Fresh water is essential for life and the organisms contained therein constitute valuable natural resources for economic, cultural, aesthetic, scientific and educational enrichment. The conservation and management of freshwater ecosystems are critical to the interests of all humans, nations, and governments. Fresh water is also critical for humanity beyond drinking water and habitat for aquatic organisms by being the fuel for hydropower systems, a resource for industrial use, and supplies for irrigated agriculture and recreation. However, fresh waters throughout the world have become an increasingly scarce resource and, as a consequence, the ecological goods and services they provide have come under chronic, severe and increasing stress.