Deep sea discovery
Read Deep sea discovery and check the IELTS Reading answers. Nico Michiels is an ecologist from the University of Tubingen in Germany who spends part of each year in Egypt, where he dives in the Red Sea, observing fish life and gathering data on its coral reefs. In September 2007 he decided to find…
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Nico Michiels is an ecologist from the University of Tubingen in Germany who spends part of each year in Egypt, where he dives in the Red Sea, observing fish life and gathering data on its coral reefs. In September 2007 he decided to find out how far red light could penetrate the ocean depths. Seawater absorbs different colours at different depths, and as an experienced diver, Michiels was aware that red light is extinguished not far below the surface whereas blue-green light penetrates deeper. To find out the depth at which red disappeared in this particular ocean, however, he attached a special plastic filter to his dive mask which was designed to block out all colours except red. Then he began to descend. In theory, once he reached about 15 metres, he should have been plunged into darkness. Instead, something totally unexpected happened. Sure enough, 20 metres down it was as dark as night. 'All the fish disappeared. With no light from the surface, they were effectively black and had become invisible,' he says. But it didn't stay black for long. Then I saw a group of goby fish with bright red eyes lit up against the background. After that red spots began to show up all over the reef.'
Vocabulary from this passage
10 words worth learning before you sit the test, each with the sentence it appears in.
- compelling adjective
Evincing interest, attention, or admiration in a powerfully irresistible way; convincing
The scientist presented a compelling argument for the conservation of coral reefs.
- confined adjective
Restricted in area or volume; limited to a particular location or scope
The infection was fortunately confined to a single ward of the hospital.
- distinguish verb
To recognize or treat someone or something as different; to perceive a difference
It is often difficult to distinguish between cause and effect in complex systems.
- emit verb
To produce and discharge something, such as gas, radiation, or light
Certain minerals emit a faint glow when exposed to ultraviolet light.
- extinguish verb
To put an end to something; to cause a light or fire to cease to burn or shine
Certain wavelengths of light are extinguished rapidly as they travel through water.
- fluorescence noun
The emission of light by a substance that has absorbed light or other electromagnetic radiation
The discovery of fluorescence in deep-sea fish suggests complex visual communication methods.
- indication noun
A sign or piece of information that indicates something; a symptom or suggestion
There is no clear indication that the economy will recover in the next quarter.
- penetrate verb
To force a way into or through something; to be understood or realized by someone
Sunlight can only penetrate the ocean to a certain depth before it is absorbed.
- predominantly adverb
Mainly; for the most part; seeing the strongest or main element
The research team was composed predominantly of marine biologists and ecologists.
- systematic adjective
Done or acting according to a fixed plan or system; methodical and organized
A systematic review of the data revealed patterns that previous studies had missed.
Answers with explanations
- 1. TRUE
The statement claims Michiels **expected to encounter total darkness** at 15 metres. The text confirms this, stating that **in theory**, he **should have been plunged into darkness** once he reached about **15 metres**. Answer: TRUE.
- 2. TRUE
The statement claims Michiels could see the **red markings** without the **red filter**. The text explicitly states that **even with the red filter removed**, he could **pick them out without much trouble**. Answer: TRUE.
- 2-3: monoculture
2: The statement claims Michiels could see the **red markings** without the **red filter**. The text explicitly states that **even with the red filter removed**, he could **pick them out without much trouble**. Answer: TRUE.
3: The statement claims **other divers** had **assumed** they would see red markings. The text directly contradicts this, stating that **no one saw it because no one expected to see it**. Answer: FALSE.
- 3. FALSE
The statement claims **other divers** had **assumed** they would see red markings. The text directly contradicts this, stating that **no one saw it because no one expected to see it**. Answer: FALSE.
- 3-4: A
3: The statement claims **other divers** had **assumed** they would see red markings. The text directly contradicts this, stating that **no one saw it because no one expected to see it**. Answer: FALSE.
4: The statement claims **all** fish with red markings came from the **Red Sea**. While the text mentions his dives in the Red Sea and that he **found many others since**, it does not explicitly confirm that *every* fish found in his subsequent research originated there (Paragraph D mentions buying tropical fish in Germany). Since the origin of all fish is not confirmed, the information is missing. Answer: NOT GIVEN.
- 4. NOT GIVEN
The statement claims **all** fish with red markings came from the **Red Sea**. While the text mentions his dives in the Red Sea and that he **found many others since**, it does not explicitly confirm that *every* fish found in his subsequent research originated there (Paragraph D mentions buying tropical fish in Germany). Since the origin of all fish is not confirmed, the information is missing. Answer: NOT GIVEN.
- 5. FALSE
The statement claims he **first thought** of fluorescence in **Germany**. The text indicates he **suspected fluorescence** while diving at **20 metres down** (in Egypt), and only **confirmed** it later in Germany. This chronology contradicts the statement. Answer: FALSE.
- 6. TRUE
The statement claims Michiels is **uncertain** about what creates the fluorescence. The text explicitly says they are **still not sure exactly what is fluorescing**, supporting the claim. Answer: TRUE.
- 7. head
The note asks for the location of **markings** on the fish. The text states that the **most common markings** tend to be on the body towards the **head**. The word fits grammatically and contextually. Answer: head.
- 8. communication
The note states red fluorescence is used specifically for [blank] purposes. The text identifies a **very particular function**, which is **communication** with other members. Answer: communication.
- 9. enemies
The note mentions using fluorescence to keep [blank] away. The text mentions using it to **ward off** (keep away) **enemies**. Answer: enemies.
- 10. location
The note states **gobies** depend on fluorescence to show their [blank]. The text explicitly says **red-eyed gobies use signals to indicate their location**. Answer: location.
- 11. species
The note discusses variations in markings among similar [blank]. The text states that **closely related species** do not have **identical markings**. The noun **species** fits the gap. Answer: species.
- 12. corals
The note says fish cannot be easily seen near backgrounds of [blank] emitting red light. The text describes **corals** that **glow a dark but faint red**, making fish **hard to distinguish**. Answer: corals.
- 13. seahorse
The note asks for the only fish **proven to have this ability** (seeing red). The text identifies **one exception**, the **seahorse**, whose eyes are **sensitive to red**. Answer: seahorse.