VOA慢速英语2012 SCIENCE IN THE NEWS - Condition of Oceans Affects Human Health

 

SCIENCE IN THE NEWS - Condition of Oceans Affects Human Health

From VOA Learning English, this is SCIENCE IN THE NEWS in Special English. I’m Shirley Griffith.

And I’m Christopher Cruise. Today, we tell about a new way to measure the health of the world’s oceans. We also tell about efforts to develop medicines from underwater organisms. And we tell about a newly identified species found in the Caribbean Sea.

A new system has been developed to measure the health of the world’s oceans. Scientists say the system will change the way we think about oceans and how they affect our lives. It is called the Ocean Health Index. The index is designed to tell if anything is wrong with the oceans and, if so, what can be done about it.

Greg Stone is chief ocean scientist for the environmental group Conservation International. He is also vice-chairman of the Global Agenda Council on Oceans at the World Economic Forum¹.

“The Ocean Health Index is the first global, totally scientific and transparent² measure of ocean health that we’ve ever had. It’s meant to guide policymakers and the public to the underlying³ importance that the oceans are the life support system of the Earth and that we’d better take care of them if we are to survive on this planet.”

Greg Stone spoke⁴ to VOA from the Cook Islands in the South Pacific. Representatives from sixteen island nations met there earlier this year to talk about caring for the ocean. Mr. Stone says oceans are the Earth’s most important resource.

“You can’t manage anything that you can’t measure. So, like any good portfolio⁵ investments, if you want to make sure you are prospering⁶ and you’re taking care of your investments -- and believe me, the health of our planet is no greater investment that there could be -- you need a metric in order to measure it and see that we have a sustainable relationship with this resource on an ongoing⁷ basis.”

He says the Ocean Health Index will help end a lot of ignorance about the seas.

“You may have heard from one source or another that, ‘Oh, hey, the oceans are in trouble’ and you say ‘Why are they in trouble?’ And then somebody says ‘Well, the coral reefs are dying.’ And then the next day someone will tell you that ‘the tuna fish are all gone’ or ‘the haddock are all gone’ or ‘the halibut are all gone.’ And you say ‘Oh OK, I hear that.’ And then someone else will say ‘The oceans are turning acidic’ -- which they are. It’s been a very confusing landscape of information.”

And he says whether you live in the United States or in the middle of Africa, you should care about what happens to the oceans.

“Most of the oxygen that you breathe comes from the ocean. The oceans are the primary climate adaptation system. They absorb carbon. Hey, listen, if you want to know what the Earth would be like without an ocean you’ve got plenty of examples in our solar system -- all those hot, dusty, dry, cold inhospitable places are basically that way because they do not have a liquid ocean to provide all these benefits, including food. One out of four people on the planet get their daily source of protein from the ocean.”

The Ocean Health Index uses two hundred separate measurements. Once a year, scientists will use it to announce whether the oceans successfully passed the test.

People have looked to nature for medicines since ancient times. And modern scientists have searched the world’s rainforests for new medicines. But the ocean may be an even better source. At least twenty-six drugs that come from sea organisms are currently being used or developed. And a new generation of chemists hopes to increase that number.

Chemist Mande Holford has an unusual partner in her hunt for new medicines: a fierce, little snail⁸ that eats fish. But she admits that her studies of the creature are not all scientific.

“I fell in love with snails⁹ because their shells are gorgeous.”

Yet the tongue-like proboscides of the snails are deadly. They inject their victims with venom¹⁰ made of poisonous chains of amino acids called peptides.

“What I like to say is that the snails produce sort of a cluster bomb. Inside of each venom, you have between fifty to two hundred peptides, and all of those peptides target something major along the nervous system. One thing that they hit is a pain signal. When they silence the pain signal, the prey¹¹ doesn’t go into fight or flight mode.”

So the fish stays calmer than it normally would, even as it is being eaten! Mande Holford says chemists have already had one major success using the snail’s peptides. It is a drug called Prialt. It eases pain for people with cancer and HIV, the virus that causes AIDS.

“On your neurons, you have these ‘gates’ that allow things to pass back and forth¹². The gate that controls chronic¹³ pain, they found a way to shut it down using one of the peptides.”

At first, Mande Holford may have wanted to study snails because of their beauty. But she is part of a larger movement toward marine¹⁴, or undersea, research.

David Newman directs the Natural Products Branch of America’s National Cancer Institute.

“We’ve found some absolutely fascinating chemistry.”

After years of collecting organisms on land, Mr. Newman’s team now collects only sea creatures such as sponges or corals. He says that because these creatures cannot move, they use chemicals to fight.

“I have been known to say that weapons of mass destruction are alive and well on a coral reef, if you happen to be a fellow sponge who’s trying to encroach or you’re a starfish that’s trying to eat the sponge. These are extremely toxic¹⁵ agents because of the dilution¹⁶ effect of seawater.”

For an organization looking for ways to kill cancerous cells, such powerful chemicals are an inviting¹⁷ weapon.

William Fenical directs the Center for Marine Biotechnology and Biomedicine at the Scripps Institute for Oceanography in California. He says that about nine kilometers underwater lies what may be an even more promising¹⁸ source of medicine -- mud.

“Close to seventy percent of the surface of the earth is really deep ocean mud.”

His team studies microorganisms living on the ocean floor.

“These muds contain about one billion cells in the volume of a sugar cube.”

For comparison, that is one-million times the organic matter you are likely to find in a similar amount of soil on land. The large number of sea creatures excites Mr. Fenical.

“For the last fifty years, microorganisms that occur on land have been exploited for the production of antibiotics¹⁹, cancer drugs, and cholesterol-lowering drugs. What we believe is that the ocean is a completely new resource for such microbial products.”

His team already has two drugs in development. And he believes there will be many discoveries of ocean-based medicines.

A small blood-sucking crustacean²⁰ has been discovered in the Caribbean waters off the Virgin²¹ Islands. The creature may help increase scientists’ understanding of how disease is passed among marine animals.

The new species is called Gnathia marleyi. It was named for the reggae star Bob Marley. Paul Sikkel is a marine biologist at Arkansas State University. He says the species is the first new find in the crustacean-like gnathiid family in twenty years.

“What’s interesting about them is that they’re only parasitic²² in the juvenile²³ stage. So they only feed when they are juveniles²⁴, and they go through three different juvenile stages -- one bigger than the other, each bigger than the other. And they look a little bit like, like ticks or fleas²⁵. They look very similar to, you know, to terrestrial blood feeding organisms.”

Paul Sikkel captured the juvenile marleyi at what researchers call a “cleaning station.” That is a place on the coral reef where big fish gather so smaller fish and shrimp²⁶ can eat parasites²⁷ that have joined to their skin. Parasites depend on other creatures for food and shelter. However, the adult male marleyi do not eat. They just mate and die.

Mr. Sikkel studied the species in a laboratory.

“Adult males look a little bit like bulldozers. They have square heads, and they have these pincers on their head and they are very cool-looking. And the females -- small head and a really big body that’s full of eggs.”

About eighty percent of all organisms found on coral reefs are parasites. Gnathiids are among the most important parasites in the oceans. Mr. Sikkel says the levels of gnathiids can show how healthy a reef is. In some waters, he is seeing fish more heavily covered with gnathiids -- marleyi among them. 

“Too many gnathiids hurt the fish and too little coral, we think, leads to more gnathiids. So in a, in a nice healthy, you know, coral-rich environment, we don’t find very many gnathiids -- fish, you know, just get a few of them. But in areas where there isn’t much live coral, there are a lot more gnathiids and the fish get much heavier loads on them.”

Mr. Sikkel suspects that Gnathia marleyi may also be important in passing a malaria-like fish disease that weakens the animal’s natural defenses. His team is currently studying whether this pathogen is also present in the Caribbean.

“And then from there, once we find the species of fish that are infected, then we’ll do experiments to determine whether or not the gnathia marleyi actually plays a role in transmitting those blood-born organisms.”

Paul Sikkel hopes his discovery will lead to more information about parasites and the effect they can have on marine environments.

1 forum   

n.论坛，讨论会

参考例句：

• They're holding a forum on new ways of teaching history.他们正在举行历史教学讨论会。
• The organisation would provide a forum where problems could be discussed.这个组织将提供一个可以讨论问题的平台。

2 transparent   

adj.明显的，无疑的；透明的

参考例句：

• The water is so transparent that we can see the fishes swimming.水清澈透明，可以看到鱼儿游来游去。
• The window glass is transparent.窗玻璃是透明的。

3 underlying   

adj.在下面的，含蓄的，潜在的

参考例句：

• The underlying theme of the novel is very serious.小说隐含的主题是十分严肃的。
• This word has its underlying meaning.这个单词有它潜在的含义。

4 spoke   

n.（车轮的）辐条；轮辐；破坏某人的计划；阻挠某人的行动 v.讲，谈（speak的过去式）；说；演说；从某种观点来说

参考例句：

• They sourced the spoke nuts from our company.他们的轮辐螺帽是从我们公司获得的。
• The spokes of a wheel are the bars that connect the outer ring to the centre.辐条是轮子上连接外圈与中心的条棒。

5 portfolio   

n.公事包；文件夹；大臣及部长职位

参考例句：

• He remembered her because she was carrying a large portfolio.他因为她带着一个大公文包而记住了她。
• He resigned his portfolio.他辞去了大臣职务。

6 prospering   

成功，兴旺( prosper的现在分词 )

参考例句：

• Our country is thriving and prospering day by day. 祖国日益繁荣昌盛。
• His business is prospering. 他生意兴隆。

7 ongoing   

adj.进行中的，前进的

参考例句：

• The problem is ongoing.这个问题尚未解决。
• The issues raised in the report relate directly to Age Concern's ongoing work in this area.报告中提出的问题与“关心老人”组织在这方面正在做的工作有直接的关系。

8 snail   

n.蜗牛

参考例句：

• Snail is a small plant-eating creature with a soft body.蜗牛是一种软体草食动物。
• Time moved at a snail's pace before the holidays.放假前的时间过得很慢。

9 snails   

n.蜗牛；迟钝的人；蜗牛( snail的名词复数 )

参考例句：

• I think I'll try the snails for lunch—I'm feeling adventurous today. 我想我午餐要尝一下蜗牛——我今天很想冒险。 来自《简明英汉词典》
• Most snails have shells on their backs. 大多数蜗牛背上有壳。 来自《简明英汉词典》

10 venom   

n.毒液，恶毒，痛恨

参考例句：

• The snake injects the venom immediately after biting its prey.毒蛇咬住猎物之后马上注入毒液。
• In fact,some components of the venom may benefit human health.事实上，毒液的某些成分可能有益于人类健康。

11 prey   

n.被掠食者，牺牲者，掠食；v.捕食，掠夺，折磨

参考例句：

• Stronger animals prey on weaker ones.弱肉强食。
• The lion was hunting for its prey.狮子在寻找猎物。

12 forth   

adv.向前；向外，往外

参考例句：

• The wind moved the trees gently back and forth.风吹得树轻轻地来回摇晃。
• He gave forth a series of works in rapid succession.他很快连续发表了一系列的作品。

13 chronic   

adj.(疾病)长期未愈的，慢性的；极坏的

参考例句：

• Famine differs from chronic malnutrition.饥荒不同于慢性营养不良。
• Chronic poisoning may lead to death from inanition.慢性中毒也可能由虚弱导致死亡。

14 marine   

adj.海的；海生的；航海的；海事的；n.水兵

参考例句：

• Marine creatures are those which live in the sea. 海洋生物是生存在海里的生物。
• When the war broke out,he volunteered for the Marine Corps.战争爆发时，他自愿参加了海军陆战队。

15 toxic   

adj.有毒的，因中毒引起的

参考例句：

• The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
• There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。

16 dilution   

n.稀释，淡化

参考例句：

• There is no hard and fast rule about dilution.至于稀释程度，没有严格的规定。
• He attributed this to a dilution effect of the herbicide.他把这归因于除草剂的稀释效应。

17 inviting   

adj.诱人的，引人注目的

参考例句：

• An inviting smell of coffee wafted into the room.一股诱人的咖啡香味飘进了房间。
• The kitchen smelled warm and inviting and blessedly familiar.这间厨房的味道温暖诱人，使人感到亲切温馨。

18 promising   

adj.有希望的，有前途的

参考例句：

• The results of the experiments are very promising.实验的结果充满了希望。
• We're trying to bring along one or two promising young swimmers.我们正设法培养出一两名有前途的年轻游泳选手。

19 antibiotics   

n.（用作复数）抗生素；（用作单数）抗生物质的研究；抗生素，抗菌素( antibiotic的名词复数 )

参考例句：

• the discovery of antibiotics in the 20th century 20世纪抗生素的发现
• The doctor gave me a prescription for antibiotics. 医生给我开了抗生素。

20 crustacean   

n.甲壳动物；adj.甲壳纲的

参考例句：

• Seafood is a valuable lobster crustacean section.名贵海珍品龙虾属甲壳科。
• The illustrious Cuvier did not perceive that a barnacle was a crustacean.大名鼎鼎的居维叶也未看出藤壶是一种甲壳动物。

21 virgin   

n.处女，未婚女子；adj.未经使用的；未经开发的

参考例句：

• Have you ever been to a virgin forest?你去过原始森林吗？
• There are vast expanses of virgin land in the remote regions.在边远地区有大片大片未开垦的土地。

22 parasitic   

adj.寄生的

参考例句：

• Will global warming mean the spread of tropical parasitic diseases?全球变暖是否意味着热带寄生虫病会蔓延呢？
• By definition,this way of life is parasitic.从其含义来说，这是种寄生虫的生活方式。

23 juvenile   

n.青少年，少年读物；adj.青少年的，幼稚的

参考例句：

• For a grown man he acted in a very juvenile manner.身为成年人，他的行为举止显得十分幼稚。
• Juvenile crime is increasing at a terrifying rate.青少年犯罪正在以惊人的速度增长。

24 juveniles   

n.青少年( juvenile的名词复数 )；扮演少年角色的演员；未成年人

参考例句：

• Do you think that punishment for violent crimes should be the same for juveniles and adults? 你对暴力犯罪的惩罚对于青少年和成人应一样吗？ 来自生活英语口语25天快训
• Juveniles Should we not exactly in need of such strength and conviction? 少年的我们难道不正是需要这种力量和信念吗？ 来自互联网

25 fleas   

n.跳蚤( flea的名词复数 )；爱财如命；没好气地（拒绝某人的要求）

参考例句：

• The dog has fleas. 这条狗有跳蚤。
• Nothing must be done hastily but killing of fleas. 除非要捉跳蚤，做事不可匆忙。 来自《简明英汉词典》

26 shrimp   

n.虾，小虾；矮小的人

参考例句：

• When the shrimp farm is built it will block the stream.一旦养虾场建起来，将会截断这条河流。
• When it comes to seafood,I like shrimp the best.说到海鲜，我最喜欢虾。

27 parasites   

寄生物( parasite的名词复数 )； 靠他人为生的人； 诸虫

参考例句：

• These symptoms may be referable to virus infection rather than parasites. 这些症状也许是由病毒感染引起的，而与寄生虫无关。
• Kangaroos harbor a vast range of parasites. 袋鼠身上有各种各样的寄生虫。