首页
登录
职称英语
(1)More and more of the world’s supply of seafood is coining from farms.
(1)More and more of the world’s supply of seafood is coining from farms.
游客
2023-10-23
19
管理
问题
(1)More and more of the world’s supply of seafood is coining from farms.
(2)Although 80% of the world’s seafood comes from marine harvests, there is a major shift under way toward aquaculture now.
(3)Nearly 40% of salmon marketed today are raised in captivity, compared with 6% a decade ago. Forty percent of all clams, oysters, and mussels are produced in farm environments, along with 65% of freshwater fish. Between 1990 and 1996, fish-farming production rose from 12.4 million to 23 million tons worldwide, writes Anne Piatt McGinn in an article for World Watch magazine.
(4) "The fact that world seafood supplies continue to increase at all is due almost entirely to the phenomenal growth in aquaculture," says McGinn, a research associate at the World Watch Institute. Commercial aquaculture is driven by rising human population at a time when over harvested wild fish stocks are in decline and conventional farm production has leveled off.
(5)Biotechnology is contributing to high-yield aquaculture through transgenics—the transfer of genes from one species to another. Researchers introduce desirable genetic traits into fish, creating hardier stocks. For example, some species of fish have a protein that allows them to live in Arctic waters. By transplanting this "anti-freeze" gene into other species, researchers have created more fish that can survive in extremely cold water, according to Ag-West Biotech, Inc., in Saskatchewan, Canada.
(6)Biotechnologists are attempting to improve a wide range of genetic traits in fish used for aquaculture, developing fish that are larger and faster-growing, more efficient in converting feed into muscle, more tolerant of low oxygen levels in water, and better able to resist disease.
(7)Researchers also are seeking plant-based sources of food as a more efficient alternative to fishmeal. The use of plant protein on fish farms could take some of the pressure off wild fish stocks and address the problem of phosphorous pollution because plants do not contain high phosphorus levels. Wheat, canola, and canola oil are being used as alternative feed for aquaculture, according to Ag-West Biotech, Inc.
(8)While aquaculture produces a reliable source of protein, the industry is rife with environmental problems, asserts McGinn. Perhaps the biggest concern is water pollution: Fish waste and uneaten food accumulates at farm sites and can float directly downstream into water supplies. Farm-related nutrient wastes as well as nitrogen and phosphorus also promote the spread of algal "blooms" that deplete oxygen and kill marine life.
(9)Aquaculture is also an inefficient user of resources, McGinn charges. Fish farms need protein feed, and about 17% of ocean fish, an over harvested wild resource, becomes food for captive-bred fish. "An estimated five kilograms of oceanic fish reduced into fishmeal are required to raise one kilogram of farmed ocean fish or shrimp, representing a large net protein loss," says McGinn.
(10)Fish farming does not have to be an inefficient or polluting industry. McGinn predicts that many consumers will choose sustainably produced fish in the future, just as they prefer dolphin-free tuna today. [br] The author’s attitude towards aquaculture is ________.
选项
A、optimistic
B、negative
C、indifferent
D、uncertain
答案
A
解析
观点题。根据末段首句可以推断作者认为水产养殖业在利用率和防污染方面都将有所改善。因此可以看出作者对水产业是乐观的,因此选项A最恰当。文中虽然有多处批评水产养殖业造成的问题。但是那些都是McGinn的看法,而非作者的看法,因此其他三个选项分别意为“否定的”、“漠然的”和“不确定的”,都不能恰当形容作者的态度。
转载请注明原文地址:https://tihaiku.com/zcyy/3123333.html
相关试题推荐
Ifthisbillisnotpaidwithintendays,yourgassupplywillbecut_____.A、in
Streetsellers,particularlyindevelopingcountries,supplylargeamountsoffo
Streetsellers,particularlyindevelopingcountries,supplylargeamountsoffo
Streetsellers,particularlyindevelopingcountries,supplylargeamountsoffo
Once_______,thispowerstationwillsupplyalltheneighboringtownsandvilla
Once________,thispowerstationwillsupplyalltheneighboringtownsandvill
_____adecliningbirthrate,therewillbeanover-supplyof25,000primarysch
A.apparentlyB.part-writtenC.treatsD.workE.securedF.supplyG.
A.apparentlyB.part-writtenC.treatsD.workE.securedF.supplyG.
A.apparentlyB.part-writtenC.treatsD.workE.securedF.supplyG.
随机试题
Democracyisnotanewconception.TheancientAthenians【M1】______hadademocr
Manymeteoritesarethoughttohaveoriginatedfrom______thatonceexistedbet
[originaltext]Asaresultofrisinguniversitycosts,manystudentsarefin
隧道机电分部工程包含的分项工程有()。A.10个 B.11个 C.12个
患者,男性,64岁,嗜烟40年,吸烟指数>400。慢性咳嗽、咳痰近20年,每年冬
对风险模型进行压力测试是风险管理的关键,因为压力测试既能够说明极端事件的影响程
内部控制应当坚持风险为本、审慎经营的理念,设立机构或开办业务均应坚持内控优先,这
根据《刑法》与司法解释的规定,国家工作人员挪用公款进行营利活动、数额达到1万元或
投资项目决策分析与评价的基本要求包括贯彻落实科学发展观、资料数据准确可靠和()
反映医患之间权利关系的正确观点是:强调维护A.医生的权利 B.医院院长的权利
最新回复
(
0
)