Horton (an environmental columnist for The Baltimore Sun ) updates his 1991 work describing the ecosystem of the Chesapeake Bay, into which waters from the states of Virginia, Maryland, Pennsylvania, and New York flow, and assessing the state of its environment and efforts to clean it up. He argues that progress on pollution has been uneven and makes recommendations for programs and policies to be implemented by the federal government and the involved states. Annotation (c) Book News, Inc., Portland, OR (booknews.com)