The acidification of oceans is increasing. Why is this phenomenon a cause of concern?

1. The growth and survival of calcareous phytoplankton will be adversely affected.
2. The growth and survival of coral reefs will be adversely affected.
3. The survival of some animals that have phytoplanktonic larvae will be adversely affected.
4. The cloud seeding and formation of clouds will be adversely affected.

Which of the statement(s) given above is/are correct?

[UPSC Civil Services Exam – 2012 Prelims]

(a) 1, 2 and 3 only

(b) 2 only

(c) 1 and 3 only

(d) 1, 2, 3 and 4

Answer: (a)

Explanation:

Ocean Acidification is caused by excess absorption of carbon dioxide which causes a decline in ocean pH. Human activities are responsible for releasing an estimated 30-40% of carbon dioxide into oceans, lakes and rivers. This process impacts the ocean ecosystem in several ways:

• The concentration of carbon dioxide increases, which increases carbonic acid and decreases carbonate ions, making it more difficult for marine calcifying organisms such as coral to survive.
• Calcareous phytoplankton growth and survival are adversely affected.
• Some animals that have phytoplanktonic larvae are also negatively affected.
• Although the majority of atmospheric sulphur comes from the ocean in the form of dimethylsulfide produced by phytoplankton, ocean acidification negatively impacts the development of phytoplankton, which leads to a decrease in sulphur emissions, and consequently a decrease in cloud formation. Hence, statement 4 is incorrect.

Therefore, option (a) is the correct answer.