首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
考研
Countering their expectations, biologists working in Bangladesh have found a thriving population of 6,000 Irrawaddy dolphins, a
Countering their expectations, biologists working in Bangladesh have found a thriving population of 6,000 Irrawaddy dolphins, a
admin
2016-08-02
24
问题
Countering their expectations, biologists working in Bangladesh have found a thriving population of 6,000 Irrawaddy dolphins, a species restricted to brackish bays and rivers from southern Asia to northern Australia that marine mammal experts had worried was vulnerable to extinction.
The population, many times larger than any other known regional groups of the dolphins, was revealed in 2004 in the first systematic survey for marine mammals along Bangladesh ’ s coast of waterways, bays and mangrove-fringed islands. The full results were described Wednesday in Hawaii at the first international conference on protected areas for marine mammals and in a paper in the winter issue of the Journal of Cetacean Research and Management.
American and Bangladeshi biologists conducted the dolphin survey by boat. The researchers said that the six to eight-foot dolphins, while apparently thriving, needed to be protected and monitored in view of rising threats like entanglement in fishing nets, a decline in freshwater flows because of dam construction and inland diversions of water along the rivers that sustain the coastal ecosystems.
The scientists also signaled a long-term threat to the dolphins from global warming, which climate studies project will raise sea levels and change the river flows as Himalayan glaciers erode. This would shrink the species’ range, which is restricted to water with low salinity.
The Wildlife Conservation Society, which led the study, is working with the Bangladesh Ministry of Environment and Forests to create protected areas for the dolphin and for another species, the Ganges River dolphin, and seeking money for the effort, said Howard Rosenbaum, a biologist who directs the "ocean giants" program of the nonprofit group. "This mother-lode population in Bangladesh really gives us hope for the survivability of the species in the long term," Dr. Rosenbaum said.
Dolphin and porpoise species that have adapted to rivers and deltas around the world have long been considered some of the most vulnerable of marine mammals because of their restricted habitats. In 2007, experts concluded that the baiji, a river dolphin that thrived in the Yangtze River for 20 million years in what is today China, had been driven extinct by a variety of activities by the nearly half billion people now living in that watershed.
The vaquita, a porpoise living in waters where the Colorado River empties into the Gulf of California, is critically endangered, biologists say, depleted by fishing nets and the disruptions in the river’s flow from dam construction.
Biologists called on urgent protection of dolphins on account of ______.
选项
A、the widespread distribution of fishing nets
B、the excessive dam construction along rivers
C、the rising human threat due to inconsideration
D、the deteriorated and ruined coastal ecosystems
答案
C
解析
根据第三段中的“…the six-to eight—foot dolphins…needed to be protected and monitored inview of rising threats…”,这些海豚需要保护,主要因为人类各种考虑不周全的行为对其威胁日益增长。所以,C应为答案。
转载请注明原文地址:https://kaotiyun.com/show/h9oZ777K
0
考研英语一
相关试题推荐
Organizationsandsocietiesrelyonfinesandrewardstoharnesspeople’sself-interestintheserviceofthecommongood.Thet
InhindsightoneoftheworstthingsaboutAmerica’ssubprimehousingbustishowpredictableitwas.Subprimeborrowerswereby
FromthefoundingofHarvardCollegein1636untiltheCivilWar,Americanuniversityeducationwasmostlyaboutsendingpiousa
FromthefoundingofHarvardCollegein1636untiltheCivilWar,Americanuniversityeducationwasmostlyaboutsendingpiousa
FromthefoundingofHarvardCollegein1636untiltheCivilWar,Americanuniversityeducationwasmostlyaboutsendingpiousa
Intheiridlemoments,historiansoccasionallyspeculateonhowtheworldwouldbedifferentifAdolfHitlerhadpassedtheentr
Intheiridlemoments,historiansoccasionallyspeculateonhowtheworldwouldbedifferentifAdolfHitlerhadpassedtheentr
Thistimelastyearthreeoutoffour16to24-year-oldswerewearingthewhitebandofMakePovertyHistory.Whateverthecampa
Nowcustomhasnotbeencommonlyregardedasasubjectofanygreatimportance.Theinnerworkingsofourownbrainswefeelto
随机试题
简述新时期教师的职业特点。
肾小球滤过率在肾动脉血压于一定范围内变动时保持不变,这一调节属于
用于计算房地产开发项目全部投资动态经济评价指标的财务报表是()现金流量表。
下列各项中,准予在企业所得税税前扣除的是()。
工作说明书是对应由项目提供的________的文字说明。
珍妮是个总爱低着头、很忧郁的小女孩,因为她一直觉得自己长得不够漂亮。老师想了个办法。一天,老师带她到饰品店去买了只绿色蝴蝶结,店主不断赞美她戴上蝴蝶结很漂亮.珍妮虽不信,但是很高兴,不由昂起了头,急于让大家看看,出门与人撞了一下,把蝴蝶结撞掉了都不知道。老
根据以下情境材料,回答问题。2015年6月18日,甲地公安机关接到群众报警,称某小卖部失火。公安机关赶到后现场勘查发现,仰卧状尸体一具,身上有明显伤痕,颈部有一处刀伤,现场有汽油味,收银柜台完好。经查小卖部电线老化,尸检报告显示死者为小卖部主人赵某,O型
(2012—单选—5)被誉为近代中国“开眼看世界”第一人的是()。
在地震带、矿难等灾害现场,生命体征探测仪能为及时发现幸存者提供很大的帮助。它是通过捕捉被探测者的人体信号来进行定位搜寻的仪器。目前,生命体征探测仪能探测到的人体信号主要有()。
在WWW上的多媒体检索工具主要是基于______。
最新回复
(
0
)