The Decline of Freshwater Ecosystems , demonstrates that giant dams, massive irrigation systems, and widespread logging often bring few economic benefits, and instead cause environmental degradation, poverty, and suffering, as well as irreplaceable loss of biodiversity. Billions of dollars spent for flood control, plus the effects of land degradation, actually increased the severity and cost of flooding on the Columbia, Rhine, and Mississippi rivers. Pollution and diversion have driven freshwater fisheries into collapse worldwide, and the extinction of freshwater species far outpaces the extinction of mammals and birds. Wetlands worth billions of dollars to the public for fisheries, water purification, and groundwater renewal have been converted to less beneficial uses.
Freshwater ecosystems are both disproportionally rich and disproportionally imperiled.
By destroying species faster than nature can create new ones we are running a 'biodiversity deficit' that can never be recovered. Beyond their obvious benefits for agriculture and industry, intact freshwater ecosystems are vital to human health and economies worldwide. They provide clean drinking water, natural flood control, as well as income and food from fisheries. But the human desire for immediate profit and 'quick fixes' has led to a cascade of damage. Hydroelectric dams, water diversions for agriculture, flood control levees, dredging, air and water pollution, habitat degradation such as logging, as well as exotic species such as the zebra mussel, are combining to disrupt and destroy freshwater species and functioning ecosystems worldwide.