首页
登录
职称英语
(1)More and more of the world’s supply of seafood is coming from farms. (2
(1)More and more of the world’s supply of seafood is coming from farms. (2
游客
2023-10-27
18
管理
问题
(1)More and more of the world’s supply of seafood is coming 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。
转载请注明原文地址:https://tihaiku.com/zcyy/3134474.html
相关试题推荐
A、Theincreasingage.B、Noenoughtime.C、Thelackofpractice.D、Brainbecoming
[originaltext]M:HeySusan,whatareyoucomingasthisyear?W:Comingas?M:
(1)Moreandmoreoftheworld’ssupplyofseafoodiscomingfromfarms.
PASSAGETWO[br]Whatgoeswithasciencebecomingmoreadvanced?Theagreementa
(1)Easternmedicinesarebecomingmorepopularinthewest,butfewpeopler
Tobefrank,I’dsooneryou______agoodreviewyesterdayforthecomingtest.A
Alongwiththeletterwashispromise______hewouldvisitmethiscomingChris
Thetuitionfeesare______tostudentscomingfromlow-incomefamilies.A、approa
(1)Easternmedicinesarebecomingmorepopularinthewest,butfewpeoplere
(1)Moreandmoreoftheworld’ssupplyofseafoodiscomingfromfarms.(2
随机试题
Somepeoplesaythatgivingaidtopoorcountrieshasmorenegativeeffects
[originaltext]M:Whatdoyouthinkofmynewsweater,Tracy?W:Well.It’svery
当悬窗开窗角小于()时,其有效排烟面积按窗最大开启时的水平投影面积计算。A.
突然扩大管段的局部水头损失hj=()。A.(vv2)2g B. C.
下列关于北交所上市公司发行证券,说法正确的有()。 Ⅰ上市公司发行证券拟
良性前列腺增生是老年男性常见疾病,其最典型的临床表现是A.夜尿增多 B.尿急
社会工作者在专业价值观念指导下,根据服务对象个人特殊需要,为其提供个案服务;针对
人在每一瞬间,将心理活动选择了某些对象而忽略了另一些对象。这一特点指的是注意的(
一个国家各级各类学校的系统,具体规定着学校的性质、任务、人学条件、修业年限以及它
"健康所系,性命相托"这一提法出自A.1991年《中国医学生誓词》 B.200
最新回复
(
0
)