/Pulau Pari, Pulau Kotok Besar, Pulau Hantu/Pulau Pantara). In order to connect the information-base to the community at large, an "international" group of media correspondents responsible for "environment reporting" has also been trained in the interpretation of scientific findings and exposed to the activity as participants.
The array of hard-coral forms that can be easily scored by a high school class in this form of investigation may be conveniently summarized as: (1) encrusting (lichen-like), (2) branched (staghorn-like), (3) massive (rock-like), (4) sub-massive (pillar-like), (5) tabulate (table-like), (6) foliose (scroll-like), (7) solitary. Other organisms include (1) algae, (2) soft corals, (3) sponges, (4) other forms. Physical conditions include (1) coral sand, (2) deadcoral/rubble. What matters is the detection of systemic change in existing patterns or trends and not necessarily the particular elements chosen for inclusion in the survey.
Implementation of the simplified assessment procedure above, across the range of degraded reefs that can be identified as the result of Umbgrove's 1929 report, would have been more than sufficient to map the changes that have occurred in the interim. The aggregate of class data gathered has at all times been sufficient to enable students to clearly detect significant and consistent differences in reef structure with respect to depth (1 and 3 metres) and in relation to the exposure. A critical element in this exercise is the high degree of replication since a class of 30-40 students works in groups of 4-6. Each group is responsible for 3 x 60 metre line-intercept transects at each of two depths and two locations (exposed and sheltered). Normally, such a procedure generates data from 30-60 separate transects (if not more) and "observation errors" are swamped by the "environmental effects".
A low-profile, widely distributed programme of the nature described above would clearly be able to track coral reef changes and could also cover broad areas of reef structures and so be liable, both by accident and design to encounter anomalous situations.
The reef systems of Jakarta Bay are extensively damaged by the immediate and obvious discharges from the city of Jakarta. These include heavy nutrient loads, heavy metals, toxic organicchemicals as well as sediments. In spite of strenuous efforts which have been made recently, the possibility of locating reef structures removed from the negative effects of human activity is now quite low or even negligible.
Low population density situation, Dravuni Island, Fiji
A three week Science and Resource Management Workshop from November 27th to December 12th, 1989, was held by UNESCO for high school teachers at the University of the South Pacific Field Station on Dravuni Island, inside the Great Astrolabe Reef, Fiji. Among other things, the participants carried out assessments of the reefs and of beach-litter.
Beach-litter was divided into 4 categories: (1) polythene bags, (2) polystyrene blocks, (3) footwear and (4) other. Participants picked up all materials between the water edge and a distance of 10 metres or so above the upper strand-line. Material was then sorted, counted and weighed. There was 200 kg in 1.7 km of beach on the windward side of Dravuni Island and 1.7 kg on 1.6 km of beach on the sheltered side. The volume of beach debris in the mid-Pacific on Dravuni was found to be unexpectedly high. By comparison, data gathered by the UNESCO workshop in Indonesia indicated that the level of contamination corresponds to the same amount of debris found on islands about 20 to 25 km from Jakarta, one of the largest cities in south-east Asia (estimated population 8.8 million).
The population of Fiji is 727 000 people of which only 120 reside on Dravuni Island, this fact, associated with the level of beach-drift industrial debris collected, poses a significant question: from whence did, where did, all this debris come? Although Fiji is marginally industrialised, most of the debris apparently originated from industrialized countries on the Pacific Rim. Many items carried brand names from surrounding countries (Japan, Australia, New Zealand, U.S.A.). Significant items included PVC bottles, aluminium beer and soft drink cans, pieces of drift and gill nets, net floats, styrene and urathane foam blocks, footwear, inhalers and a syringe.The breakdown products arising from such plastics include PCBs (polychlorinated bi-phenyls), unreacted curative or hardening agents from resin systems such as 4,4'methylene bis di-chloro aniline (Curene or MBOCA) and many other as yet unknown chemicals which have the potential for invasion of the food chain. This may pose a problem for situations where such chemicals might accumulate over long periods. Plastic debris stranded on the beaches of the Persian Gulf, for instance, lasts only a matter of 1-2 months before it is reduced to fine powder under the influence of extended periods of direct sunlight and abrasion.
Participants were unable to agree upon an appropriate disposal method for materials.
Silt and associated run-off
Further findings arising from the field study concerned the practice of goat grazing on small islands such as Yanuyanuiloma Island (Goat Island) about 2 km south-west of Dravuni Island. The factors of assessment were the distribution of butterfly and hard-coral cover. Two areas were investigated in detail by using standard observation and counting methods involving two observers per transect line. The Dravuni area appeared to be a relatively healthy inshore fringing reef whereas the Goat Island area was exposed to silt-run-off from the small adjacent overgrazed island. Overgrazing was judged in comparison to the situation on Dravuni Island. The difference being that no green ground-level vegetation was apparent on Goat Island, the bare ground having been exposed by the goat population whereas Dravuni Island supported an almost continuous cover of ground-level vegetation.
Fourteen butterfly fish species were recorded on Dravuni Island reefs with 40% - 60% coral cover and only four species of butterfly fish with 5%-10% coral cover at Yanuyanuiloma Island. Overgrazing has resulted in excessive soil erosion which has left the island almost barren and has silted up the coastline and the fringing reef. This island, an emergent rock-outcrop, was badly overgrazed to the extent that all surface groung-level vegetation appeared to have been removed leaving only bare soil with evidence of extensive silt run-off onto the adjacent reef. Adjacent islands were covered in green vegetation in contrast, but Yanuyanuiloma was, on the contrary, red-brown due to the appearance of the bare soil which supported only a few upright green trees, heavily grazed around the trunks.
This brief comparison between reef conditions in the Thousand Islands region in the Java Sea, Indonesia, a relatively densely populated area and of Dravuni Island, Fiji, in the south Pacific is instructive. This is because a deliberate attempt was made to seek a coral reef structure in a comparatively undisturbed location (Dravuni Island) after it was realized that heavily fished reefs in south-east Asia could not be used as teaching areas when assessment procedures for larger fish species were to form part of the field teaching, exercises associated with reef evaluation.
The reef systems of Jakarta Bay are extensively damaged by the immediate and obvious discharges from the city of Jakarta. These include heavy nutrient loads, heavy metals, toxic organic chemicals as well as sediments. The Dravuni system is also damaged by sediment run-off and is presumably also exposed to chemical derived from plastic drift accumulations.
are Already Detectable!
Long-Term Anthropogenic Effects
The degree of inter-species competition is greatest in high diversity systems such as tropical rain forests and coral reefs and as a consequence of this complex organiation, high diversity systems may also be expected to collapse towards species-poor associations when faced with the effects of rapid global climatic change, as has been documented in paleontological records for the deep past (at least for coal-mire systems) as well as in modern communities exposed to the stress of man-made pollutants. Fossil records have also shown that carbon sequestering systems of the past (e.g. coal-forming mires) which remained in virtual unchanged stasis for tens of millions of years, were susceptible to climate change and that change produced community structure collapse when relatively few (probably <20% of species) were lost from well adapted systems as dryer conditions developed. However, fossil records show that such changes did not occur uniformly throughout the globe at the same time so that the Lycopod dominated swamp-forests were able to persist in China and Europe long after they had been replaced in America by a suite of plants adapted to more arid conditions which were perhaps induced by the carbon sequestering swamp forests themselves.
In general, if a central intrinsically adapted community is eliminated by physical change, then previously unsuccessful competitors may penetrate a re-established community if the original dominant species are either all extinct or in some way prevented from setting up dominance structures.
Where there has been rapid environmental change in the past it is always associated with enhanced rates of extinction, community and biosphere restructuring has, for terrestrial systems, "required" prolonged recovery lasting more than a million years. The best documented discontinuity (a global catastrophe) of this type was at the end of Cretaceous, 65 million years ago, which was associated with change in global climate, long term vegetation restructuring, and a major change in the northern hemisphere biota, presumably resulting from a meteorite impact.
The first indication of such changes should be the elimination of dominance hierarchies through the removal of one or two "key-species" as in the case of recent massive sea-urchin die-backs in the Caribbean, with a resulting re-aggregation of the surviving species into new communities.
The wide-spread break-down of dominance hierarchies has yet to manifest itself on a broad basis in south-east Asia, the present changes being maintained by the action of consistent although sometimes relatively constrained mortality patterns such as those found in Jakarta Bay. On the other hand, large areas of the Philippines' reefs have been exposed to such intensive harvesting pressures that a depauperate structure is often wide-spread. We can however, ask if there are any preconditions that appear to be in place that would in turn impose the necessary adjustments to species patterns so permitting wide-spread community collapse. The overall effects of temperature change on the Pulau Seribu system are difficult to assess however; it would appear that even in Umbgroves' time (1929), a change was already underway both in the form of anthropogenic run-off and in temperature effects.
The UNESCO session at the 7th International Coral Reef Symposium in Guam (1992) entitled "Coral reef monitoring: what to do and how to do it" considered a number of assessment protocols for the determination of reef health. As previously explained, the method currently in general use for the evaluation of gross impact to coral reefs is known as the "growth-forms protocol" which is associated with a line-intercept technique and now is used on a global scale. As indicated, the method has certain advantages in that the procedures are easily transmitted to students and the resulting data can be used to readily determine areas of gross damage, provided sampling transcets are located strategically across degraded structures.
As the result of recent work it has become apparent however, that a number of significant shortcomings are associated with the growth-forms assessment protocol. These are:
In summary, the gross coral growth-forms assessment procedure fails at both the micro and macro levels while being adequate at the intermediate level.
The centre of coral species diversity from a global perspective is found in a limited area which includes eastern Indonesia. In order to search for and determine a new and broader assessment paradigm, UNESCO operated a 4 day workshop in this high-species diversity region centred in the Banda Sea in east Indonesia during November 1994.
Corals in east Indonesia
The main study-site was centred on reefs around Gunung Api in the Banda Island group. In 1988 the volcano erupted pouring two sets of larva around 800 metres in width into the sea destroying the coral reef. Since that time a spectacular recolonization event has occurred to the extent that up to 20 species of hard corals may be recorded on a single square metre of larva. Growth has also been extremely high by normal standards so that table-form corals have reached diameters of over 1 metre in around 4 years or so. In Jakarta Bay for instance such growth may be a mere 2-4 cm a year.
Surrounding undamaged reefs were observed to be dominated by relatively few species but the exact representation seems to change rapidly from one place to another in response to physical conditions. For instance, exposed regions tend to be dominated by sub-massive growth-forms represented by Heliopora sp., quieter regions by tabulate Acropora, particularly where there is water movement and intermediate situations, for instance where there is some kind of shelter, by large Porites boulders. In locations between these kinds of situations there is a constant adjustment of different species representation over scales of just a few metres so that a very large array of representative formats may be seen in stretches of reef measuring only a few tens or hundreds of metres in extent. Quiet lagoons are dominated by dense thickets of branching and folios forms represented by comparatively few species (4-6) each dominating patches of tens of metres in extent.
|Gunung Api, 1988. Photo: R. Harger|
Over 112 species have so far been recovered from the recolonized area alone along with two new species, giving some hope that similar healing can be coaxed into play in damaged areas next to major areas of human population if the primary mortality factors can be reduced. It is not known what exact combination of conditions in the surrounding reefs leads to this "healing effect" although initial lack of predators and a complex substrate have something to do with it in terms of initial survival. A further factor seems to involve the relatively abundant representation of corals in the reefs surrounding the impacted area together with the high through-flow of clean water within this comparatively unpolluted area. It is perhaps not to be wondered at that the giant hump-head parrot fish (1.5-2.0 metres in length), is also found in these "high diversity" waters.
Among other attributes, the region of east Indonesia is characterized by very high growth rates for hard-corals (Scleractinia) and, in specific circumstances, explosive settlement densities as well as a high number of species. Throughout the Indonesian and Philippines Archipelagos there may be perhaps as many as 400 species overall. In a relatively circumscribed region such at Spermonde archipelago of south-west Sulawesi (40 x 80 km) as many as 78 genera of Scleractinia have been recorded with 262 species. The environment in eastern Indonesia is a complex of semi-isolated seas and islands and also influenced directly by the "Western Pacific Warm Pool". This area of periodically fluctuating sea-water temperature apparently influences the strength of the "Western Pacific Dry Event" associated with the El Nino - Southern Oscillation and the temperature-pulse involved, coupled with the associated drought appears to spread globally from the region under particular circumstances. There is currently some concern that El Nino-associated warm events are increasing in frequency and intensity as global warming proceeds. In Indonesia the two warmest and driest of such events for over 100 years have occurred in the last 13 years or so and the longest period containing such influences (5 years to the beginning of 1995) in the instrumental record.
The implications posed by this species-diversity-hot-spot include, but are not limited to, the following:
The Australian Aboriginal belief (arising from as much as 60,000 or perhaps even 150,000 years of pondering the issue) is that species arise as the result of "expressed local potential". They arise directly from the alignments and energies generated by their particular locality. Humans, animals and plants are the "dream" of the landscape which in turn arises as an externalization of the essence generated and deposited by the "great ancestors". By this notion, the magnetic, volcanic, inter textural nature of the semi-enclosed and enclosed seas in the region of east Indonesia are the species-generating mechanisms. The earth itself is the dreamer and, among other things perhaps the geomagnetic field is the dreaming with animals, plants, humans the manifest results, themselves dreamers within the greater dream. This is not exactly a strange idea particularly if the fresh-water fish (Cichlid) species swarms of East Africa are considered and in particular the single-form crater-lake associations in Cameroon.
|Students arriving at the UNESCO Coral Reef Assessment and Evaluation Workshop, Ambon. Photo: R. Harger|
|Participants examining coral reef over larva flow. Photo: R. Harger|
Whatever the case, the extremely fine subdivision of ecological space in this area by organic form and function made it an ideal site for the evaluation of assessment approaches. There may indeed be some substance to the claim that all other coral reefs are derivative of those found in east Indonesia. If reef structures in this now comparatively healthy, but none-the-less significantly threatened diversity hot-spot are pushed into decline, then the reefs of the world may well be lost.
The UNESCO Coral Reef Assessment and Evaluation Workshop Ambon, 27 November 1994 and Banda Naira, Indonesia, 28 Nov.- 01 Dec. 1994 was aimed at a combination of senior coral reef specialists of world renown and regional experts. The workshop defined the major questions and factors to be considered in deciding how coral reefs should be assessed on a global scale. The conclusions and recommendations from the activity are presented below.
Coral reef ecosystem assessment
Sustainable use in coral reefs
This will involve answering the following forms of questions: What is sustainable use for a coral reef "ecological system"? What are the principal economic relationships and the major variables affecting the ecology? the use-patterns and "demands"? the existing community relationships? the manageable components or adjustment that can be made by the human community?
Assessment for sustainable use
The objective of any such global, regional or local evaluation is to determine the manner by which sustainable use of coral reef ecosystems or other natural-resource-systems can be obtained. In this regard, the following criteria for success may be specified:
Methods for achieving objectives
Management should be focused at a scale of islands, naturally bounded systems, island- groups (e.g. in the Indonesian Archipelago Banda Naira, Ambon, north Sulawesi), etc. using ecologically significant units and appropriate spatial scales.
Resource uses by humans should be determined and the effects of human verses natural influences on ecosystem structure and function should be evaluated. The major items involved are:
The human community
It is clear that coral reefs are very important ecological communities throughout the world. For the reasons outlined above, UNESCO, through its Intergovernmental Oceanographic Commission, is now involved in developing a Global Coral Reef Monitoring System as described in Part II of this article. Because of the extensive community connections developed during the initial part of the project, an activity aiming to reverse some of the worst influences within the region of Jakarta Bay has now been mounted by UNESCO's recently formed Coastal Areas and Small Islands unit. This activity is attempting to use community-action to help people understand the causes of the deterioration that has affected the coral reefs adjacent to Jakarta Bay. The project will also look into ways in which existing biodiversity can be maintained and used to re-invigorate some of the degraded systems.
Umbgrove, J.H.F. 1929 De Koraalriffen der Duizend Eilanden, dienst mijnb. Ned. Indie, Wetensch. Meded. 7, 1-69.
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