TABLE 2.
Descriptive statistics for the mesocosm studya
| Location | Season | Treatment | n | Water Cu (μg/liter) |
Water Zn (μg/liter) |
Sediment Cu (μg/g dry) |
Sediment Zn (μg/g dry) |
Observed OTUs |
Shannon index |
||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mean | StdDev | Mean | StdDev | Mean | StdDev | Mean | StdDev | Mean | StdDev | Mean | StdDev | ||||
| Upstream | Fall | Control | 4 | 2.35 a | 2.65 | 0.05 a | 0.17 | 43.07 a | 17.85 | 1311.91 a | 229.62 | 4715 a | 2706 | 6.78 a | 0.12 |
| Downstream | Fall | Control | 4 | 1.33 a | 0.92 | 0.23 a | 0.77 | 75.93 b | 19.63 | 1600.16 b | 36.47 | 3728 a | 599 | 6.30 b* | 0.01 |
| Upstream | Fall | Metals | 4 | 17.21 A | 6.31 | 588.85 A | 57.08 | 162.71 A | 68.09 | 2451.97 A | 645.75 | 5668 A | 3493 | 6.72 A | 0.11 |
| Downstream | Fall | Metals | 4 | 18.04 A | 4.94 | 613.53 A | 49.32 | 656.28 B | 161.64 | 7280.31 B | 1578.52 | 3608 A | 1007 | 6.11 A** | 0.13 |
a
Different letters refer to a statistically significant difference (α = 0.05) between upstream and downstream control samples (lower case), and between upstream and downstream metal-treated samples (upper case). Asterisks refer to statistically significant difference (α = 0.05) between control and metal-treated samples for each location. Target water metal concentrations were 25 μg/liter for Cu and 650 μg/liter for Zn. OTU, operational taxonomic unit.