John Waldman, a professor of biology at Queens College, New York, works on the ecology and evolution of anadromous fishes, historical ecology, and urban waterways. Before joining Queens College, he worked for 20 years at the Hudson River Foundation for Science and Environmental Research. Waldman's books include Running Silver: Restoring Atlantic Rivers and Their Great Fish Migrations, Heartbeats in the Muck: A Dramatic Look at the History, Sea Life, and Environment of New York Harbor, and The Dance of the Flying Gurnards: America's Coastal Curiosities and Beachside Wonders.