Habitat loss, fragmentation, and the genetic status of Roanoke bass

Roanoke bass (Ambloplites cavifrons) persist in five river basins in the eastern U.S., where they are threatened by invasive species, habitat loss and degradation, and hydrologic fragmentation. We conducted the first conservation genetic study of A. cavifrons, analyzing variation at 19 nuclear microsatellite DNA loci and the cytochrome B mitochondrial DNA gene to estimate population structure and demography, genetic relationships among populations, and the role of landscape features in regulating genetic diversity and differentiation. Most streams harbored genetically distinguishable populations, with high connectivity among reaches within streams but no contemporary dispersal among streams. In contrast, mitochondrial divergence within and among basins was weak, suggesting historically higher range-wide connectivity. Most populations exhibited small effective population sizes and evidence of past population bottlenecks. Genetic diversity correlated positively with patch size but negatively with watershed urban and agricultural development, suggesting that habitat loss, degradation, and fragmentation have acted in concert to reduce population viability. Mitigating these impacts may require a combination of tactics, including restoring habitat, limiting the spread of invasive competitors, and reestablishing historical connectivity.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author