Water availability strongly impacts population genetic patterns of an imperiled Great Plains endemic fish

• Published in: Conservation genetics 2014-08, Vol.15 (4), p.771-788
• Main Authors: Fitzpatrick, S. W, Crockett, H, Funk, W. C
• Format: Article
• Language: English
• Subjects: Animal Genetics and Genomics; basins; Biodiversity; Biomedical and Life Sciences; Candidate species; Climate change; Conservation; Conservation Biology/Ecology; Conservation genetics; Ecology; ecosystems; Endangered & extinct species; Endangered species; Endemic animals; Etheostoma; Etheostoma cragini; Evolutionary Biology; Fish; Fish populations; Fisheries management; Genetic diversity; Genetic structure; genetic variation; Genetics; Habitat fragmentation; Habitats; indigenous species; landscapes; Life Sciences; Metapopulations; microsatellite repeats; Natural populations; Plant Genetics and Genomics; Population genetics; population size; Research Article; streams; Water availability; Water diversion
• ISSN: 1566-0621; 1572-9737
• DOI: 10.1007/s10592-014-0577-0

Genetic, demographic, and environmental processes affect natural populations synergistically, and understanding their interplay is crucial for the conservation of biodiversity. Stream fishes in metapopulations are particularly sensitive to habitat fragmentation because persistence depends on dispersal and colonization of new habitat but dispersal is constrained to stream networks. Great Plains streams are increasingly fragmented by water diversion and climate change, threatening connectivity of fish populations in this ecosystem. We used seven microsatellite loci to describe population and landscape genetic patterns across 614 individuals from 12 remaining populations of Arkansas darter (Etheostoma cragini) in Colorado, a candidate species for listing under the U.S. Endangered Species Act. We found small effective population sizes, low levels of genetic diversity within populations, and high levels of genetic structure, especially among basins. Both at- and between-site landscape features were associated with genetic diversity and connectivity, respectively. Available stream habitat and amount of continuous wetted area were positively associated with genetic diversity within a site, while stream distance and intermittency were the best predictors of genetic divergence among sites. We found little genetic contribution from historic supplementation efforts, and we provide a set of management recommendations for this species that incorporate a conservation genetics perspective.