Question

Which of the following statements is correct?

• A. Biomagnification refers to increase in concentration of the toxicant at successive trophic levels.
• B. Presence of large amount of nutrients in water restricts ‘Algal Bloom’
• C. Algal Bloom decreases fish mortality
• D. Eutrophication refers to increase in domestic sewage and waste water in lakes.

Answer 1

The Correct Option is A

A is correct - Biomagnification is the process through which certain substances, such as toxins or pollutants, become more concentrated as they move up the food chain. This results in higher concentrations of these substances in organisms at higher trophic levels.
B is incorrect - Presence of a large amount of nutrients in water, often caused by excessive nutrient runoff, can actually promote algal bloom, not restrict it.
C is incorrect - Algal blooms can lead to fish mortality due to a decrease in oxygen levels as the algae die and decompose. This process can create "dead zones" in water bodies.
D is incorrect - Eutrophication refers to the excessive nutrient enrichment of water bodies, often from sources like agricultural runoff or sewage, leading to increased plant growth (algae and other aquatic plants). This excessive growth can disrupt the balance of the ecosystem and lead to issues like oxygen depletion.

So, the correct option is (A): Biomagnification refers to increase in concentration of the toxicant at successive trophic levels.