Table 3.
Results of the redundancy analysis for the occurrence of alien fish species and environmental variables in the Karun River Basin, Iran. Bold variables are influential in the distribution of alien fish species.
| Variable | Axis1 | Axis 2 | F-Ratio | p-Value |
|---|---|---|---|---|
| Altitude | 0.70 | 0.64 | 12.77 | 0.005 ** |
| Depth (D) | −0.80 | −0.43 | 12.56 | 0.005 ** |
| Electrical conductivity (EC) | −0.55 | −0.72 | 10.79 | 0.005 ** |
| Water temperature (WT) | −0.63 | −0.37 | 7.52 | 0.005 ** |
| Turbidity | −0.50 | −0.52 | 6.74 | 0.005 ** |
| Width (W) | −0.63 | −0.24 | 6.32 | 0.005 ** |
| Dissolved Oxygen (DO) | 0.57 | 0.09 | 4.50 | 0.02 * |
| Alkalinity | −0.37 | −0.06 | 1.78 | 0.165 |
| Biological Oxygen Demand (BOD) | −0.11 | 0.30 | 1.21 | 0.295 |
| Nitrate (NO3) | −0.16 | 0.08 | 0.74 | 0.505 |
| Chemical Oxygen Demand (COD) | −0.18 | −0.10 | 0.56 | 0.69 |
| Phosphate (PO4) | −0.18 | −0.02 | 0.41 | 0.735 |
| Cumulative percentage of the variance of the species abundance | 36.24 | 25.33 | ||
| Cumulative percentage of the relation of species abundance and environmental variables | 53.14 | 37.14 |
Note:
**
= significant at α = 0.01;
*
significant at α = 0.05. Bold rows indicate the most influential variables on distribution of alien fish species.