Conservation biologists have begun a concerted effort to educate the public, resource administrators, and politicians about the decline of temperate ecosystems, including their fishes. The United States harbors the most diverse temperate freshwater fish fauna in the world with about 790 species represented, about 90% of which are nongame fishes. From a state-by-state perspective, diversity of fishes in the United States is concentrated in the South, primarily in Alabama, Kentucky, Georgia, Mississippi, Tennessee, and Virginia, each of which supports at least 200 native fish species. Endemicity of fishes is high in both the South and West; in the latter region, up to 70% of fishes in some drainages (e.g., Colorado River) are endemic. Imperilment apparently is not confined to particular taxonomic groups. Of the five most diverse fish families in the United States, total imperilment ranges from 7% in the Centrarchidae to 50% in nonanadromous salmonids and indicates widespread and pervasive degradati...