In Australia's Kakadu National Park, introduced species such as water buffaloes and mimosa thickets threaten the wetland habitat necessary for the survival of the native crocodiles, birds and other animals. As the crew traces the Murray River to Southern Australia, encroaching salt water threatens not only the river, but also farming in the Victoria area. Last, Flinders Chase National Park, on Kangaroo Island is visited, a refuge for kangaroos.
—Anonymous