Table 6 Statistical comparisons (t tests) of biotic indexes and stream habitat variables at sites on the South Fork Whitewater River, Minnesota, USA near springs (n = 10; sites 13 through 22) and without springs (n = 12; sites 1 through 12) (see Fig. 1 for site locations)
From: Aquatic community structure and stream habitat in a karst agricultural landscape
Variable | Near springs | Without springs | t | P |
|---|---|---|---|---|
Fish IBI | 49.5 (19.6) | 5.8 (14.3) | 5.86 |  < 0.001 |
Fish taxa richness | 5.0 (1.7) | 10.4 (2.5) | 6.01 |  < 0.001 |
Benthic IBI | 23.2 (6.3) | 23.8 (11.7) | 0.15 | 0.883 |
Percent EPT | 73.8 (10.8) | 48.9 (31.8) | 2.55 | 0.023 |
Fish habitat score | 70.1 (12.5) | 39.0 (15.7) | 5.17 |  < 0.001 |
Buffer width (m) | 136.7 (78.9) | 20.3 (39.8) | 4.23 |  < 0.001 |
Percent fines | 26.8 (20.5) | 65.2 (21.3) | 4.30 |  < 0.001 |
Embeddedness | 3.9 (1.0) | 4.8 (0.4) | 2.82 | 0.016 |
Percent run | 51.0 (17.8) | 72.4 (27.7) | 2.19 | 0.041 |