20 - Inland aquatic environments I – wetland diversity and physical and chemical processes

Summary

Trouble in Kakadu

Water is a primary requisite for life. As human populations expand, demand for fresh water increases exponentially. Only about 2.5% of the world's water is fresh and of this 2.4% (or 99.6% of the total fresh water) is frozen in glaciers, in permanent snow cover or hidden in ground water. Only 0.1% of the world's fresh water flows freely in aquatic systems. Not surprisingly, there is most conflict between people and the environment where water is most readily available to humans: in inland aquatic ecosystems.

Human use of water and, at times, ignorance of how aquatic systems function have led to wetlands disappearing at alarming rates globally. Inland aquatic ecosystems are among the most productive ecosystems on Earth, supporting an enormous biodiversity as well as providing water for much terrestrial life. Aquatic ecosystems maintain water quality, support biodiversity and underpin the Earth's ecology. We harm them at our own expense.

In the Northern Territory of Australia, Kakadu's World Heritage-listed freshwater wetlands cover 195000 hectares. Three million waterbirds feed and breed there and they are also home for turtles, frogs and fish. The wetlands are valued for ecological importance on a global scale, because they support many migratory waders. However, within the original boundaries of the National Park is a uranium mine with potential to pollute downstream wetlands.