READING PASSAGE 14
Questions 37-49
Summary
Complete the summary below ,using NO MORE THAN TWO WORDS from the Reading Passage for each answer.
EI nino and Seabirds
A Rhythm of the asons cannot always be relied upon. At times the tropical Pacific Ocean and large expans of the global atmosphere em to be marching to the beat of a different drummer, disrupting the normal patterns of countless species of plants and animals along with hundreds of millions of human beings. So that they may anticipate the occasional laps in the march of the asons and help societies plan accordingly, scientists are eking to understand the competing rhythms: the strongest of which is the alternation between the "normal climate" and a different but still recurrent t of climatic conditions in t
he Pacific region called El Niño.
B Seabirds are prominent and highly visible components of marine ecosystems that will be affected by global climate change. The Bering Sea region is particularly important to abirds; populations there are larger and more diver than in any similar region in North America—over 90% of abirds breeding in the continental United States are found in this region. Seabirds, so named becau they spend at least 80% of their lives at a, are dependent upon marine resources for food. As prey availability changes in respon to climatically driven factors such as surface a temperature and extent of a ice, so will populations of abirds be affected.
C Seabirds are valued as indicators of healthy marine ecosystems and provide a “vicarious u value” or existence value—people appreciate and value abirds simply becau they are there and enjoy them through venues such as pictures, nature programs, and written accounts without ever directly obrving abirds in their native environment. A direct measure of this value is demonstrated by Federal legislation that es
tablished specific national wildlife refuges to protect abirds and international treaty obligations that provide additional protection for abirds. Seabirds are also an important subsistence resource for many who live within the Bering Sea region. Furthermore, the rich knowledge
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ba about abirds makes them a valuable resource as indicator species for measurement of change in the marine environment.
D The most abundant breeding species in Alaska are northern fulmars, storm-petrels, kittiwakes, murres, auklets and puffins. The species also form the largest colonies. Fulmars, storm-petrels and kittiwakes are surface feeders, picking their prey from the surface or just below the surface; murres, auklets, and puffins dive for their food. Fulmars nest primarily on island groups in and around the Bering Sea. They take a wide variety of prey (e.g., fish, squid, zooplankton, jellyfish) from the surface or just below the surface. Storm-petrels are strictly nocturnal and
buildingblocknest below ground in either burrows or crevices between rocks.They forage on zooplankt
什么事英文on and squid; in some areas they are dependent upon small fish such as capelin and sand lance caught at the surface.Black-legged kittiwakes are widespread throughout Alaska, Canada and Eurasia while red-legged kittiwakes are found only in the
Bering Sea region. Both are surface feeders although black-legged kittiwakes feed primarily on small fish and forage over the continental shelf and shelf break.
六级真题听力o培训班E Marine mammals have exhibited similar signs of food stress in recent years.Harbor als at Tugidak Island in the Gulf of Alaska declined by about 85% between 1976 and 1988.Steller a lion populations declined by 36% in the Gulf of Alaska between 1977 and 1985,and by another 59% between 1985 and 1990.Northern fur als declined about 35% by 1986 from their average numbers in the 1970s, although numbers had rebounded somewhat (20%) by 1990 . Associated with the declines in Steller a lions are declines in birth rate, fewer breeding females, fewer pups, decread adult body condition, decread juvenile survival, and a change in population age structure.
F Walker noticed that monsoon asons with low-index conditions are often marked by dr
ought in Australia, Indonesia, India, and parts of Africa. He also claimed that low-index winters tend to be unusually mild in western Canada. One of his British colleagues chided him in print for suggesting that climatic conditions over such widely parated regions of the globe could be linked. In his reply Walker predicted, correctly, that an explanation would be forthcoming, but that it would require a knowledge of wind patterns above ground level, which were not routinely being obrved at that time.
G The need for long-term ries It ems obvious that without baline data ornithologists are doomed to be surprid by the arrival of El Niño every few years.Even when ornithologists and ecologists are at hand to take advantage of an incoming El Niño ,niorhighlack of preexisting data,and of monitoring afterwards,makes it difficult 134 F.M .&J.M. Farina,and the normal years .Indeed ,according to Jakic, during the last century there were 12 英语四级阅读El Niño 文字翻译years and 12 La Nina years,thus leaving about 76'normal'years in between.Thus,by heavily concentrating attention no only12% of the time of span El Niño ,and of neglecting possibly another 76% of the time。This situation maybe reminded only as long as data are logged on a regular or continuous basis,that is,as long-term time ri
英文日期格式es.The recipe prescribed by Schreiber & Schreiber to understand El Niño 金融时报英文版effects on birds still stands:'....carry out long-term studies that will shed further light on the interactions between global atmospheric cycles,,ocean ographic phenomena,and avian populations.
