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.

Ecological and socioeconomic aspects of subterranean hydrosystems have changed during the past 40–50 years. The major environmental pressures (mainly anthropogenic ones) impact the quantity and quality of groundwater resources and the state of subsurface ecosystems, and it is expected that the environmental pressures on groundwater will continue, at least until 2025, unless new environmental policies change this state of affairs. The world demographic increase and the general rise of water demand constitute one of the major environmental pressures on groundwater ecosystems especially in less developed countries in Africa, Asia and South America. Specific human activities leading to the depletion of groundwater reserves include agricultural practices, landscape alteration, urbanization demand for domestic and public drinking water, various industrial activities such as thermoelectric production and mining, and the rise of tourism in coastal areas. Climate change is contributing to the water crisis too, especially in areas with arid climate and/or in some humid monsoonal countries. The overload of aquifers with pollutants derived from agriculture (fertilizers and pesticides), from industry (release of hydrocarbon chemicals, especially spills), from waste and industrial waters, from domestic and industrial landfills, from the infiltration of pollutants from surface and from the intrusion of saline water affect groundwater quality. The dangerous increase in contaminated subsurface sites with chemicals and microbial pathogens brings with it health risks to humans. Changes of redox condition in groundwater zones, changes of biological diversity, vegetation changes with modification of agriculture practices and impacts at the biosphere scale, such as the increase in the concentration of nitrous oxides in the atmosphere, all impact groundwater ecosystems. Groundwater ecosystems must be better investigated and understood. Economic, social and ecological lines of thinking have to be combined in order to achieve meaningful policies for the sustainable development of groundwater reserves and for the protection of subsurface ecosystems. Practical measures and ideas for the development of policies up to the 2025 time-horizon should improve the sustainable usage of the world's groundwater resources.

Mesoamerica (Southern Mexico, Guatemala, Belize, El Salvador, Honduras, Nicaragua, Costa Rica and Panama) is a culturally diverse region considered a conservation priority due to its biotic richness and high endemism. The Convention on Biological Diversity (CBD) sets out obligations and objectives for national parties to cope with biodiversity reduction, and encourages these national parties to develop measures to conserve and manage biodiversity. This paper presents trends in Mesoamerican countries in the implementation of the CBD, specifically in relation to the general measures for conservation and sustainable use (Article 6), identification and monitoring (Article 7), and in situ conservation (Article 8) derived from examination of reports from the CBD National Reports unit, questionnaires to national focal points, and interviews in the field. In general, there was increased effort toward CBD implementation and related issues. The scientific capacity, political stability, and accessibility to resources in each country, however, influenced the rate at which capacity was being built and the relative importance governments afforded to each of the CBD articles. Lack of resources or institutional limitations are identified as major impediments to fulfilling obligations. The CBD is also poorly known among actors in civil society and at several levels of administration. Overall, Costa Rica and Mexico are exceptions in the region with regard to inventory and monitoring, and the efforts to incorporate biodiversity into broader intersectoral policies. However, the measures required to ensure the fair and equitable sharing of benefits arising from biodiversity are poorly developed, or not developed at all, in the region. It is pivotal that, since Mesoamerica is one of the poorest regions in the world, any attempt to conserve biodiversity in the region must include sustainable use and equity.

Contingent valuation (CV) is a popular method in economics for eliciting individuals' preferences for non-market environmental resources, but very few attempts have been made to apply it to distant environmental goods of global importance. This paper reports the results of a CV study in the UK and Italy, which evaluated non-users' willingness to pay for the implementation of a proposed programme of protected areas in Brazilian Amazonia. The main focus of the survey was the wealth of biodiversity in the region proposed for protection and the ecosystem services provided by such areas. Taking both countries together, respondents were willing to pay, on average, £30 (US$ 45.60) per household per annum to fund the implementation of a protection programme covering 5% of Brazilian Amazonia and £39 (US$ 59.28) per household per annum to fund a 20% programme. Aggregated across households, an annual fund to conserve 5% of Brazilian Amazonia as strictly protected areas could yield around £600 million (US$ 912 million) in the UK and a similar amount in Italy. It should be noted that respondents appeared to show a high degree of uncertainty in the bid decision process for such an unfamiliar and distant good, leading to questions as to the validity and reliability of results. Nevertheless, responses were non-random and systematically related to a range of socio-economic characteristics and attitudinal variables. Thus initiatives such as international financial transfers from wealthy developed countries to support the protection of threatened areas of global significance could attract widespread support in those countries.

A method of environmental classification has been applied twice to surveys of the whole of England, Scotland and Wales (the United Kingdom). Such experience is now being extended to the European continent. The paper draws on the unpublished working-papers of the relevant scientists and institutions in reconstructing both the motives and circumstances in which a methodology was developed in the UK for the assessment of the ecological resources of the wider countryside. The principles of strategic classification and subsequent sampling from defined strata were initially devised for broadleaved woodland, and first tested at a regional level. They drew on classical regression theory, with the environmental classification being the independent, and the vegetation or habitat the dependent, variable. The approach was linked to the development of efficient algorithms for analysis and classification, and more recently remote sensing and geographical information systems. Successive Countryside Surveys of the UK, carried out since 1978, have provided an objective measurement of the decline in the quality of vegetation and habitats. Such a statistically robust approach can be used to measure the rates of vegetation and habitat change at the strategic European level, and as an aid to devising appropriate rural-resources policies.

Cave temperature monitoring was carried out in the Cueva del Agua de Iznalloz, Granada, Spain, a cave that has great tourist potential and which has been maintained under natural conditions for over 30 years. The cave temperature under natural conditions was used to identify possible anthropogenic influences, in order to distinguish these from the variations directly related to natural changes. In particular, the relative influence of external weather conditions, thermal modification caused by visitors and the subsequent thermal recovery of the cave were identified. In addition, controlled experiments investigated the effect of two large-scale visits (980 and 2088 visitors day−1) to the cave interior, before any tourist activities in the cave were undertaken. Correlation and spectral analyses of time series were used to determine the thermal behaviour of the cave over time. The effect of both mass visits on the air temperature in the interior of the cave was very rapid (2.5 min). The maximum perturbation of air temperature within the cave during the two experiments was after 30 and 70 min. The memory effect for temperature whilst the cave was open to the public was estimated to be 5–6 h, whilst the response to external meteorological changes exceeded one week. A permanent visitor capacity of 53 people ensures that the natural cave temperature can be regained within 4–5 h. The cave can only support small groups of visitors, not the massive visits characteristic of show caves.

Reclamation of saline lands seems difficult for climatic and economic reasons, but cultivation of salt-tolerant plants is an approach to increasing productivity and improvement of salt-affected wastelands. A five-year field study was conducted to evaluate the effects of growing a salt-tolerant species Leptochloa fusca (L.) Kunth (kallar grass) on chemical properties of a saline sodic soil irrigated with poor quality groundwater. Soil salinity, sodicity and pH decreased exponentially by growing kallar grass as a result of leaching of salts from surface (0–20 cm) to lower depths (>100 cm). Concentrations of soluble cations (Na+, K+, Ca2+ and Mg2+) and anions (Cl−, SO42− and HCO3−) were reduced through to greater soil depths. A significant decline in soil pH was attributed to release of CO2 by grass roots and solublization of CaCO3. Both soil salinity and soil pH were significantly correlated with Na+, Ca2+, Mg2+, K+, Cl−, HCO3− and sodium adsorption ratio (SAR). Significant correlations were found between soluble cations (Na+, Ca2+ and K+), soluble anions (Cl−, SO42− and HCO3−) and the SAR. In contrast, there were negative correlations between soil organic matter content and all chemical properties. The ameliorative effects on the soil chemical environment were pronounced after three years of growing kallar grass. Cultivation of kallar grass enhanced leaching and interactions among soil chemical properties and thus restored soil fertility. The soil maintained the improved characteristics with further growth of the grass up to five years suggesting that growing salt-tolerant plants is a sustainable approach to biological amelioration of saline wastelands.

Waza National Park, Cameroon, is representative of trends towards more participatory protected area management in Africa. It has no transition zone and interactions with the surrounding human population are complex. A recently adopted management plan allows experiments with limited consumptive use of natural resources, in exchange for people's collaboration. In order to determine which resources are desired and which resources are liabilities, people in the Park's vicinity were interviewed. Respondents' attitudes towards conservation were positive, motivated by both use and intrinsic values, and with reference to future generations. Attitudes were significantly related to locally perceived benefits. Respondents found most of the Park's resources useful but differences between user groups were significant. User groups also differed in their complaints about human-wildlife conflicts, but overall they considered the animals most important for tourism as the main nuisance. This case study shows that local aspirations cannot all be met, but indicates that limited outreach can improve existing public support for conservation measures.

In the wake of apartheid, South African protected areas have come under increasing pressure to reconcile a wealth of natural resources with the acute social and economic needs of the black rural majority. Demands for land reform, poverty alleviation and job creation have all had profound implications for the conservation and management of the nation's protected areas. An attitudinal study was conducted within three diverse South African communities, and among employees of the Kwa Zulu-Natal Nature Conservation Service (KZN Wildlife) to assess how the Greater St Lucia Wetland Park (GSWP) and the authorities charged with its management are perceived in the context of post-apartheid South Africa. Despite significant revisions to South Africa's conservation policies in the post-apartheid era, attitudinal research has continued to focus on rural black communities, leaving white residents, urban black populations and the conservation authorities themselves largely under-represented. As a result, the relationships between local communities, protected areas and conservation authorities remain largely unknown and outdated. Qualitative analysis of 90 semi-structured interviews indicated limited support (5%) for the abolition of the GSWP. The potential loss of the GSWP was associated with negative economic (88%) and environmental (66%) impacts by all respondents, regardless of race, gender, age or residency. Contrary to previous research conducted during the apartheid era, an overwhelming majority of Zulu respondents perceived a positive association between nature conservation, tourism and improved local economic welfare. Thus, local attitudes towards protected areas appeared to be improving. There remained however a discrepancy between support for the GSWP and the management authorities, particularly among respondents with limited contact with conservation staff. This is consistent with previous surveys where residents expressed support for the concept of conservation, but significant hostility towards local conservation authorities. The distinction is critical, as negative attitudes towards conservation authorities are often misinterpreted as a lack of support for conservation in general. Local residents (regardless of race or socioeconomic status) also expressed high expectations of KZN Wildlife to address issues of unemployment, poverty and tourism in the region. If these expectations are not met, support for the GSWP, as well as the conservation authorities, is likely to decline dramatically.

The value of traditional ecological knowledge for biodiversity research and conservation is widely recognized. The value of wildlife knowledge provided by recent migrants is less clear. Photographs of 10 mammal species were shown to 622 individuals in communities near Way Kambas National Park in Sumatra, Indonesia, to assess wildlife knowledge among recent migrants and to identify socio-economic variables that can be used to identify more knowledgeable informants. Knowledge scores were categorized by taxonomic family, genus and species. Large, charismatic and abundant animals were identified more frequently than smaller and more secretive animals. Higher knowledge scores were significantly associated with males, higher educational attainment and past experience with these animals. Number of years respondents had lived in the area and respondent age were also good predictors of higher scores. The characteristics of animals that were likely to be identified more accurately were assessed. Generic terms used to describe animals can confound individual responses. Biodiversity research, conservation and education programmes frequently rely on ‘local’ knowledge to inform management and policy. This information can be a valuable addition to field-based efforts to identify the distribution and abundance of rare endangered species. With more and more migrants living near the world's wildlife protected areas, care must be taken to understand how human demographic shifts may affect such studies.

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.