Environmental Issues Question 3
Question: Which one of the following statement is not correct?
(1) The amount of some toxic substances of industrial waste water increases in the organisms at successive trophic levels.
(2) 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.
(3) Algal blooms caused by excess of organic matter in water improve water quality and promote fisheries.
(4) Water hyacinth grows abundantly in eutrophic water bodies and leads to an imbalance in the ecosystem dynamics of the water body.
Show Answer
Answer: (3) Algal blooms caused by excess of organic matter in water improve water quality and promote fisheries.
Explaination-
Algal bloom (accumulatiom of nutrients like nitrogen and phosphorus) deplete oxygen in water, also release chemicals harmful to fishes, shellfish and marine mammals
