Challenges for freshwater biodiversity research: science plan and implementation strategy

The environmental vitality of freshwater ecosystems and their inherent biodiversity are at the heart of social and economic sustainability. Fresh water is essential for nearly any form of human activity, including industrial production, navigation, domestic water requirements, waste assimilation, health, and food production. Moreover, the roles of biodiversity in freshwater processes (e.g., self-purification, protein production) are of crucial importance for sustaining goods and services underpinning the vitality of human populations. Globally, freshwater biodiversity is under critical threat because there are, in addition to environmental needs, expanding human demands for water. However, economic expansion and environmental integrity do not need to be mutually exclusive as long as the environmental requirements for water are thoughtfully and effectively incorporated into economic development. The critical importance of fresh water is now widely recognized. In December 2003, the United Nations General Assembly adopted resolution 58/217 proclaiming 2005 to 2015 as an International Decade for Action – ‘Water for Life’. The resolution calls for a greater focus on water issues and development efforts, and recommits countries to achieving the water-related goals of the 2000 Millennium Declaration and of Agenda 21; in particular, to halve by 2015 the proportion of people lacking access to safe drinking water and basic sanitation. These are highly important matters, yet their importance should not obscure the fact that the ‘Water for Life’ resolution comes at a time when biodiversity and the biological resources of inland waters are facing unprecedented and growing threats from human activities. Fresh water makes up only ~0.01% of the world’s water and ~0.8% of the Earth’s surface. Yet over 10,000 fish species live in fresh water, making up 40% of global fish diversity and one quarter of global vertebrate diversity. When amphibians, aquatic reptiles and mammals are added, around one third of vertebrate species are confined to fresh water. This disproportionate richness is also evident from the fact that approximately 100,000 species out of ~1.3 million thus far described by scientists (~8%) live in fresh water. Conservation of freshwater biodiversity represents thus a great challenge to scientists, local managers and policy makers. Management of freshwater biodiversity has to take into account trade offs between biodiversity protection and sustainable use. A first requisite in developing an effective conservation strategy, given the current impediment of insufficient data, is to improve the geographic and taxonomic knowledge of freshwater biodiversity. A second requisite is to better understand linkages between freshwater biodiversity and ecosystem functioning and the numerous valuable goods and services supported by freshwater biodiversity. A final requisite is to develop a network of freshwater users (e.g., local populations, managers of water resources, scientists and political institutions) because effective conservation actions and conflict resolutions require a close collaboration between the different users of fresh water. The international programme of biodiversity science, DIVERSITAS, has identified a science agenda for conservation and sustainable use of freshwater biodiversity to inspire and facilitate a new generation of research on this topic. This science agenda recognises the importance of freshwater biodiversity as a basic support for all life on Earth and for the provision of valuable human-related goods and services. The intention of DIVERSITAS is to advance knowledge on topics of international concern that are not receiving sufficient attention or are newly emerging issues with potential consequences for ecosystems and for humanity. This document, the science plan and implementation strategy of a new DIVERSITAS cross-cutting theme called “freshwaterBIODIVERSITY” is the result of numerous meetings, consultations and discussions over the past two years involving scientists of diverse backgrounds, disciplines and countries. This document is by no means an end in itself, but is meant to evolve as new knowledge is generated. We hope that it will involve more and more scientists working on freshwater biodiversity issues and that it will contribute, in the context of the post Millennium Ecosystem Assessment era, to a new generation of scientific work and to an expanded perspective on the overwhelming importance of freshwater biodiversity.