经济学人精读|海龟误食塑料，原来不是因为长得像食物

本文节选自《经济学人》2020.3.14期Science & technology版块的一篇文章《Why turtles eat plastic》，介绍了海龟为什么会吃塑料袋的新研究

本文总共6段，建议大家先自主阅读原文，再学习精读笔记。

文末会总结此次学习写作可以使用的词句，读者也可自己总结。会定期将内容进行总结，做成word分享，希望大家也能坚持学习

Turtles have an unfortunate habit of devouring plastic objects floating in the sea. These thenget snared in their alimentary canals, cannot be broken down by the animals’ digestive enzymes and may ultimately kill them. It is widely assumed that this penchant for plastics is a matter of mistaken identity. Drifting plastic bags, for instance, look similar to jellyfish, which many types of turtles love to eat. Yet lots of plastic objects that end up inside turtles have no resemblance to jellyfish. Joseph Pfaller of the University of Florida therefore suspects that something more complicated is going on. As he writes in Current Biology, he thinks that the odorof marine microorganisms which colonize floating plastic objects induces turtles to feed.

have an unfortunate habit of：有一个不幸的习惯

devour：to eat all of sth quickly, especially because you are very hungry【词汇积累】

get snared in their alimentary canals：残留在消化系统中，可以记住be snared in这个词组。snare意为伴住，缠住，be snared in意为被缠住，alimentary canals表示消化系统【词组积累】

be broken down：被分解，A be broken down into sth，A被分解成……，文中指的是塑料物在消化系统中无法被分解【词组积累】

ultimately：最终

It is widely assumed that ……：人们普遍认为，assume释义为认为，to think or accept that sth is true but without having proof of it【句式】

penchant for：喜好某事【词汇积累】

sth is a matter of mistaken identity：a matter of表示“……的问题”，mistaken identity认错身份，弄错身份。文中是指海龟喜欢吃塑料是认错【词汇积累】

jellyfish：水母

end up inside turtles：最终落在海龟肚中

have no resemblance to jellyfish：和水母不像，have no resemblance to sth与某物不相像，look similar to sth则表示与某物相似。【词组积累】

odor：气味

colonize：~ sth（在某一地区）聚居，大批生长to live or grow in large numbers in a particular area。Colonize 后面的名词可表示地点。【词汇积累】

induces turtles to feed：induce sb to do sth诱使某人做某事，这里和下一段中的lure sb to do sth是相似的意思，lure animals to their doom引诱动物步入死亡，doom表示厄运，毁灭和死亡【词组积累】

海龟有吞食漂浮在海上的塑料物的不幸习惯。这些塑料物残留在消化系统中，无法被消化酶分解，最终可能会杀死他们。人们普遍认为这种对塑料的喜爱是因为把塑料认错了的原因。例如，漂浮的塑料袋和水母看上去很像，而很多海龟都喜欢吃水母。然而，很多最终被吞食到海龟肚中的塑料物和水母并不相像。因此Joseph Pfaller怀疑这之中还有更复杂的原因。在当代生物学中，他写道海洋微生物在漂浮的塑料物处繁殖，其气味吸引海龟来食用。

The idea that the smell of plastic flotsam might lure animals to their doom first emerged in 2016. Researchers at the University of California, Davis, noticed that certain chemicals, notably dimethyl sulphide, which are released into the air by micro-organism-colonized plastics, are those which many seabirds sniff to track down food. These chemicals mark good places to hunt because they indicate an abundance of the algae and bacteria that lie at the bottom of marine food chains. The researchers also found that birds which pursue their food in this way are five or six times more likely to eat plastic than those which do not.

The idea first emerged in 2016：某个想法第一次出现于……【句式】

plastic flotsam：塑料漂浮物，flotsam表示漂浮物，这里这个词组代替了上文中的plastic objects floating in the sea【词汇积累】

certain chemicals, notably dimethyl sulphide：特定的化学物质，尤其是二甲硫化物，这里notably与especially意义相近【同意替换】

micro-organism-colonized plastics：布满微生物的塑料物

sniff to track down food：track down food追踪食物，sniff表示闻，即通过闻气味的方式追踪食物，下文中还有pursue their food，同样表示追踪食物【同意替换】

mark good places to hunt：标志了优良的捕猎场所，mark，标记，信号笔也是mark

an abundance of……：丰富的……【词组积累】

algae and bacteria：algae and bacteria：藻类和细菌

塑料的味道可能会引诱动物步入死亡，这个想法初次出现于2016年，研究者们发现某些特定的化学物质，尤其是二甲硫化物，这种由布满微生物的塑料释放到空气中的物质，很多海鸟通过闻它来追踪食物。这些物质标志了优良的捕猎场所，因为他们表明那里存在着丰富的藻类和细菌，是海洋食物链的底层。研究者们也发现以这种方式追踪食物的鸟类误食塑料的机率是其他鸟类的5到6倍。

Since turtles are known to break the surface periodically and sniff the air when navigating towards their feeding areas, Dr Pfaller theorized that they are following these same chemicals, and are likewise fooled into thinking that floating plastic objects are edible.

are known to break the surface periodically and sniff the air：break the surface表示露出水面，通常是break the surface of water，are known to表示某件事为人所知【词组积累】

theorize that：theorize是theory的动词形式，表示形成理论，建立理论【词汇积累】

are fooled into thinking：be fooled into doing意为被骗做某事，误以为……做某事【词组积累】

edible：可食用的

因为海龟在前往捕食场所时会露出水面呼吸空气，Pfaller认为它们也以这种同样的物质作为导航指向，并有可能被误导，认为漂浮塑料是可食用的。

To test that idea, he and his colleagues set up an experiment involving loggerhead turtles, a species frequently killed by plastic. They arranged for 15 of the animals, each around five months old, to be exposed, in random order, to four odours delivered through a pipe to the air above anexperimental arena. The odors were: the vapor from deionized water; the smell of turtle-feeding pellets made of shrimp and fish meal; the smell of a clean plastic bottle chopped up into ten pieces; and the smell of a similarly chopped bottle that had been kept in the ocean for five weeks to allow algae and bacteria to grow on it.

set up an experiment involving loggerhead turtles：建立了一个以蠵龟为对象的实验，这里involving是which involves，以简洁的方式说明实验对象为蠵龟【句式】

experimental arena：实验平台

deionized water：去离子水

turtle-feeding pellets：海龟饲料球

chopped up into ten pieces：切成十个碎片，chop up意为切断【词组积累】

为了验证这个想法，他和同事们建立了一个实验，使用蠵龟作为实验对象，这是一种经常被塑料杀死的种类。他们安排了15只，每只的年龄都在5个月左右，他们以随机次序暴露于4种气味，通过管道传送至实验平台。这些气味是：去离子水蒸气味，由虾和鱼肉制成的海龟饲料球的气味，切成10片的干净的塑料瓶的气味，以及被放在海里5周，拥有海藻和细菌生成于上的相同的塑料碎片的气味。

Two of the smells proved far more attractive to the animals than the others. When sniffing both the odor of food pellets and that of five-week-old bottles turtles kept their nostrils out of the water more than three times as long, and took twice as many breaths as they did when what was on offer was the smell of fresh bottle-plastic or deionized-water vapor. On the face of it, then, the turtles were responding to the smell of old bottles as if it were the smell of food.

A proved far more attractive to B：A的气味对B更具吸引力

On the face of it：从表面上看起来，乍一看起来。表示初步判断，没有经过更细致的检测【词组积累】

两种气味比其他两种更具吸引力，当闻到食物球气味和放置于海里5周的塑料瓶碎片的气味时，海龟探出鼻子呼吸的时间长度是原来的3倍，呼吸次数是其他两种气味的两种。初步看起来，海龟对于放置于海中较久时间的塑料瓶，会把它们当做食物的味道。

Though they have not yet tested whether dimethyl sulphide is the culprit, Dr Pfaller and his colleagues think it is the most likely candidate. In an unpolluted ocean, pretty well anything which had this smell would be edible—or, at least, harmless. Unfortunately, five-week-old plastic bottles and their like are not.

it is the most likely candidate.：这是最有可能的犯罪凶手，candidate是候选人，最理想的对象，这里指的是最理想的culprit【词汇积累】

pretty well：差不多，几乎【词汇积累】

A and their like：their like指的是A这种物质的同类物质【词汇积累】

尽管它们没有检测二甲硫化物是不是罪魁祸首，但Pfaller和他的同事们认为它是最有可能的元凶。在一片未受污染的海域，几乎任何拥有这种气味的东西都是可食用的，或者，至少是无害的。不幸的是，5周时间的塑料瓶，以及同类的物质并非无害。

总结