Freshwater biodiversity is the over-riding conservation priority during the International Decade for Action - 'Water for Life' - 2005 to 2015. Fresh water makes up only 0.01% of the World's water and approximately 0.8% of the Earth's surface, yet this tiny fraction of global water supports at least 100000 species out of approximately 1.8 million - almost 6% of all described species. Inland waters and freshwater biodiversity constitute a valuable natural resource, in economic, cultural, aesthetic, scientific and educational terms. Their conservation and management are critical to the interests of all humans, nations and governments. Yet this precious heritage is in crisis. Fresh waters are experiencing declines in biodiversity far greater than those in the most affected terrestrial ecosystems, and if trends in human demands for water remain unaltered and species losses continue at current rates, the opportunity to conserve much of the remaining biodiversity in fresh water will vanish before the 'Water for Life' decade ends in 2015. Why is this so, and what is being done about it? This article explores the special features of freshwater habitats and the biodiversity they support that makes them especially vulnerable to human activities. We document threats to global freshwater biodiversity under five headings: overexploitation; water pollution; flow modification; destruction or degradation of habitat; and invasion by exotic species. Their combined and interacting influences have resulted in population declines and range reduction of freshwater biodiversity worldwide. Conservation of biodiversity is complicated by the landscape position of rivers and wetlands as 'receivers' of land-use effluents, and the problems posed by endemism and thus non-substitutability. In addition, in many parts of the world, fresh water is subject to severe competition among multiple human stakeholders. Protection of freshwater biodiversity is perhaps the ultimate conservation challenge because it is influenced by the upstream drainage network, the surrounding land, the riparian zone, and - in the case of migrating aquatic fauna - downstream reaches. Such prerequisites are hardly ever met. Immediate action is needed where opportunities exist to set aside intact lake and river ecosystems within large protected areas. For most of the global land surface, trade-offs between conservation of freshwater biodiversity and human use of ecosystem goods and services are necessary. We advocate continuing attempts to check species loss but, in many situations, urge adoption of a compromise position of management for biodiversity conservation, ecosystem functioning and resilience, and human livelihoods in order to provide a viable long-term basis for freshwater conservation. Recognition of this need will require adoption of a new paradigm for biodiversity protection and freshwater ecosystem management - one that has been appropriately termed 'reconciliation ecology'.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/96AA265E3D88C95FB802E7A73CCB4332/S1464793105006950a.pdf/div-class-title-freshwater-biodiversity-importance-threats-status-and-conservation-challenges-div.pdf

Freshwater biodiversity: importance, threats, status and conservation challenges

https://www.jstor.org/stable/10.1641/0006-3568(2000)050%5B0793:LSHCIT%5D2.0.CO;2

Large-scale hydrological changes in tropical Asia: Prospects for riverine biodiversity

▪ Abstract Tropical Asian rivers support a rich but incompletely known biota, including a host of fishes, a diverse array of benthic invertebrates, and an assemblage of mammals adapted to riverine wetlands. River ecology is dominated by flow seasonality imposed by monsoonal rains with profound consequences for fishes and zoobenthos. Information on life histories, feeding, and the trophic base of production of these animals is summarized. Widespread use of allochthonous foods by fishes and zoobenthos is apparent. Migration by fishes is often associated with breeding and results in seasonal occupation of different habitats. Riverine biodiversity is threatened by habitat degradation (pollution, deforestation of drainage basins), dams and flow regulation, as well as over-harvesting. Conservation efforts in tropical Asia are constrained by a variety of factors, including lack of ecological information, but the extent of public awareness and political commitment to environmental protection are likely determinan...

The Ecology of Tropical Asian Rivers and Streams in Relation to Biodiversity Conservation

https://www.cbd.int/financial/values/Kenya-BiodivCosts.pdf

The opportunity costs of biodiversity conservation in Kenya

The purpose of this report is to give attention to Asian freshwater biodiversity. Asia is home to some 3500 species of fishes, hundreds of other organisms which spend their entire lives in water, and to many types of freshwater habitats. Many of these are of considerable economic values and are an important source of food for many poor people. This freshwater biodiversity can be adversely affected by many types of projects. Current international agreements and World Bank policies support actions to consider and conserve freshwater biodiversity. Freshwater biodiversity concerns are not always wholly addressed by attention to fisheries management or wetland conservation. The countries of Asia differ in their national capacity and expertise in freshwater biodiversity. Straightforward and relatively inexpensive steps to ameliorate the situation are: a) encouraging awareness of and attention to freshwater biodiversity issues; b) acknowledging that in order to make appropriate environmental management decisions it is important to collect good and current data; c) executing studies to understand the economic value of freshwater biodiversity; d) preparing field guides and manuals; e) nurturing partnerships between engineers and biodiversity specialists to achieve better project designs and more effective mitigation measures; and f) encouraging the release of scientific data collected by project proponents as part of environmental assessments.

Freshwater Biodiversity in Asia: With Special Reference to Fish

Loss of biological diversity through the extinction of species, the conversion and degradation of natural habitats, and the disruption of ecological processes, is occurring throughout the world at an unprecendented rate. As species and their habitats disappear, so do products of present and future value, genes with which to improve crop varieties and livestock, and the natural resiliencies of the world's living resources to respond to climatic and enviornmental change. Nowhere else is the loss of biodiversity expected to be higher during the coming decades than in the Asia-Pacific region. The loss of biodiversity is irreversible. Recognizing this, the Asia Environment Division prepared this paper which is intended to identify priority areas of investment in the Asia-Pacific region. The paper accepts the importance of biodiversity conservation and suggests that policy change coupled with the establishment of protected area systems will be critical to success. A wide range of interventions will be needed to support these efforts toward conserving biodiversity - interventions involving national and local governments, national and international nongovernmental organizations and, most importantly, local people. The strategy defined in this paper is intended to complement existing national and international initiatives and to build partnerships in conservation for the 1990s.

Braatz, Susan Davis, Gloria Shen, Susan Rees, Colin

Papers

Conserving biological diversity : a strategy for protected areas in the Asia-Pacific region