. Aquatic surveys and re-assessment of sites within the Middle Powder River Watershed. Aquatic ecology; Aquatic biology; Invertebrates; Mayflies; Coalbed methane. decreasing trend and showed more variability in the upper sites by the Wyoming border (Figure 8). As measured by the MTDEQ plains MMI and O/E model in 2011, the biological condition for all assessed Powder River sites, except POW5Q (O/E), was nonimpaired, as it was in 2005 (Figure 8). However, as measured by the O/E p>, all samples fell below the impairment threshold, indicating a signficant departure (, taxa loss or replac
. Aquatic surveys and re-assessment of sites within the Middle Powder River Watershed. Aquatic ecology; Aquatic biology; Invertebrates; Mayflies; Coalbed methane. decreasing trend and showed more variability in the upper sites by the Wyoming border (Figure 8). As measured by the MTDEQ plains MMI and O/E model in 2011, the biological condition for all assessed Powder River sites, except POW5Q (O/E), was nonimpaired, as it was in 2005 (Figure 8). However, as measured by the O/E p>, all samples fell below the impairment threshold, indicating a signficant departure (, taxa loss or replacement) from expected biological community conditions (Figure 8). But when applying the O/E p>0 5 all samples fall below the impairment threshold indicating a significant departure (ie. taxa loss or replacement) from expected biological community conditions (Figure 8). Selected site patterns in biological condition observed in 2005 were repeated in 2011 with appreciable increases in the MMI scores at sites POW2 and POWMOOR and decreases in integrity at POW1 and POW5 (Figure 8). Although all sites ranked unimpaired with MMI, there was a ca. 20-point scoring spread between the lowest MMI score of (2011, POW5 RW) and (2005, POW5 RW). Thus, site POW5 (RW) had the most severe macrinvertebrate community integrity decline between years, although it should be noted that RW samples are always more variable than targeted Riffles (Figure 8).. Figure 8. Powder River study reach macroinvertebrate MMI for 2005 and 2011 (top) and Observed/Expected (O/E p>0, O/E p> ) Scores for 2011 (bottom). Horizontal red line is the impairment threshold. 16. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Stagliano, David M. ,author; Montana Natural Heritage Program; United States. Bureau of Land Management. Miles Ci
Size: 1453px × 1719px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bhlcoll, bookleafnumber25, booksubjectinvertebrates, bookyear2012
