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
外语
Don’t Waste Our Oceans A)For too long, marine life has been largely open for the taking by anyone possessing the means to exploi
Don’t Waste Our Oceans A)For too long, marine life has been largely open for the taking by anyone possessing the means to exploi
admin
2015-04-30
82
问题
Don’t Waste Our Oceans
A)For too long, marine life has been largely open for the taking by anyone possessing the means to exploit it. Rapid advances in technology have meant that the ability, reach and power of vessels and equipment used to exploit marine life now far outweigh nature’s ability to maintain it. If left unchecked, this will have far reaching consequences for the marine environment and for people who depend on it. Ocean life comes in an incredible array of shapes and sizes — from microscopic plankton to the largest of the great whales. Yet many species have been, or are being, driven towards extinction through devastating human impacts. The key threats facing our ocean creatures include:
Industrial Fishing
B)Many marine ecologists think that the biggest single threat to marine ecosystems today is overfishing. Our appetite for fish is exceeding the oceans’ ecological limits with devastating impacts on marine ecosystems. Scientists are warning that overfishing results in profound changes in our oceans, perhaps changing them forever. Not to mention our dinner plates, which in future may only feature fish and chips as a rare and expensive delicacy.
The fish don’t stand a chance
C)More often than not, the fishing industry is given access to fish stocks before the impact of their fishing can be assessed, and regulation of the fishing industry is, in any case, woefully inadequate. The reality of modern fishing is that the industry is dominated by fishing vessels that far out-match nature’s ability to replenish fish. Giant ships using state-of-the-art fish-finding sonar can pinpoint schools offish quickly and accurately. The ships are fitted out like giant floating factories—containing fish processing and packing plants, huge freezing systems, and powerful engines to drag enormous fishing gear through the ocean. Put simply: the fish don’t stand a chance.
Ocean life health check
D)Population of top predators, a key indicator of ecosystem health, are disappearing at a frightening rate, and 90 percent of the large fish that many of us love to eat, such as tuna, swordfish, marlin, cod, halibut, skate, and flounder — have been fished out since large-scale industrial fishing began in the 1950s. The depletion of these top predator species can cause a shift in entire oceans ecosystems where commercially valuable fish are replaced by smaller, plankton-feeding fish. This century may even see bumper crops of jellyfish replacing the fish consumed by humans. These changes endanger the structure and functioning of marine ecosystems, and hence threaten the livelihoods of those dependent on the oceans, both now and in the future.
Fisheries collapse
E)The over-exploitation and mismanagement of fisheries has already led to some spectacular fisheries collapses. The cod fishery off Newfoundland, Canada collapsed in 1992, leading to the loss of some 40,000 jobs in the industry. The cod stocks in the North Sea and Baltic Sea are now heading the same way and are close to complete collapse. Instead of trying to find a long-term solution to these problems, the fishing industry’s eyes are turning towards the Pacific — but this is not the answer. Politicians continue to ignore the advice of scientists about how these fisheries should be managed and the need to fish these threatened species in a sustainable way.
Bycatch
F)Many fisheries catch fish other than the ones that they target and in many cases these are simply thrown dead or dying back into the sea. In some trawl fisheries for shrimp, the discard may be 90 percent of the catch. Other fisheries kill seabirds, turtles and dolphins, sometimes in huge numbers.
G)Estimates vary as to how serious a problem bycatch is. Latest reports suggest that around eight percent of the total global catch is discarded, but previous estimates indicated that around a quarter of which might be thrown overboard. Simply no one knows how much of a problem this really is. The incidental capture, or bycatch, of mammals, seabirds, turtles, sharks and numerous other species is recognized to be a major problem in many parts of the world. This figure includes non-target species as well as targeted fish species that cannot be landed because they are, for instance, undersized. In short, anywhere between 6.8 million and 27 million tones offish could be discarded each year, reflecting the huge uncertainties in the data on this important issue.
H)The scale of this mortality is such that bycatch in some fisheries may affect the structure and function of marine systems at the population, community and ecosystem levels. Bycatch is widely recognized as one of the most serious environmental impacts of modern commercial fisheries.
The victims
I)Different types of fishing practices result in different animal species being killed as bycatch: nets kill dolphins, porpoises and whales, longline fishing kills birds, and bottom trawling devastates marine ecosystems.
J)It has been estimated that a staggering 100 million sharks and rays are caught and discarded each year. Tuna fisheries, which in the past had high dolphin bycatch levels, are still responsible for the death of many sharks. An estimated 300,000 cetaceans(whales, dolphins and porpoises)also die as bycatch each year, because they are unable to escape when caught in nets. Birds dive for the bait planted on long fishing lines, swallow it(hook included)and are pulled underwater and drowned. Around 100,000 albatrosses are killed by longline fisheries every year and because of this, many species are facing extinction.
K)Bottom trawling is a destructive way of "strip-mining" the ocean floor, harvesting the species that live there. As well as the target fish species, this also results in bycatch of commercially unattractive animals like starfish and sponges. A single pass of a trawl removes up to 20 percent of the seafloor fauna and flora. The fisheries with the highest levels of bycatch are shrimp fisheries: over 80 percent of a catch may consist of marine species other than the shrimp being targeted.
Technology
L)Many technical fixes exist to reduce bycatch. Turtle exclusion devices are used in some shrimp fisheries to avoid killing turtle species. In the case of longline fisheries, the process of setting the hooks can be changed and bird-scaring devices employed which radically cut the numbers of birds killed. To avoid dolphins being caught in nets, other devices can be used. Pingers are small sound-emitting and dolphin-deterring devices that are attached to nets, but they are not always effective. Escape hatches(consisting of a widely spaced metal grid, which forces the cetacean up and out of the net)have also been used.
M)Although these devices may have a role to play, they cannot address the whole problem. Such devices need continual monitoring to check how well they work and assess any potential negative effects they may have. Realistically they will probably only be used in areas with well-developed fishery management and enforcement agencies.
N)On a global level, probably the only effective way to address the problems of bycatch is to control fishing effort. This will be best achieved through the creation of marine reserves. Nonetheless, in the case of highly mobile species such as seabirds and cetaceans, the only effective way of preventing bycatch is to discontinue the use of particularly damaging fishing methods.
Defending Our Oceans
O)Fundamental changes need to be made in the way our oceans are managed. This means that we must act to make sure that human activities are sustainable, in other words that they meet human needs of current and future generations without causing harm to the environment. Accordingly, governments must set aside 40 percent of our oceans as marine reserves. Marine reserves can be defined as areas of the ocean in which the exploitation of all living resources is prevented, together with the exploitation of non-living resources such as sand and gravel and other minerals.
The large-scale fishing industry started in the middle of the 20th century.
选项
答案
D
解析
细节题。由句中的关键词The large-scale fishing industry可定位至D)段第一句,由这句话的后半部分可知,大规模的商业捕鱼行为开始于20世纪50年代,即20世纪中期。
转载请注明原文地址:https://kaotiyun.com/show/noQ7777K
0
大学英语六级
相关试题推荐
A、ThediplomasofYale-N.U.S.CollegewouldbeissuedbytheNationalUniversityofSingapore.B、YaleUniversitywouldnotrecei
Youmightthinkyoulefttheworldofcliques(小团体)andin-crowdsbehindwhenyoulefthighschool.You’dbewrong.Thebenefi
Forthispart,youareallowed30minutestowriteanessaycommentingontheremark"Lifeisn’taboutwaitingforthestormto
BringOurSchoolsoutofthe20thCentury[A]There’sadarklittlejokeexchangedbyeducatorswithanopposingtrace:RipVanW
Peoplebornintheautumnlivelongerthanthoseborninthespring.Andtheyarelesslikelytofall【B1】______illwhentheyare
A、Lookthroughhermaterials.B、Makepreparationfortheinterview.C、Payattentiontothepresentation.D、Addsomethingtomake
Somepeople’searsproducewaxlikebusylittlebees.Thiscanbeaproblemeventhoughearwax(耳垢)appearstoserveanimportant
A、Towatchthejewelrystorerobbery.B、Tocollectmaterialsforherstory.C、Tobuysomevaluablejewelry.D、Totakesomephoto
Greece,economically,isintheblack.Withverylittletoexportotherthansuchfarmproductsastobacco,cottonandfruit,th
A、Pricesforfarmproductsrose.B、Farmersbecamemoredependentonloansfrombanks.C、Jeffersonestablishedgovernmentprogram
随机试题
A.评价外来化合物蓄积毒性的试验 B.检测化学物致突变作用的试验 C.检测化学物对生殖过程的损害的试验 D.检测外源化学物最大未观察到有害作用剂量的试验 E.检测化学物毒性强度分级的试验遗传毒性试验是
人身保险合同中由投保人指定的,在保险事故发生后享有保险赔偿与保险金请求权的人是()。
评价体系评价因子的选择应遵循以下原则中的()。
假远期信用证,就出口商的收汇时间来说,等于()。
宏观分析所需的有效资料一般包括( )。Ⅰ.公司的财务资料Ⅱ.贸易统计资料Ⅲ.国民收入统计与景气动向Ⅳ.突发性非经济因素
某公司年初负债总额为400万元(流动负债120万元,长期负债280万元),年末负债总额为560万元(流动负债180万元,长期负债380万元)。年初资产总额660万元,年末资产总额840万元。则权益乘数(平均数)为( )
某工人每天生产的A产品的个数是B产品的5倍。某天该工人总共生产了108个产品,那么他生产的A产品和B产品分别是()。
某工厂新近购买了一台标准电能表,用作企业最高计量标准以检定本厂生产的电能表,按照我国《计量法》的规定,该标准电能表属于强制检定的范围,必须经有关机构检定合格后方能使用。该标准电能表的强制检定应由()具体执行。
2009年以来,我国连续发生了多起酒后驾车引起多人死亡事件,再次给我们敲响警钟。全国掀起整治酒后驾驶的风暴,刚性执法将成为常态。根据《机动车驾驶员驾车时血液中酒精阈值与测试方法》,机动车驾驶员血液中酒精含量时驾驶机动车定为“酒后驾车”。
ThecoastofthestateofMaineisoneofthemostirregularintheworld.Astraightlinerunningfromthesouthernmostcoastal
最新回复
(
0
)