Introduction : Assessment overview ; Structure of the book ; The challenge

Approach : Delineation of ecoregions and geographic scope of the study ; Assignment of major habitat types ; Discriminators ; Biological distinctiveness index (BDI)-overview ; Conservation status-overview ; Integrating biological distinctiveness and conservation status

Biological distinctiveness of North American ecoregions : Species richness ; Diversity, levels of imperilment, and cryptic fishes in the southeastern United States / N. M. Burkhead and H. L. Jelks ; The Mississippi river basin: its megafauna and hydrological modifications / B. M. Burr and J. B. Ladonski ; Preserving North America's unique crayfish fauna / C. A. Taylor ; Freshwater mussels: a complicated resource to conserve / G. T. Watters ; Endemism ; Subterranean freshwater biodiversity in northeaster Mexico and Texas / D. A. Hendrickson and J. Krejca ; Rare ecological or evolutionary phenomena ; Connecting the land to the sea: anadromous fish / P. B. Moyle ; Rare habitat type ; Synthesis of biological distinctiveness data ; Western springs: their faunas and threats to their existence / W. L. Minckley and P. J. Unmack ; California vernal pools / B. Vlamis ; Prairie potholes in decline / M. H. Stolt

Conservation status of North American ecoregions : Snapshot conservation status ; Conservation snapshot criteria ; Invasive nonindigenous species: a major threat to freshwater biodiversity / J. D. Williams and G. K. Meffe ; Threat assessment ; Final conservation status ; Additional conservation status data ; Categorizing imperiled and vulnerable species / L. L. Master ; Canadian freshwater biodiversity / D. McAllister

Setting the conservation agenda: integrating biological distinctiveness and conservation status : The valley of Cuatro Ciénegas, Coahuila: its biota and its future / S. Contreras-Balderas

Recommendations : North America's global responsibilities for biodiversity conservation ; Targets requiring urgent action ; North America's freshwater invertebrates: a research priority / D. L. Strayer ; Conservation of aquatic karst biotas: shedding light on troubled waters / S. J. Walsh

Site-specific conservation : Dams ; Reoperation and decommissioning of hydropower dams: an opportunity for river rehabilitation / A. Fahlund ; Additional site-selection tools

Appendixes : Methods for assessing the biological distinctiveness of freshwater ecoregions

Methods for assessing the conservation status of freshwater ecoregions

Biological distinctiveness data and scores ; Conservation status assessment and scores ; Statistical analysis of biological distinctiveness and conservation status data ; Integration matrices for the eight major habitat types ; Ecoregion descriptions ; Conservation partner contact information.