| Station number | Average concentrations (µg/g) dry weight | |||
| Winter | Spring | Summer | Autumn | |
| 1 | 15.84 | 12.44 | 6.67 | 10.83 |
| 2 | 12.86 | 9.95 | 6.20 | 8.60 |
| 3 | 0.31 | 0.12 | 0.021 | 0.15 |