2006年VOA标准英语-Scientists Study Asian Snakehead Invasion of Po

By Malcolm Brown
Washington, D.C.
24 November 2006
 
watch Snakehead report

An aquatic¹ interloper appears to have adjusted easily to life in the Potomac River system near Washington, DC -- far from its native Asia, where it is regarded as a delicacy². The fierce-looking snakehead fish is far less popular in the United States, where scientists fear that it could damage local ecosystems⁴. While snakeheads have achieved unusual notoriety, Malcolm Brown reports the Asian fish is just one example among many of what are described as 'invasive species'.

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Snakehead fish can take over an ecosystem by devouring other fish species

Looking for northern snakeheads in a tributary⁶ of the Potomac.  The technique uses an electric current to stun⁷ nearby fish.

In the water is John Odenkirk, a biologist with the state of Virginia, who has watched the numbers rise.  "The most likely scenario⁸ is that this population will expand for a period of time and then drop back to a lower level and stabilize⁹, as this species kind of finds its niche¹⁰ in the system, as so many other exotics have done. Now, it's possible that it could be somewhat catastrophic. It's just impossible to say at this point."

Scientists have been studying the snakehead population closely to gauge¹¹ its impact ever since anglers first started catching¹² the voracious¹³ predator¹⁴ in the Potomac and its tributaries¹⁵ in 2004.  It is thought the snakeheads -- dubbed¹⁶ by the media as "Frankenfish" -- may have been introduced by an aquarium¹⁷ owner, or by someone looking to establish a new food resource.

The worry is that snakeheads like to eat other fish. Angling is a major sport on the Potomac and, consequently, big business.

It's how Steve Chaconas makes his living as a fishing guide. "Bass¹⁸ fishing here on the Potomac is really big. The Potomac is considered by a lot of the guys and pretty much industry people as one of the top five bass fisheries in the country.  What that translates to is every year you have a couple of top professional bass tournaments here that bring in a lot of money into the local economies."

Anglers worry that the snakeheads will eat young bass and compete for food, so they're doing their part to keep numbers down.

Derek Radoski is aiming to become an expert snakehead fisherman, but with some trepidation¹⁹.

"I am concerned about promoting the sport of snakehead fishing that people would move the snakeheads to other bodies of water to make it a sport there as well. So, that's not what I am looking to do. But to say that I am pleased about it; no, but it's a hell of a fun thing to do on the weekend, when I am not selling security equipment Monday through Friday."

Since their arrival in these waters, snakeheads have captured a lot of attention, but they are far from the only interloper in the region's waters.

Scientist Greg Ruiz studies invasive species for the Smithsonian Environmental Research Center. For him, the discovery of Chinese mitten²⁰ crab²¹ in the nearby Chesapeake Bay earlier in the year is potentially worrying, but not surprising.

"We know of hundreds of non-native species that are established in our bays and estuaries²². When you include fresh water, the number goes up; 500 to 1,000 perhaps."

An increase Ruiz attributes to the effects of globalization. "The number of non-native species arriving to our waters in North America is going up dramatically over time. Many people believe that's driven by trade; increasing trade, increasing opportunities for organisms to be moved around."

For those looking to stem that tide, the snakehead's success so far is not encouraging.

1 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。

2 delicacy   

n.精致，细微，微妙，精良；美味，佳肴

参考例句：

• We admired the delicacy of the craftsmanship.我们佩服工艺师精巧的手艺。
• He sensed the delicacy of the situation.他感觉到了形势的微妙。

3 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。

4 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

5 devouring   

吞没( devour的现在分词 )； 耗尽； 津津有味地看； 狼吞虎咽地吃光

参考例句：

• The hungry boy was devouring his dinner. 那饥饿的孩子狼吞虎咽地吃饭。
• He is devouring novel after novel. 他一味贪看小说。

6 tributary   

n.支流；纳贡国；adj.附庸的；辅助的；支流的

参考例句：

• There was a tributary road near the end of the village.村的尽头有条岔道。
• As the largest tributary of Jinsha river,Yalong river is abundant in hydropower resources.雅砻江是金沙江的最大支流，水力资源十分丰富。

7 stun   

vt.打昏，使昏迷，使震惊，使惊叹

参考例句：

• When they told me she had gone missing I was totally stunned.他们告诉我她不见了时，我当时完全惊呆了。
• Sam stood his ground and got a blow that stunned him.萨姆站在原地，被一下打昏了。

8 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。

9 stabilize   

vt.（使）稳定，使稳固，使稳定平衡；vi.稳定

参考例句：

• They are eager to stabilize currencies.他们急于稳定货币。
• His blood pressure tended to stabilize.他的血压趋向稳定。

10 niche   

n.壁龛；合适的职务(环境、位置等)

参考例句：

• Madeleine placed it carefully in the rocky niche. 玛德琳小心翼翼地把它放在岩石壁龛里。
• The really talented among women would always make their own niche.妇女中真正有才能的人总是各得其所。

11 gauge   

v.精确计量；估计；n.标准度量；计量器

参考例句：

• Can you gauge what her reaction is likely to be?你能揣测她的反应可能是什么吗？
• It's difficult to gauge one's character.要判断一个人的品格是很困难的。

12 catching   

adj.易传染的，有魅力的，迷人的，接住

参考例句：

• There are those who think eczema is catching.有人就是认为湿疹会传染。
• Enthusiasm is very catching.热情非常富有感染力。

13 voracious   

adj.狼吞虎咽的，贪婪的

参考例句：

• She's a voracious reader of all kinds of love stories.什么样的爱情故事她都百看不厌。
• Joseph Smith was a voracious book collector.约瑟夫·史密斯是个如饥似渴的藏书家。

14 predator   

n.捕食其它动物的动物；捕食者

参考例句：

• The final part of this chapter was devoted to a brief summary of predator species.本章最后部分简要总结了食肉动物。
• Komodo dragon is the largest living lizard and a fearsome predator.科摩多龙是目前存在的最大蜥蜴，它是一种令人恐惧的捕食性动物。

15 tributaries   

n. 支流

参考例句：

• In such areas small tributaries or gullies will not show. 在这些地区，小的支流和冲沟显示不出来。
• These tributaries are subsequent streams which erode strike valley. 这些支流系即为蚀出走向谷的次生河。

16 dubbed   

v.给…起绰号( dub的过去式和过去分词 )；把…称为；配音；复制

参考例句：

• Mathematics was once dubbed the handmaiden of the sciences. 数学曾一度被视为各门科学的基础。
• Is the movie dubbed or does it have subtitles? 这部电影是配音的还是打字幕的？ 来自《简明英汉词典》

17 aquarium   

n.水族馆，养鱼池，玻璃缸

参考例句：

• The first time I saw seals was in an aquarium.我第一次看见海豹是在水族馆里。
• I'm going to the aquarium with my parents this Sunday.这个星期天，我要和父母一起到水族馆去。

18 bass   

n.男低音(歌手)；低音乐器；低音大提琴

参考例句：

• He answered my question in a surprisingly deep bass.他用一种低得出奇的声音回答我的问题。
• The bass was to give a concert in the park.那位男低音歌唱家将在公园中举行音乐会。

19 trepidation   

n.惊恐，惶恐

参考例句：

• The men set off in fear and trepidation.这群人惊慌失措地出发了。
• The threat of an epidemic caused great alarm and trepidation.流行病猖獗因而人心惶惶。

20 mitten   

n.连指手套，露指手套

参考例句：

• There is a hole in the thumb of his mitten.他的手套的姆指上有个洞。
• He took her money in one hand and with the other hand he grasped her mitten and said "Take me to where you live.I want to see your brother and meet your parents".他一手接过她的钱，一手抓起她的连指手套，“带我去你住的地方，我想见见你的弟弟和你的父母。

21 crab   

n.螃蟹，偏航，脾气乖戾的人，酸苹果；vi.捕蟹，偏航，发牢骚；vt.使偏航，发脾气

参考例句：

• I can't remember when I last had crab.我不记得上次吃蟹是什么时候了。
• The skin on my face felt as hard as a crab's back.我脸上的皮仿佛僵硬了，就象螃蟹的壳似的。

22 estuaries   

（江河入海的）河口，河口湾( estuary的名词复数 )

参考例句：

• We also recognize the diversity and complexity of controlling in fluences in estuaries. 我们也认识到在河湾内控制影响的多样性和复杂性。
• Estuaries also contribute to economy through tourism and fishing. 河口还为人类提供了休闲和教育的场所。