Illustration of three interconnected food webs in the basin of the Mara River in Kenya. In the background (upper left) is the forest habitat where much of the ecosystem input comes from fallen leaves with an inset showing fish feeding on insect larvae. At centre, human impact (grazing, farming and settlement) cause algal blooms. The final downstream portion (foreground) is the Masai Mara, with the upstream ecology affecting the ecosystem downstream. Animals shown in the foreground include antelopes, a vulture, a hippopotamus, a crocodile, and numerous fishes.