View of the Mississippi River from Perot State Park

International Conference on Rivers and Civilization:
Multidisciplinary Perspectives on Major River Basins


La Crosse, Wisconsin USA
June 25-28, 2006

HOST AND PRESENTER INSTITUTIONS
University of Wisconsin-La Crosse Home Page National Mississippi River Museum and Aquarium Home Page

CONFERENCE SPEAKER

David Dudgeon (University of Hong Kong, China): Conservation of Riverine Biodiversity in the Human-Dominated Landscapes of Monsoonal Asia. (Abstract)

photo of David Dudgeon David Dudgeon has served more than 20 years at The University of Hong Kong, documenting the biodiversity of animals in the streams, rivers, and wetlands of Asia.  His recent work has focused on ecological factors that influence biodiversity in degraded fresh waters and on the re-establishment of animal populations as a conservation tool.  He is particularly concerned about the application of ecological and scientific knowledge to the conservation of biodiversity.  He is the author or editor of many scientific articles and several books, including Tropical Asian Streams (1999), Tropical Stream Ecology (in press), Conservation of Freshwater Biodiversity in Asia (in press), The Ecology and Biodiversity of Hong Kong.
http://www.hku.hk/ecology/dd.htm

Abstract: Freshwater biodiversity is under threat worldwide, but the intensity of threat in monsoonal Asia (the Oriental biogeographic region) is exceptional. Asia is the most densely populated region on Earth and five Asian countries account for around half of the world's annual population growth rate. Many rivers of that region are grossly polluted and significant portions of their drainage basins and floodplains have been deforested or otherwise degraded. Flow regulation has been practiced for centuries, and thousands of dams have been constructed so that most rivers are now dammed - often at several points along their course. Irrigation, hydropower and flood security are among the perceived benefits. Recent water engineering projects in Asia have been exceptionally aggressive, and include the world's largest and tallest dams (in China), and a water transfer scheme intended to link India's major rivers. Some of these projects (on the Mekong, for example) have important international ramifications that have yet to be played out fully. Over-exploitation has exacerbated the effects of habitat alterations on riverine biodiversity, with the result that fish stocks are over-exploited and a variety of vertebrate species are critically endangered. The pressure from large, impoverished human populations, increasingly concentrated in cities, has forced governments to prioritise economic development over environmental protection and conservation, and river scientists in Asia seem to have little influence on policy makers or the implementation of water development projects. Contamination of water and threats to human health have resulted in the introduction of legislation to control water pollution, but these laws are not explicitly intended to protect biodiversity or ecosystem functioning. Nonetheless, where legislation has been enforced it can be effective against point-source polluters, but has had negligible impact on the huge quantities of organic pollution arising from agriculture and domestic sources that contaminate rivers such as the Ganges and Yangtze. To date, human demands from agriculture and industry dominate water allocation policies; in-stream flow needs for ecosystem functioning have yet to be addressed. Restoration of Asian rivers to their original state is impractical given the constraints prevailing in the region, and rehabilitation will be possible only if the relevant scientific information is communicated and applied with urgency. Opportunities do exist, and the 2003 introduction of an annual fishing moratorium along the Yangtze River, as well as breeding and restocking programmes for endangered fishes in the Yangtze and Mekong, offer the chance to leverage other initiatives that enhance river health, such as the establishment of aquatic nature reserves on the Yangtze. Preliminary data indicate that some elements of freshwater biodiversity persist in degraded rivers, thus providing a basis for rehabilitation. As a matter of urgency it will be important to identify which ecological features facilitate persistence and which increase vulnerability to human impacts, because this information will be essential for the formulation of successful rehabilitation schemes.