GMAT阅读科技类内容的练习

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　　Fish Learn to Cope in a High Carbon Dioxide World, New Study Suggests

　　ScienceDaily (July 3, 2012) — Some coral reef fish may be better prepared to cope with rising CO2 in the world&aposs oceans -- thanks to their parents.

　　Researchers at the ARC Centre of Excellence for Coral Reef Studies (CoECRS) recently reported in the journal Nature Climate Change, encouraging new findings that some fish may be less vulnerable to high CO2 and an acidifying ocean than previously feared.

　　"There has been a lot of concern around the world about recent findings that baby fish are highly vulnerable to small increases in acidity, as more CO2 released by human activities dissolves into the oceans," says Dr Gabi Miller of CoECRS and James Cook University.

　　"Our work with anemone fish shows that their babies, at least, can adjust to the changes we expect to occur in the oceans by 2100, provided their parents are also raised in more acidic water."

　　"Human activity is expected to increase the acidity of the world&aposs oceans by 0.3 to 0.4 pH by the end of this century, on our present trends in CO2 emissions," co-researcher Prof Philip Munday says.

　　"Previous studies, and our own research, have shown that growth and survival of juvenile fish can be seriously affected when the baby fish are exposed to these sorts of CO2 and pH levels," he says.

　　"However when we exposed both parents and their offspring in more acidic water we found that the anemone fish, at least, were able to compensate for the change" says Dr Miller. Whether this effect lasts all their lives, remains to be seen." she adds.

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　　How parent fish actually pass on this ability to deal with acidity to their offspring is still a mystery, says Prof Munday. "The time interval is too short for it to be genetic adaptation in the normal sense. However, it&aposs an important parental effect that we need to factor in as we assess the vulnerability of the world&aposs fish stocks to the planet-wide changes in ocean chemistry that humans are now causing."

　　Based on evidence from past major extinction events, scientists have long feared that the acidity caused by the release of high levels of CO2could cause havoc among sea-life, especially those which depend on calcium to form their bones and shells. New research has also shown that higher CO2 levels can cause the nervous systems of some marine species to malfunction.

　　The recent increase in ocean acidity due to human activity in releasing carbon -- about 0.1 of a pH unit over the last half century -- is thought to be steeper even than in any of the past major extinctions, which eliminated between 70-90 per cent of marine species.

　　"What this research shows is that some species, at least, may have more capacity to cope than we thought -- which could help buy time for humanity to bring its CO2 emission under control," Prof Munday says.

　　However Dr Miller cautions that anemone fish are particularly hardy by nature, and may not be typical of all fish in the ocean. "They are definitely not the &aposcanary in the coal mine&apos, as they have quite a large ability to cope with changed conditions anyway," she says. "We need to extend these studies to other types of fish, especially those which humans rely on for food."

　　Both scientists warn that the major impact on ocean acidification is likely to be on the corals themselves, and the reefs which they form, which in turn provide the habitat for small fish such as the anemone fish. The fate of the world&aposs reefs under a high human CO2 regime remains highly uncertain, they caution.

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　　Six Natural Wonders Declared World Heritage Sites

　　ScienceDaily (July 3, 2012) — Sangha Trinational -- shared between Cameroon, the Central African Republic and the Republic of Congo; Lakes of Ounianga in Chad and Chengjiang fossil site in China have been inscribed on the World Heritage List, following the recommendations of IUCN (International Union for Conservation of Nature). Lena Pillars Nature Park in Russia and Western Ghats in India were also added to the prestigious list by the World Heritage Committee, a 21-nation panel.

　　IUCN, the official World Heritage advisory body on nature, presented the findings of its comprehensive evaluations of the natural values of nine sites to the World Heritage Committee. Chad is joining the World Heritage family for the first time.

　　Sangha Trinational is a chain of national parks shared between Cameroon, the Central African Republic and the Republic of Congo. Forming a broad network of well preserved and diverse landscapes, the forests and rivers are home to an outstanding diversity of plants and animals. The area hosts the largest intact populations of forest elephants and great apes, including the critically endangered Western Lowland Gorilla and the endangered Chimpanzee.

　　"Sangha Trinational is not a fragment but part of a much larger intact environment with good conservation prospects, and harbouring critically endangered species," says Tim Badman, Director of IUCN&aposs World Heritage Programme. "We welcome the fact that this globally significant forest landscape has been recognized by the World Heritage Committee."

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　　The Lakes of Ounianga consist of a series of 18 mostly freshwater lakes in the heart of the Sahara desert in northeastern Chad. Relics of a single, much larger lake occupying the basin less than 10,000 years ago, these lakes are an exceptional example of permanent lakes in a desert.

　　"The Lakes of Ounianga are a jewel of the Sahara, not only of overwhelming natural beauty, but a testimony to the fragile and unique equilibrium of life on earth," says Youssouph Diedhiou of IUCN&aposs Protected Areas Programme in Central and Western Africa. "IUCN is delighted that Chad&aposs first outstanding natural area is joining the prestigious World Heritage list."

　　The rocks of the Chengjiang Fossil Site, near the city of Kunming in the Yuann Province of China, are evidence of the rapid appearance and diversification of species and evolutionary development, also known as the Cambrian explosion, which took place over 530 million years ago. The exceptional remains of species recorded at Chengjiang are key to understanding the early evolution of life on Earth.

　　"The inscription of The Chengjiang Fossil Site on the World Heritage List recognises this iconic site, which provides direct evidence of the origin of animal diversity," says Tim Badman. "The preservation of this exceptional window on the earliest stages of the evolution of biodiversity on our planet is of great scientific importance for the future."

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　　Lena Pillars Nature Park, known for the spectacular natural rock formations along the Lena River, is home to a wide range of rare plants and animals, including the Siberian Musk Deer, the Red Deer, the Siberian chipmunk, and 99 species of nesting birds. Located in the central part of the Sakha Republic (Yakutia), it is an area with an extreme continental climate with an annual temperature range of almost 100° C, ranging from around -60° C in winter to around +40° C in summer.

　　A series of protected areas across the Western Ghats in India were added to UNESCO&aposs list of iconic places after a persistent campaign for World Heritage status by the Indian government. Mountains, rainforests, rivers and waterfalls are all part of the 160,000 km2 area, recognised as a global biodiversity hotspot. The Western Ghats are home to a number of flagship mammals including the endangered endemic lion-tailed Macaque, the endangered Asian elephant and Tiger.

　　"The Western Ghats and Lena Pillars are certainly regions that hold spectacular natural values, but IUCN&aposs evaluations considered that more work was needed on these nominations to meet the standards the Convention has set in its Operational Guidelines." says Tim Badman. "We welcome these sites to the World Heritage List, but note the conservation challenges that they face will need additional monitoring by the World Heritage Committee to ensure that these sites meet the requirements that accompany listing as flagships for global conservation. IUCN is ready to assist the States in that task."

　　Two days ago the exceptional marine site of Rock Islands Southern Lagoon became Palau&aposs first World Heritage Site, following IUCN&aposs recommendation. With the new additions announced in St. Petersburg July 2 the number of natural and mixed (natural and cultural) sites is 217.

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