India's mighty Ganges, a river revered by a billion Hindus as a living goddess, is in trouble. Jeremy Wade is on a 1,500-mile mission to investigate the problems first hand and discover what is being done to save this holy river.

China's Yangtze River is threatened by over-fishing, industrial pollution and the loss of iconic monster fish. Jeremy Wade journeys upstream to find out if there are any fish left, and meets the heroes fighting for the future of the river.

The Mighty Mississippi is threatened on several fronts - from alien invaders pushing out iconic native fish, to vast blooms of green algae strangling life from the river. Jeremy Wade meets scientists, fishermen and leaders fighting to save the river.

The Danube's scenic route through ten European countries has made it a tourist magnet. But poachers, invasive species and engineering projects have made it one of the most endangered rivers on Earth. Jeremy Wade investigates what can be done to save it.

The Amazon is the mightiest of all the rivers, but it is also under immense pressure. Jeremy Wade traces the epic migration of the dorado catfish and discovers the issues putting this great river at risk from leaking pipelines to impassable dams.

Wild and unnavigable, Africa's Zambezi boasts the world's mightiest waterfall, heart-pounding rapids and man-eating crocs. From the upper reaches in Zambia to the delta in Mozambique, Jeremy investigates the threats to this mighty river.