密歇根新闻广播 研究人员利用鳗鱼梯子来捕杀八目鳗

 

The sea lamprey is an invasive fish with a round mouth like a suction cup. It latches¹ onto big fish like lake trout² and salmon³, drills its razor sharp tongue into them, and gets fat drinking their blood and body fluids. A single lamprey can kill up to 40 pounds of fish in its lifetime.

We spend about $20 million dollars a year to control lampreys. One of the main ways people do that is with a pesticide⁴, but researchers are working on other ways to control the invasive species.

Michigan State University researchers are testing something called a sea lamprey ladder.

Michael Wagner is a sea lamprey expert and an associate professor in the Department of Fisheries and Wildlife at MSU.

He compares the ladder to a classic game: Plinko.

“It’s a board and studded with pegs⁵. It’s put into the water at a steep angle - about 45 degrees - and it has water running over the surface of it. And eel-like fishes, like sea lamprey and American eels⁶, can climb this ladder by pushing off against these pegs, where most other fishes can’t,” says Wagner.

The ladders are designed to control the flow of sea lamprey through dams. Wagner says the idea is to guide the lamprey to one side of the dam, using an “alarm cue” scent⁷ that sea lamprey release when facing a predator⁸.

Wagner explains the ladder system this way:

“So imagine now that we have this fish ladder over on one side of the dam, and we’re pumping this alarm cue down it that the sea lamprey smell and they don’t want anything to do with going over there. And then on the other side of the dam, we installed these trapping devices with this ladder on it," he says. "So we guide the sea lamprey over there. They can go up this ladder and they get trapped. But any of the other fish that encounter it can’t go over it, and don’t get trapped.”

Wagner says they've had some success but they still have a ways to go.

"We’re very early in the research. This project that we started this year is the first attempt to try to prove the concepts underlying⁹ one of these selective fish passage devices,” he says.

1 latches   

n.（门窗的）门闩( latch的名词复数 )；碰锁v.理解( latch的第三人称单数 )；纠缠；用碰锁锁上（门等）；附着（在某物上）

参考例句：

• The virus latches onto the red blood cells. 这种病毒附着在红细胞上。 来自《简明英汉词典》
• The opposite end latches onto the pathogen. 相对的一端锁在病原体上。 来自英汉非文学 - 生命科学 - 预防生物武器

2 trout   

n.鳟鱼；鲑鱼(属)

参考例句：

• Thousands of young salmon and trout have been killed by the pollution.成千上万的鲑鱼和鳟鱼的鱼苗因污染而死亡。
• We hooked a trout and had it for breakfast.我们钓了一条鳟鱼，早饭时吃了。

3 salmon   

n.鲑，大马哈鱼，橙红色的

参考例句：

• We saw a salmon jumping in the waterfall there.我们看见一条大马哈鱼在那边瀑布中跳跃。
• Do you have any fresh salmon in at the moment?现在有新鲜大马哈鱼卖吗？

4 pesticide   

n.杀虫剂，农药

参考例句：

• The pesticide was spread over the vegetable plot.菜田里撒上了农药。
• This pesticide is diluted with water and applied directly to the fields.这种杀虫剂用水稀释后直接施用在田里。

5 pegs   

n.衣夹( peg的名词复数 )；挂钉；系帐篷的桩；弦钮v.用夹子或钉子固定( peg的第三人称单数 )；使固定在某水平

参考例句：

• She hung up the shirt with two (clothes) pegs. 她用两只衣夹挂上衬衫。 来自辞典例句
• The vice-presidents were all square pegs in round holes. 各位副总裁也都安排得不得其所。 来自辞典例句

6 eels   

abbr. 电子发射器定位系统（=electronic emitter location system）

参考例句：

• Eels have been on the feed in the Lower Thames. 鳗鱼在泰晤士河下游寻食。
• She bought some eels for dinner. 她买回一些鳗鱼做晚餐。

7 scent   

n.气味，香味，香水，线索，嗅觉；v.嗅，发觉

参考例句：

• The air was filled with the scent of lilac.空气中弥漫着丁香花的芬芳。
• The flowers give off a heady scent at night.这些花晚上散发出醉人的芳香。

8 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。

9 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。