thumbnail

Environmental drivers of fish functional diversity and composition in the Lower Colorado River Basin

Canadian Journal of Fisheries and Aquatic Sciences

By:
, , ,
DOI: 10.1139/F10-095

Links

Abstract

Freshwater conservation efforts require an understanding of how natural and anthropogenic factors shape the present-day biogeography of native and non-native species. This knowledge need is especially acute for imperiled native fishes in the highly modified Lower Colorado River Basin (LCRB), USA. In the present study we employed both a taxonomic and functional approach to explore how natural and human-related environmental drivers shape landscape-scale patterns of fish community composition in the LCRB. Our results showed that hydrologic alteration, watershed land use, and regional climate explained 30.3% and 44.7% of the total variation in fish community taxonomic and functional composition, respectively. Watersheds with greater dam densities and upstream storage capacity supported higher non-native functional diversity, suggesting that dams have provided additional "niche opportunities" for non-native equilibrium life-history strategists by introducing new reservoir habitat and modifying downstream flow and thermal regimes. By contrast, watersheds characterized by greater upstream land protection, lower dam densities, and higher variation in spring and summer precipitation supported fish communities with a strong complement of native species (opportunistic-periodic strategists). In conclusion, our study highlights the utility of a life-history approach to better understand the patterns and processes by which fish communities vary along environmental gradients.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Environmental drivers of fish functional diversity and composition in the Lower Colorado River Basin
Series title:
Canadian Journal of Fisheries and Aquatic Sciences
DOI:
10.1139/F10-095
Volume
67
Issue:
11
Year Published:
2010
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Canadian Journal of Fisheries and Aquatic Sciences
First page:
1791
Last page:
1807
Number of Pages:
17