The Use of Structural and Functional Indicators to Develop Numeric Nutrient Criteria for Utah’s Wadeable Streams
Location
ECC 307/309
Event Website
http://water.usu.edu/
Start Date
4-3-2012 11:40 AM
End Date
4-3-2012 12:00 PM
Description
Utah, like many States, is in the process of developing scientifically defensible numeric nutrient criteria for its waterbodies. In 2010 the Utah Division of Water Quality conducted a project to determine the affects of nutrients (nitrogen & phosphorus) on stream ecosystem structure and function. The effects of nutrient enrichment are often non-toxic to biologic communities (except in extreme situations). More often changes in biologic community structure are a secondary response to changes in ecosystem processes. These processes can be directly altered in reaction to nutrient enrichment. In an ideal situation we would be able to detect changes in stream function before we saw a loss of biologic condition, enhancing environmental manager’s abilities to proactively protect biota. For this project we sampled 35 wadeable stream sites that represent different levels of nutrient enrichment. We sampled each site for physical habitat, biologic condition, water chemistry and ecosystem function. We focused on measuring nutrient limitation, whole stream metabolism, organic matter storage and decomposition rates as these processes have been shown to relate to eutrophication in a number of academic studies. The Utah DWQ will use these functional indicators of nutrient enrichment along with compositional indicators derived from this study and other State and National programs to develop numeric nutrient criteria. We used a combination of Taxonomic Identifier Threshold Analysis (TITAN), Classification & Regression Trees (CART) and nonparametric changepoint analysis to develop multiple thresholds of TN & TP. This multiple lines of evidence approach will be the framework for Utah’s development of numeric nutrient criteria for wadeable streams.
The Use of Structural and Functional Indicators to Develop Numeric Nutrient Criteria for Utah’s Wadeable Streams
ECC 307/309
Utah, like many States, is in the process of developing scientifically defensible numeric nutrient criteria for its waterbodies. In 2010 the Utah Division of Water Quality conducted a project to determine the affects of nutrients (nitrogen & phosphorus) on stream ecosystem structure and function. The effects of nutrient enrichment are often non-toxic to biologic communities (except in extreme situations). More often changes in biologic community structure are a secondary response to changes in ecosystem processes. These processes can be directly altered in reaction to nutrient enrichment. In an ideal situation we would be able to detect changes in stream function before we saw a loss of biologic condition, enhancing environmental manager’s abilities to proactively protect biota. For this project we sampled 35 wadeable stream sites that represent different levels of nutrient enrichment. We sampled each site for physical habitat, biologic condition, water chemistry and ecosystem function. We focused on measuring nutrient limitation, whole stream metabolism, organic matter storage and decomposition rates as these processes have been shown to relate to eutrophication in a number of academic studies. The Utah DWQ will use these functional indicators of nutrient enrichment along with compositional indicators derived from this study and other State and National programs to develop numeric nutrient criteria. We used a combination of Taxonomic Identifier Threshold Analysis (TITAN), Classification & Regression Trees (CART) and nonparametric changepoint analysis to develop multiple thresholds of TN & TP. This multiple lines of evidence approach will be the framework for Utah’s development of numeric nutrient criteria for wadeable streams.
https://digitalcommons.usu.edu/runoff/2012/AllAbstracts/30