The habitat associations of three species of black bass Micropterus spp. were examined in six habitat types (i.e., sediment, gravel, rock, riprap, brush, and aquatic plants) along a cascade of 10 reservoirs in the Tennessee River. We tested whether habitat selection differed among the three species and whether species' co-occurrence depended on habitat type. We found that some species occurred in some habitats in proportion to habitat availability (some at higher frequencies and some at frequencies lower than availability) and that juveniles and adults exhibited similar occurrence patterns. Our habitat selection results largely corroborate previous descriptions of black bass habitat associations and generally track preference for lithic habitats, as reported in native streams. We expected the different black bass species to show negative co-occurrence to avoid competitive interactions. Nevertheless, we found that with few exceptions, adults co-occurred in habitats mostly as expected by chance and juveniles co-occurred more often than was expected by chance. Our findings imply that environmental filtering, rather than competitive interactions that dominate in natural environments, may be the dominant mechanism shaping black bass assemblages in reservoirs of the Tennessee River. The observed patterns of habitat selection and co-occurrence further suggest that the conservation and management of black bass assemblages in reservoirs can be supported through habitat management activities. Protecting and enhancing the remaining lithic habitat in the reservoirs as well as recovering habitat that is blanketed by sediment could provide desirable environments for all black bass species.

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Identification of imperiled species ranges from rapid, qualitative, expert opinion‐based assessments to time‐intensive, quantitative assessments. The purpose of our study was to develop a methodology to rapidly quantify species of greatest conservation need by incorporating the concepts of resiliency, redundancy, and representation, which are used by the U.S. Fish and Wildlife Service to identify imperiled species. We compiled records of species occurrences (a measure of redundancy), commonality (a measure of representation), and reported absences (a measure of resiliency) for 50 species of fish within three ecoregions of the southwestern USA. We used multivariate analysis to describe interrelationships among reach, drainage, and region occurrences; percent rare occurrences; and percent absent among reaches. Weighted summations of species scores for principal component axes I and II were sorted from least (i.e., towards low redundancy, representation, and resiliency) to greatest, and species were ranked. With a few limitations, our methodology provided a revisable, documented, and transparent approach to aid in the identification of species of greatest conservation need.