Ocean Acidification Reading Answers
In the Ocean Acidification Reading Answers there are questions to answer. Candidates' reading abilities are assessed in the IELTS Reading section by presenting them with a passage and questions. Candidates must react to a variety of questions, each of which is unique. The IELTS Reading part tests students' comprehension skills using a range of problem types. In this portion - Ocean Acidification Reading Answers - there are two sorts of questions for the passage
- No more than three words
- Choose the correct letter
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Section 1
Read the Passage to Answer the Following Questions
Ocean Acidification Reading Answers
Caspar Henderson reports on some new concerns.
- A few years ago, biologist Victoria Fabry, saw the future of the world’s oceans in a jar. She was aboard a research ship in the North Pacific, carrying out experiments on a species of pteropod – small molluscs with shells up to a centimetre long, which swim in a way that resembles butterfly flight, propelled by small flaps. Something strange was happening in Fabry’s jars. ‘The pteropods were still swimming, but their shells were visibly dissolving,’ says Fabry. She realised that the animals’ respiration had increased the carbon dioxide (C02) in the jars, which had been scaled for 48 hours, changing the water’s chemistry to a point where the calcium carbonate in the pteropods’ shells had started to dissolve. What Fabry had stumbled on was a hint of ‘the other C02 problem’.
- It has taken several decades for climate change to be recognised as a serious threat. But another result of our fossil- fuel habit – ocean acidification – has only begun to be researched in the last few years. Its impact could be momentous, says Joanie Kleypas of the National Centre for Atmospheric Research in Boulder Colorado.
- C02 forms the carbonic acid when it dissolves in water, and the oceans are soaking up more and more of it. Recent studies show that the seas have absorbed about a third of all the fossil-fuel carbon released into the atmosphere since the beginning of the industrial revolution in the mid-eighteenth century, and they will soak up much more over the next century. Yet until quite recently, many people dismissed the idea that humanity could alter the acidity of the oceans, which cover 71 % of the planet’s surface to an average depth of about four kilometres. The ocean’s natural buffering capacity was assumed to be capable of preventing any changes in acidity even with a massive increase in C02 levels.
- And it is – but only if the increase happens slowly, over hundreds of thousands of years. Over this timescale, the release of carbonates from rocks on land and from ocean sediments can neutralise the dissolved C02, just like dropping chalk in an acid. Levels of C02 are now rising so fast that they are overwhelming the oceans’ buffering capacity.
- In 2003 Ken Caldeira of the Carnegie Institution in Stanford and Michael Wickett at the Lawrence Livermore National Laboratory calculated that the absorption of fossil C02 could make the oceans more acidic over the next few centuries than they have been for 300 million years, with the possible exception of rare catastrophic events. The potential seriousness of the effect was underlined in 2005 by the work of James Zachos of the University of California and his colleagues, who studied one of those rare catastrophic events. They showed that the mass extinction of huge numbers of deep-sea creatures around 55 million years ago was caused by ocean acidification after the release of around 4500 giga-tonnes of carbon. It took over 100,000 years for the oceans to return to their normal state.
- Around the same time as the Zachos paper, the UK’s Royal Society published the first comprehensive report on ocean acidification. It makes grim reading, concluding that ocean acidification is inevitable without drastic cuts in emissions. Marine ecosystems, especially coral reefs, are likely to be affected, with fishing and tourism-based around reefs losing billions of dollars each year. Yet the report also stressed that there is huge uncertainty about the effects on marine life.
- The sea creatures most likely to be affected are those that make their shells or skeletons from calcium carbonate, including tiny plankton and huge corals. Their shells and skeletons do not dissolve only because the upper layers of the oceans are supersaturated with calcium carbonate. Acidification reduces carbonate Ion concentrations, making it harder for organisms to build their shells or skeletons. When the water drops below the saturation point, these structures will start to dissolve. Calcium carbonate comes in two different forms, aragonite and calcite, aragonite being more soluble. So organisms with aragonite structures such as corals will be hardest hit.
- So far the picture looks relentlessly gloomy, but could there actually be some positive results from adding so much C02 to the seas? One intriguing finding, says Ulf Riebesell of the Leibniz Institute of Marine Sciences in Kiel Germany, concerns gases that influence climate. A few experiments suggest that in more acidic conditions, microbes will produce more volatile organic compounds such as dimethyl sulphide, some of which escapes to the atmosphere and causes clouds to develop. More clouds would mean cooler conditions, which could potentially slow global warming.
- Calculating the effect of ocean acidification on people and economies is virtually impossible, but it could be enormous. Take the impact on tropical corals, assuming that warming and other pressures such as pollution do not decimate them first. Reefs protect the shorelines of many countries. Acidification could start eating away at reefs just when they are needed more than ever because of rising sea levels.
- ‘No serious scientist believes the oceans will be devoid of life,’ says Caldeira. ‘Wherever there is light and nutrients, something will live. A likely outcome will be a radical simplification of the ecosystem. ‘Taking this and other scientists’ views into account, it seems clear that acidification will mean the loss of many species so our children will not see the amazingly beautiful things that we can. It is important to tell them to go and see the corals now before it is too late.
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Section 2
Solution with Explanation
Questions 1-7:
Answer the Questions below
Choose NO MORE THAN THREE WORDS AND/OR A NUMBER for each answer
- What does a Pteropod use to move through the water?
Answer: (Small) flaps
Supporting Sentence: She was aboard a research ship in the North Pacific, carrying out experiments on a species of pteropod – small molluscs with shells up to a centimetre long, which swim in a way that resembles butterfly flight, propelled by small flaps.
Keyword: Pteropod, swim
Keyword Location: Paragraph 1, 3rd & 4th Line
Explanation: the passage mentions that the scientist noticed pteropods swam like butterflies and their small flaps took them forward which means
these flaps are used by Pteropods to move through water.
- Which parts of Pteropods were being damaged by increased acidification?
Answer: (Their/The) Shells
Supporting Sentence: But another result of our fossil- fuel habit – ocean acidification – has only begun to be researched in the last few years.
Keyword: Pteropods, acidification
Keyword Location: Paragraph 1, 9th & 12th lines
Explanation: the passage says the fossil fuel habits have led to ocean acidification and fossil fuels are known for emitting CO2 which means this gas is causing ocean acidification. The passage seems to suggest that calcium carbonate in Pteropods’ shells is being dissolved/damaged due to this CO2. Hence, Ocean acidification is caused by the entry of CO2 into the Ocean and its damaging Pteropod shells.
- What proportion of Carbon released over the last 200 years has been taken in by the oceans?
Answer: (About) 1/3
Supporting Sentence: Recent studies show that the seas have absorbed about a third of all the fossil-fuel carbon released into the atmosphere since the beginning of the industrial revolution in the mid-eighteenth century, and they will soak up much more over the next century.
Keyword: carbon, absorbed
Keyword Location: Paragraph 2, 3rd Line
Explanation: The studies mentioned in the passage say that oceans have absorbed about one-third of released carbon since the Industrial Revolution that was in the mid-eighteenth century and we are in the 21st century now which is roughly 200 years apart from the eighteenth century.
- Where do carbonates enter the oceans from?
Answer: Rocks (on land)
Supporting Sentence: Over this timescale, the release of carbonates from rocks on land and from ocean sediments can neutralise the dissolved C02, just like dropping chalk in an acid.
Keyword: carbonates
Keyword Location: Paragraph 3, 2nd Line
Explanation: Passage here makes a direct mention of carbonates being released from rocks on land and ocean sediments. Since ocean sediments are already from Ocean the only external source from which carbonates can “enter” the ocean are Rocks on land.
- How long did the oceans need to recover after the destruction of marine life by acidification 55 million years ago?
Answer: (Over) 100,000 Years
Supporting Sentence: It took over 100,000 years for the oceans to return to their normal state.
Keyword: ocean acidification, mass extinction
Keyword Location: Paragraph 4, 8th & 9th Line.
Explanation: the passage mentions mass extinction of deep-sea creatures 55 million years ago due to ocean acidification which is effectively a destruction of Marine life because deep sea creatures are marine life and mass extinction would amount to destruction. Now, returning to normal state would also mean recovery for the ocean which the passage categorically states happened in 100,000 years.
- Which businesses will suffer if reefs are damaged?
Answer: Fishing and Tourism
Supporting Sentence: Marine ecosystems, especially coral reefs, are likely to be affected, with fishing and tourism-based around reefs losing billions of dollars each year.
Keyword: reefs, affected
Keyword Location: Paragraph 5, 4th Line
Explanation: the passage says there are fishing, and tourism based on coral reefs. So, naturally if there is some damage to reefs, the businesses of Fishing and Tourism will be affected. Now, these fishing and tourism are businesses because the passage states that they will be losing billions of dollars each year and only a commercial activity has potential to generate that kind of revenue every year.
- What type of creatures make their skeleton out of Aragonite?
Answer: Coral(s)
Supporting Sentence: The sea creatures most likely to be affected are those that make their shells or skeletons from calcium carbonate, including tiny plankton and huge corals.
Keyword: aragonite, skeletons, creatures
Keyword Location: Paragraph 6, 1st, 2nd & 9th Line
Explanation: the passage says organisms with aragonite structures like corals which means corals have something made of aragonite. Now, aragonite is one of the two forms of Calcium Carbonate as mentioned in the passage and the passage also mentions that there are sea creatures that make their skeleton out of Calcium Carbonate. So, the aragonite structures in corals are likely to be their skeleton.
Questions 8-12:
Complete the flowchart below
Choose NO MORE THAN THREE WORDS AND/OR A NUMBER from the passage for each answer
A possible benefit from increased CO2 levels in the Sea
Increased ocean acidification
Larger quantities of organic compounds made by (8) ………transfer to (9) …….
(10) ……. are formed
(11) …….. temperatures
Reduction in the rate of (12) …….
Question 8:
Answer 8: Microbes
Supporting Sentence: A few experiments suggest that in more acidic conditions, microbes will produce more volatile organic compounds such as dimethyl sulphide, some of which escapes to the atmosphere and causes clouds to develop.
Keyword: organic compounds, produce
Keyword Location: Paragraph 7, 5th Line
Explanation: the passage clearly mentions that microbes will produce more volatile organic compounds. Producing is also equal to making so organic compounds are being made by microbes.
Question 9:
Answer 9: (The) Atmosphere
Supporting Sentence: A few experiments suggest that in more acidic conditions, microbes will produce more volatile organic compounds such as dimethyl sulphide, some of which escapes to the atmosphere and causes clouds to develop.
Keyword: escapes to
Keyword Location: Paragraph 7, 6th Line
Explanation: the passage says organic compounds are made by Microbes and some of it escapes to the atmosphere, this escape can also be called transferred because in natural processes there will be no manual intervention so the matter escapes to occupy a different place and it is called transfer of matter.
Question 10:
Answer 10: Clouds
Supporting Sentence: A few experiments suggest that in more acidic conditions, microbes will produce more volatile organic compounds such as dimethyl sulphide, some of which escapes to the atmosphere and causes clouds to develop.
Keyword: develop
Keyword Location: Paragraph 7, 7th Line
Explanation: the only thing being formed are Clouds as the passage suggests once organic compounds have escaped to atmosphere, they cause Clouds to develop over there. Since the development of Clouds here is being done from scratch it means Clouds are being formed.
Question 11:
Answer 11: Cooler
Supporting Sentence: More clouds would mean cooler conditions, which could potentially slow global warming.
Keyword: cooler
Keyword Location: Paragraph 7, 7th Line
Explanation: after the clouds are formed, the obvious next step as stated in the passage is cooler conditions. And how do you determine that conditions are cooler when compared to previous conditions? You see the difference between temperatures so cooler conditions would mean cooler temperatures.
Question 12:
Answer 12: Global Warming
Supporting Sentence: More clouds would mean cooler conditions, which could potentially slow global warming.
Keyword: potentially slow
Keyword Location: Paragraph 7, 8th Line
Explanation: the question is asking for reduction in the rate of and the passage mentions potentially slow global warming. Now, slowing something down is equivalent to reducing its rate and here the only thing being slowed down is Global warming.
Question 13:
Choose the correct letter A, B, C, or D
- Which of the following statements best summarises the writer’s view of the passage?
- We will have to wait and see if acidification has serious effects.
- It is clear that acidification will cause huge damage to marine life.
- It is likely that increased CO2 will change marine ecosystems considerably.
- The theory that increased CO2 could have positive results is believable.
Answer: C
Supporting Sentence: A likely outcome will be a radical simplification of the ecosystem.
Keyword: radical simplification, ecosystem
Keyword Location: Paragraph 9, 3rd Line
Explanation: The passage towards the end says that a likely outcome of ocean acidification will be a radical simplification of the ecosystem which means a considerable shift in marine ecosystem because as of now marine ecosystem is radically complex.
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