Part 1 of 2. Holding one-fifth of the world's river water, the Amazon travels through nine countries, with an outflow nearly 12 times larger than that of the Mississippi. There are more species of fish in the Amazon than in the entire Atlantic Ocean. Once a year, the river rises as high as 40 feet, forcing an intersection of wildlife - including piranhas, spiders the size of birds, pink dolphins, river otters, flocks of parrots and monkeys. Rainforests, where trees are being cut down at a staggering rate, are disappearing. Human enterprise and development not only compromise the health and ecology of these waters, but inflict global consequences.