雅思阅读 1: The Deep Sea's Secret Larder（深海的秘密粮仓）

改编自 University of Southern Denmark / Science Advances 研究报道（2026）。本文为雅思阅读 Section 3 难度，约 950 词。 素材来源：https://www.sciencedaily.com/releases/2026/07/260711010127.htm

Reading Passage

A. For more than a century, oceanographers have described the deep sea as a biological desert. Beyond the reach of sunlight, where photosynthesis cannot occur, organisms were believed to survive on the barest trickle of organic material — the occasional dead plankton, a stranded fish, a scrap of detritus drifting from the sunlit surface layers. This "marine snow," as it is poetically known, was understood to descend slowly through the water column, reaching the seabed largely intact, where it was buried in sediment or consumed by bottom-dwelling creatures. The model was simple: what sinks, stays. Yet a study published in Science Advances in July 2026 has forced a radical re-examination of that picture, suggesting that the deep ocean is far more nourished, and far more dynamically active, than anyone had suspected.

B. The research team, led by Associate Professor Peter Stief at the University of Southern Denmark, set out to investigate what actually happens to marine snow as it descends through kilometres of increasingly pressurised water. Marine snow is not a single substance but a heterogeneous aggregate — clumps of dead algae, excreted particles, discarded mucus webs and assorted microbial remains that stick together as they fall. The conventional view held that these particles preserved their chemical integrity on the way down, losing only a small fraction of their content to bacterial scavenging. Stief's team, however, suspected that pressure itself was doing something to the particles that no one had properly measured. "The pressure acts almost like a giant juicer," Stief explained. "At two to six kilometres depth, the hydrostatic force begins to squeeze dissolved organic compounds right out of the particles, and microbes in the surrounding water can take them up immediately."

C. To test this hypothesis, the researchers recreated marine snow in the laboratory using diatoms — microscopic algae that naturally clump together as they sink. They placed these artificial aggregates inside specially designed rotating pressure tanks that kept the particles suspended, preventing them from settling and allowing precise measurement of what leaked out at different pressures. The results were striking. Sinking particles lost as much as 50% of their original carbon content and between 58% and 63% of their original nitrogen during descent through deep waters. Most of the released material consisted of proteins and carbohydrates — precisely the compounds that free-living deep-sea microbes can most readily consume. Within just two days of exposure, bacterial abundance increased thirtyfold, and respiration rates rose sharply, confirming that the leaked nutrients were not merely accumulating in the water but were being rapidly metabolised. Crucially, the team observed the same leakage pattern across multiple diatom species, indicating that the mechanism is likely to be widespread rather than confined to a particular organism.

D. The implications extend well beyond the ecology of deep-sea microbes. Scientists have long assumed that a substantial fraction of the carbon carried by marine snow eventually becomes permanently locked away in deep-ocean sediments, where it can remain for millions of years. Much of the oil and natural gas extracted today formed through precisely this long-term burial process. If, however, up to half of that carbon leaks out into the water column before the particles reach the seafloor, then the ocean's capacity as a long-term carbon store may have been substantially overestimated. The leaked carbon does not simply vanish; it remains suspended in deep waters, where it can circulate for hundreds or even thousands of years before gradually upwelling to the surface and, eventually, returning to the atmosphere. "This process affects how much carbon the ocean can sequester and for how long," Stief noted. "It is directly relevant to climate modelling, and our existing models may need to be revised." The finding is particularly provocative given that ocean carbon storage is frequently cited as a natural buffer against anthropogenic emissions — a buffer that now appears less robust than previously assumed.

E. The research is not without its limitations. All experiments were conducted under laboratory conditions with artificially constructed particles; the team has yet to verify the leakage rate in situ, where temperatures, oxygen levels and particle composition are far more variable. Their next expedition, aboard the German research vessel Polarstern, will target the Arctic Ocean, where they hope to detect the molecular fingerprints of pressure-driven leakage in natural deep waters. Some oceanographers have cautioned that while the laboratory results are robust, extrapolating them to global scales requires considerable caution. Nevertheless, the study has already triggered a shift in how researchers think about the deep sea. It is no longer a static, food-deprived wilderness that depends entirely on surface-derived detritus; it is a dynamic system in which pressure itself unlocks nutrients, sustaining a far more active microbial community than anyone had credited. As one commentator observed, the deep ocean may have been hiding its larder in plain sight all along.

Questions 1-5

Choose the correct heading for paragraphs B, C, D and E from the list of headings below.

List of Headings i. The industrial consequences of long-term burial ii. A laboratory experiment reveals the scale of nutrient loss iii. Why the deep ocean was once considered lifeless iv. Pressure as an unseen force extracting nutrients v. How the finding challenges established climate models vi. The commercial value of deep-sea microorganisms vii. Field verification and a cautious reassessment

1. Paragraph B: ____
2. Paragraph C: ____
3. Paragraph D: ____
4. Paragraph E: ____

Questions 5-8

Choose the correct letter, A, B, C or D.

5. What did Stief's team find about marine snow particles at great depths? A. They lose most of their weight due to bacterial decomposition. B. They release dissolved compounds under the influence of pressure. C. They break apart into single-celled organisms before reaching the seabed. D. They absorb nitrogen from the surrounding water as they descend.

6. What happened to bacterial populations within two days of the experiment? A. They declined due to competition for limited resources. B. They became dependent on particles rather than dissolved matter. C. They multiplied dramatically after accessing the leaked compounds. D. They shifted toward species that tolerate high-pressure conditions.

7. Why does the study matter for climate models? A. It proves that ocean sediments store more carbon than expected. B. It suggests that upwelling is slower than previously calculated. C. It implies that less carbon may be permanently buried than assumed. D. It demonstrates that Arctic waters absorb carbon most efficiently.

8. What caveat does the article raise about the laboratory findings? A. The rotating tanks did not accurately simulate deep-sea temperatures. B. The diatoms used were genetically modified to enhance leakage. C. The results have not yet been confirmed in natural ocean conditions. D. The carbon and nitrogen measurements were based on estimates rather than direct sampling.

Questions 9-13

Do the following statements agree with the claims of the writer?

Write:

• TRUE if the statement agrees with the information
• FALSE if the statement contradicts the information
• NOT GIVEN if there is no information on this

9. For over a century, researchers believed that most marine snow reached the ocean floor with little chemical alteration.
10. Stief's team was the first group to study marine snow under laboratory pressure.
11. The carbon leaked from marine snow returns to the atmosphere within decades.
12. The German research vessel Polarstern has already completed its Arctic expedition.
13. Some experts have warned against applying the laboratory results directly to global calculations.

Questions 14-15

Complete the summary below using NO MORE THAN TWO WORDS from the passage.

The researchers found that deep-sea pressure behaves like a (14) __________, forcing dissolved organic matter out of sinking particles. This material, consisting largely of proteins and carbohydrates, is immediately consumed by (15) __________ living in the surrounding water.

答案与解析

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