Practice in Reading: Dealing with Marine Debris

Rochman is a member of the National Center for Ecological Analysis and Synthesis’s marine-debris working group, a collection of scientists who study, among other things, the growing problem of marine debris, also known as ocean trash. Plenty of studies have sounded alarm bells about the state of marine debris; in a recent paper published in the journal Ecology, Rochman and her colleagues set out to determine how many of those perceived risks are real.

According to Rochman, scientists often conclude their papers by speculating on the broader implications of their findings. For instance, a study might reveal that certain seabirds ingest plastic bags and then warn that entire bird populations are at risk of extinction. ‘However, the reality was that no one had actually tested these perceived threats,’ Rochman explains. ‘There was a lack of concrete information.’

Rochman and her colleagues reviewed over one hundred studies on the effects of marine debris published up to 2013. In each study, they examined the perceived threats – a total of 366 – and the actual findings.

In 83% of cases, the perceived dangers of ocean litter were validated. In the remaining cases, the research group identified flaws in study design and data that compromised the reliability of their conclusions – for example, lacking a control group or using flawed statistical methods.

Interestingly, Rochman notes that only one well-executed study did not find the effect it was seeking, an inquiry into mussels consuming tiny fragments. Researchers discovered that the plastic moved from the mussels’ stomachs into their bloodstream, where it remained for weeks, but did not appear to stress the shellfish.

While mussels may be fine eating trash, though, the analysis also gave a clearer picture of the many ways that ocean debris is bothersome.

Among the studies examined, most identified risks stemmed from plastic waste rather than other materials such as metal or wood. Many hazards involved large pieces of debris – for instance, animals becoming entangled or ingesting trash and sustaining serious injuries.

However, a significant portion of ocean debris consists of 'microplastics', pieces smaller than five millimeters. These could be components from cosmetics and toiletries, fibers shed from synthetic clothing during washing, or weathered remnants of larger debris. Compared to research on large-scale debris, Rochman's team found limited studies on the effects of these small particles. 'There are still many unanswered questions regarding microplastics,' Rochman remarks, although she notes an increase in publications on the topic since 2013, the cutoff year for their analysis.

She also mentions numerous uncertainties about how ocean debris contributes to the deaths of marine creatures. Many studies have examined the impact of plastic on individual animals, their tissues, or cells, rather than entire populations. In laboratory settings, scientists often use higher concentrations of plastic than those found in the ocean. None of this provides insight into the potential number of deaths among birds, fish, or sea turtles due to plastic pollution – or how the demise of one species might affect its predators or the broader ecosystem.

'We need to pose more ecologically relevant questions,' Rochman suggests. Typically, scientists do not fully comprehend the environmental repercussions of major incidents, such as a tanker accidentally spilling its entire load of oil and contaminating vast stretches of ocean, until after they occur. 'We fail to pose pertinent questions soon enough,' she asserts. However, if ecologists can grasp how the gradual impact of oceanic debris harms ecosystems, they may be able to mitigate future degradation.

Posing appropriate questions can guide policymakers and the public in determining where to concentrate their efforts. Issues that appear sensational may not necessarily be the most critical starting points. For instance, the name 'Great Pacific Garbage Patch' evokes an image of a massive floating island of trash in the northern Pacific Ocean. However, much of the debris is minuscule or beneath the surface; one could sail through the area without spotting any trash at all. 'The Ocean Cleanup', a Dutch initiative, is currently devising plans to deploy mechanical devices in the Pacific Garbage Patch and similar zones to extract plastic. Yet, recent research using simulations demonstrates that strategically siting cleanup devices nearer to shore would yield more effective long-term pollution reduction.

'Dispelling these misconceptions is crucial,' asserts Rochman. She notes that both scientists and the media contribute to a perception that plastic debris is responsible for widespread oceanic casualties such as strandings and entanglements. Analyzing existing scientific literature can aid ecologists in discerning which issues warrant immediate attention and which, like the mussels, can be absorbed and disregarded.

Questions 27-33

Do the statements below align with the information provided in Reading Passage 3?

In boxes 27-33 on you answer sheet, 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

27   Rochman and her colleagues were the first people to research the problem of marine debris.

28   The creatures most in danger from ocean trash are certain seabirds.

29   The studies Rochman has reviewed have already proved that populations of some birds will soon become extinct.

30   Rochman analysed papers on the different kinds of danger caused by ocean trash.

31   Most of the research analysed by Rochman and her colleagues was badly designed.

32   One study examined by Rochman was expecting to find that mussels were harmed by eating plastic.

33   Some mussels choose to eat plastic in preference to their natural diet.

Questions 34-39

Fill in the blanks below.

Choose ONE WORD ONLY from the passage for each answer.

Write your answers in boxes 34-39 on your answer sheet.

Discoveries concerning oceanic waste

Studies of marine debris found the biggest threats were

•   plastic (excluding metal or wood)

•   bits of debris that were 34………………………….. (harmful to animals)

There was little research into 35…………………………. e.g. from synthetic fibres.

Drawbacks of the studies examined

•   most studies concentrated on individual animals, not entire 36 ………………………..

•   the 37…………………….. of plastic used in the lab did not always reflect those in the ocean

•   there was insufficient data regarding

–   potential impact on animal populations

–   the impact of a reduction in numbers on the 38……………………….. of that species

–   effects on the environment

Rochman says more information is needed on the possible impact of future 39………………………… (e.g. involving oil).

Question 40

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

Write the correct letter in box 40 on your answer sheet.

40   What would be the best title for this passage?

A   Assessing the threat of marine debris

B   Marine debris: who is to blame?

C   A new solution to the problem of marine debris

D   Marine debris: the need for international action

Responses

27. FALSE (Đoạn 2, “Plenty of studies have sounded alarm bells about the state of marine debris” → Trước khi Chelsea Hochman và nhóm này nghiên cứu là đã có những người đưa ra cảnh báo rồi; Họ không phải những người đầu tiên)

28. NOT GIVEN (Không có thông tin về việc loài vật nào chịu ảnh hưởng nặng nề nhất)

29. FALSE (Đoạn 3, “For example, a study could show that certain seabirds eat plastic bags, and go on to warn that whole bird populations are at risk of dying out. ‘But the truth was that nobody had yet tested those perceived threats,’ Rochman says. ‘There wasn’t a lot of information.’” → Không có nhiều bằng chứng chỉ ra rằng loài chim sẽ bị tuyệt chủng

30. TRUE (Đoạn 4, “Rochman and her colleagues examined more than a hundred papers on the impacts of marine debris that were published through 2013. Within each paper, they asked what threats scientists had studied – 366 perceived threats in all” → Nghiên cứu hơn 100 bài viết nói về vấn đề này)

31. FALSE (Đoạn 4, “In 83 percent of cases, the perceived dangers of ocean trash were proven true. … design and content which affected the validity of their conclusions – they lacked a control group, for example, or used faulty statistics.” → Chỉ là báo cáo hiện tại có một vài lỗi, chứ không phải hầu hết ca trước đó bị sai)

32. TRUE (Đoạn 6, “Strikingly, Rochman says, …The plastic moved from the mussels’ stomachs to their bloodstreams, scientists found, and stayed there for weeks – but didn’t seem to stress out the shellfish.” → Rochman mong muốn tìm ra những trai đang gặp nguy hại vì ăn phải nhựa dưới đại dương)

33. NOT GIVEN (Không có thông tin về việc Trai phải ăn nhựa vì không có sự lựa chọn nào khác)

34. Large (Đoạn 8, “Most of the dangers also involved large pieces of debris”)

35. Microplastic (Đoạn 9, “But a lot of ocean debris is ‘microplastic’”)

36. Populations (Đoạn 10, “Many studies have looked at how plastic affects an individual animal, or that animal’s tissues or cells, rather than whole populations.”)

37. Concentrations (Đoạn 10, “And in the lab, scientists often use higher concentrations of plastic than what’s really in the ocean.”)

38. Predators (Đoạn 10, “or how deaths in one species could affect that animal’s predators, or the rest of the ecosystem.”)

39. Disasters (Đoạn 11, “Rochman says. Usually, scientists don’t know exactly how disasters such as a tanker accidentally spilling its whole cargo of oil….”