Utah

To meet state bioassessment criteria, Utah uses an O/E index built by the UT DEQ in 2015. To apply the index, samples should be identified to NAMC’s standard taxonomic resolution and samples can be collected at any point during the year.

Index # Reference Sites # Degraded Sites Index Mean Index SD Moderate departure from reference benchmark Major departure from reference benchmark Narative Condition
Utah 181 NA 1 0.21 < 0.76 < 0.69 Good, Fair, Poor 

 

Utah and surround states with black dots representing MMI response sites
Utah macroinvertebrate reference sites

Box plots of catch elevation(m) on a scale of 0 to 3500 with a mean of 2250, mean annual precipitation (mm) on a scale of 0 to 4000 with a mean of 1000, temperature (C) on a scale of 0 to 16 with a mean of 5 and log watershed area (km2) on a scale of 0 to 4 with a mean of 1.5
Environmental gradients for reference sites used for Utah and used for NAMC’s model applicability test

  • Method for accounting for natural environmental gradients: Random forest model predicting group membership
  • Predictors of reference assemblages or metrics: 
    • Latitude of the point
    • Mean elevation across the watershed
    • Average of min elevation in the watershed
    • Mean of Evi_max (landsat enhanced vegetation index) in the watershed
    • Average first freeze day at the watershed
    • Precipitation max at the watershed
    • Mean of max number of wet days at the watershed
    • Mean precipitation at the watershed
    • Relative humidity mean at the watershed
    • Area of the watershed in sq km
    • Average of max temperature at the watershed
    • Temperature max at the point
    • Average of mean temperature at the watershed
    • Average temperature at the point
    • Minimum temperature at the watershed
  • # of Macroinvertebrate groups obtained by hierarchical cluster analysis: 6
  • Fixed count: 400
  • Minimum count: 150
  • Operational Taxonomic Unit (OTU) applied: Yes
  • Rare taxa <0.5 probability of capture included: No