VOA慢速英语2014 藻类群体的增加污染水道

 

AS IT IS 2014-08-10 Increase in Algae¹ Population Infects Waterways 藻类群体的增加污染水道

The American city of Toledo, Ohio faced a serious problem earlier this month.  Four hundred thousand people could not drink from the city’s public water supply.  The water comes from Lake Erie.  It was polluted with a toxin², or harmful substance, linked to the overgrowth of algae.  Too many of these simple organisms can lead to harmful algal blooms, covering a large area. 

The water in Toledo is now safe to drink.  Yet harmful algal blooms are not going away any time soon, either in the United States or around the world. 

The harmful algae entered Toledo’s water intake³ pipes and turned the water green.  People had to depend on bottled water supplies.

“We’re happy to have this.”

“It was stressful at first.  Definitely!  I have a couple of dogs at home and four children, and I wanted to make sure we had enough water to brush our teeth and be able to drink it.”

Lake Erie supplies water to 11 million people in the north central United States.  Algal overload⁴ is common in waterways worldwide.  It results from chemical fertilizers polluting water supplies and poor waste treatment systems. 

Laura Johnson is a researcher with the National Center for Water Quality at Heidelberg University in Tiffin, Ohio.  She says overgrowth of algae can reduce oxygen levels in water and kill fish.

“It also becomes a problem when the type of algae that are growing is a cyanobacteria that can produce toxins⁵.  And when that happens, then we have issues, because then those toxins can be in places like our drinking water, or we can get in contact with it if we’re trying to swim there.”

It can also damage the human nervous system and liver.  Climate change is making the problem worse.  Changing weather systems produce stronger, more intense winds and storms.  These can take minerals and other important nutrients⁶ away from the land.

The U.S. National Oceanic and Atmospheric⁷ Administration studies Algal blooms from space.  Richard Stumpf is an oceanographer.

“So we can use the satellite data to actually find the bloom, (and) estimate the concentration.  We can’t tell you if it’s toxic⁸.  But we can tell you if it’s there and how much there is.”

This information helps scientists and government officials to take action.  Richard Stumpf says the U.S. National Oceanic and Atmospheric Administration is also gathering⁹ information on phosphorous, a chemical that fuels the reproduction of algae.

“It’s only the spring phosphorous -- the phosphorus in the spring time -- that creates the bloom in the summer.  Knowing that means that you can now create a strategy for how do you modify fertilizing¹⁰ practices, how do you modify cultivating practices so that the phosphorous stays on the fields, which is what the farmers, they don’t want this to go somewhere else, and so it stays there and doesn’t run into the rivers and then into the lake?”

Laura Johnson says the long-term goal must be to keep nutrients on the land.

Activists¹¹ for clean water want the government to enact¹² stronger controls.  They also want to persuade farmers to cut back on fertilizers by paying them.  Farmers often resist additional rules and recently faced a reduction in federal assistance.                                                                  

As the debate continues, one thing is clear.  The algal problem is not going away any time soon.  I’m Jonathan Evans.

1 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。

2 toxin   

n.毒素，毒质

参考例句：

• Experts have linked this condition to a build-up of toxins in the body.专家已把这一病症与体内毒素的积累联系起来。
• Tests showed increased levels of toxin in shellfish.检验表明水生有壳动物的毒素水平提高了。

3 intake   

n.吸入，纳入；进气口，入口

参考例句：

• Reduce your salt intake.减少盐的摄入量。
• There was a horrified intake of breath from every child.所有的孩子都害怕地倒抽了一口凉气。

4 overload   

vt.使超载；n.超载

参考例句：

• Don't overload the boat or it will sink.别超载，否则船会沉。
• Large meals overload the digestive system.吃得太饱会加重消化系统的负担。

5 toxins   

n.毒素( toxin的名词复数 )

参考例句：

• The seas have been used as a receptacle for a range of industrial toxins. 海洋成了各种有毒工业废料的大容器。
• Most toxins are naturally excreted from the body. 大部分毒素被自然排出体外。 来自《简明英汉词典》

6 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》

7 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。

8 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。

9 gathering   

n.集会，聚会，聚集

参考例句：

• He called on Mr. White to speak at the gathering.他请怀特先生在集会上讲话。
• He is on the wing gathering material for his novels.他正忙于为他的小说收集资料。

10 fertilizing   

v.施肥( fertilize的现在分词 )

参考例句：

• Sometimes the preliminary step must be taken of reducing weed population before fertilizing. 有时候，在施肥之前，必须采取减少杂草密度的预备性步骤。 来自辞典例句
• The self fertilizing garden can also be planted in raised beds. 自我施肥的菜园也可以在苗圃床中种植。 来自互联网

11 activists   

n.（政治活动的）积极分子，活动家( activist的名词复数 )

参考例句：

• His research work was attacked by animal rights activists . 他的研究受到了动物权益维护者的抨击。
• Party activists with lower middle class pedigrees are numerous. 党的激进分子中有很多出身于中产阶级下层。 来自《简明英汉词典》

12 enact   

vt.制定(法律)；上演，扮演

参考例句：

• The U.S. Congress has exclusive authority to enact federal legislation.美国国会是唯一有权颁布联邦法律的。
• For example,a country can enact laws and economic policies to attract foreign investment fairly quickly.例如一个国家可以很快颁布吸引外资的法令和经济政策。