Iowa DNR
River & Stream Biological Monitoring
Fish and Benthic Macroinvertebrate Surveys
Physical Habitat Assessments


  • Biological Sampling and Physical Habitat Assessment Standard Operating Procedure for Iowa Wadeable Streams and Rivers, July 24, 2015
    • The Iowa Department of Natural Resources uses benthic macroinvertebrate and fish sampling data to assess stream biological condition and the support status of designated aquatic life uses. Stream physical habitat data assist with the interpretation of biological sampling results by quantifying important physical characteristics that influence a stream’s ability to support a healthy aquatic community. This document describes aquatic community sampling and physical habitat assessment procedures currently followed in the Iowa stream biological assessment program.
  • Biological Assessment of Iowa's Wadeable Streams, October 2004
    • The TMDL and Water Quality Assessment Section of the Iowa DNR Environmental Services Division have released the report entitled, “Biological Assessment of Iowa’s Wadeable Streams.” The report describes a framework for conducting stream bioassessments and how it is used to evaluate the biological condition of Iowa’s wadeable rivers and streams. The document also serves as a foundation for developing biological water quality standards for the protection of designated aquatic life uses and measuring progress toward the achievement of Federal Clean Water Act goals.
    • NOTE: The formula for Benthic invertivore fish species richness - Missouri Basin in Table 5-9 on page 5-55 has an error. The proper formulas for this calculation are:
      • If LDA <=2.25, the formula should be (BINVSP/(3.11*LDA))*10
      • If LDA > 2.25, the formula should be (BINVSP/7)*10
      • These are reversed in the document. This will be corrected in a future version.
  • Fish Habitat Indicators for the Assessment of Wadeable, Warmwater Stream, December 2015
    • Physical habitat characteristics such as stream width, depth, instream cover, and substrate composition are important environmental factors that shape Iowa’s stream fish species assemblages. The Iowa Department of Natural Resources (DNR) stream biological assessment program collects physical habitat data to help interpret fish assemblage sampling results in order to assess stream health condition and the attainment status of designated aquatic life uses. The quantitative habitat indicators and interpretative guidelines developed in this study are designed for specific applications within the stream bioassessment program. These tools might also be useful to natural resource managers for purposes such as stream habitat improvement prioritization, goal-setting, and performance assessment.
  • Development of a Coldwater Benthic Index in Iowa, August 2012
    • Benthic macroinvertebrate assemblages do not appear to differ as markedly between coldwater and warmwater streams (in Iowa, at least) as do fish assemblages, and to our knowledge no parallel evaluation of benthic macroinvertebrate communities in coldwater streams has been conducted. What is known is that many taxa are exclusively collected in coldwater environments and are considered “rare” in Iowa from a biogeographical perspective. While the warmwater BMIBI has generally proven to work well as a diagnostic tool for Iowa’s streams, the streams of Iowa’s Paleozoic Plateau tend to group in the “excellent” to “good” qualitative rating categories. The streams of this area tend to be more ecologically intact than other areas of the state; however, there are some artifacts of the current warmwater BMIBI (most specifically metric scoring related to watershed size) that skew IBI values higher. Our objective is to develop a Coldwater Benthic Index (CBI) which will provide a more accurate assessment of streams classified, or potentially classifiable, as coldwater.
  • Biological Assessment of Iowa's Streams and Rivers, 2001
    • Summary of biological monitoring of Iowa's streams and rivers.
  • Floods of 2008: How Did Aquatic Life in Streams Fare?
    • Summary of biological water quality data collected during the Floods of 2008.
  • Bouncing Back, Recovery of Fish Populations, 2003
    • Summary of study regarding fish population recovery following fish kill events.
  • Common Iowa Fish, 2008
    • This fact sheet will give Iowans the chance to determine the common fish species generally found in interior streams and rivers located near them and highlight the differences in types of fish species found in Iowa’s two major river drainage basins.

This page was created 5/21/2015 3:28:47 PM and was last updated 4/4/2022 9:28:53 AM