Freshwater Ecosystems

The world's freshwater ecosystems are rich but greatly imperiled. At least 20 percent of all freshwater species globally are extinct or at risk; the figure is twice as high in North America. Freshwater systems suffered in the 20th century from huge increases in water withdrawals for human use, extensive pollution, a proliferation of dams, and widespread draining of wetlands. Worldwatch research examines how to promote and maintain healthy freshwater systems, in order to protect aquatic species and to provide clean water, flood control, abundant fisheries, and other services of vital interest to human societies.