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科学美国人60秒: 不可思议的鲑鱼

lzy 于2017-11-21发布 l 已有人浏览
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不可思议的鲑鱼
    小E英语欢迎您,请点击播放按钮开始播放……
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Salmon Sex Changes Entire Landscape
不可思议的鲑鱼
Sex. It drives people to do crazy things. Animals too. They’ll make unsettling sounds, perform complex dances, or show off giant plumes of colorful feathers. And, famously, salmon will swim hundreds of kilometers upstream to get down to business. They also inadvertently rework the landscape.
性。会让人们做些疯狂的事情。动物也不例外。它们会发出让人心绪不宁的声音,表演舞蹈,抑或是骚首弄姿炫耀绚丽的羽毛。最出名的是,鲑鱼会向上游游数百千米来办事。无意之中,它们也改造了景观。
“Adult salmon spend most of their life out in the ocean and then they come in to freshwater to mate.” Washington State University ecologist Alex Fremier.
成年鲑鱼一生中多数的时间在海里,然后然后它们游到淡水区去交配。Alex Fremier是华盛顿大学的生态学家。
“What the female salmon will do is, she digs a hole in the streambed.”
词性鲑鱼所需要做的就是在河床上挖一个洞。
That little hole is called a redd. That’s where the salmon lays her eggs. And Fremier says when she builds it, she basically “unpacks” the stream bed, making all those loose sands and gravels more mobile. High water and flooding events move that sediment, which in turn exposes bedrock to further erosion.
挖的这个小洞叫做“redd”。这是鲑鱼产卵的地方。Fremier表示,当雌性鲑鱼建造好这个洞以后,她基本上就算将这个洞“打包”了。让松软沙子和碎石更易流动。涨潮期以及汛期会移动砂石沉积物,反过来也会让增加基岩的腐蚀程度。

“It’s quite impressive. We did not expect to have salmon, in some cases, changing the vertical position of a river channel up to 30 percent more than it would have without salmon in it.”
Fremier hypothesized that salmon not only influence landscape evolution, but that the evolution of salmon as a species itself has a landscape-level impact. To test the idea, he and colleagues recreated salmon redds in an experimental flume. Then they compared findings from the flume with real field observations.

“确实让人印象深刻。与没有鲑鱼的河道相比,我们没有想过鲑鱼会将河道的垂直距离改变30%多。,”

They cross-referenced all that data with discoveries from a study that modelled river profile erosion over five million years.
Fremier假设道鲑鱼不仅可以影响景观演化,同时鲑鱼这种物种自身的进化也会影响自然景观。为了验证想法的正确性,Fremier和同事们在实验的水槽中制造了鲑鱼的“redd”。之后,他们将研究结果与实地中的观察结果进行了比较。并将发现的所有数据和之前模拟的五百万年前的河流横断面的研究进行了对照。
“We were stunned by the fact that it actually had a larger scale effect, given that we account for tectonic uplift, the big floods, like a lot of flood water moving downstream, different conditions of the gravel sizes on the river. I think we were all surprised by the fact that salmon could have such a large effect at that million-year scale.” The study is in the journal Geomorphology.
实际上,鉴于构造隆起、洪水,如大量洪水向下游移动,河流里不同的沙砾大小。我认为,鲑鱼对上百万年的地貌产生如此大的影响,让我们都很吃惊。
So the next time you’re hip-deep in water angling for the big one, just remember: were it not for the risqué behavior of your future dinner, the terrain around you could look vastly different.
该研究结果发表在《地形学》杂志上。
所以,下次,你如果想在水里找一个大个的鲑鱼,那么请记住:要不是因为以后的晚餐这种行为,那么你周围的地貌会有很大的不同。
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