Flow management for hydropower extirpates aquatic insects, undermining river food webs

BioScience
By: , and 

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Abstract

Dams impound the majority of rivers and provide important societal benefits, especially daily water releases that enable on-peak hydroelectricity generation. Such “hydropeaking” is common worldwide, but its downstream impacts remain unclear. We evaluated the response of aquatic insects, a cornerstone of river food webs, to hydropeaking using a life history–hydrodynamic model. Our model predicts that aquatic-insect abundance will depend on a basic life-history trait—adult egg-laying behavior—such that open-water layers will be unaffected by hydropeaking, whereas ecologically important and widespread river-edge layers, such as mayflies, will be extirpated. These predictions are supported by a more-than-2500-sample, citizen-science data set of aquatic insects from the Colorado River in the Grand Canyon and by a survey of insect diversity and hydropeaking intensity across dammed rivers of the Western United States. Our study reveals a hydropeaking-related life history bottleneck that precludes viable populations of many aquatic insects from inhabiting regulated rivers.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Flow management for hydropower extirpates aquatic insects, undermining river food webs
Series title BioScience
DOI 10.1093/biosci/biw059
Volume 66
Issue 7
Year Published 2016
Language English
Publisher American Institute of Biological Sciences
Publisher location Washington, D.C.
Contributing office(s) Southwest Biological Science Center
Description 15 p.
First page 561
Last page 575
Online Only (Y/N) N
Additional Online Files (Y/N) N