The coral reefs of Papua New Guinea are among the most species diverse in the world, support an important artisanal fishery, but lack an effective national conservation programme. Increased commercialization, population growth, promotion of fisheries development projects, and the live reef food fish trade are expected to increase demand for the country's reef fish. This paper examines how socioeconomic factors affect the condition of the artisanal multi-species coral reef fishery in six sites in Papua New Guinea. Catch characteristics such as diversity, trophic level and body size by landing site were examined along a fishing pressure gradient. Both exogenous factors such as markets and endogenous factors such as fishing pressure were related to the condition of fish catch. In general, the trophic level and lengths of fish captured in Papua New Guinea were relatively high, but were reduced on reefs with high fishing effort near fish markets. Fisheries showed signs of depletion above c. 25 fishing trips per km2 per day and the proximity of markets was a better indicator of overfishing than human population size. A cross-scale approach to fisheries management is required in Papua New Guinea to coordinate decentralized local management, limit the intrusion of extractive enterprises, and develop policies that seek to minimize exogenous pressures on marine resources.

Efforts to promote popular participation in forest management in Sub-Saharan Africa have faced many obstacles and disappointments. Although promises of improvements in relation to forest management, rural livelihoods and local enfranchisement have been achieved in some cases, accounts of frustration outnumber those of success. Focusing on participation through democratic decentralization (namely the transfer of meaningful discretionary powers to local representative authorities), this paper reviews recent empirical studies on the outcomes of popular participation in forest management. The implementation of decentralization of forest management, and ecological, livelihood and democracy outcomes are examined, and misconceptions in analyses of decentralized forestry are explored. The expected benefits of democratic decentralization within forestry are rarely realized because democratic decentralization is rarely established. In most cases, local authorities do not represent the local population or their space of discretion is so narrow that they have little effect on management. There is little official local management taking place, even under so-called decentralized or participatory management arrangements. If ever significant space for local discretion under democratic authorities is created, researchers will have the opportunity to study whether democratic decentralization can deliver the theoretically promised positive outcomes. Nevertheless, some cases shed light on effects of local decision making. Three general observations are made on effects of decentralization. First, environmental, livelihood and democracy objectives are not always mutually reinforcing, and under some circumstances they may be at odds. Second, environmental effects of improved forest management often result in benefits accruing to distant or higher-scale aggregate populations, while local communities carry the costs. Third, poor peoples' use of natural resources to maintain their livelihoods often conflicts with profit and revenue interests of local elites, national commercial interests and governments. A negotiated minimum social and environmental standards approach to decentralization of forest management may safeguard essential ecological functions and at the same time protect essential livelihood and economic values of forests at all scales of society. The remainder of decisions, such as how forests are used, by whom and for what, could then be safely placed at the discretion of responsive local representatives.

Participation by local communities in management is widely considered a means of sustaining protected areas. In parts of the world with a history of armed conflict, the chances of such an approach being successfully adopted might seem remote. One such area is the Maputo Elephant Reserve in southern Mozambique. The aim was to improve understanding of the local people's use of natural resources and perceptions of the Reserve's impact. Interviews and questionnaires distributed in four different villages were used to estimate the relative value of these resources in relation to the attitude of the local people towards the Reserve. The people gave a relative value rank for each specific use of each plant, animal and fish resource. On average 60% of the households exploited more than two different resource categories. The plant resources of the Reserve were used by 71% of the households and were valued more highly than animal and fish resources. Plants were used for many purposes; construction material, fuelwood and fruits had the highest relative values. Antelopes, hippopotamus and elephants were valued highest amongst a range of animal species which were hunted by 21% of households. Amongst uses of animals, consumption, use of the skins and commercial sale of the meat were especially important. When asked if they liked the Reserve, 88% of respondents answered positively. The attitude towards the Reserve was correlated with crop damage experiences; people with crop damage caused by elephants, hippos or bushpigs, were more negative. Attitude of respondents was inversely related to the number of species invading their agricultural fields. Resource use intensity, use purpose, resource value and attitude were different amongst sites and dependent on site-specific circumstances, different management strategies could be necessary for the four sites. A resource management plan should be drawn up, local people should be included in the management team and steps should be taken to improve the relationship between the Reserve's authorities and the local population generally.

Recent ‘bleaching’ and death of hermatypic (reef-building) corals has occurred extensively in Pacific Ocean waters of Panamá (Gulf of Chiriquí), near the Panamá-Costa Rica border. All hydrocorals (Millepora spp.) and scleractinian corals (5 genera) have been affected to some degree in the non-upwelling environment of Chiriquí. No other members of the macrobenthos showed signs of stress (lowered activities, morbidity) or reduced abundance. The affected area, including the mainland, nearshore and offshore islands, and adjacent waters, is about 10,000 km2. Further surveys in the Gulf of Chiriquí may reveal even more extensive mortality.

This disturbance began in the dry season (January–April 1983), during a period of clear skies, low rainfall, and minimal river drainage. I first observed large, ‘bleached’ coral patches (up to 100 m2 in area) in mid-March, and observations by others indicate that coral ‘bleaching’ occurred in February and possibly as early as mid-January. Normal and ‘bleached’ corals observed in mid-March were ‘bleached’ and dead, respectively, by the end of April, suggesting that the disturbance is protracted. By the end of the dry season, 80 to 95% of all corals in the affected areas were severely ‘bleached’ or dead.

What are the effects of no-take marine reserves on trophic relationships of coral reef fish? Previous studies often have lacked detailed dietary information on major predators, and have often been confounded by differences in habitat complexity between reserve and fished sites. This study investigates the effects of marine reserve protection on predator-prey interactions of coral reef fish on the inshore islands of the Great Barrier Reef (GBR). The abundance of species of prey fish of Plectropomus leopardus (Serranidae), a piscivore and the major target of the hook and line fisheries on the GBR, were estimated in protected and fished zones. These prey species were identified from previous detailed studies of the diet of P. leopardus. Fish populations and habitat characteristics were surveyed by underwater visual census. Previous studies had determined that the biomass of P. leopardus was 3–4 times higher in protected than fished zones in the Whitsunday and Palm Islands, central GBR, after 14 years of protection. Eight of the nine prey species had a higher density within fished zones than protected zones, six significantly so. The density of all prey fish was twice that in the fished than the protected zone (p < 0.001). There were no significant differences in availability of different sized refuge holes, structural complexity or live coral cover between zones. Thus, important attributes of habitat complexity did not confound the comparisons between reserve and fished zones. Finally, a significant negative correlation (r = 0.46) between coral trout biomass and summed prey fish biomass suggested that predation may be an important structuring process in this system. The results have implications for the conservation of fishery targets and their prey. The study highlights the potential ecosystem implications of the use of no-take marine reserves as conservation and fisheries management tools.

Human occupation and development of alluvial river floodplains are adversely affected by river channel lateral migration, which may range as high as several hundred metres per year. Reservoirs that reduce the frequency and duration of high flows typically reduce lateral migration rates by factors of 3 to 6. The ecology of riverine corridors is dependent upon the processes of erosion and sedimentation, which lead to lateral migration. Multiple-objective use of floodplains adjacent to active rivers therefore requires tools for assessing the probability and magnitude of channel movements. Existing approaches for predicting river channel movement may be classified as empirical or mechanistic, and are inadequate for widespread application. The Missouri River downstream from Fort Peck Dam in Montana, a major alluvial river with flow highly perturbed by regulation, was selected for case study. Maps and aerial photographs were available before and after dam construction. This imagery was analysed by digitizing channel centrelines at successive coverages under pre-dam and post-dam conditions, and mean migration rates were computed by bend and by reach. The mean rate of channel centreline migration fell from 6.6 m yr-1 to 1.8 m yr-1 after impoundment. Bend-mean channel activity rates were only weakly correlated with variables describing channel form and geometry. Results indicate that flow regulation for flood control and hydropower production typical of the study reach had profound effects on river corridor dynamism, with implications for habitat type distribution and ecosystem integrity.

Marine protected areas (MPAs) may be important for protecting the marine environment, but they may also have substantial socio-cultural impacts about which very little is currently known, or acknowledged. In the Mediterranean, few data are available on the socio-economic consequences of MPAs. The present study reviews the existing data on MPAs in Spain, France, Italy and Greece. A general increase in tourist activities in Mediterranean MPAs is evident, as are increases in the abundances of larger fish species, although there are no data indicating yields for fisheries increase adjacent to MPAs. A large increase in the number of divers and vessels using MPAs has already had impacts on natural benthic communities as a result of diver damage, mooring and the feeding of large fish by divers. Emphasis has been given in only a few MPAs to promoting public awareness of these impacts. Although the conservation of nature should be considered the fundamental objective of MPAs, neglecting their social, cultural and economic impacts has at times led to poor local consensus, if not hostility. We believe that planning and managing MPAs should be conducted on a multidisciplinary basis. Nonetheless, no single model can be considered valid for the whole Mediterranean. The very variable characteristics of coastal areas, from those of small uninhabited islands to those of cities, require different weightings to be assigned for each factor in order to achieve a durable equilibrium and realize the original objectives of each MPA. Only with such flexibility of management will it be possible to reach a greater understanding of the MPA system and create a lasting consensus in favour of conservation, a consensus which would mean an overwhelming majority of people actively avoiding damaging nature and preventing others from doing so.

An extensive literature has appeared since 1990 on the study of ‘no-take’ marine reserves and their potential to make significant contributions to the conservation and management of fisheries, especially in tropical environments (see Polunin 1990; Roberts & Polunin 1991; DeMartini 1993; Roberts 1997; Allison et al. 1998; Guénette et al. 1998). The literature describes many potential benefits of marine reserves to fisheries, including increases in spawner-biomass-per-recruit and increases in larval supply from protecting ‘source’ populations (Jennings 2000). The important word here is ‘potential’. Some claims made by advocates of marine reserves might be regarded as optimistic, whereas critics of reserves might sometimes have been unduly harsh. Conservation goals for marine reserves are often poorly defined, and differences of opinion regarding the efficacy of reserves for fulfilling any of their stated goals can frequently be attributed to a lack of good information with which to predict their effects. Here, we critically examine the literature from 1990–2001 to determine (1) the relative effort put into empirical and theoretical approaches to predict reserve effects, and (2) the quality of empirical evidence available to support theoretical predictions. It is not the purpose of this article to single out particular studies for criticism (although this is sometimes inevitable to provide examples), nor to draw conclusions concerning the efficacy of marine reserves.

Non-compliance with marine protected area (MPA) regulations is a problem worldwide, and this is being addressed through community programmes. Park service and fisheries department personnel, and fishers living adjacent to three parks were studied to determine their perceptions of MPAs. The hypotheses that positive perceptions towards the management of fisheries exclusion and gear-restricted areas would increase with the wealth, education, age and years of employment of the person, the history of community participation and the age of the MPA were tested. The strongest factor was employment, with fishers having significantly less positive perceptions towards areas closed to fishing than government managers, although all groups agreed area management benefited the nation. Government personnel thought that fishers and their communities benefited from area management, while most fishers did not share this view. Increasing wealth or community participation were not significant factors, but secondary education was associated with more positive perceptions of area management. Fishers adjacent to the oldest MPA held significantly more positive perceptions than fishers living adjacent to the newest MPA, although only a slight majority agreed that they and their communities benefited. The results point to a need for patience in expecting change in resource users' perceptions, adopting an approach in which there is more communication between fishers and managers, so that both are more aware of MPA functions, particularly closed areas and the indirect benefits.

Conservation covenants (or easements) are flexible but legally enforceable documents attached to a land title restricting the use of that land, providing for the protection of important conservation values, while allowing the landholder to retain possession. Given the attractiveness of covenants to those who seek to expand national and regional nature conservation initiatives, it is important to understand landholder motivations for participation in programmes that covenant for nature conservation. This paper examines the likely influences on landholder decision making when it comes to conservation initiatives. A review of literature highlights key motivations and determinants, such as landholder demographics and the nature of the land tenure in question, their knowledge and awareness of the programme, financial circumstances, and perceptions of financial and other risks and benefits of the programme itself, including incentives and compensation. Underpinning, or mediating, the decision-making processes will be landholder philosophies and values, and five constructs are determined from the review, namely economic dependence on property, private property rights, confidence in perpetual covenant mechanisms, nature conservation equity and nature conservation ethic. Using these constructs, a series of explicit hypotheses is drawn, applicable to agencies dealing with conservation covenants and testable through an adaptive management approach. A conceptual model is presented to show hypothesized relationships between motivational factors and the five constructs that will lead to the uptake of covenants by landholders, providing direction for policy makers and managers of incentive programmes for nature conservation on private lands.

Existing hydroelectric dams in Brazilian Amazonia emitted about 0.26 million tons of methane and 38 million tons of carbon dioxide in 1990. The methane emissions represent an essentially permanent addition to gas fluxes from the region, rather than a one-time release. The total area of reservoirs planned in the region is about 20 times the area existing in 1990, implying a potential annual methane release of about 5.2 million tons. About 40% of this estimated release is from underwater decay of forest biomass, which is the most uncertain of the components in the calculation. Methane is also released in significant quantities from open water, macrophyte beds, and above-water decay of forest biomass.

The concept of ‘biosphere reserve’ emerged from the programme of Man and the Biosphere (MAB) of which it constitutes an essential part. This paper describes how the concept has progressively evolved as the Programme was being implemented, and as the multiple objectives and characteristics of Biosphere Reserves were clearly identified.

The primary function of Biosphere Reserves remains the in situ long-term conservation of plant and animal genetic resources, together with research on ecosystem management and conservation, monitoring of changes in The Biosphere, training of specialists, and environmental education. They are being progressively integrated into a world-wide network of ‘representative ecological areas’ that is intended to cover all major representative natural and semi-natural ecosystems.

The paper stresses the flexibility and versatility of the new concept, and gives examples of how this concept is being implemented. It underlines current trends in the building-up of the international network, which now includes 214 Biosphere Reserves in 58 countries, and the future prospects for its full development. The paper also suggests that the direct involvement of the local population in the management of Biosphere Reserves, together with the maintenance of research and monitoring activities in them, constitute the best guarantee for long-term conservation of genetic resources on a world-wide basis. It announces the proposed ‘International Conference on Biosphere Reserves’, which it is hoped can be held in Minsk (USSR) in the autumn of 1983.

Among the larger mammals, marine types offer some unique insights and problems for management. United States laws require that they be managed ‘to maintain the health and stability of the marine ecosystem.’ The relevant statute (Marine Mammal Protection Act of 1972) requires maintenance of an ‘optimal sustainable population’, which is being interpreted as a range between the level giving a maximum sustainable yield (MSY) and asymptotic levels. Emerging evidence pertaining to marine mammals, and perhaps applicable to a larger class of vertebrates, indicates that the MSY point may be well above the logistic-curve 50% point.

‘Reproduction curves’ of various sorts are used in management as operational representations of population self-regulation (density-dependence). A variety of theories and hypotheses concerning such regulation now exists, though none is adequately supported as yet. A general model for self-regulation in long-lived species is suggested as being comprised of stages of regulation. Immature mortality is postulated as the first stage, followed by age of first reproduction and then reproductive rates of adult females. The fourth and last stage, as populations reach maximum sustainable levels, is assumed to involve changes in adult survival.

Although a model of the kind suggested here offers some useful insights as to harversting strategies, a more quantitative (functional) basis will be needed for actual management applications.

Animal tolerance to human approaches may be used to establish buffers for wildlife that can minimize the probability that animals will be disturbed by human activity. Alert distance (the distance between an animal and an approaching human at which point the animal begins to exhibit alert behaviours to the human) has been proposed as an indicator of tolerance mainly for waterbirds; however, little is known about its utility for other bird species. The factors that influenced alert distances of four bird species to pedestrian approaches in five large wooded fragments in the city of Madrid (Spain) were analysed. Location of human activity affected only Passer domesticus alert distances, which increased in the proximity of pathways. Habitat structure modified alert distances of all the species (Passer domesticus, Turdus merula, Columba palumbus, and Pica pica), increasing bird tolerance with greater availability of escape cover (shrub and coniferous cover, and shrub height). Alert distances varied among species, with large species being less tolerant of human disturbance than small ones. Alert distance appears to be a more conservative indicator of tolerance than flight distances, because it includes a buffer zone (the difference between alert and flight distance) in which birds may adapt their reaction to the behaviour of visitors. Alert distance may be used in the determination of minimum approaching areas, allowing people to enjoy their visit to parks, and birds to use patches for foraging and breeding without being displaced.

Myanmar is one of the most forested countries in mainland South-east Asia. These forests support a large number of important species and endemics and have great value for global efforts in biodiversity conservation. Landsat satellite imagery from the 1990s and 2000s was used to develop a countrywide forest map and estimate deforestation. The country has retained much of its forest cover, but forests have declined by 0.3% annually. Deforestation varied considerably among administrative units, with central and more populated states and divisions showing the highest losses. Ten deforestation hotspots had annual deforestation rates well above the countrywide average. Major reasons for forest losses in these hotspots stemmed from increased agricultural conversion, fuelwood consumption, charcoal production, commercial logging and plantation development. While Myanmar continues to be a stronghold for closed canopy forests, several areas have been experiencing serious deforestation. Most notable are the mangrove forests in the Ayeyarwady delta region and the remaining dry forests at the northern edge of the central dry zone.

This explanatory note is intended to accompany the map included in this issue. The map is on a scale of 1:30,000,000 (1 cm = 300 km) and shows regional-scale ‘ecosystem’ units, or ecoregions, differentiated according to a scheme modified from J.M. Crowley (1967), and using climate and vegetation as indicators of the extent of each unit. The units are similar in concept to ‘ecobiomes’ as proposed by Polunin (1984). The map was developed following a proposal by Bailey & Hogg (1986) to supplement the Udvardy (1975) system of biogeographical provinces with a treatment of higher resolution. Three levels or categories of this hierarchy are shown. Of these the broadest, domains, and within them divisions, are based largely on the broad ecological climate zones following the Koppen system as modified by Trewartha (1968), and summarized in our Tables I and II. Climate is emphasized at the broadest levels because of its overriding effect on the composition and productivity of ecosystems etc. from region to region.

Since China is a leading market for a number of types of seafood, and much of this seafood is imported from other countries, Chinese consumption of seafood is an issue of vital importance to many of the world's fisheries. Focusing on luxury seafood, in particular bêche-de-mer, shark fin and live reef food fish, this paper firstly examines the links between Chinese consumption and species population trends in source countries. After a discussion of current efforts at conservation and management of these fisheries, the paper shows how the consumption of luxury seafood in contemporary China is intertwined with broader historical trends, including the expansion of Southern Chinese cuisine; cultural beliefs and traditions, in particular surrounding elements of traditional Chinese medicine; and most importantly, notions of social status and conspicuous consumption linked to the development of the Chinese economy and social stratification. The paper points to the role of the historical, cultural and social processes that underlie Chinese luxury seafood consumption, and to the need for greater levels of action among various actors to address this consumption if sustainability is to be achieved.

Various management approaches have been proposed to address the alarming depletion of marine coastal resources. Prominent among them are community-based management and the establishment of marine protected areas (MPAs). The overall poor performance of MPAs can be traced to a failure to effectively include local communities in the design and implementation of relevant measures. Recent efforts have incorporated aspects of community-based management into a hybrid form of management, which ideally builds upon existing local management practices. A key challenge lies in the development of appropriate frameworks that allow for the successful participation of local communities in management. A review of studies on MPA design and community-based marine resource management and fieldwork observations provides suggestions on how to address current socioeconomic shortcomings in MPA design and implementation, successfully involving local communities in order to provide a better local basis for effective larger MPA networks. A combination of MPA tools as the formal frame and community-based natural resource management as the adaptive core that recognizes local communities as allies, not aliens, is needed to develop successful conservation approaches.

Tropical wetlands assume important functions in the landscape and contribute considerably to the welfare of large parts of the human population, but they are seriously threatened because they are considered free resources of land and water. This review summarizes long-term environmental trends for tropical wetlands and predicts their future to the time horizon 2025. Many tropical countries do not have the economic strength, scientific and technological capacity, and/or administrative infrastructure to adequately react to the challenges of increasing population pressure and globalization of the economy with respect to the sustainable use of the resources. Furthermore, political instability and armed conflicts affect large areas in several tropical countries, hindering wetland research and management. Detailed wetland inventories are missing in most countries, as are plans for a sustainable management of wetlands in the context of a long-term integrated watershed management. Despite large regional variability, a continental ranking shows, in decreasing order of wetland integrity, South America, Africa, Australia and Asia, while efforts to mitigate human impacts on wetlands are largest and most advanced in Australia. Analysis of demographic, political, economic and ecological trends indicates fairly stable conditions for wetlands in tropical Australia, slight deterioration of the large wetland areas in tropical South America excepting the Magdalena and Cauca River flood plains where human population is larger, rapidly increasing pressure and destruction on many African and Central American wetlands and serious threats for the remaining wetlands in tropical Asia, by the year of 2025. Policy deficiencies, deficient planning concepts, limited information and awareness and institutional weakness are the main administrative reasons for wetland degradation and must be overcome to improve wetland management and protection in future. Intensification of international cooperation and assistance is considered of fundamental importance for most tropical countries to solve problems related to wetland research, protection and sustainable management.

Payments for ecosystem services (PES) are a relatively new economic policy instrument, and the factors that drive and explain their environmental performance are poorly understood. Here a meta-analysis of causal relationships between the institutional design and environmental performance of 47 payments for watershed services (PWS) schemes worldwide showed a significant effect on environmental achievement of the terms and conditions of scheme participation, including the selection of service providers, community participation, the existence and monitoring of quantifiable objectives, and the number of intermediaries between service providers and buyers. Direct payments by downstream hydropower companies to upstream land owners for reduced sediment loads were identified as a successful PWS example. No other significant explanatory factors, such as specific type of watershed service, age or scale of implementation of the PWS scheme were detected. The results are highly dependent on the reliability of the input variables, in particular the measurement of the environmental performance variable. Despite efforts to find quantitative information on the environmental performance of existing PWS schemes, such empirical evidence is lacking in many of the schemes studied. International monitoring guidelines are needed to facilitate comparisons, identify success factors and support the future design of cost-effective PWS schemes.