美国国家公共电台 NPR The Gulf Of Mexico's Dead Zone Is The Biggest Ever Seen

 

DAVID GREENE, HOST:

This summer, a record-setting dead zone has appeared in the Gulf¹ of Mexico. This is a zone where water does not have enough oxygen for fish to survive. One major cause of this is pollution from farms. And this has provoked a debate about how to reduce that pollution, as NPR's Dan Charles reports.

DAN CHARLES, BYLINE²: A dead zone appears every summer in the Gulf of Mexico, and we know this because 32 years ago, Don Scavia and his colleagues at the National Oceanic and Atmospheric³ Administration asked scientists to go look for it.

DON SCAVIA: We expected it to be there. We had no idea how big it actually was until we funded the work to go out and measure it.

CHARLES: They expected it because they knew that when the Mississippi River empties into the Gulf of Mexico, it brings a heavy load of nutrient⁴ pollution - nitrogen and phosphorus.

SCAVIA: Most of the nitrogen and phosphorus that drives this problem comes from the upper Midwest. It's coming from agriculture.

CHARLES: Farmers spread it on their fields as fertilizer. Rain washes it into nearby streams and rivers. And in the Gulf, those nutrients⁵ cause blooms of algae⁶ which then decompose⁷. And that's what uses up the oxygen in a layer of water at the bottom of the Gulf along the coastline.

SCAVIA: Fish that can swim will move out of the way. Organisms that are living in the bottom that the fish feed on can't move, and they often die.

CHARLES: Scientists have continued to measure the dead zone. And this year, they found the biggest one yet - as big as the state of New Jersey⁸, 8,776 square miles. It's because heavy rains in the Midwest flushed a lot of nutrients into the Gulf.

SCAVIA: You know, it's 8,000 square miles of no oxygen. That can't be good.

CHARLES: Don Scavia is now at the University of Michigan. He says the dead zone also has real economic costs. It puts Louisiana's shrimp⁹ harvest in danger. Federal and state governments have been trying to shrink the dead zone. They're encouraging Midwestern farmers to try to keep nutrients from washing away. For instance, by planting wide grassy¹⁰ strips alongside streams to trap fertilizer runoff. But Scavia says these voluntary measures are not enough.

SCAVIA: We definitely need to do a lot more.

CHARLES: Scavia argues the Gulf should get the same kind of protection as the Chesapeake Bay did on the East Coast. The bays had a similar dead zone problem, but in 2010, despite fierce objections from farmers, the federal government set mandatory¹¹ limits on nutrient pollution there. State governments spent billions of dollars meeting those targets. Now, pollution in the bay is down. And there, some wildlife is starting to recover. Dan Charles, NPR News.

(SOUNDBITE OF NOSAJ THING'S "REALIZE")

1 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。

2 byline   

n.署名；v.署名

参考例句：

• His byline was absent as well.他的署名也不见了。
• We wish to thank the author of this article which carries no byline.我们要感谢这篇文章的那位没有署名的作者。

3 atmospheric   

adj.大气的，空气的；大气层的；大气所引起的

参考例句：

• Sea surface temperatures and atmospheric circulation are strongly coupled.海洋表面温度与大气环流是密切相关的。
• Clouds return radiant energy to the surface primarily via the atmospheric window.云主要通过大气窗区向地表辐射能量。

4 nutrient   

adj.营养的，滋养的；n.营养物，营养品

参考例句：

• Magnesium is the nutrient element in plant growth.镁是植物生长的营养要素。
• The roots transmit moisture and nutrient to the trunk and branches.根将水分和养料输送到干和枝。

5 nutrients   

n.（食品或化学品）营养物，营养品( nutrient的名词复数 )

参考例句：

• a lack of essential nutrients 基本营养的缺乏
• Nutrients are absorbed into the bloodstream. 营养素被吸收进血液。 来自《简明英汉词典》

6 algae   

n.水藻，海藻

参考例句：

• Most algae live in water.多数藻类生长在水中。
• Algae grow and spread quickly in the lake.湖中水藻滋蔓。

7 decompose   

vi.分解；vt.（使）腐败，（使）腐烂

参考例句：

• The eggs began to decompose after a day in the sun.鸡蛋在太阳下放了一天后开始变坏。
• Most animals decompose very quickly after death.大多数动物死后很快腐烂。

8 jersey   

n.运动衫

参考例句：

• He wears a cotton jersey when he plays football.他穿运动衫踢足球。
• They were dressed alike in blue jersey and knickers.他们穿着一致，都是蓝色的运动衫和灯笼短裤。

9 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。

10 grassy   

adj.盖满草的；长满草的

参考例句：

• They sat and had their lunch on a grassy hillside.他们坐在长满草的山坡上吃午饭。
• Cattle move freely across the grassy plain.牛群自由自在地走过草原。

11 mandatory   

adj.命令的；强制的；义务的；n.受托者

参考例句：

• It's mandatory to pay taxes.缴税是义务性的。
• There is no mandatory paid annual leave in the U.S.美国没有强制带薪年假。