2020年经济学人为什么海龟吃塑料垃圾(2)（打印版）

To test that idea, he and his colleagues set up an experiment involving loggerhead turtles, a species frequently killed by plastic.

为了验证这个想法，他和他的同事们做了一个实验，实验对象是经常被塑料杀死的红海龟。

They arranged for 15 of the animals, each around five months old, to be exposed, in random order,

他们安排了15只动物，每只大约5个月大，按照随机的顺序，让它们闻四种气味，

to four odours delivered through a pipe to the air above an experimental arena.

这些气味通过管道输送到实验场地上方的空气中。

The odours were: the vapour from deionised water; the smell of turtle-feeding pellets made of shrimp and fish meal;

这四种气味是：去离子水的蒸汽；由虾和鱼粉制成的喂海龟的小丸的味道

the smell of a clean plastic bottle chopped up into ten pieces;

一个被切成10块的干净的塑料瓶的味道；

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.

以及类似被切块的瓶子的味道，这个瓶子在海洋里漂了五周，上边长满了海藻和细菌。

Two of the smells proved far more attractive to the animals than the others.

事实证明，其中两种气味对动物的吸引力要比其他气味大得多。

When sniffing both the odour of food pellets and that of five-week-old bottles

当海龟闻食物颗粒的气味和那个五周瓶子的气味时，

turtles kept their nostrils out of the water more than three times as long,

它们鼻子离水时间是闻到新鲜塑料瓶或去离子水蒸汽气味时的三倍，

and took twice as many breaths as they did when what was on offer was the smell of fresh bottle-plastic or deionised-water vapour.

呼吸的次数是闻到新鲜塑料瓶或去离子水蒸汽气味时的两倍。

On the face of it, then, the turtles were responding to the smell of old bottles as if it were the smell of food.

从表面上看，海龟对旧瓶子的气味的反应就像闻到食物的气味一样。

Though they have not yet tested whether dimethyl sulphide is the culprit,

尽管他们还没有测试过是否二甲基硫化物是罪魁祸首，

Dr Pfaller and his colleagues think it is the most likely candidate.

但Pfaller博士和他的同事认为它是最有可能的候选者。

In an unpolluted ocean, pretty well anything which had this smell would be edible—or, at least, harmless.

在一个没有污染的海洋里，任何有这种气味的东西都是可以食用的——或者至少是无害的。

Unfortunately, five-week-old plastic bottles and their like are not.

不幸的是，漂浮五周的塑料瓶和类似的东西却不是。