科学美国人60秒 SSS 年轻大白鲨吃底栖鱼类

This is Scientific American's 60-second Science, I'm JasonGoldman.

这里是科学美国人——60秒科学系列，我是杰森·古德曼。

The image of a dorsal¹ fin² cutting through the sea surface is iconic.

背鳍划破海面是种标志性画面。

But scientists studying the stomach contents of young great white sharks off the coast of Australia were in for a surprise

但是，研究澳大利亚沿海年轻大白鲨胃内容物的科学家，

when they learned that the predators⁴ seem to spend a lot of time patrolling the seafloor.

在发现这种食肉动物似乎花大量时间在海底巡游时，还是大吃了一惊。

"They have a predominantly fish-based diet, which is not unexpected for juvenile⁵ white sharks.

“它们的食物以鱼类为主，这对幼年大白鲨来说不足为奇。

The most important prey⁶ species we identified was eastern Australian salmon⁷."

我们此前识别出的最重要猎物种类是东澳大利亚三文鱼。”

University of Sydney graduate student Richard Grainger.

悉尼大学研究生理查德·格兰杰说到。

He and his team sorted through the stomach contents of more than 50 juvenile white sharks

他和团队将50多只幼年大白鲨的胃内容物进行了分类，

that died after being entangled⁸ in shark exclusion⁹ nets meant to protect swimmers.

这些大白鲨因被用来保护游泳者的防鲨网缠住而死亡。

"The overall unexpected finding was just the diversity and importance of bottom-dwelling fishes.

“全部出乎意料的发现是，底栖鱼类的多样性和重要性。

Things like stargazers—which bury themselves in the sand, they're quite strange-looking fish—and flathead but also stingrays."

比如将自已埋进沙子的胆星科鱼，它们的外表非常奇怪，还有鲬科鱼和黄貂鱼。”

People actually did not have a good idea of the particulars of great white shark diets.

人们其实并不太了解大白鲨饮食的特殊性。

As Grainger points out, the sharks enjoy protections throughout the world.

正如格兰杰所指出，大白鲨享受着世界各地的保护。

So most researchers estimated their diets through the chemical markers that they can ethically¹⁰ access by taking small skin samples.

因此，大多数研究人员通过化学标志物来估计大白鲨的饮食，这些化学标志物可以从小块皮肤样本上道德地获取。

These measurements indicate at what level of the food chain the predator³ is feeding but not the actual critters that make up their meals.

这些测量结果显示的是这种食肉动物在食物链的哪个层次进食，而不是其饮食由哪些实际生物组成。

"There's quite a lot of evidence that lots of different animals,

“有相当多的证据表明，它们吃许多不同的动物，

so even carnivores, omnivores, herbivores self-select different prey or food based on a particular balance of nutrients¹¹."

有食肉动物、杂食动物、草食动物，也会根据特定营养平衡自行选择不同的猎物或食物。”

Grainger hopes that by further understanding what juvenile white sharks like to eat,

格兰杰希望，通过进一步了解幼年大白鲨喜欢的食物，

he can begin to piece together how and why they make their predatory choices.

他可以开始拼凑出它们做出捕食选择的方式和原因。

The study was published in the journal Frontiers in Marine¹² Science.

这项研究发表在《海洋科学前沿》期刊上。

"Understanding and predicting when sharks might be more abundant in certain areas would be an ultimate end goal."

“最终目标是，了解和预测大白鲨在某些地区何时会数量更为丰富。”

Avoiding or mitigating¹³ human-shark conflicts means understanding the sharks' nutritional¹⁴ goals.

避免或缓解人类与鲨鱼的冲突，意味着了解鲨鱼的营养目标。

And if researchers can anticipate where and when sharks are likely to spend their time hunting,

如果研究人员能够预测鲨鱼可能在何时何地捕食，

they can better protect humans from getting bitten—and sharks from getting killed.

他们就能更好地保护人类不被咬伤，同时保护鲨鱼不被杀死。

Thanks for listening for Scientific American's 60-second Science. I'm Jason Goldman.

谢谢大家收听科学美国人——60秒科学。我是杰森·古德曼。

1 dorsal   

adj.背部的，背脊的

参考例句：

• His dorsal fin was down and his huge pectorals were spread wide.它的脊鳍朝下耷拉着，巨大的胸鳍大张着。
• The shark's dorsal fin was cut off by the fisherman.鲨鱼的背鳍被渔夫割了下来。

2 fin   

n.鳍；(飞机的)安定翼

参考例句：

• They swim using a small fin on their back.它们用背上的小鳍游动。
• The aircraft has a long tail fin.那架飞机有一个长长的尾翼。

3 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。

4 predators   

n.食肉动物( predator的名词复数 )；奴役他人者（尤指在财务或性关系方面）

参考例句：

• birds and their earthbound predators 鸟和地面上捕食它们的动物
• The eyes of predators are highly sensitive to the slightest movement. 捕食性动物的眼睛能感觉到最细小的动静。 来自《简明英汉词典》

5 juvenile   

n.青少年，少年读物；adj.青少年的，幼稚的

参考例句：

• For a grown man he acted in a very juvenile manner.身为成年人，他的行为举止显得十分幼稚。
• Juvenile crime is increasing at a terrifying rate.青少年犯罪正在以惊人的速度增长。

6 prey   

n.被掠食者，牺牲者，掠食；v.捕食，掠夺，折磨

参考例句：

• Stronger animals prey on weaker ones.弱肉强食。
• The lion was hunting for its prey.狮子在寻找猎物。

7 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？

8 entangled   

adj.卷入的；陷入的；被缠住的；缠在一起的v.使某人（某物/自己）缠绕，纠缠于（某物中），使某人（自己）陷入（困难或复杂的环境中）( entangle的过去式和过去分词 )

参考例句：

• The bird had become entangled in the wire netting. 那只小鸟被铁丝网缠住了。
• Some military observers fear the US could get entangled in another war. 一些军事观察家担心美国会卷入另一场战争。 来自《简明英汉词典》

9 exclusion   

n.拒绝，排除，排斥，远足，远途旅行

参考例句：

• Don't revise a few topics to the exclusion of all others.不要修改少数论题以致排除所有其他的。
• He plays golf to the exclusion of all other sports.他专打高尔夫球，其他运动一概不参加。

10 ethically   

adv.在伦理上，道德上

参考例句：

• Ethically , we have nothing to be ashamed about . 从伦理上说，我们没有什么好羞愧的。
• Describe the appropriate action to take in an ethically ambiguous situation. 描述适当行为采取在一个道德地模棱两可的情况。

11 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》

12 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。

13 mitigating   

v.减轻，缓和( mitigate的现在分词 )

参考例句：

• Are there any mitigating circumstances in this case ? 本案中是否有任何情况可以减轻被告的罪行？ 来自辞典例句
• A sentencing judge is required to consider any mitigating circumstances befor imposing the death penalty. 在处死刑之前，要求量刑法官必须考虑是否有任何减轻罪行之情节。 来自口语例句

14 nutritional   

adj.营养的，滋养的

参考例句：

• A diet lacking in nutritional value will not keep a person healthy.缺乏营养价值的饮食不能维持人的健康。
• The labels on food products give a lot of information about their nutritional content.食品上的标签提供很多关于营养成分的信息。