We report the first confirmed records of the pathogenic protozoa Giardia lamblia and Cryptosporidium parvum from small remote streams in pristine protected areas in Australia, beyond the reach of urban or agricultural contamination.

The Atlantic hurricanes of 1999 caused widespread environmental damage throughout the Caribbean and US mid-Atlantic coastal regions. However, these storms also proved beneficial to certain microbial habitats; specifically, cyanobacteria-dominated mats. Modern mats represent the oldest known biological communities on earth, stromatolites. Contemporary mats are dominant biological communities in the hypersaline Bahamian lakes along the Atlantic hurricane track. We examined the impacts of varying levels of hypersalinity on 2 processes controlling mat growth, photosynthesis and nitrogen fixation, in Salt Pond, San Salvador Island, Bahamas. Hypersalinity (> 5 times sea-water salinity) proved highly inhibitory to these processes. Freshwater input from Hurricane Floyd and other large storms alleviated this salt-inhibition. A predicted 10 to 40 year increase in Atlantic hurricane activity accompanied by more frequent “freshening” events will enhance mat productivity, CO₂ sequestration and nutrient cycling. Cyanobacterial mats are sensitive short- and long-term indicators of climatic and ecological changes impacting these and other waterstressed environments.

Possible links between the occurrence of Vaccinium myrtillus, V. vitisidaea and Deschampsia flexuosa and rates of nitrogen deposition were investigated in 557 coniferous forest stands. In areas with high N-deposition, V. myrtillus was less frequent, less abundant and more susceptible to the leaf pathogen Valdensia heterodoxa than in areas with lower levels of N-deposition. The occurrence of V. vitis-idaea was also strongly negatively correlated with in-creasing N-deposition, but no such trend was found for D. flexuosa. In regions with high N-deposition, V. myrtillus was more common in stands dominated by Scots pine than in stands dominated by Norway spruce. This was not the case in regions with lower levels of N-deposition. The patterns observed accord with results from N-addition experiments that demonstrate significant effects on vegetation, caused by N-deposition. The data suggest that even low rates of N-deposition may decrease the abundance of the most dominant species in coniferous forest ground flora.

The status of fish populations in 3821 lakes in Norway, Sweden and Finland was assessed in 1995–1997. The survey lakes were chosen by stratified random sampling from all (126 482) Fennoscandian lakes ≥ 0.04 km². The water chemistry of the lakes was analyzed and information on fish status was obtained by a postal inquiry. Fish population losses were most frequent in the most highly acidified region of southern Norway and least common in eastern Fennoscandia. According to the inquiry results, the number of lost stocks of brown trout (Salmo trutta), roach (Rutilus rutilus), Arctic char (Salvelinus alpinus) and perch (Perca fluviatilis) was estimated to exceed 10 000. The number of stocks of these species potentially affected by the low alkalinity of lake water was estimated to exceed 11 000. About 3300 lakes showed high total phosphorus (> 25 µg L^–1) and cyprinid dominance in eastern Fenno-scandia, notably southwestern Finland. This survey did not reveal any extinction of fish species due to eutrophication. One-third of the lakes had been artificially stocked with at least one new species, most often brown trout, whitefish (Coregonus lavaretus s.l.), Arctic char, rainbow trout (Oncorhynchus mykiss), pike-perch (Stizostedion lucio-perca), grayling (Thymallus thymallus), pike (Esox lucius), bream (Abramis brama), tench (Tinca tinca) and European minnow (Phoxinus phoxinus). The number of artificially manipulated stocks of these species in Fennoscandian lakes was estimated to exceed 52 000. Hence, the number of fish species occurring in Nordic lakes has recently been changed more by stockings than by losses of fish species through environmental changes such as acidification.

Industrial tree plantations in the tropics usually follow short rotations and intensive site management including slash and burn, and the use of heavy machinery. We attempt to quantify the implied nutrient losses (harvest export, erosion, slash and burn, leaching) in order to give plantation managers a chance to understand the significance of their planning and decisions. We used the scarce globally available information and a case study plantation in East Kalimantan, Indonesia (Acacia mangium and Eucalyptus deglupta). Adaptation involves problems and is discussed in some detail. Results are approximate only. Assuming a harvest volume of 200 m³ ha^–1, we assessed a loss of 427–680 kg ha^–1 N, 12–13 kg ha^–1 P, 178–252 kg ha^–1 Ca, 276–370 kg ha^–1 K, and 45–57 kg ha^–1 Mg per rotation. Of this overall loss, stand harvest accounted for 18–29% (N), 21–30% (P), 56–26% (K), 48–64% (Ca) and 22–37% (Mg). This means that the cumulative loss by erosion, slash and burn, and leaching exceeds that of the harvest. These losses can be influenced by management.

This paper uses examples from Kenya and the Sudan to argue that the scale at which we pitch our analysis when trying to identify the basic properties of pastoral ecosystems may not be appropriate when it comes to recommending policy measures to secure the continued viability of pastoral herding. Pastoral households are always parts of large-scale economic and social structures. In many cases, such integration has provided the basis for the continued viability of pastoral adaptations. In other cases, the changing nature of local economies and social relations following from integration into large systems, has threatened the viability of pastoral herding or led to increasing differentiation within and between local communities. This paper raises the issue of how we most fruitfully define and delimit ecological and social systems in different local settings. It also questions conventional approaches to community-based natural resource management, which are now attracting widespread international attention.

An integrated socioeconomic and erosion study on the sustainability of traditional shifting cultivation (Jhum) carried out in 1998 and 1999 in the Chittagong Hill Tracts (CHT) of Bangladesh showed the system to be nonsustainable under the current conditions with fallow periods of only 3–5 years and lack of land rights. An estimated input (mainly labor) of USD 380 ha^–1 yr^–1 results in only a total output of USD 360 ha^–1 yr^–1 and Jhum cultivated areas suffer severe loss of soil and valuable plant nutrients along with runoff during the rainy season. To compensate these losses by commercial fertilizers will cost nearly USD 2 million yr^–1 for CHT. To ensure long-term productivity of the soils, Jhum should therefore be adjusted to a tolerable level and farmers should be given rights and title to the land to motivate them to switch to improved, settled farming systems.

The paper presents an overview of the present situation of the Mexico City Metropolitan Area (MCMA). The analysis indicates an urgent need to radically improve the current water supply and wastewater management practices, to become sustainable. The MCMA is one of the most rapidly growing urban centers of the world, with a population of about 21 million people, a very high rate of immigration and numerous illegal settlements. In order to meet the increasing water demand, successive governments have focused almost exclusively on supply management and engineering solutions, which have resulted in investments of hundreds of millions of USD and the construction of major infrastructure projects for interbasin water transfer. Environmental, economic and social policies associated with water management are mostly inadequate and insufficient, which is resulting in increasing deterioration in the environment, health and socioeconomic conditions of a population living in one of the largest urban agglo-merations of the world. Surprisingly, however, no long-term strategies on demand-management, reuse, conservation, and improved water-management practices have been developed so far.

The international trade in corals has been identified as a potential cause of localized depletion of coral populations in the major coral-exporting countries. The international coral trade is regulated by the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES) agreement, which requires that export of corals is not detrimental to the species. The primary coral importing regions (USA and Europe) have threatened to limit or ban coral imports unless sustainable practices can be demonstrated. The spatial and temporal scale at which sustainability is defined is important in evaluating sustainability, e.g. at geological, regional or local scales. Other major issues are: the ecology of the target species; management options including provision of no-take areas; and the potential for coral culture. Implementation of practices that enhance ecological sustainability in the coral harvest fishery is possible, but may be difficult in some developing countries because of limited natural-resource management capacity.

Inhaca Island, southern Mozambique, is located towards the southerly latitudinal limits of coral reef growth. Reef development is restricted to the margins of channels which dissect intertidal flats on the Maputo Bay side of the island, and to depths of around 6 m. In contrast to lower latitude reefs, reef development is therefore both spatially and bathymetrically restricted (largely due to high turbidity levels). These natural stress levels were exacerbated, via increased freshwater and sediment discharge, during the severe floods of late 1999/early 2000. Flood impacts varied but were most significant on reefs on the inner (western) side of the island where live coral cover (LCC) decreased from 60.5% (1999) to 24.0% (2001). This is attributed to freshwater-induced bleaching. Dead in situ coral cover increased from 18.6% (1999) to 51.3% (2001). Reefs on the southern tip of the island, by contrast, were relatively unaffected. It is suggested that this largely reflects a closer proximity to the open Indian Ocean which mitigated the effects of freshwater dilution.

There are more than 200 marine protected areas (MPAs) in the Caribbean and Central America that contain coral reefs and are therefore theoretically attractive to scuba divers. One fifth of dive operators in 30 countries were surveyed for their use of MPAs: the majority are located within 20 km of at least one MPA and 46% conduct at least 80% of their diving within a MPA. An estimated 15 million dives take place outside of Florida each year, half of these occurring inside MPAs. Only 25% of MPAs containing coral reefs charge divers an entry or user fee, which is most usually USD 2–3 levied per dive or per diver. The revenue generated by these fees is estimated at USD 1–2 million annually, but the potential for generating income has not been fully realized. A significant contribution to the cost of regional conservation could be achieved if higher fees were applied more widely than at present.

This study focuses on assessing the state of population distribution, land cover distribution, biodiversity hotspots, and protected areas in global coastal zones. The coastal zone is defined as land within 100 km of the coastline. This study attempts to answer such questions as: how crowded are the coastal zones, what is the pattern of land cover distribution in these areas, how much of these areas are designated as protected areas, what is the state of the biodiversity hotspots, and what are the interconnections between people and coastal environment. This study uses globally consistent and comprehensive geospatial data-sets based on remote sensing and other sources. The application of Geographic Information System (GIS) layering methods and consistent datasets has made it possible to identify and quantify selected coastal zones environmental issues and their interconnections. It is expected that such information provide a scientific basis for global coastal zones management and assist in policy formulations at the national and international levels.

In the Adayar riverbed and its estuary 5 undisturbed sediment cores were drilled using a petrol-driven hammer. Cores of a depth of 4–5 m were sampled in 0.5 m steps. The distribution of heavy metals (Cr, Mn, Ni, Cu, Zn, Cd and Pb) in the top layers of fluvial and estuarine sediments indicates recent anthropogenic input: Revealing that the river acts as a sink for drainage from the residential and industrial zones. In this study, the mobilization of heavy metals into greater depths and their probable effects on the groundwater body are discussed. The high concentra-tion of heavy metals and the influent character of the river Adayar allow the mobilization of metal ions and their transport into the deeper layers of the sediment. A changing environment due to effects such as saltwater intrusion and monsoon floods is the driving force for this phenomenon.

This study focuses on assessing the state of population distribution, land cover distribution, biodiversity hotspots, and protected areas in global coastal zones. The coastal zone is defined as land within 100 km of the coastline. This study attempts to answer such questions as: how crowded are the coastal zones, what is the pattern of land cover distribution in these areas, how much of these areas are designated as protected areas, what is the state of the biodiversity hotspots, and what are the interconnections between people and coastal environment. This study uses globally consistent and comprehensive geospatial data-sets based on remote sensing and other sources. The application of Geographic Information System (GIS) layering methods and consistent datasets has made it possible to identify and quantify selected coastal zones environmental issues and their interconnections. It is expected that such information provide a scientific basis for global coastal zones management and assist in policy formulations at the national and international levels.

In the Adayar riverbed and its estuary 5 undisturbed sediment cores were drilled using a petrol-driven hammer. Cores of a depth of 4–5 m were sampled in 0.5 m steps. The distribution of heavy metals (Cr, Mn, Ni, Cu, Zn, Cd and Pb) in the top layers of fluvial and estuarine sediments indicates recent anthropogenic input: Revealing that the river acts as a sink for drainage from the residential and industrial zones. In this study, the mobilization of heavy metals into greater depths and their probable effects on the groundwater body are discussed. The high concentra-tion of heavy metals and the influent character of the river Adayar allow the mobilization of metal ions and their transport into the deeper layers of the sediment. A changing environment due to effects such as saltwater intrusion and monsoon floods is the driving force for this phenomenon.