SCIENCE IN THE NEWS - Study Measures Environmental Damage fr

SCIENCE IN THE NEWS - Study Measures Environmental Damage from Human Activities
By Shelley Gollust

Broadcast: Tuesday, April 19, 2005

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VOICE ONE:

This is SCIENCE IN THE NEWS, in VOA Special English. I'm Barbara Klein.

VOICE TWO:

 
 
And I'm Bob Doughty¹. Millions of people around the world will celebrate Earth Day on Friday. On our program this week, a report on the health of the world's coral reefs. And we tell about plants that can change their own genes³.

VOICE ONE:

But first, a study that shows how people have affected⁴ Earth's environment.

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VOICE ONE:

Experts have released a report that measures damage to the environment from human activities. The report measures the damage to the services that nature provides for people.

The report was released last month. It is part of a project called the Millennium⁵ Ecosystem⁶ Assessment⁷. United Nations Secretary-General Kofi Annan proposed the project five years ago.

More than one thousand three hundred ecologists and other scientists from ninety-five countries prepared the report. They studied the ability of ecosystems⁸ to perform activities like providing food and making water pure. An ecosystem is a group of living things and the environment in which they live.

VOICE TWO:

The report says people have changed ecosystems to meet growing demands for food, fresh water, and energy. These changes have helped improve the lives of thousands of millions of people. But they have weakened the ability of nature to provide important services for people.

The report identified several problems. They include reduced numbers of fish in the world's oceans and dangers to people living in dry areas. Another problem is a growing threat to ecosystems from climate change and pollution.

VOICE ONE:

The study found that sixty percent of the world's ecosystems are being harmed by human actions. These include fishing too much and clearing land to grow crops.

The study considered many kinds of services that an ecosystem provides. These include things like a forest's ability to store water and cool the air. It also includes cultural services, like providing a place for recreation. And, it includes life-support services like soil formation and the process by which plants make food.

VOICE TWO:

The scientists say many of the areas where the environment is most quickly being damaged are among the world's poorest areas. As a result, they said, damaged environments are likely to harm efforts to help poor people and reduce disease in developing countries.

The report said rich countries also were responsible for some problems. One of them is the increased use of chemical fertilizers. The fertilizers are washed into rivers and coastal⁹ waters. Nitrogen in the fertilizers creates areas in the water where nothing can live.

VOICE ONE:

Many earlier studies examined loss of forests and other wild places on land and in the oceans. The new report also deals with losses in dry-land ecosystems.

The scientists say this is where human populations are growing fastest and depend most heavily on natural systems. One example is Africa south of the Sahara Desert. That is where they say dry conditions and growing demands for water have added to social problems.

VOICE TWO:

The report says action is needed to prevent additional damage to the environment. The scientists who led the project released a statement. It says: "We must learn to recognize the true value of nature – both in an economic sense and in the richness it provides to our lives."

The statement also said protecting the environment should no longer be seen as something a country considers after more important concerns are dealt with. It said measures to protect natural resources are more likely to be successful if local communities are involved in decisions and share the gains.

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VOICE ONE:

Another report says the world's coral reefs are in trouble. It warns that more than two-thirds of the reefs are threatened or have been destroyed.

Two hundred forty scientists from more than ninety countries studied the condition of corals worldwide.

Corals are groups of small organisms, called polyps. They live within a skeleton made of a substance called limestone¹⁰. Corals are found in warm water. Millions of corals grow together to form coral reefs. The reefs support many kinds of sea life. Reefs protect coastal communities in storms. They also can be important to local and national economies.

VOICE TWO:

The Global Coral Reef Monitoring Network produced the report. Clive Wilkinson is coordinator¹¹ of the group. He says the problems are everywhere. In the Persian Gulf¹², for example, sixty-five percent of the coral reefs have been destroyed. South and Southeast Asia have lost nearly half their reef cover.

The report names several threats to coral reefs. They include pollution, coastal development, poor land use, and destructive fishing activities. Rising ocean temperatures are another problem. This causes a damaging condition called bleaching¹³, or whitening.

Higher than normal water temperatures cause corals to expel the small plants they feed on. If the water stays too warm, the corals die. Mister Wilkinson says extreme weather severely¹⁴ damaged coral reefs seven years ago. Some of the reefs are recovering. Yet, Mister Wilkinson says many reefs show little signs of renewal¹⁵.

VOICE ONE:

The report urges governments, lending organizations, international agencies, and environmental groups to work together to protect coral reefs.

Mister Wilkinson says Australia has taken the lead by expanding protected areas around the Great Barrier Reef. This reef extends more than two thousand kilometers along Australia's northeast coast. Scientists believe the Great Barrier Reef is about thirty million years old. It is the largest group of coral reefs in the world.

VOICE TWO:

Last year, the Australian government declared one-third of the reef a "no-take zone." The government barred fishing there. People also are barred from collecting live fish or coral in the area.

The Global Coral Reef Monitoring Network supports protected no-take zones. The group also called for a reduction in pollution and a ban of destructive fishing activities. Clive Wilkinson says the coral reefs can recover. But he believes more government involvement is needed.

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VOICE ONE:

American scientists have discovered that some plants are able to correct mistakes in their own genetic¹⁶ material. They say the plants do this by using other genes passed to them from plant ancestors.

The scientists reported their work in the publication Nature. They say that understanding how this gene² correction takes place will make it possible to develop new kinds of crops. They also say scientists could learn how to use the process to control the genetic mistakes that lead to disease.

VOICE TWO:

The discovery appears to dispute the scientific laws of heredity first described by Gregor Mendel in the nineteenth century. Mendel observed how some qualities in plants were passed down from their immediate¹⁷ ancestors, but others were not. He proposed the laws of heredity to explain this. His theory says plants get their qualities from their ancestors. Now, scientists at Purdue University in Indiana say his work may need to be re-examined.

The Purdue scientists studied one kind of plant called Arabidopsis. Arabidopsis is self-reproducing. This means it does not need anything from another plant to reproduce. Some of the plants had a changed gene that caused its flowers to grow together instead of separately.

VOICE ONE:

Mendel's laws would lead scientists to believe the resulting plants of reproduction also should have the changed gene. The scientists found, however, that ten percent of the resulting plants had no copy of the changed gene.

The scientists studied Arabidopsis for more than a year before they found the plant was fixing itself. They believe that the plant had been storing much more genetic information than anyone had ever thought.

Some of the information came from ancestors that were already dead. The scientists say this other information is affecting the plant so that it does not have the changed gene.

The American scientists still do not understand how this is happening. The scientists say they want to investigate a possible similar genetic situation in animals.

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VOICE TWO:

This program was written by Shelly Gollust, Jill Moss¹⁸ and Edward Stautberg. Cynthia Kirk was our producer. I'm Bob Doughty.

VOICE ONE:

And I'm Barbara Klein. Join us again next week for SCIENCE IN THE NEWS in VOA Special English.

1 doughty   

adj.勇猛的，坚强的

参考例句：

• Most of successful men have the characteristics of contumacy and doughty.绝大多数成功人士都有共同的特质：脾气倔强，性格刚强。
• The doughty old man battled his illness with fierce determination.坚强的老人用巨大毅力与疾病作斗争。

2 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

3 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪

4 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

5 millennium   

n.一千年，千禧年；太平盛世

参考例句：

• The whole world was counting down to the new millennium.全世界都在倒计时迎接新千年的到来。
• We waited as the clock ticked away the last few seconds of the old millennium.我们静候着时钟滴答走过千年的最后几秒钟。

6 ecosystem   

n.生态系统

参考例句：

• This destroyed the ecosystem of the island.这样破坏了岛上的生态系统。
• We all have an interest in maintaining the integrity of the ecosystem.维持生态系统的完整是我们共同的利益。

7 assessment   

n.评价；评估；对财产的估价，被估定的金额

参考例句：

• This is a very perceptive assessment of the situation.这是一个对该情况的极富洞察力的评价。
• What is your assessment of the situation?你对时局的看法如何？

8 ecosystems   

n.生态系统( ecosystem的名词复数 )

参考例句：

• There are highly sensitive and delicately balanced ecosystems in the forest. 森林里有高度敏感、灵敏平衡的各种生态系统。 来自《简明英汉词典》
• Madagascar's ecosystems range from rainforest to semi-desert. 马达加斯加生态系统类型多样，从雨林到半荒漠等不一而足。 来自辞典例句

9 coastal   

adj.海岸的，沿海的，沿岸的

参考例句：

• The ocean waves are slowly eating away the coastal rocks.大海的波浪慢慢地侵蚀着岸边的岩石。
• This country will fortify the coastal areas.该国将加强沿海地区的防御。

10 limestone   

n.石灰石

参考例句：

• Limestone is often used in building construction.石灰岩常用于建筑。
• Cement is made from limestone.水泥是由石灰石制成的。

11 coordinator   

n.协调人

参考例句：

• The UN Office for the Coordination of Humanitarian Affairs, headed by the Emergency Relief Coordinator, coordinates all UN emergency relief. 联合国人道主义事务协调厅在紧急救济协调员领导下，负责协调联合国的所有紧急救济工作。
• How am I supposed to find the client-relations coordinator? 我怎么才能找到客户关系协调员的办公室？

12 gulf   

n.海湾；深渊，鸿沟；分歧，隔阂

参考例句：

• The gulf between the two leaders cannot be bridged.两位领导人之间的鸿沟难以跨越。
• There is a gulf between the two cities.这两座城市间有个海湾。

13 bleaching   

漂白法，漂白

参考例句：

• Moderately weathered rock showed more intense bleaching and fissuring in the feldspars. 中等风化岩石则是指长石有更为强烈的变白现象和裂纹现象。
• Bleaching effects are very strong and show on air photos. 退色效应非常强烈，并且反映在航空象片上。

14 severely   

adv.严格地；严厉地；非常恶劣地

参考例句：

• He was severely criticized and removed from his post.他受到了严厉的批评并且被撤了职。
• He is severely put down for his careless work.他因工作上的粗心大意而受到了严厉的批评。

15 renewal   

adj.(契约)延期，续订，更新，复活，重来

参考例句：

• Her contract is coming up for renewal in the autumn.她的合同秋天就应该续签了。
• Easter eggs symbolize the renewal of life.复活蛋象征新生。

16 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

17 immediate   

adj.立即的；直接的，最接近的；紧靠的

参考例句：

• His immediate neighbours felt it their duty to call.他的近邻认为他们有责任去拜访。
• We declared ourselves for the immediate convocation of the meeting.我们主张立即召开这个会议。

18 moss   

n.苔，藓，地衣

参考例句：

• Moss grows on a rock.苔藓生在石头上。
• He was found asleep on a pillow of leaves and moss.有人看见他枕着树叶和苔藓睡着了。