雅思阅读 107: The Jellyfish Comeback (水母的反扑)

改编自 Smithsonian Magazine / Lisa-ann Gershwin。雅思阅读 Section 3 难度，约 1050 词。 素材来源：https://www.smithsonianmag.com/science-nature/jellyfish-the-next-king-of-the-sea-679915/

Reading Passage

A. On the night of December 10, 1999, the Philippine island of Luzon, home to some 40 million people, abruptly lost power. Malls full of Christmas shoppers plunged into darkness; a president meeting with senators waited tensely for a generator to kick in. Rumours of a coup spread. The cause, when it was announced the next day, was not political but biological. Several dump trucks' worth of jellyfish had been sucked into the cooling pipes of a coal-fired power station, triggering a cascading failure. "Here we are, in the age of cyberspace," fumed a local newspaper, "and we are at the mercy of jellyfish." That episode is now part of a growing catalogue. Jellies have halted diamond mining off Namibia by clogging machinery, asphyxiated more than 100,000 farmed salmon off Ireland in a swarm 35 feet deep, and capsized a ten-ton Japanese trawler hauling in giant 450-pound Nomura's jellyfish. From Norway's fjords to Thailand's resorts, gelatinous creatures are behaving as if they mean to take the ocean back. In summertime the Mediterranean can appear to boil with them; one year the Spanish Red Cross treated nearly nineteen thousand stung swimmers on a single stretch of coast. Contact with the deadliest box jellyfish can stop a human heart within minutes, and jellies kill dozens of people a year in the Philippines alone. To the swimmer, the diver and the coastal engineer, the message is the same: these ancient animals have discovered that a damaged ocean suits them very well.

B. The word "jellyfish" lumps together animals that look alike but are not closely related: the bell-shaped "true jellies" and comb jellies that swim with hairlike cilia, alongside colonial siphonophores such as the Portuguese man-of-war. All told, about 1,500 species bear the name. They are, by any standard, strange: boneless, bloodless and brainless, with a mouth that doubles as an anus, drifting at the mercy of currents though many pulse gently to push themselves along. Their tentacles, in some species up to 100 feet long, are armed with microscopic poison harpoons that fire on contact, letting them immobilise larval fish and krill without a struggle. Yet their lineage is ancient. Exquisite fossils from Utah, with muscles, reproductive organs and tentacles intact, date back more than 500 million years — long before fish, which appeared only 370 million years ago, evolved. In an ocean remade by humans, it seems, the old designs may once again have the edge.

C. No single villain explains the global rise. Overfishing removes the large predators — tuna, swordfish and sea turtles — that once kept jellies in check, while the harvest of small plankton-eating fish such as anchovies leaves more plankton on the table for jellies to gorge on. Pollution compounds the effect. Nutrient runoff fuels algal blooms; when the algae die, bacteria decompose them and strip the water of oxygen, creating "dead zones" where few fish can survive but jellyfish often thrive. The number of such coastal dead zones has doubled every decade since the 1960s and now stands near 500. Warming waters may help too. In controlled experiments, moon jellyfish reproduced freely even in the highly acidic conditions projected for the next century, and warmer sea water made the tiny dormant polyps bud off far more young: at one temperature each polyp produced about 20 juveniles, at a warmer 50, and at the warmest a record 69. A jellyfish polyp can also sit dormant for years, waiting for conditions to turn favourable before releasing its young — a waiting game that fish, with their constant demands, cannot easily play.

D. The most notorious invasion illustrates how these pressures combine. In 1982, the Black Sea, already strained by heavy anchovy fishing, received the warty comb jelly, a species native to the east coast of North America, almost certainly carried across the Atlantic in a ship's ballast water. With few predators and abundant plankton, it exploded: by 1990 an estimated 900 million tons of it filled the sea, helping to collapse the anchovy fishery and pushing the beluga sturgeon, source of fine caviar, toward commercial extinction. The invasion was eventually slowed by two events no one planned for: the fall of the Soviet Union reduced agricultural fertiliser runoff and improved water quality, and a second exotic comb jelly, accidentally introduced, happened to prey on the first. It is a reminder that jellyfish booms are ecological symptoms rather than the disease itself.

E. Not everyone agrees that the ocean is being taken over. A leading zooplankton scientist cautions that there is simply not enough historical data to distinguish a genuine, long-term increase from natural fluctuations — or, for that matter, from a world in which more people notice and report jellies than ever before. Are the creatures changing, he asks, or is our attention? The uncertainty matters. Where jellyfish are genuinely on the rise, the usual remedies are modest: releasing jelly-eating filefish or sea turtles into coastal waters, dispatching spotter boats, ringing beaches with hotlines, or — most frankly — learning to eat them. A dozen firm-bellied species are already harvested in Asia and, increasingly, in the United States; in China jellies have been eaten for a thousand years, and adventurous chefs have lately experimented with everything from jellyfish ice cream to cocktails. Whether jellies are the ocean's vengeful underclass or merely a visible sign of deeper damage, one conclusion is hard to avoid: an ecosystem degraded by overfishing, pollution and warming is one that jellyfish, rather than fish, find easiest to love. The choice, the experts suggest, is not really between fish and jellies. It is between an ocean we have ruined enough to prefer the jellies, and one we have not — a choice that, on present trends, is being made for us one overfished trawl and one fertilised estuary at a time.

Questions 1-4

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

List of Headings i. Strange animals with a very old family tree ii. The multiple pressures that favour jellyfish iii. The Black Sea invasion as a cautionary tale iv. Is the ocean really being taken over? v. How the 1999 blackout was caused by a coup vi. The history of the Philippine power grid vii. Why comb jellies cannot reproduce

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 the 1999 Luzon blackout ultimately turn out to be caused by? A. A military coup. B. Jellyfish blocking a power station's cooling pipes. C. A failure of Christmas lights. D. A ship's ballast water.

6. Why are jellyfish described as having an "edge" in a human-remade ocean? A. They are older than fish and tolerate overfishing, pollution and warming better. B. They have sharp teeth for catching prey. C. They can live on land. D. They eat only fish larvae.

7. What happened in the controlled warming experiments? A. Polyps produced fewer juveniles as water warmed. B. Warmer water made polyps bud off more young jellyfish. C. Acidic water killed all the polyps. D. Polyps stopped reproducing entirely.

8. How was the Black Sea comb-jelly invasion eventually slowed? A. By chemical warfare against the jellies. B. By reduced fertiliser runoff and the accidental arrival of a predator. C. By banning all shipping in the Black Sea. D. It was never slowed and continues today.

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. Jellyfish fossils found in Utah date back more than 500 million years.
10. The number of coastal ocean dead zones has roughly doubled every decade since the 1960s.
11. Most scientists agree that jellyfish populations have definitely increased globally.
12. Jellyfish are harvested for food in some parts of the world.
13. Box jellyfish are native to the Mediterranean Sea.

Questions 14-15

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

The warty comb jelly reached the Black Sea in 1982, most likely carried across the Atlantic in a ship's (14) __________ water. By 1990 some 900 million (15) __________ of it filled the sea.

答案与解析

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