Which one of the following statements is NOT correct?
1
The micro-organisms involved in biodegradation of organic matter in a sewage polluted water body consume a lot of oxygen causing the death of aquatic organisms.
2
Algal blooms caused by excess of organic matter in water improve water quality and promote fisheries.
3
Water hyacinth grows abundantly in eutrophic water bodies and leads to an imbalance in the ecosystem dynamics of the water body.
4
The amount of some toxic substances of industrial waste water increases in the organisms at successive trophic levels.