The freshwaters of North America are populated by a rich tapestry of native fishes, some of which possess enough charisma and colour to rival their marine and tropical counterparts. While names such as trout and bass are well-embedded into the American vernacular, the less familiar monikers of darter, madtom, and dace remain relatively unknown. However, it is more often these lesser known groups function as valuable bioindicators of biological integrity, thereby providing important information to scientists regarding the health of our nation's waterways. This book provides reference for environmental and fisheries professionals, naturalists, and educators on the use of fishes and mussels as biological indicators.