Question

The figure given below shows a situation of a pond situated near an oil palm estate.


What could be the possible reason for the death of the fish in the pond next to the oil palm estate?

• A. The waste products given out by the plants.
• B. The practice of crop rotation in the estate.
• C. The use of biological control in the estate.
• D. The use of chemical fertilisers in the estate.

Answer 1

The correct option is D The use of chemical fertilisers in the estate.

The fertilisers used in the fields get washed away during rains and irrigation. They get deposited in the nearby waterbodies which in this case is the pond. Fertilisers (organic and chemical) can cause serious problems if they contaminate freshwater and marine ecosystems. The same nutrients in fertilisers that nourish crops, lawns, and golf courses can cause rapid growth of algae in the water bodies. This is also known as an algal bloom. Dying algae in turn feed bacteria, which consume too much dissolved oxygen devoiding fish and plants of oxygen. Eventually leading to the death of aquatic organisms.