MACROINVERTEBRATE COMMUNITY CONDITION ASSOCIATED WITH THE SEVERITY OF STREAMFLOW ALTERATION
Article first published online: 21 NOV 2012
Published 2012. This article is a U.S. Government work and is in the public domain in the USA.
River Research and Applications
Volume 30, Issue 1, pages 29–39, January 2014
How to Cite
Carlisle, D. M., Nelson, S. M. and Eng, K. (2014), MACROINVERTEBRATE COMMUNITY CONDITION ASSOCIATED WITH THE SEVERITY OF STREAMFLOW ALTERATION. River Res. Applic., 30: 29–39. doi: 10.1002/rra.2626
- Issue published online: 6 JAN 2014
- Article first published online: 21 NOV 2012
- Manuscript Accepted: 22 OCT 2012
- Manuscript Revised: 16 OCT 2012
- Manuscript Received: 29 FEB 2012
- hydrologic alteration;
- biological integrity;
- predictive models
Natural streamflows play a critical role in stream ecosystems, yet quantitative relations between streamflow alteration and stream health have been elusive. One reason for this difficulty is that neither streamflow alteration nor ecological responses are measured relative to their natural expectations. We assessed macroinvertebrate community condition in 25 mountain streams representing a large gradient of streamflow alteration, which we quantified as the departure of observed flows from natural expectations. Observed flows were obtained from US Geological Survey streamgaging stations and discharge records from dams and diversion structures. During low-flow conditions in September, samples of macroinvertebrate communities were collected at each site, in addition to measures of physical habitat, water chemistry and organic matter. In general, streamflows were artificially high during summer and artificially low throughout the rest of the year. Biological condition, as measured by richness of sensitive taxa (Ephemeroptera, Plecoptera and Trichoptera) and taxonomic completeness (O/E), was strongly and negatively related to the severity of depleted flows in winter. Analyses of macroinvertebrate traits suggest that taxa losses may have been caused by thermal modification associated with streamflow alteration. Our study yielded quantitative relations between the severity of streamflow alteration and the degree of biological impairment and suggests that water management that reduces streamflows during winter months is likely to have negative effects on downstream benthic communities in Utah mountain streams. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.