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Article
Fish Assemblages in a Western Iowa Stream Modified by Grade Control Structures
North American Journal of Fisheries Management
  • Mary E. Litvan, Iowa State University
  • Clay L. Pierce, United States Geological Survey
  • Timothy W. Stewart, Iowa State University
  • Chris J. Larson, Iowa Department of Natural Resources
Document Type
Article
Publication Version
Published Version
Publication Date
1-1-2008
DOI
10.1577/M07-098.1
Abstract

Over 400 riprap grade control structures (GCSs) have been built in streams of western Iowa to reduce erosion and protect bridges, roads, and farmland. In conjunction with a companion study evaluating fish passage over GCSs in Turkey Creek, we evaluated the differences in fish assemblage and habitat characteristics in reaches immediately downstream from GCSs (GCS sites) and reaches at least 1 km from any GCS (non-GCS sites). The GCS sites were characterized by greater proportions of pool habitat, maximum depths, fish biomass, and abundance of juvenile largemouth bass Micropterus salmoides than were non-GCS sites. Index of biotic integrity (IBI) scores were poor or fair (<43 on a 0–100 scale) and not significantly different between the GCS and non-GCS sites. Additionally, we investigated both the longitudinal changes in fish assemblages in this GCS-fragmented stream and the changes in fish assemblages after slope modifications of three GCSs to facilitate fish passage. Thirteen fish species were present throughout the study area, whereas another 15 species exhibited truncated distributions not extending to the most upstream sampling location. After modification of the GCSs, IBI scores increased at seven of nine sites (mean increase = 4.6 points). Also, channel catfish Ictalurus punctatus were detected 7.3 km upstream at sites where, 2 years before GCS modification, they had been absent from collections. Given the number and distribution of GCSs in western Iowa streams, understanding the effects of these structures is vital to the conservation and management of fish assemblages in this and other regions where GCSs or similar structures are used.

Comments

This article is from North American Journal of Fisheries Management 28 (2008): 1398, doi:10.1577/M07-098.1.

Rights
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.
Language
en
Date Available
2015-03-06
File Format
application/pdf
Citation Information
Mary E. Litvan, Clay L. Pierce, Timothy W. Stewart and Chris J. Larson. "Fish Assemblages in a Western Iowa Stream Modified by Grade Control Structures" North American Journal of Fisheries Management Vol. 28 Iss. 5 (2008) p. 1398 - 1413
Available at: http://works.bepress.com/clay_pierce/6/