VOA标准英语2010年-Ocean 'Time Machine' Illustrates Globa

Baby oysters² could be the "canaries in the mine shaft³" for another dimension of global warming.

Pacific Northwest scientists are studying how the oceans suck in excess carbon dioxide from the atmosphere. The process changes seawater chemistry - locally and globally. An experiment now under way in Seattle, Washington to find out how sea critters are coping with the changes.

Time machine

Paul McElhany's lab is like an ocean time machine.

"In one of the tanks we're simulating pre-industrial conditions, before people started burning fossil fuels," says McElhany, a federal biologist working at the Northwest Fisheries Science Center in Seattle.

Multicolored tubes and pipes run every which way in the cramped⁴ aquatic⁵ lab. The researcher controls his time machine by bubbling carbon dioxide into the seawater at different concentrations.

"The next tank over, we're setting conditions of doubling of the current CO2 levels, which the models that have been done project we'll reach by 2100, by the end of the century or before," says McElhany.

 
VOA - T. Banse
NOAA Fisheries biologist Paul McElhany in his Seattle lab.
Ocean acidification

There's one additional setup with an even worse scenario⁶. McElhany explains the oceans absorb a big chunk⁷ of the CO2 we pump into the atmosphere. This is the lesser⁸ known twin of atmospheric⁹ warming. Scientists call it "ocean acidification."

"As the CO2 that's put out by burning fossil fuels goes into the ocean, it changes the chemistry of the ocean itself and makes it more acidic," he says. "It's sort of the same way as when you have carbon dioxide in a soda¹⁰ pop, that makes the soda pop more acidic."

Ocean acidification is not going to affect all species equally. McElhany's team is trying to determine just who wins and who loses. On the one hand, algae¹¹ and seaweed could prosper¹² under elevated carbon dioxide levels. On the other, shellfish in the larval stage seem quite vulnerable.

"If the acidity¹³ gets low enough," says McElhany, "they can actually start to dissolve."

First into the bath, baby oysters. The little creatures are taking an extended dip now with the ghosts of oceans past, present and future. Next up, abalone, geoducks, clams¹⁵, mussels and krill. Grad students check the tanks and jars every day to monitor how many larvae¹⁶ survive and in what condition.

Oyster¹ test

At Oregon State University, researchers are waiting to hear if the National Science Foundation will provide money for a similar experiment. Fisheries professor Chris Langdon says oysters are likely to show the effects of a more acidic ocean first.

"From what we can tell, the larvae of the Pacific oyster seem to be much more sensitive to what's going on than larvae of mussels or clams. So they are kind of the canary in the mine shaft."

Pacific Northwest oyster growers already report having serious problems with oyster seed survival. They blame it on acidified water. Langdon says a frustrating¹⁷ discovery is that it's hard to get high levels of dissolved carbon dioxide out of seawater once it's in there.

So where does that leave people like western Washington oysterman and clam¹⁴ grower Bill Dewey?

"The likelihood of turning it around anytime soon is not good," says Dewey. "So we're definitely, in our industry, we're in the adaption mode, trying to find things we can do to the seawater chemistry in our hatcheries to allow us to produce the seed."

Researchers hope to explore possible water treatments for aquaculture farms and Dewey says he's heartened by the scientific attention directed at his industry's problem.

Future of the world's oceans

Separately, Norwegian, German and British scientists are looking at how marine¹⁸ species from their waters respond to rising acidity.

American researchers met recently with counterparts from the United Kingdom to coordinate¹⁹ experiments and discuss how best to model the future of the world's oceans.

Another area with high vulnerability are coral reefs.

They are already showing the effects of a warmer and more acidic ocean. For purposes of science, the rub is that corals are harder to keep alive in a lab. But there's an important reason to keep trying. Coral reefs are hugely important breeding grounds for many fish. And although reefs cover less than one percent of the sea floor, they support about 25 percent of all life in the ocean.
 

1 oyster   

n.牡蛎；沉默寡言的人

参考例句：

• I enjoy eating oyster; it's really delicious.我喜欢吃牡蛎，它味道真美。
• I find I fairly like eating when he finally persuades me to taste the oyster.当他最后说服我尝尝牡蛎时，我发现我相当喜欢吃。

2 oysters   

牡蛎( oyster的名词复数 )

参考例句：

• We don't have oysters tonight, but the crayfish are very good. 我们今晚没有牡蛎供应。但小龙虾是非常好。
• She carried a piping hot grill of oysters and bacon. 她端出一盘滚烫的烤牡蛎和咸肉。

3 shaft   

n.(工具的)柄，杆状物

参考例句：

• He was wounded by a shaft.他被箭击中受伤。
• This is the shaft of a steam engine.这是一个蒸汽机主轴。

4 cramped   

a.狭窄的

参考例句：

• The house was terribly small and cramped, but the agent described it as a bijou residence. 房子十分狭小拥挤，但经纪人却把它说成是小巧别致的住宅。
• working in cramped conditions 在拥挤的环境里工作

5 aquatic   

adj.水生的，水栖的

参考例句：

• Aquatic sports include swimming and rowing.水上运动包括游泳和划船。
• We visited an aquatic city in Italy.我们在意大利访问过一个水上城市。

6 scenario   

n.剧本，脚本；概要

参考例句：

• But the birth scenario is not completely accurate.然而分娩脚本并非完全准确的。
• This is a totally different scenario.这是完全不同的剧本。

7 chunk   

n.厚片，大块，相当大的部分（数量）

参考例句：

• They had to be careful of floating chunks of ice.他们必须当心大块浮冰。
• The company owns a chunk of farmland near Gatwick Airport.该公司拥有盖特威克机场周边的大片农田。

8 lesser   

adj.次要的，较小的；adv.较小地，较少地

参考例句：

• Kept some of the lesser players out.不让那些次要的球员参加联赛。
• She has also been affected,but to a lesser degree.她也受到波及，但程度较轻。

9 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。

10 soda   

n.苏打水；汽水

参考例句：

• She doesn't enjoy drinking chocolate soda.她不喜欢喝巧克力汽水。
• I will freshen your drink with more soda and ice cubes.我给你的饮料重加一些苏打水和冰块。

11 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。

12 prosper   

v.成功，兴隆，昌盛；使成功，使昌隆，繁荣

参考例句：

• With her at the wheel,the company began to prosper.有了她当主管，公司开始兴旺起来。
• It is my earnest wish that this company will continue to prosper.我真诚希望这家公司会继续兴旺发达。

13 acidity   

n.酸度，酸性

参考例句：

• This plant prefers alkaline soil,though it will readily tolerate some acidity.这种植物在酸性土壤中也能生存，但硷性土壤更加适宜。
• Gastric acidity would not prevent the organism from passing into the gut.胃的酸度不能防止细菌进入肠道。

14 clam   

n.蛤，蛤肉

参考例句：

• Yup!I also like clam soup and sea cucumbers.对呀！我还喜欢蛤仔汤和海参。
• The barnacle and the clam are two examples of filter feeders.藤壶和蛤类是滤过觅食者的两种例子。

15 clams   

n.蛤；蚌，蛤( clam的名词复数 )v.（在沙滩上）挖蛤( clam的第三人称单数 )

参考例句：

• The restaurant's specialities are fried clams. 这个餐厅的特色菜是炸蚌。 来自《简明英汉词典》
• We dug clams in the flats et low tide. 退潮时我们在浅滩挖蛤蜊。 来自辞典例句

16 larvae   

n.幼虫

参考例句：

• Larvae are parasitic on sheep.幼虫寄生在绵羊的身上。
• The larvae prey upon small aphids.这种幼虫以小蚜虫为食。

17 frustrating   

adj.产生挫折的，使人沮丧的，令人泄气的v.使不成功( frustrate的现在分词 )；挫败；使受挫折；令人沮丧

参考例句：

• It's frustrating to have to wait so long. 要等这么长时间，真令人懊恼。
• It was a demeaning and ultimately frustrating experience. 那是一次有失颜面并且令人沮丧至极的经历。 来自《简明英汉词典》

18 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。

19 coordinate   

adj.同等的，协调的；n.同等者；vt.协作，协调

参考例句：

• You must coordinate what you said with what you did.你必须使你的言行一致。
• Maybe we can coordinate the relation of them.或许我们可以调和他们之间的关系。