This review examines the status of temperate-zone freshwater wetlands and makes projections of how changes over the 2025 time horizon might affect their biodiversity. The six geographic regions addressed are temperate areas of North America, South America, northern Europe, northern Mediterranean, temperate Russia, Mongolia, north-east China, Korea and Japan, and southern Australia and New Zealand. Information from the recent technical literature, general accounts in books, and some first-hand experience provided the basis for describing major wetland types, their status and major threats. Loss of biodiversity is a consequence both of a reduction in area and deterioration in condition. The information base for either change is highly variable geographically. Many countries lack accurate inventories, and for those with inventories, classifications differ, thus making comparisons difficult. Factors responsible for losses and degradation include diversions and damming of river flows, disconnecting floodplain wetlands from flood flows, eutrophication, contamination, grazing, harvests of plants and animals, global warming, invasions of exotics, and the practices of filling, dyking and draining. In humid regions, drainage of depressions and flats has eliminated large areas of wetlands. In arid regions, irrigated agriculture directly competes with wetlands for water. Eutrophication is widespread, which, together with effects of invasive species, reduces biotic complexity. In northern Europe and the northern Mediterranean, losses have been ongoing for hundreds of years, while losses in North America accelerated during the 1950s through to the 1970s. In contrast, areas such as China appear to be on the cusp of expanding drainage projects and building impoundments that will eliminate and degrade freshwater wetlands. Generalizations and trends gleaned from this paper should be considered only as a starting point for developing world-scale data sets. One trend is that the more industrialized countries are likely to conserve their already impacted, remaining wetlands, while nations with less industrialization are now experiencing accelerated losses, and may continue to do so for the next several decades. Another observation is that countries with both protection and restoration programmes do not necessarily enjoy a net increase in area and improvement in condition. Consequently, both reductions in the rates of wetland loss and increases in the rates of restoration are needed in tandem to achieve overall improvements in wetland area and condition.

Running waters are perhaps the most impacted ecosystem on the planet as they have been the focus for human settlement and are heavily exploited for water supplies, irrigation, electricity generation, and waste disposal. Lotic systems also have an intimate contact with their catchments and so land-use alterations affect them directly. Here long-term trends in the factors that currently impact running waters are reviewed with the aim of predicting what the main threats to rivers will be in the year 2025. The main ultimate factors forcing change in running waters (ecosystem destruction, physical habitat and water chemistry alteration, and the direct addition or removal of species) stem from proximate influences from urbanization, industry, land-use change and water-course alterations. Any one river is likely to be subjected to several types of impact, and the management of impacts on lotic systems is complicated by numerous links between different forms of anthropogenic effect. Long-term trends for different impacts vary. Concentrations of chemical pollutants such as toxins and nutrients have increased in rivers in developed countries over the past century, with recent reductions for some pollutants (e.g. metals, organic toxicants, acidification), and continued increases in others (e.g. nutrients); there are no long-term chemical data for developing countries. Dam construction increased rapidly during the twentieth century, peaking in the 1970s, and the number of reservoirs has stabilized since this time, whereas the transfer of exotic species between lotic systems continues to increase. Hence, there have been some success stories in the attempts to reduce the impacts from anthropogenic impacts in developed nations. Improvements in the pH status of running waters should continue with lower sulphurous emissions, although emissions of nitrous oxides are set to continue under current legislation and will continue to contribute to acidification and nutrient loadings. Climate change also will impact running waters through alterations in hydrology and thermal regimes, although precise predictions are problematic; effects are likely to vary between regions and to operate alongside rather than override those from other impacts. Effects from climate change may be more extreme over longer time scales (>50 years). The overriding pressure on running water ecosystems up to 2025 will stem from the predicted increase in the human population, with concomitant increases in urban development, industry, agricultural activities and water abstraction, diversion and damming. Future degradation could be substantial and rapid (c. 10 years) and will be concentrated in those areas of the world where resources for conservation are most limited and knowledge of lotic ecosystems most incomplete; damage will centre on lowland rivers, which are also relatively poorly studied. Changes in management practices and public awareness do appear to be benefiting running water ecosystems in developed countries, and could underpin conservation strategies in developing countries if they were implemented in a relevant way.

Salt lakes are geographically widespread, numerous and a significant part of the world's inland aquatic ecosystems. They are important natural assets with considerable aesthetic, cultural, economic, recreational, scientific, conservation and ecological values. Some features, notably the composition of the biota, uniquely distinguish them from other aquatic ecosystems. The paper reviews the nature of environmental impacts and their effects upon salt lakes. Its aims are two-fold: to draw attention to the extensive damage that salt lakes have now undergone, and to indicate the likely status of salt lakes in 2025. Salt lakes develop as the termini of inland drainage basins where hydrological inputs and outputs are balanced. These conditions occur in arid and semi-arid regions (approximately one-third of total world land area). Many human activities threaten or have already impacted salt lakes, especially surface inflow diversions, salinization and other catchment activities, mining, pollution, biological disturbances (e.g. introduction of exotic species), and anthropogenically-induced climatic and atmospheric changes. The effects of such activities are always adverse and include changes to the natural character of salt lakes, loss of biodiversity and fundamental limnological changes. The effects are geographically widespread, mostly irreversible, and degrade the values of salt lakes. Four salt lakes are discussed, namely the Aral Sea in central Asia, Mono Lake in California, USA, and Lake Eyre and Lake Cantara South, in Australia. By 2025, most natural salt lakes will have undergone some adverse change. Many permanent ones will have decreased in size and increased in salinity, and many unnatural saline water-bodies will have appeared. In certain regions, many seasonally-filled salt lakes are likely to be drier for longer periods. The extent to which episodically-filled salt lakes will change by 2025 will largely depend upon the nature of climate change in arid regions. Objective cost/benefit analyses of adversely affecting salt lakes are rare, and international bodies have not properly recognized salt lakes as important inland aquatic ecosystems. To redress this situation, there is a need to raise awareness of: (1) the values of salt lakes, (2) the nature of threats and impacts from human activities, and (3) their special management requirements. More effective management and conservation measures need to be implemented. Mono Lake provides an example of what can be achieved in the conservation of salt lakes. Its conservation was largely brought about by (1) the commitment of a non-governmental organization which recognized its non-economic values, (2) the freedom to express views, (3) a legal system which took account of non-economic values, and (4) a legislature which implemented judicial findings. The conservation of Mono Lake was difficult; the conservation of other salt lakes is likely to be even more difficult. Only international pressure from appropriate organizations will be effective for the conservation of many.

Rocky shores occur at the interface of the land and sea. Typically they are open ecosystems, with steep environmental gradients. Their accessibility to man has rendered them susceptible to a variety of impacts since prehistoric times. Access can be regulated, however, and they are more amenable to management than open ocean habitats. This review uses examples from throughout the world to demonstrate the extent to which rocky shores have been, and are currently, affected by pollution (examples used are endocrine disrupters, oil, eutrophication), over-collection of living resources, introduced alien species, modification of coastal processes (coastal defences, siltation) and global change (climate, sea level). These impacts are put into the context of natural fluctuations in time and variability in space of both the environment and the organisms. The relative magnitudes of some anthropogenic disturbances differ between the industrialized, developed world and the developing world. For example, in developed, industrialized countries pollution based impacts should diminish over the next 25 years due to improved regulation and a reduction in older ‘dirtier’ heavy industry. Conversely, in many developing countries pollution will increase as a consequence of growth in the human population and industrialization. Except for large-scale disasters such as oil spills, pollution tends mainly to influence embayed coastlines. Chronic effects such as eutrophication can have broader-scale impacts over whole coastlines and elevated nutrient levels have also been implicated in a trend of increasing frequency of catastrophic kills due to harmful algal. Direct removal of living resources has had major effects on coastlines at both local and regional scales and is likely to increase over the next 25 years, especially in developing countries where rapidly expanding human populations will put further pressure on resources. Impacts from recreational activities are likely to increase with greater leisure time in wealthier regions of the world, and cheaper travel will spread these impacts to poorer regions. Invasions by alien species have increased in frequency during the last 20 years leading to some dramatic effects on native assemblages. Problems associated with alien species, especially pathogens, will continue to increase over the next few decades. The proportion of the coastline modified by artificial structures (breakwaters, seawalls, groynes) will increase because of coastal development and defences against sea-level rise and the greater frequency of storms. This will increase connectivity between areas of rocky habitat. Siltation will continue to increase due to urbanization of catchments and estuaries, and changes in agricultural practice. This may have considerable impacts at local and regional scales, favouring sediment tolerant organisms such as turf algae and anemones. In the future, greater frequency of environmental extremes is likely, including large-scale events such as the El Niño Southern Oscillation (ENSO). Global change in temperature, sea-level rise and increases in the frequency of storms will affect rocky shores throughout the world, but this will occur over long time scales; over the next 25 years most of the responses by rocky shore communities will mostly be quite subtle. Thus rocky shores will be subject to increasing degradation over the next 25 years. They are, however, less vulnerable than many other aquatic habitats due to their hard substratum (rock), their relative lack of large biogenic structures and to their generally open nature. They are also remarkably resilient, and recovery can occur rapidly due to recruitment from unaffected areas. Their susceptibility to both terrestrial and marine disturbances does make them more vulnerable than sublittoral and offshore habitats. There are considerable gaps in knowledge, particularly of certain microhabitats such as crevices, boulders, sand-scoured areas and rock pools. These have been much less studied than more accessible assemblages on open, freely draining rock. More research is needed to establish the effects of increasing sediment loads, ultraviolet radiation and introduced species on rocky shore communities. Strategic and applied research programmes should integrate field experiments and carefully selected monitoring programmes to verify management regimes. Hindcasting from the palaeo-record would be valuable, to compare rates of predicted change with periods when change was rapid in the past. This information could, in principle, be used to help conserve rocky shores through networks of marine protected areas and a general reduction of environmental pollution.

Seagrasses cover about 0.1–0.2% of the global ocean, and develop highly productive ecosystems which fulfil a key role in the coastal ecosystem. Widespread seagrass loss results from direct human impacts, including mechanical damage (by dredging, fishing, and anchoring), eutrophication, aquaculture, siltation, effects of coastal constructions, and food web alterations; and indirect human impacts, including negative effects of climate change (erosion by rising sea level, increased storms, increased ultraviolet irradiance), as well as from natural causes, such as cyclones and floods. The present review summarizes such threats and trends and considers likely changes to the 2025 time horizon. Present losses are expected to accelerate, particularly in South-east Asia and the Caribbean, as human pressure on the coastal zone grows. Positive human effects include increased legislation to protect seagrass, increased protection of coastal ecosystems, and enhanced efforts to monitor and restore the marine ecosystem. However, these positive effects are unlikely to balance the negative impacts, which are expected to be particularly prominent in developing tropical regions, where the capacity to implement conservation policies is limited. Uncertainties as to the present loss rate, derived from the paucity of coherent monitoring programmes, and the present inability to formulate reliable predictions as to the future rate of loss, represent a major barrier to the formulation of global conservation policies. Three key actions are needed to ensure the effective conservation of seagrass ecosystems: (1) the development of a coherent worldwide monitoring network, (2) the development of quantitative models predicting the responses of seagrasses to disturbance, and (3) the education of the public on the functions of seagrass meadows and the impacts of human activity.

Globally, humans impact environments and ecosystems faster than they become aware of their effects. The marine pelagic ecosystem includes a tremendously large and diverse environment, which might accordingly be considered to be resilient to externally forced changes, whether from humans or climate. This review considers that general hypothesis by pursuing two objectives. The first is to document the current status of and recent anthropogenic impacts on the marine pelagic ecosystem, with emphasis on the epipelagic zone (0-200 m) where organisms are concentrated and human impacts have been greatest. It shows that humans have proven capable of assuming the role of top carnivore in pelagic ecosystems where living resources are attractive and financially amenable to exploitation, and that overexploitation is the rule under such circumstances. Other anthropogenic activities associated with changes in various marine pelagic ecosystems, such as increased diseases, mortalities, extinctions, habitat invasions, and species replacements, function as sentinels and indicate that portions of the pelagic ecosystem are under considerable stress. It is argued that, without attention, these problems can be expected to worsen up to the year 2025 and beyond. In addition to a comprehensive evaluation of status and trends relating to conservation of the marine pelagic ecosystem, a second major objective is to evaluate whether current paradigms of ecosystem function are sufficient to improve the ability of the scientific community to predict future changes and to recommend relevant management strategies. This review differs from previous ones by proposing that current conceptual models have failed to provide the basis for accurately predicting patterns and features of pelagic communities, notably why specific organisms occur where and when they do. It is argued that predation pressure is shaped by natural selection in the sea as on land, and that it influences organism behaviour, life history strategy and morphology, all of which determine marine pelagic ecosystem structure, and therefore should be used to interpret function. From this perspective, attempting to understand present patterns and predict the future of marine pelagic ecosystems, without understanding the intertwined roles of evolution and predation in forging contemporary pelagic communities, is a hopeless endeavour. It is proposed that both perspectives, resource availability and predation pressure, be incorporated into a revised paradigm of pelagic ecosystem structure and function, a necessity if policies are to predict anthropogenic impacts and environmental conservation is to be effective.

The impact of human exploitation depends mostly on the size of the catch and the species targeted. The value of a species is an important explanatory variable in understanding human impact. Co-management of resources should take into account these different resource values, when evaluating exploitation strategies. The prey choice and foraging behaviour of women and children searching for crabs and shells on the intertidal area at Inhaca Island, South Mozambique, were investigated using optimal foraging theory. This theoretical framework offers the possibility to understand the reasoning of an exploitation strategy and the preference for certain prey species. The number of people was registered, catches were analysed, and timing and substrate choice were recorded. The value of species was estimated using contingency tables. Women were more efficient than children, as their catch was heavier, and the mean weight/animal was larger. The density of women and their timing were positively correlated to prey availability. During neap tide, they spread their visit over more of the low water period and collected crabs by digging in the mangrove forests. No digging occurred during spring tide when a larger area was exposed, the total abundance of species increased, and more species became available. Women then switched to a second strategy, targeting swimming crabs in the tidal channel. Mean neap and spring tide catches were equal (133 g ash-free dry weight per person), but spring catches comprised significantly fewer animals per catch (42 against 123 per person), and mean animal weight was larger (5.4 against 3.0 g ash-free dry-weight per person). Diet breadth was narrower during spring tide, and decreased significantly with increased catch weight. Species with profitabilities (energy intake/handling time) lower than the mean intake rate of 0.024–0.028 g ash-free dry weight s−1 were generally excluded from the diet. The prey preference was positively related to the relative value ranks of the prey species, as measured by ranking of species by women. Women maximized the cumulative relative value ranks during spring tide, instead of total weight. Using this analysis, differences in prey choice and spatial differences in exploitation can be understood as a strategy aimed at maximizing intake and the relative value of a prey species.

The literature on non-wood forest products (NWFPs) often emphasizes the commercial potential of certain species. However, the utility of the forest to human communities located in or around it often exceeds the cash income residents get from the sale of commercial NWFPs, as indicated by limiting the harvest of the most marketable NWFPs in a forest-edge Philippine village that was formerly highly dependent on rattan (Calamus sp.) collection and processing as a cottage industry. A village survey showed that there was a correlation between specific socio-economic factors such as age, education, size and income of a household, and household food expenditure, and the knowledge and use of non-commercial NWFPs, which were collected for various purposes. The forest was still important and valued by the community for other uses. These other uses, including the extensive, habitual reliance on subsistence non-wood forest products, are described to illustrate the possibility that these products may be the only source of necessities until the greater economic conditions improve.