Flying over the Cerrado, you get a vivid sense both of the great transformations the land has undergone and of the factors that are challenging the water supply to the Pantanal. For as far as the eye can see, the region unfolds in a vast patchwork of cultivated land and forest. Cattle graze immense tracts of ranchland, where only a few skeletons of trees remain where the forest has been cleared. In some areas the ravines caused by soil erosion are clearly visible. Strips of riparian forest mark the presence of a spring, or the winding course of the streams and tributaries leading into the broad twisting band of the Sepotuba river. At two points along the river huge dams can be seen – part of an extensive programme to generate power for the region which, over the course of the next five years, will result in 137 dams having been constructed along the headwaters, providing a growing threat to the natural ‘pulse’ of the Pantanal and to fish migration, the effects of which are keenly felt by the fishing communities downstream.