Table 6.

Comparison of responsiveness between the diatom MMIs developed for the East, Plains, and West regions in this study, and existing NRSA and NLA MMIs within each of the three regions. Performance is based on the responsiveness of the MMI using t-scores to compare mean values between least-disturbed (LD) and most-disturbed (MD) sites; the higher the t-score, the greater the MMI responsiveness. Note, the range of t-scores represents the minimum and maximum t-scores associated with each component ecoregion for a given region, wsshile a single t-score represents all sites across all ecoregions for a region.

	RESPONSIVENESS (t-score between mean LD & MD sites)
	MMI Type River and Stream Diatoms	Stream Macroinvertebrates	Stream Fish	Lake Macroinvertebrates	Lake Zooplankton
Region
East	18	10.1–14.7	7.7–15.4	7.3–8.5	4.9–5.8
Plains	9.6	5.7–9.7	5.9–9.8	6.0	4.5
West	8.5	14.7–15.7	7.6–8.7	9.4	6.3