There is a concern over the increase in harmful algal blooms in the seawaters of India. What could be the causative factors for this phenomenon?
- Discharge of nutrients from the estuaries.
- Run-off from the land during the monsoon.
- Upwelling in the seas.
Select the correct answer from the codes given below:
[UPSC Civil Services Exam – 2011 Prelims]
(a) 1 and 3
(b) 1 and 2 only
(c) 2 and 3 only
(d) 1, 2 and 3
Answer: (d)
Explanation:
Algal Bloom:
- An algal bloom is defined as the rapid growth of the population of algae in aquatic ecosystems.
- Algal blooms are caused by excessive amounts of nitrates, phosphates, and nutrients entering an aquatic ecosystem, often via discharges from sewage treatment plants and septic tanks, estuaries, and stormwater run-off from fertilized lawns and farms. Hence, statements 1 and 2 are correct.
- Other factors that responsible for algal growth include sunlight and slow-moving water.
- Upwelling, the formation of mud banks, nutrient discharges from estuaries, and run-off from the land during southwest and northeast monsoons cause some algae blooms in coastal waters. Hence, statement 3 is correct.
