The world?s rivers, crucial sources of fresh water and important habitats for plants and animals, are in crisis and more threatened than ever by pollutants and development, according to an ambitious study led by a UW-Madison zoologist. Peter B. McIntyre, a senior author of the new study, said it is shocking to see how many problems remain despite so many years of effort. McIntyre, a professor of zoology at UW-Madison?s Center for Limnology, said rivers in this country would be much worse were it not for the Clean Water Act, passed in the 1970s.