Read the passage and answer the questions given below it.
In the summer of 1998, divers in the Lakshadweep lagoons surfaced with a strange report. The reefs had gone white. Branching corals that should have been brown and green stood pale as chalk under warm, clear water. The word for this is bleaching, and it misleads. It suggests something scrubbed clean and finished with. A bleached coral, for a while at least, is still alive.
A coral is a colony of tiny animals called polyps, and it does not live alone. Inside its tissue live even tinier algae. They make food from sunlight, pass most of it on to the coral and give it its colour. When the sea stays too hot for too long, the coral throws the algae out. What is left is clear tissue over a white skeleton. The coral has not died. It has started to starve.
If the water cools in time, the algae can return, and the colour with them. Even a reef that loses much of its coral can grow back, given enough quiet years. Many Lakshadweep reefs did so in the years after 1998. That mattered on land too, because the reef breaks the ocean swell before it reaches the houses on these coral islands.
The trouble lies in the gap between one hot spell and the next. The reefs bleached again in 2010, and again in the marine heatwaves of recent summers. To a reef that needs years to heal, heat that once came as a rare visitor can begin to seem almost unremitting. A coral still weak from the last bleaching meets the next one with less to spare. Where corals die, seaweed spreads over the bare rock, and young corals struggle to settle there.
Which of the following can be inferred about the reefs that the divers saw in 1998?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Their corals had pushed out their algae because the water had stayed too warm.
The first two paragraphs together explain why the reefs looked white.
- The divers saw corals “pale as chalk under warm, clear water”.
- The second paragraph says that when the sea stays “too hot for too long”, the coral throws its algae out. What is left is “clear tissue over a white skeleton”.
- Joining the two, the white reefs of 1998 were corals that had pushed out their algae in the heat.
Why the Other Options are Incorrect?
Option 1: Their corals were already dead by the time the divers reached them. — Incorrect. Contradicted: The writer says a bleached coral “is still alive” for a while. White does not mean dead.
Option 2: They had been covered by seaweed, which hid the true colour of the corals. — Incorrect. Wrong link: Seaweed comes in only after corals die, over the bare rock. The white colour came from the loss of the algae.
Option 3: They had lost their colour because the visits of divers had upset the algae. — Incorrect. Not mentioned: The divers only saw and reported the change. The passage puts it down to the hot sea.