Table 3.
Lowest-observable-effect concentrations (LOEC) and no-observable-effect concentrations (NOEC) derived by Monte Carlo permutation tests followed by redundancy analyses (RDA) and by by ANOVA followed by the Games–Howell post hoc test for the adapted SPEARmesocosm index (SPEAR) (see also Fig. 3)
| Time after contamination (weeks) | LOEC (μg/l) | NOEC (μg/l) | ||
|---|---|---|---|---|
| RDA | SPEAR | RDA | SPEAR | |
| First-year contamination | ||||
| 2 | 3.2 | <0.1 | 0.1 | <0.1 |
| 13 | 3.2 | <0.1 | 0.1 | <0.1 |
| 34 | ND | <0.1 | ND | <0.1 |
| 48 | NS | <0.1 | NS | <0.1 |
| Second-year contamination | ||||
| 2 | 3.2 | <0.1 | 0.1 | <0.1 |
| 8 | 3.2 | <0.1 | 0.1 | <0.1 |
| 38 | 100 | <0.1 | 3.2 | <0.1 |
ND not determined; LOEC and NOEC cannot be determined precisely, because a significant effect was only found for all concentrations together (complete models), but no significant effect was found for any of the concentrations analysed separately (see Fig. 3)
NS not significant; no significant (P < 0.05) effects were detected