Zone of the water body | Major chemicals, trace elements | Biogenic substances | Pollutants |
Pelagic areas | |||
Trophogenic layer | 10 - 12 | 7 - 10*) | 5 - 7 |
Deep water zones of three basins | 10 - 12 | 7 - 10 | 5 - 7 |
Bottom layers | 10 - 12 | 10 - 12 | 7 - 10 |
Anthropogenic impact areas, near-delta areas of major tributaries | |||
Trophogenic layer | 7 - 10 | 5 - 7*) | 3 - 5 |