Identifying preservation and restoration priority areas for desert fishes in an increasingly invaded world.
A commonly overlooked aspect of conservation planning assessments is that wildlife managers are increasingly focused on habitats that contain non-native species. We examine this management challenge in the Gila River basin (150,730 km(2)), and present a new planning strategy for fish conservation. By applying a hierarchical prioritization algorithm to >850,000 fish records in 27,181 sub-watersheds we first identified high priority areas (PAs) termed "preservation PAs" with high native fish richness and low non-native richness; these represent traditional conservation targets. Second, we identified "restoration PAs" with high native fish richness that also contained high numbers of non-native species; these represent less traditional conservation targets. The top 10 % of preservation and restoration PAs contained common native species (e.g., Catostomus clarkii, desert sucker; Catostomus insignis, Sonora sucker) in addition to native species with limited distributions (i.e., Xyrauchen texanus, razorback sucker; Oncorhynchus gilae apache, Apache trout). The top preservation and restoration PAs overlapped by 42 %, indicating areas with high native fish richness range from minimally to highly invaded. Areas exclusively identified as restoration PAs also encompassed a greater percentage of native species ranges than would be expected by the random addition of an equivalent basin area. Restoration PAs identified an additional 19.0 and 26.6 % of the total ranges of two federally endangered species-Meda fulgida (spikedace) and Gila intermedia (Gila chub), respectively, compared to top preservation PAs alone-despite adding only 5.8 % of basin area. We contend that in addition to preservation PAs, restoration PAs are well suited for complementary management activities benefiting native fishes.
School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA 98195, USA. thomaspool@univ-tlse3.fr
Thomas K
TK
Pool
Angela L
AL
Strecker
Julian D
JD
Olden
D000818:Animals; D044822:Biodiversity; D003198:Computer Simulation; D003247:Conservation of Natural Resources / Q000379:methods*; D003889:Desert Climate; D005399:Fishes; D058865:Introduced Species; D008962:Models, Theoretical; D009010:Monte Carlo Method; D015206:Southwestern United States; D014881:Water Supply