Paragraph: Geographers analyzed 175 satellite images of ocean colour,
which is an indicator of Phytoplankton productivity at the ocean’s surface, and found that giant icebergs are responsible for storing up to 20 percent of carbon in the Southern Ocean. The researchers discovered that melting water from giant icebergs which contains iron and other nutrients, supports hitherto unexpectedly high levels of phytoplankton growth.
Q. Based on the above passage, the following assumptions have been made:
1. Giant icebergs have a bearing on primary productivity and food chains of the Southern Ocean.
2. Melting of giant icebergs can produce climate change effects and impact world fisheries.
Which of the assumptions given above is/are valid?
a) 1 only
b) 2 only
c) Both 1 and 2
d) Neither 1 nor 2
Correct answer: a) 1 only
Question from UPSC Prelims 2024 CSAT
Explanation :
Assumption 1 is valid:
The passage clearly states that melting water from giant icebergs contains iron and other nutrients, which support unexpectedly high levels of phytoplankton growth. Phytoplankton form the base of marine food chains, and their productivity directly influences primary productivity and the entire food web in the Southern Ocean. Thus, giant icebergs indeed have a bearing on primary productivity and food chains.
Assumption 2 is valid:
The passage mentions that giant icebergs are responsible for storing up to 20 percent of carbon in the Southern Ocean. Phytoplankton growth, stimulated by nutrients from melting icebergs, plays a significant role in carbon sequestration. Changes in carbon storage and phytoplankton productivity can influence global climate patterns. Additionally, phytoplankton productivity directly impacts marine ecosystems and fisheries worldwide, as phytoplankton form the foundation of marine food webs.
Thus, both assumptions are logically valid based on the information provided in the passage.
