BBC Ganges 3: Waterlands

Having watched the rise of the Ganges in the Himalayas and its flow through the plains of India, in the final episode we see the effect the river has when it meets the Bay of Bengal and forms the largest delta system in the world.

The delta itself straddles both India and Bangladesh, part of which is the world's largest mangrove swamp, the Sunderbans, which is home not only to Giant Asian Honey Bees, which provide a bountiful harvest of honey for those brave enough to enter the swamp, but also to aggressive man-eating tigers which take many lives each year.

The film follows a scientific team as they tranquilise and place a tracking-collar on a tigress, and follow her journeys through the swamps and temporary villages they hold in a hope of understanding more of how they live and survive in such inhospitable lands.

The swamp also plays home to many other creatures, from mud-skippers, who are thoroughly adopted to their environment, and can use their fins to walk on dry land, to otters which are bred by fishermen and help drive fish into their nets. Astonishingly an otter may sell for up to US$100 they are so useful to the fishermen.

The delta itself is also home to the largest density of human population of earth, in a land around the size of Britain, six times more people find their living, and all thanks to the river, which not only brings water, but also fertile mud to the area making 3 rice crops a year possible.

We watch the changes the land undergoes through the dry season, where water levels can drop as much as 6 metres in 6 months, and into the rainy season, where water levels dramatically rise causing animals and humans alike to migrate as erosion takes its toll.

The documentary ends by wondering once again whether the river can survive as populations increase, drinking and using up the precious water as it flows through the land, and sees hope in the reverence the river has always commanded from the Hindu religion and its adherents, as we watch 1,000,000 pilgrims gather at Sagar Island to give thanks to the river before it enters the sea.