Developing macroinvertebrate indicators for the mid-continent great rivers: Lessons from EMAP-GRE

As part of the Environmental Monitoring and Assessment Program for Great River Ecosystems (EMAP-GRE) we developed new macroinvertebrate-assemblage based indicators of condition. In this presentation, we will summarize some of the practical and philosophical challenges encountered in this effort including: 1) where in the riverscape to collect samples, 2) how to most efficiently collect samples, 3) how to classify the samples, 4) how to determine reference expectations, 5) how to deal with major uncontrolled source of variation, 6) what approach to take in developing multimetric indices, and 7) how to optimize the indicators when the local-scale stressor effects on great river assemblages were generally weak.