Prospects for monitoring freshwater ecosystems towards the 2010 targets.
Human activities have severely affected the condition of freshwater ecosystems worldwide. Physical alteration, habitat loss, water withdrawal, pollution, overexploitation and the introduction of non-native species all contribute to the decline in freshwater species. Today, freshwater species are, in general, at higher risk of extinction than those in forests, grasslands and coastal ecosystems. For North America alone, the projected extinction rate for freshwater fauna is five times greater than that for terrestrial fauna--a rate comparable to the species loss in tropical rainforest. Because many of these extinctions go unseen, the level of assessment and knowledge of the status and trends of freshwater species are still very poor, with species going extinct before they are even taxonomically classified. Increasing human population growth and achieving the sustainable development targets set forth in 2002 will place even higher demands on the already stressed freshwater ecosystems, unless an integrated approach to managing water for people and ecosystems is implemented by a broad constituency. To inform and implement policies that support an integrated approach to water management, as well as to measure progress in halting the rapid decline in freshwater species, basin-level indicators describing the condition and threats to freshwater ecosystems and species are required. This paper discusses the extent and quality of data available on the number and size of populations of freshwater species, as well as the change in the extent and condition of natural freshwater habitats. The paper presents indicators that can be applied at multiple scales, highlighting the usefulness of using remote sensing and geographical information systems technologies to fill some of the existing information gaps. Finally, the paper includes an analysis of major data gaps and information needs with respect to freshwater species to measure progress towards the 2010 biodiversity targets.
Revenga
C
C
Global Priorities Group, The Nature Conservancy, 4245 North Fairfax Drive, Arlington, VA 22203, USA. crevenga@tnc.org
Campbell
I
I
Abell
R
R
de Villiers
P
P
Bryer
M
M
D003247:Conservation of Natural Resources / Q000379:methods* / Q000639:trends*; D017753:Ecosystem; D004777:Environment; D005618:Fresh Water; D005843:Geography; D007391:International Cooperation; D011156:Population Density; D011157:Population Dynamics; D013045:Species Specificity