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
Complete the notes below. Write NO MORE THAN TWO WORDS for each answer. Mass Strandings of Whales and Dolphi
Complete the notes below. Write NO MORE THAN TWO WORDS for each answer. Mass Strandings of Whales and Dolphi
admin
2014-09-29
18
问题
Complete the notes below.
Write NO MORE THAN TWO WORDS for each answer.
Mass Strandings of Whales and Dolphins
Mass strandings: situations where groups of whales, dolphins, etc. swim onto the beach and die
Common in areas where the【L31】______can change quickly
Several other theories:
Parasites
e.g. some parasites can affect marine animals’【L32】______, which they depend on for navigation
Toxins
Poisons from【L33】______or______are commonly consumed by whales
e.g. Cape Cod (1988) - whales were killed by saxitoxin
Accidental Strandings
Animals may follow prey ashore, e.g. Thurston (1995)
Unlikely because the majority of animals were not【L34】______when they stranded
Human Activity
【L35】______from military tests are linked to some recent strandings
The Bahamas (2000) stranding was unusual because the whales
were all【L36】______
were not in a【L37】______
Group Behaviour
More strandings in the most【L38】______species of whales
1994 dolphin stranding - only the【L39】______was ill
Further Reading
Marine Mammals Ashore (Connor) - gives information about stranding【L40】______
【L36】
Good afternoon everyone. Well, with some of you about to go out on field work it’s timely that in this afternoon’s session I’ll be sharing some ideas about the reasons why groups of whales and dolphins sometimes swim ashore from the sea right onto the beach and, most often, die in what are known as ’mass standings’.
Unfortunately, this type of event is a frequent occurrence in some of the locations that you’ll be travelling to, where sometimes the tide goes out suddenly, confusing the animals. However, there are many other theories about the causes of mass strandings.
The first is that the behaviour is linked to parasites. It’s often found that stranded animals were infested with large numbers of parasites. For instance, a type of worm is commonly found in the ears of dead whales. Since marine animals rely heavily on their hearing to navigate, this type of infestation has the potential to be very harmful.
Another theory is related to toxins, or poisons. These have also been found to contribute to the death of many marine animals. Many toxins, as I’m sure you’re aware, originate from plants, or animals. The whale ingests these toxins in its normal feeding behaviour but whether these poisons directly or indirectly lead to stranding and death, seems to depend upon the toxin involved.
In 1988, for example, fourteen humpback whales examined after stranding along the beaches of Cape Cod were found to have been poisoned after eating tuna that contained saxitoxin, the same toxin that can be fatal in humans.
Alternatively, it has also been suggested that some animals strand accidentally by following their prey ashore in the confusion of the chase. In 1995 David Thurston monitored pilot whales that beached after following squid ashore. However, this idea does not seem to hold true for the majority of mass strandings because examination of the animals’ stomach contents reveal that most had not been feeding as they stranded.
There are also some new theories which link strandings to humans. A growing concern is that loud noises in the ocean cause strandings. Noises such as those caused by military exercises are of particular concern and have been pinpointed as the cause of some strandings of late.
One of these, a mass stranding of whales in 2000 in the Bahamas coincided closely with experiments using a new submarine detection system. There were several factors that made this stranding stand out as different from previous strandings. This led researchers to look for a new cause. For one, all the stranded animals were healthy. In addition, the animals were spread out along 38 kilometres of coast, whereas it’s more common for the animals to be found in a group when mass strandings occur.
A final theory is related to group behaviour, and suggests that sea mammals cannot distinguish between sick and healthy leaders and will follow sick leaders, even to an inevitable death. This is a particularly interesting theory since the whales that are thought to be most social - the toothed whales - are the group that strand the most frequently.
The theory is also supported by evidence from a dolphin stranding in 1994. Examination of the dead animals revealed that apart from the leader, all the others had been healthy at the time of their death.
Without one consistent theory however it is very hard for us to do anything about this phenomenon except to assist animals where and when we can. Stranding networks have been established around the world to aid in rescuing animals and collecting samples from those that could not be helped. I recommend John Connor’s Marine Mammals Ashore as an excellent starting point if you’re interested in finding out more about these networks, or establishing one yourself.
选项
答案
healthy
解析
转载请注明原文地址:https://jikaoti.com/ti/CQtYFFFM
本试题收录于:
雅思听力题库雅思(IELTS)分类
0
雅思听力
雅思(IELTS)
相关试题推荐
Thereseemstobeno(i)_______thereadingpublic’sthirstforbooksaboutthe1960’s:indeed,thenormallevelofinteresthas
ItisnoaccidentthatmostpeoplefindDavis’bookdisturbing,foritis(i)______toundermineanumberofbeliefstheyhavel
Inspiteofthefactthatitisconvenienttodividethelifespanofanimalsintoseparatestagessuchasprenatal,adolescent,
TheMinoancivilizationflourishedontheislandofCretearound2000B.C.ThediscoveryonCreteoflargenumbersofbronzeimpl
Orcasaresmallwhalesthatgenerallytravelingroupscalledpods.Orcasthatfeedonmarinemammalstravelinverysmallpods,
IntroductionandInterview(4-5minutes)Introduction(compulsory)Interview(choose1)Let’stalkaboutwhereyoul
HowcanpeoplefindreliableinformationontheInternet?
随机试题
行政领导方式
无产阶级专政的最终目标是
患者,男,15岁。外周血为白细胞:2.0×109/L,红细胞:2.0×1012/L,血小板:75×109/L,临床诊断为再生障碍性贫血。问题2:该患者白细胞相对增多的是
急性阑尾炎患者出现寒战、黄疸时,应考虑
服用苯二氮卓类药后,可产生过度镇静、肌肉松弛作用,觉醒后可发生颤抖、认知功能障碍等症状,尤其是老年人,称为
隧道超前地质预报,下列超前地质预报的物探方法中可用于长距离预报的是()。
房地产投资是一种长期投资。国外的研究表明,房地产的经济寿命与其使用性质相关。一般来说,下列说法不正确的一项是()。
在河床中修筑围堰围护基坑,并将河道中各时期的上游来水量按预定的方式导向下游,以创造干地施工的条件叫()。
甲公司为增值税一般纳税人,适用增值税税率为17%,所得税税率为25%,2017年度有关资料如下:(1)本年度销售商品收入15700万元,发生销售折让200万元,处置固定资产净收益300万元,处置无形资产净收益100万元。(2)本年度销售商品成本
随着“秦火火”妖言惑众内幕的不断曝光,人们看到其造谣生事的手段并不高明。他们不过是利用社会热点和民众情绪,把自己打扮成“社会不公”的审判者,以编造谎言、_______的手段“忽悠”民众。“谣言并非止于智者,而是止于下一个谣言”,就是他们信奉的宗旨。而其对“
最新回复
(
0
)