1 Department of Zoology, University of Colombo, Colombo 3, Sri Lanka
Abstract
Reef habitats in Sri Lanka are degraded and impacted by a multiplicity of causes. Survey work carried out on reefs constitute the bulk of recently carried out research activities. Quantitative data on reefs, reef processes and data on the diversity of the reef biota are lacking for Sri Lankan reefs.
There is little reef expertise in the country, with not more than a handful of people engaged in established reef research programmes, and this lack of trained personnel is identified as the main impediment to the collection of research data enabling effective conservation and sustainable management of Sri Lankan reefs.
Since conservation and sustainable management are inextricably linked, though not synonymous, both these objectives can be realised through the maintenance of species as well as habitat diversity and integrity for which a range of data inputs is required which can be collected through an integrated programme of training and data collection in the areas identified in this paper, which include survey work, inventorying reef organism biodiversity, collection of quantitative data on reef processes, evaluating effects of physico-chemical factors and impacting organisms, developing reef rehabilitation methods, identifying high biodiversity niches and undertaking relevant physiological studies. These constitute the directions along which future management-based ecological research should be conducted. The paper summarises the state of knowledge with respect to ecological data on Sri Lankan reefs as well on the availability of trained Sri Lankan personnel.
The multitude of current reef exploitative and degradatory practices, together with the paucity of knowledge on reef ecology, dictates that the precautionary approach incorporating an integrated course of action be speedily adopted for the sustainable management of Sri Lankan coral reefs. The training of more researchers in reef ecology would be pivotal for understanding the ecological processes that need to be incorporated into appropriate reef management strategies in Sri Lanka.
Coral Reefs of Sri Lanka
Sri Lanka is an island nation of 65,610 km 2 having a 17 million population and located off the southern coast of India. Nearshore reefs, mainly of the fringing type, are found along 2% of its 1,585 km coastline (Olsen et al, 1992). Patch reefs on rocky bottoms, reefs growing on beach-rock and sandstone as well as 3 barrier reefs and 2 ridge-colonised reef formations also contribute to enrich the reef ecosystems of Sri Lanka (Ekaratne, 1989b, 1990b; Rajasuriya and White, 1995). All reefs have not yet been surveyed, particularly those on the north and east coasts. The locations and physical status of the surveyed reefs are dealt with in Rajasuriya and White (1995). The reader is referred to the above papers for further details on reef structure and condition.
Reef Resource Use, Legal Protection Status and need for Sustainable Management
Most of the known reefs, particularly readily accessible near-shore reefs, are degraded due to human-induced damage (Ekaratne, 1990b). Reefs in better condition, with over 50% of live hermatypic cover, are present at the Bar Reef off the north west coast, at the Great and Little Basses which are located off the south east coast and a few reefs in the southern coast, including Hikkaduwa in the south-west. Reef sites at Hikkaduwa and Bar Reef constitute the only 2 legally-protected Marine Sanctuaries in Sri Lanka, the former having been accorded Sanctuary status in 1979 and the latter in 1992 (Pernetta, 1993). Although legal enactments for reef and reef-related protection are well in place, implementation and monitoring are grossly inadequate, thus effectively permitting the continuation of reef degradation practices (Ekaratne, 1990b; Nakatani et al, 1994; White and Ekaratne, 1995).
Among the foremost destructive practices adversely impacting directly on physical structure of the reef are the removal of coral for conversion into wall plastering material, reef organism removal for the export aquarium industry, fishing practices that employ explosives and the indiscriminate use of fishing nets. Particulate matter, such as sediment, arising from unsound land-use practices, agro-chemicals derived from agricultural overuse, other polluting wastes draining into reefs, including those from sewage and industry, are the major impacting agents destabilising reef ecosystem processes leading to reef degradation and loss of reef biodiversity (Herath, 1990; Ekaratne, 1990a, 1990b; White and Ekaratne, 1995; Ohman et al, 1993). The Crown-of-thorns starfish, Acanthaster planci, has been reported to periodically increase to form large populations in reefs on the north-west and the east coasts (De Bruin, 1972; Rajasuriya and Rathnapriya, 1994). Following in the wake of anthropogenic disturbances, location-specific invasions of Sri Lankan coral reefs have taken place by other organisms such as didemnids, corallivorous gastropods, sponges and algal species like Halimeda and Ulva (Ekaratne, 1997).
Thus, various reef resources are extracted and utilised by coastal communities, mostly without any practical limitations or management measures being imposed on their exploitation. Impacts resulting from land-based polluting practices further erode the resource base of the reef ecosystems, contributing to the causative factors leading to reef degradation (Ekaratne, 1990b). There seem little prospect of this trend being stemmed; on the contrary, it is thought that the projected expansion of coastal communities in Sri Lanka over the next few decades (Olsen et al, 1992) as well as the increasing focus placed on locating industries along the coastal zone would bring about greater degradative impacts on our coral reef resources. There is, therefore, an overwhelming and urgent need for sustainable management of the Sri Lankan coral reef ecosystems and their resources.
Sustainable Management and Conservation
The concept of sustainability has been around for a long time, although it has entered popular culture only relatively recently. Its recent interpretation views sustainable development as development that meets the needs of the present without compromising the ability of future generations to meet their own needs (WECD, 1987). This concept interlinks the conservation and sustainable use aspects and leads us to the concept of sustainable management of our natural resources, including our rich heritage of biological diversity.
Conservation, by itself and for its own sake, would mean keeping the natural resource without subjecting it to anthropogenic change through its utilisation and would be possible only within legally protected areas, such as marine reserves.
Such conservation would require that we identify areas which would characterise representative reef ecosystems that, in our opinion, merit their being preserved outside the influence of human intervention. For this purpose of identifying areas for conservation, it is necessary for us to have a sufficiently robust data base that would yield information as to the variety, richness and spatial functions of the habitats within reef ecosystems. Research into gathering the data for such an information base is therefore of importance if we are to delimit conservation areas or zones and to accord them legally protected status.
Conservation could also mean the conservation of a given species or a number of species which, however, would become meaningful for coral reef conservation only if such conservation of a species was carried out as part of a functioning ecosystem (as in situ conservation), rather than in isolation or away from its normal habitat (= ex situ conservation). The advantage of in situ conservation is that it would conserve not only the species in question, but other interacting species and, of course, the ecosystem as a functional entity.
As against conservation, sustainable management requires a far greater input of time, effort, personnel and other resources as well as a more detailed information data base that need to be updated continuously and related to the management strategy that is being applied. Sustainable management also requires that the user community be educated regarding the-advantages of using a resource sustainably as against using it as a "common property" natural resource where every user would exploit the resource maximally without being accountable for its long-term upkeep or sustainability.
Sustainable management is dependent on adopting a cohesive holistic approach where ecological data comprise only one of the necessary components. Aspects and data including those relating to socio-economics, education, community empowerment and reforms of policy and institutional methods as well as major land-use methods should be used simultaneously and in combination so that an integrated practical strategy becomes established through a period of time. It is not practical or opportune to go into all these aspects during the time available and this paper therefore identifies more closely with the biological and ecological aspects in relation to sustainable management.
Basic Ecological Data Base for Sustainable Management
One of the basic requirements for sustainable management of a natural resource is to know our species base (species diversity and species richness) and to know the interacting ecological processes that sustains this species base, in turn requiring that the biological diversity at the three levels (i.e. genetic, species and ecosystem levels) be understood.
The sustainable utilisation of a natural resource, such as coral reef dwelling species, requires that we have data with regard to the quantities that we can harvest without impairing its potential to maintain a population size with which the species can perpetuate itself in the long term. For estimating such quantities, we need to know the following; population sizes
· population influencing processes, such as growth, reproduction, interactions, environmental impacts, etc.· the influence that harvestable quantities would have on the population
· measures that could be adopted for stock regeneration whenever it becomes necessary to do so.
It is now considered that effective conservation and sustainable use is possible through participatory approaches (e.g. Community based resource management = CBRM).
Knowledge Base Status and Future Directions for Research
In order to look at the future directions in research and training that we may follow for conservation and sustainable management of our coral reef ecosystems and their resources in Sri Lanka, it would be instructive to review briefly the availability of research data and personnel that would be required to meet our stated objectives. It must be stated that this paper only reviews the recently-available data which would be ecologically meaningful in the present context of management. The data of earlier periods, such as of the last century and early parts of this century (e.g. Ridley, 1883; Bourne, 1905) are not included while the reader is directed to any available references summarising information, when such a work is available, rather than to individual multiple references.
With regard to the species base of our reef ecosystems, species diversity and richness are known, with some degree of comprehensiveness, only for the scleractinian coral and fish fauna from some of our reefs. Data from reef surveys, cataloguing the status and condition of reefs, are available for some of the Sri Lankan reefs. For this purpose, reef surveys have been very effectively carried out by the National Aquatic Resources Agency (NARA) of Sri Lanka and this is a necessary area where NARA can expand their surveys to include other reef areas and to assess the changes in reef condition. NARA is well equipped to do these surveys and some of the reefs have been surveyed qualitatively for fish and scleraclinian coral cover, but not for other organisms, while the extensive reef formations in the north and east have not been surveyed due to security reasons. The survey programme of NARA has revealed the existence of 183 species of stony corals, in 68 genera, and over 300 species of fish, in 62 families, including 35 species of Butterflyfish, as also the occurrence of spiny lobsters, dolphins, whale sharks and 5 species of sea turtles. The common reef-building corals belong to the families of Acroporidae, Agariciidae, Faviidae, Caryophyliidae, Merulinidae, Mussidae, Oculinidae, Pocilloporidae and Poritidae. Common octocorals include Sarcophyton, Sinularia and dendronephthids. (Mergner, and Scheer, 1974; Rajasuriya, 1994; Rajasuriya, and de Silva 1988; Ekaratne, 1997)
In relation to the smaller animals (most invertebrates), that contribute and maintain the complex inter-relationships of reef ecosystems, we know almost nothing or very little. With regard to filling of these gaps a start has only now been made, as for example with the Biodiversity Skills Enhancement Project implemented by March for Conservation (MfC) in Sri Lanka where taxonomic training is being given, particularly with regard to reef invertebrates and a data base is being compiled for these organisms (Ekaratne et al, 1997b). Such training conducted by a NGO (viz., MfC) is hardly adequate on a national scale and taxonomic training for young interested persons should be conducted on an expanded scale in the future. Another area which requires attention, specially where trained manpower is lacking such as in Sri Lanka, is the development of rapid methods for assessment of reef diversity, such as by using the concept of Recognisable Taxonomic Units (RTU's).
It is therefore necessary, in the future, to establish and maintain an inventory of reef organism biodiversity to start on the path towards conservation and sustainable use of coral reefs.
Mergner and Scheer (1974) forms the only work that documents the zonation of a reef habitat in Sri Lanka, indicating the paucity of knowledge on such issues of importance. Quantitative data on reefs are lacking and studies on reef ecological processes have commenced only recently at Colombo University. It has been found that, at Hikkaduwa Sanctuary, coral recruitment extended almost throughout the year, and was maximal from May to August. In south-west reefs, linear growth of Acropora formosa ranged from 5.0 to 18.7mm month-1, with maximum growth in February/March and a lesser peak in September/October. A. formosa weight increments were high from March to July and peaked in June/July, in phase with pre-recruitment periods. Plankton studies of reef lagoons are likewise lacking and are limited to a study by Colombo University where annual cycles of plankton availability are being documented (Ekaratne, 1997a).
Data on physico-chemical factors associated with reefs are also lacking and are limited to a few studies, including that of Colombo University. Although sediment and particulate matter have been widely identified as one of the major impacting agents on reef ecosystems (e.g., Rajasuriya and White, 1995; Ekaratne, 1990b, 1997a), surprisingly, no related documentary data existed up to last year, when Colombo University undertook a study where it was shown that south-west reefs experienced high loads of particulate matter, including sandy material, from May to November, with maximum loads of up to 3.2 kg day-1 m-2. Such studies are urgently needed for other reef locations over acceptable time scales.
The effects of other destructive practices that adversely impact on reef ecosystems need to be studied and evaluated. The removal of coral ("coral mining") for conversion into wall plastering material is well documented by the Coast Conservation Department (CCD) while reef organism removal for the export aquarium industry was the focus of a study by Wood (1986). The status of marine aquarium fish is being studied by Dr. Elizabeth Wood (with NARA, on a Darwin Initiative funding programme) which would form a very good data base on completion. Colombo University is cataloguing the exports in the aquarium export trade and together with the above-mentioned Darwin Initiative study, the results would form a robust data base on this trade practice. The Crown-of-thorns starfish, Acanthaster planci, merits further study as does the effects by other organisms on reef ecosystems such as by didemnids, corallivorous gastropods, sponges and algal species like Halimeda and Ulva; some of which studies are being presently carried out by Colombo University.
Developing in situ methods suited for sustainable management is an accepted priority area in resource management and some preliminary work carried out by the University of Colombo at Hikkaduwa Marine Sanctuary, using Acropora species, indicates the feasibility of reestablishment, restoration and rehabilitation of degraded reef areas. These methods require field testing on a broader scale and constitute another important area meriting future research focus.
A common method for in situ resource management for the conservation of genetic varieties, species and habitats in the wild is their protection through Protected Areas, such as at Hikkaduwa and Bar Reef Sanctuaries. In order to develop Protected Areas further, it is necessary to identify ecological niches of reef areas in association with the biodiversity that such niche types harbour, so that characteristics can be developed for the design of effective Protected Areas taking into consideration the physical extents that are required of each niche type in order to maintain the quantum of reef biodiversity that we desire to conserve. Identification of niche types that are associated with reef ecosystems have been carried out to a limited extent by Colombo University where 6 niche types have been identified at the Hikkaduwa Marine Sanctuary. The food and feeding studies of reef-dwelling fish species carried out by Colombo University would also assist in designing Protected Areas by identifying types and threshold levels of interacting species that are required for maintenance of the desired fish species biodiversity and richness within a defined reef area.
Reef-associated habitats having high biodiversity and nursery value also require identification for effective reef management and for planning the design of a Protected Area Network. Such habitats have been identified by Colombo University to include Halimeda mats that harbour a rich diversity of organisms that included polychaetes, amphipods, shrimps, crabs, molluscs, bryozoans, ascidians, foraminiferans, nemerteans, pycnogonids and platyhelminths. During periods of strong wave force, Halimeda clumps also served as a protective nursery habitat for a number of reef-associated organisms, including pipe fish, gobies, ophiuroids, holothuroids, echinoids, crabs, olives and other molluscs (Ekaratne, 1997a).
Physiological responses to reef impacting processes in reef organisms need to be understood in order to identify threshold values that can be allowed with regard to reef impacting processes. On a general basis, these can be extrapolated to the Sri Lankan reef organisms using data from other countries, but need to be checked for applicability to Sri Lankan species and conditions. Such studies are ongoing at Colombo university, but need expansion and adoption by other institutes.
Ecosystem level research and thinking are needed if we are to address impacting events on a long-term basis. It is only then that causative factors can eventually be controlled for effective long-term management of our reef habitats. In the absence of ecosystem level approaches, management can only be short-term, and can even be damaging in the long-term, where we will perforce have to adopt short-term remedial measures rather than long-term ecologically sustainable approaches. An example of short-term management is the total eradication at Hikkaduwa Sanctuary of the coralline alga, Halimeda, which is documented as facilitating coral recruitment, without examination of a controlled eradication approach incorporating an ecosystems level integrated strategy where the underlying causative factors would be examined and managed as a long-term sustainable management measure.
Manpower considerations
A few NGOs (Nature Conservation Group, Sub-Aqua Club, March for Conservation), University of Colombo and a government research institute (NARA) carry out hands-on reef research/surveys. Research on reef-related issues, such as on social and economic aspects, is being carried out by many organisations in Sri Lanka, including universities, government organisations and NGOs. The Department of Wildlife Conservation is mandated with managing reef protected areas and require its personnel to be trained in reef research methodology.
An analysis of the availability of manpower in Sri Lanka to conduct full-time reef research is very revealing and illustrates why reef data in Sri Lanka is very meagre. Although personnel conducting reef-related work on a part-time basis are present in some organisations such as the CCD, full-time trained researchers are present only at NARA and the University of Colombo. Of these, NARA has 2 experienced persons, while of the three persons active in reef research at Colombo University, 1 is qualified at Ph D level and the other 2 have B Sc Honours degrees and are carrying out postgraduate research studies. In an atmosphere where reef research has to be encouraged and fostered, there are only 2 Sri Lankans doing post-graduate level reef research in Sri Lanka and only 5 Sri Lankans are trained to conduct ecological-related/survey-type reef research. This situation throws into question what our institutional priorities are with regard to reef research within Sri Lanka and the situation has to be changed urgently if we are to seriously consider effective reef management. There are quite a few instances where consultants from overseas have come into Sri Lanka with good intentions of trying to carry out management of our reef resources, and ended up in mismanaging reef issues, which basically is because we continue not to train Sri Lankans in the much-needed reef research methodologies. Training a wider group of young people and recruitment of such trained research staff with requisite qualifications are therefore essential if we have reef management goals as a sincere priority.
Conclusions
The paucity of data and trained personnel in reef research require planning our research and training activities in an integrated manner if we are to manage our reef resources sustainably. One of the key areas is the expansion of training to include young post-graduate training for developing the human, financial, infrastructural and institutional capacity to address these management objectives. Since conservation and sustainable management are inextricably linked, though not synonymous, reef management objectives can be realised through the maintenance of species, as well as habitat, diversity and integrity for which a range of data inputs is required which can be collected through an integrated programme of training and data collection in the areas identified in this paper, which include survey work, inventorising reef organism biodiversity, collection of quantitative data on reef processes, evaluating effects of physico-chemicai factors and impacting organisms, developing reef rehabilitation methods, identifying high biodiversity niches and undertaking relevant physiological studies.
For optimum impact, this research and training approach has to be integrated with efforts aimed at increasing public and stake-holder awareness with regard to sustainable reef resource management, policy-level strategies and efforts to establish ethical guidelines in carrying out research activities for the benefit of the community and long-term sustainability of the resource. Until such time that effective integrated management strategies, based on a robust incrementable data base, have become accepted and are firmly in place, it behoves on us to adopt the widely accepted precautionary approach in devising reef management strategies.
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