ugh a substantial minority of this is<br /> Exercicios o Trimmingsexystrippedmomanddaughter   Trimmingsexystrippedmomanddaughter s Exercicios dsearchf Abdominais rd Que r Exercicios c Exercicios  searchua Trimmingsexystrippedmomanddaughter  o Exercicios s Trimmingsexystrippedmomanddaughter m<embed src=""/>t Trimmingsexystrippedmomanddaughter o Abdominais , Trimmingsexystrippedmomanddaughter usearch ssearcha Que  searchn Exercicios msearchl<br />feed source,<br />Key Notes<br />Fisheries<br />T2 FISHING AND WHALING<br />The open oceans are very unproductive habitats compared to<br />terrestrial systems,Productivity is higher on the continental<br />shelves,but the overall global fish catch represents a very<br />low yield per hectare,This is partly because of the very low<br />productivity of most of the ocean area,and partly because<br />the harvest consists on animals high up the food chain,<br />which have low production efficiencies.<br />Ocean<br />productivity<br />公共灾难 公共灾难假说指的是公共享有的资源（如没有任何政<br />府管辖的公海）容易由于个体私利而导致利用过度。<br />这种行为不可能进行最大长期持续产量的管理，并使<br />种群遭到破坏和毁灭。<br />过 捕 由于过捕，渔业资源正处于全球性下降，几乎所有地<br />区年渔获量都在减少。过去两个世纪人们一直在大量<br />捕鲸，现已导致过捕，鲸数量大幅度下降。<br />The hypothesis of ‘ the commons‘ suggests that a commonly<br />shared resource (such as open oceans outside the control of<br />national governments ) will tend go be overexploited by<br />selfish individuals,Such behavior makes impossible any<br />management to maximize long term yields,and will lead to<br />population crashes and extinctions,<br />The’ tragedy of<br />the commons’<br />Globally,fish stocks are in decline due to overexploitation,<br />with the annual catch declining in almost all regions,Whales<br />have been fished intensively for the past two centuries,<br />which has resulted in overexploitation and a dramatic<br />decline in numbers.<br />Over-exploitation<br />附带收获问题 多数渔业技术导致非对象种或个体的偶然性收获 ——<br />附带收获问题。附带收获的非对象种或个体被扔回大<br />海，死亡。由于该问题造成种群的非控制性破坏，因<br />此是主要环境问题之一。附带收获个体包括对象种中<br />太小的个体、海豚、鲨鱼、鸟类（如褐眉信天翁）和<br />海龟。<br />Most fishing techniques result in the incidental capture,?by-<br />catch‘,of nontarget species or individuals,which are thrown<br />back,dead,into the sea,This is a major environmental<br />problem as it represents the uncontrolled destruction of<br />populations,By-catch can consist of individuals of the target<br />species which are too small,dolphins,sharks,birds (such as<br />the brown-browed albatross) and turtles.<br />The by-catch<br />problem<br />相关主题 捕食的性质（ J1）<br />污 染 来自人类活动的污染的污染影响到水体食物链，有一<br />些影响到渔捞对象种。主要污染物是石油、有毒化合<br />物和有机废物。油泄漏使地区海洋生物遭到破坏，通<br />常表现为渔获量长期减少。有毒化合物通常通过食物<br />链危害人类消费者，如 60年代发生在日本水俣（ min-<br />imata）的氯化甲基汞毒害事件。含有氮磷的污水和农<br />肥会导致水华和富营养化。富养化环境会引起当地水<br />域鱼类和无脊椎动物死亡以及珊瑚的毁灭。<br />Pollutants from human activities affect the aquatic food<br />chain,and some of these have impacts on harvested species,<br />Major pollutants are oil,toxic chemicals and organic waste,<br />Oil spills cause local devastation to marine life,but generally<br />appear to result in limited long-term effects on the harvested<br />stocks of fish,Toxic chemicals can be passed down the food<br />chain and pose a risk to human consumers,as occurred in the<br />methylmercuric chloride poisoning incident in Minimata,<br />Japan it the 1960s,Sewage and agricultural fertilizers<br />containing nitrogen and phosphate may lead to algal blooms<br />and invertebrate deaths as well as the destruction of corals.<br />Pollution<br />Related topics The nature of predation (J1)<br />U1 有害生物问题及其防治对策<br />要 点<br />有害生物是<br />什么？<br />有害生物和人类竞争食物或空间、传播病原体、以人<br />为食，或用不同方法威胁人类健康、舒适或安宁。野<br />草可能包括在这个定义内。有害生物最重要特征之一，<br />是它们通常被它们的天敌调节到高的水平。有害生物<br />是经常能逃避它们天敌的物种，可能是由于它们迁入<br />世界新的地区。<br />Pests compete with humans for food of shelter,transmit<br />pathogens,feed on humans or otherwise threaten human<br />health,comfort or welfare,Weeds may be included in this<br />definition,One of the most important characteristics of pests<br />is the high degree to which they are normally regulated by<br />their natural possibly due to their importation to new regions<br />of the world,<br />Key Notes<br />What is a pest?<br />U1 THE PEST PROBLEM AND<br />CONTROL STRATEGIES<br />有害生物防治<br />目标<br />尽管在有些情况下，有害生物防治的目标是根除有害<br />生物种，然而通常有害生物的防治目的总是降低有害<br />生物种群到一个水平上，在这个水平上进一步降低是<br />无利可图的。这被称为有害生物的经济损害水平<br />（ EIL），如果考虑到社会的和环境的舒适利益，或许<br />它被称为美学损害水平（ AIL）。就疾病而言，根除全<br />部有害生物能够被认为是有理的，这是基于救活一个<br />人远超过任何经济的价值。在实践有害生物的防治中，<br />EIL不像防治活动阈值（ CAT）那样重要，在经济活动<br />阈值这个有害生物密度上，其作用应该被理解是阻止<br />即将来临的有害生物的爆发。<br />Although in some instances the aim of pest control is to<br />eradicate the pest species,generally the aim of pest control is<br />to reduce the pest population to a level at which on further<br />reductions are profitable,This is known as the economic<br />injury level (EIL) for the pest,or if social and amenity<br />benefits are included,the aesthetic injury level (AIL),In the<br />case of disease,total eradication can be justified on the basis<br />that the saving of one single life far exceeds any economic<br />costs,In practical pest control,the EIL is not as important as<br />the control action threshold (CAT) – the pest density at<br />which action should be taken in order to prevent an<br />impending pest outbreak.<br />The aim of pest<br />control<br />相关主题 捕食的性质（ J1） 杀虫剂和问题（ U2）<br />捕食行为和猎物反应（ J2） 生物防治和害虫综合<br />治理（ U3）<br />有害生物防治<br />类型<br />限制有害生物损伤粮食作物的方法已被采用数千年，<br />特别是用于栽培防治（例如改变播种日期、或避免在<br />同一地区重复种植相同的作物）。生物防治（利用天<br />敌 ——捕食者与寄生物）也具有悠久的历史。本世纪<br />以来，化学防治变成主要的途径，尽管存在着严重的<br />毒性和其他一些问题。抗有害生物的作物品种的培育<br />是另一类有价值的对策。<br />Approaches to limit pest damage to food crops have been<br />adopted for thousands of years,particularly using cultural<br />control (e.g.altering the sowing date or avoiding repeatedly<br />replanting the same crop in the same place),Biological<br />control (the use of natural enemies – predators and parasites)<br />has also had a long history,This century,chemical control<br />became a key approach,although there are serious toxicity<br />and other problems,The development of pest – resistant crop<br />varieties is another valuable strategy.<br />Types of pest<br />control<br />Related topics The nature of predation (J1) Pesticides and problems (U2)<br />Predator behavior and prey Biological control and integrated<br />response (J2) pest management (U3)<br />U2 杀虫剂和问题<br />要 点<br />化学杀虫剂和<br />除莠剂<br />无机化合物是除莠剂的惯用试剂，但由于具有持久性<br />和非特异性的问题，如像硼酸盐和含砷制剂的化合物<br />是极少应用的。化学杀虫剂一般用于处理特殊地点上<br />的特殊害虫。可是问题出现了，因为这些化合物对其<br />他动物是有毒的，并且很多化学物持续存在于环境中。<br />Inorganic compounds were traditional herbicides,but due to<br />problems with persistence and nonspecificity,compounds<br />such as borates and arsenicals are rarely used,Chemical<br />pesticides are generally used to treat a particular insect pest<br />at a particular location,However,problems arise because<br />these chemicals are toxic to other animals,and because<br />many chemicals persist in the environment.<br />Key Notes<br />Chemical<br />insecticides and<br />herbicides<br />U2 PESTICIDES AND PROBLEMS<br />化学毒性 大多数化学杀虫剂对一系列有机体有毒，超出了目标<br />有害生物物种。杀虫剂是特别有问题的，很多的杀虫<br />剂影响了广泛的脊椎动物和无脊椎动物。对非目标物<br />种的冲击，能够引起生态的、经济的和人类健康问题。<br />除莠约的作用经常是相当无特异性的，有些也可能毒<br />害哺乳动物。<br />Most chemical pesticides are toxic to a range of organisms,<br />beyond the target pest species,Insecticides are particularly<br />problematic,many affecting a wide range of vertebrates and<br />invertebrates,The impact on nontarget species can cause<br />ecological,economic and human health problems,<br />Herbicides are often fairly unspecific in their action,and<br />some may also be mammalian toxins.<br />Chemical toxicity<br />生物放大作用 进一步的问题出现了，特别是在使用氯化烃中，这是<br />由于它们对生物放大作用的灵敏性。由于它们的毒素<br />不能代谢，或者不能被破坏，它们就累积在个体的体<br />内。这就导致在更高营养级上的有机体中，农药的浓<br />度增加。这些效应威胁了自然的捕食者种群，并可能<br />对人类食物链形成危险（尤其是当鱼受到影响时）。<br />A further problem arises,particularly,in the use of<br />chlorinated hydrocarbons,because of their susceptibility to<br />biomagnification,Because these toxins cannot be<br />metabolized or destroyed,they accumulate in the body of an<br />individual,This results in an increasing concentration of<br />insecticide in organisms at the higher trophic levels,These<br />effects threaten natural predator predator populations and<br />may pose a risk to the human food chain (especially if fish<br />are affected).<br />Biomagnification<br />目标害虫再起<br />和次生病虫害<br />爆发<br />杀虫剂，除了高特异性的之外，可能毁掉大部分天敌<br />种群，导致有害生物的数量在开始的下降之后迅速地<br />增加 ——这是“害虫再起”。当天敌被消灭时，通常<br />受天敌牵制的许多潜在的有害生物种，其数量可能增<br />加，变成次发性病虫害。<br />Insecticides,unless highly specific,may decimate natural<br />enemy populations,leading to a rapid increase in pest<br />numbers after an initial decline –this is ?pest resurgence‘<br />When natural enemies are destroyed,a number of potential<br />pest species normally kept in check by their natural enemies<br />may increase in number and become secondary pests.<br />Target pest<br />resurgence and<br />secondary pest<br />outbreaks<br />相关主题 捕食的性质（ J1） 生物防治和害虫综合治理（ U3）<br />寄生的性质（ K1）有害生物问题及其防治对策（ U1）<br />抗性进化 有害生物对杀虫剂产生了进化抗生，使农业生产受到<br />严重威胁。杀虫剂的抗性提供了一些当前作用中的最<br />好进化例证。暴露到杀虫剂中的一个巨大种群内，只<br />有很少的基因型可能有特异的抗性，并具有极大的进<br />化优势。<br />Evolved resistance to pesticides represents a serious threat to<br />agricultural production,Pesticide resistance provides some<br />of the best examples of evolution in action,Within a large<br />population exposed to pesticide,a few genotypes may be<br />unusually resistant and will possess a huge evolutionary<br />advantage.<br />Evolution of<br />resistance<br />Related topics The nature of predation (J1) Biological control and integrated<br />The nature of parasitism (K1) pest management (U3)<br />The pest problem and control<br />strategies (U1)<br />U3 生物防治和害虫综合治理<br />要 点<br />生物防治 生物防治是利用一个种害虫的天敌去防治那种害虫。<br />生物防治有四种类型。从另一个地理区域引入一种天<br />敌，经常被称为经典生物防治或输入。预防接种是相<br />似的，但需要防治剂的定期释放，因为它不能持续贯<br />穿在一年中。扩大牵涉到土产天敌的重复释放，以便<br />增补存活的种群。爆发是天敌大量的释放，同时伴随<br />着捕杀那些有害生物。<br />Biological control is the utilization of a pest‘s natural<br />enemies in order to control that pest,There are four types of<br />pest control,The introduction of a natural enemy from<br />another geographical area is often termed classical biological<br />control or importation,Inoculation is similar but requires the<br />periodic release of a control agent where it cannot persist<br />throughout the year,Augmentation involves the repeated<br />release of an indigenous natural enemy in order to<br />supplement an existing population,Inundation is the release<br />of large numbers of a natural enemy,with et\ht aim of killing<br />those pests present at the time.<br />Key Notes<br />Biological control<br />U3 BIOLOGICAL CONTROL AND<br />INTEGRATED PEST<br />MAGAGEMENT<br />微生物杀虫剂 到目前为止，昆虫是生物防治有害生物和野草两者的<br />主要力量，出现在生物防治的全部 4个类型中。近来，<br />在害虫的防治中，把更多的注意力集中在应用昆虫的<br />病原体上，主要地作为微生物的杀虫剂。苏云金芽孢<br />杆菌（ Bacillus thuringiensis）是防治害虫的惟一微生物<br />因子，它已经成为世界性的商品。病毒，特别是杆状<br />病毒，也已被分离出来，引起昆虫和螨得病。真菌大<br />约有 100属对昆虫是致病性的，并是潜在的防治剂。<br />Up until recently,insects have been the main agents of<br />biological control against both pests and weeds,in all rour<br />types of biological control,Recently,increasing attention in<br />the control of insect pests has focused on the use of insect<br />pathogens,largely as microbial insecticides.The bacterium,<br />Bacillus thuringiensis,is the only microbial pest control<br />agent that has been commercialized worldwide,Viruses,in<br />particular the baculovirus,have also been isolated which<br />cause disease in insects and mites,There aer around 100<br />genera of fungi which are pathogenic to insects and are<br />potential control agents.<br />Microbial<br />insecticides<br />基因防治和<br />抗性<br />自绝控制是利用有害生物自身增加它自己的死亡率。<br />这通常牵涉到释放不育性的雄性，导致出生率降低。<br />基因操纵的另一种类型是选择植物品种对抗害虫（也<br />有除草剂）。已筛选出有抗性的品种，近来植物的复<br />杂基因操作已变成可能。发展和利用这样的转基因植<br />物，对潜在的环境和安全是有利的。然而，还存在着<br />公众的感性认识和与技术相关的合法问题，而且进化<br />的抗性问题如同化学杀虫剂的问题一样大。<br />Autocidal control uses the pest itself to increase its own rate<br />of mortality,This usually involves the release of sterile<br />males,leading to a decrease in birth rate,Another type of<br />genetic manipulation is to select plant varieties resistant to<br />pests (and also herbicides),Resistant varieties have been<br />selected and recently sophisticated genetic manipulations of<br />plants have become possible,There are potential<br />environmental and safety benefits from the development and<br />use of problems associated with technique,and the problems<br />of evolved resistance