Declining streamflow induces collapse and replacement of native fish in the American Southwest

Abstract

Water scarcity is a global threat to freshwater biodiversity, but connecting variation in streamflow to viability of imperiled faunas remains a challenge. Here we combined time‐series modeling techniques on long‐term ecohydrological data to quantify flow–ecology relationships on native and non‐native riverine fish in the American Southwest, and simulate likely fish trajectories and “quasi‐extinction” risks in the near future. Streamflow has been declining conspicuously over the past 30 years in the Colorado and Rio Grande river basins, and year‐to‐year variation in streamflow influences the covariation between native and non‐native fish abundance. Risks of decline are high (>50%) for nearly three‐quarters of the modeled native species, and current trends in streamflow increase quasi‐extinction risk for natives (+8.5%) but reduce this risk for non‐natives (–5.9%). Hydrological changes need to be mitigated if we are to slow down the rapid replacement of native biodiversity with non‐native species in American Southwest rivers.

Document Details

Document Type
Pub Defense Publication
Publication Date
Nov 01, 2016
Source ID
10.1002/fee.1424

Entities

People

  • Albert Ruhí
  • John L. Sabo
  • Julian D. Olden

Organizations

  • Arizona State University
  • National Science Foundation
  • United States Department of Defense
  • University of Washington

Tags

Fields of Study

  • Environmental science

Readers

  • Aquatic Ecology
  • Coastal and Marine Engineering/Sediment Transport/Hydraulic Engineering
  • Economics