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United States Department of Agriculture

Agricultural Research Service

Research Project: Integrated Strategies for Improved Water Quality and Ecosystem Integrity within Agricultural Watersheds

Location: Water Quality and Ecology Research

Title: Effects of sampling methodology on fish based IBI metrics

Author
item Knight, Scott
item Killgore, Jack

Submitted to: Journal of Agriculture and Biodiversity Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/14/2014
Publication Date: 11/28/2014
Publication URL: http://handle.nal.usda.gov/10113/60066
Citation: Knight, S.S., Killgore, J. 2014. Effects of sampling methodology on fish based IBI metrics. Journal of Agriculture and Biodiversity Research. 3(8):117-125.

Interpretive Summary: Biological indices such as the index of biotic integrity (IBI) can be useful tools in determining the ecological soundness of rivers and streams. Many methods are available to collect the necessary data on fish community structure to calculate an IBI. Because each collection method has its own unique biases different fishing gears may not be used interchangeably. A study was conducted in the Mississippi River Alluvial Plain or “Delta” to evaluate the effects of using different fish collection gear on IBI metrics. Fish were collected using electrofishing and seining. Data from these methods were used to calculate metrics that have been successfully used for calculating IBI scores in this region. Significant differences were found between the metrics calculated using the different gear types. This research shows that collection methods are important and cannot be applied interchangeably. Care should be taken by state and federal agencies that wish to compute an IBI to using data that were collected using different gear from the one or ones used to develop the IBI.

Technical Abstract: It often difficult to determine the environmental soundness of rivers and streams particularly those that may have been impaired by farming as might be the case in the Mississippi Delta. Analysis of fish data can be simplified by calculating mathematical indices that provide a simple number that indicates an impaired or healthy stream. This research shows that while the index may provide a sound way of measuring stream ecological health the methods used to collect the fish data are always a little biased are not therefore interchangeable. Because the Mississippi Department of Environmental Quality and U. S. Environmental Protection Agency routinely use the indices this, research will provide necessary information for the proper application of fisheries data when determining stream impairment.

Last Modified: 07/19/2017
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