IELTS Reading Practice: Coral Reefs Under Pressure
IELTS · ReadingA science passage on coral reefs and bleaching, with True / False / Not Given questions.
1Read the text
Coral reefs cover only a very small part of the ocean floor, yet they are home to a remarkable share of marine life. Scientists often estimate that around a quarter of all known sea species depend on reefs at some point in their lives, which is why reefs are sometimes described as the rainforests of the sea.
A reef is built by tiny animals called coral polyps. Each polyp lives alongside microscopic algae, which live inside its tissue and use sunlight to make food that the coral shares. This partnership explains why reefs are found mostly in shallow, clear, warm water. It also explains why they are sensitive to changes in temperature.
When the sea becomes unusually warm for a long period, corals can expel their algae, and the reef turns white. This is called bleaching. A bleached coral is not dead, and if the water cools quickly enough, the algae may return. If the heat continues, however, the coral may starve. Several severe bleaching events have been recorded in recent decades, and some reefs have lost a large part of their living coral.
Heat is not the only threat. Run-off from farmland carries nutrients into coastal waters, encouraging algae that smother corals, while destructive fishing methods damage the reef structure directly. Conservation projects have tried to grow fragments of coral in nurseries and fix them to damaged reefs. These projects have produced encouraging local results, but most scientists agree that they cannot replace the need to reduce the pressures that cause the damage.
2True, false or not given Tap an answer. You see why straight away.
1. Coral reefs cover a large area of the ocean floor.
2. Corals depend on algae that live inside their tissue.
3. A bleached coral is always dead.
4. Reefs are found mostly in shallow, warm water.
5. Bleaching events have become less frequent in recent decades.
6. Coral nurseries have been used in every country that has coral reefs.
Done. Your first lesson is on its way.
Answer key — IELTS Reading Practice: Coral Reefs Under Pressure
- FALSE — The passage says reefs "cover only a very small part of the ocean floor."
- TRUE — The passage says each polyp lives alongside algae "which live inside its tissue" and make food that the coral shares.
- FALSE — The passage says "A bleached coral is not dead", and the algae may return if the water cools.
- TRUE — The passage says reefs "are found mostly in shallow, clear, warm water."
- NOT GIVEN — The passage says several severe events have been recorded in recent decades, but it does not say whether they are becoming more or less frequent.
- NOT GIVEN — The passage says conservation projects have tried growing coral in nurseries, but it does not say where, or how widely.