The Pantanal of Brazil is the world's largest freshwater marsh. It is seasonally flooded, going from wet to dry to wet again throughout the year. Though remote and often difficult to navigate, this is a true ecosystem in which the natural world thrives. Predators time their breeding to coincide with the lowering water levels that expose fish to feed their young. Even the cowboys fish in flooded forests. This is one of the few places left where human development is minimal. Evironmentalists have every reason to believe it will stay that way.