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Climate Change Might Shrink Fish

气候变化会迫使鱼类变小

As the world's oceans heat up, salmon¹ are migrating earlier. Plankton² are shifting their range. But warmer water temperatures also mean warmer fish—and faster-running metabolisms⁴.

随着全球海洋升温，鲑鱼迁徙的时间也在提前，浮游生物也在变换生存范围。水温升高也意味着鱼类的体温变高，新陈代谢也变快。

\"Fish that are in water of higher temperature have a higher metabolic⁵ rate, meaning they have to consume more oxygen." Daniel Pauly, a fisheries scientist at the University of British Columbia. "Because essentially⁶ the whole metabolism³, all the chemical reactions in your body, are accelerated."

“在温度较高的水中生存的鱼类，其新陈代谢率也会较高，而这意味着它们必须消耗更多的氧气。”英国哥伦比亚大学的渔业科学家丹尼尔·保利说道，“因为本质上，身体的新陈代谢即体内的所有化学反应都在加速。”

So, how about growing bigger gills to allow for more oxygen intake⁷? Pauly did the physiological⁸ math, and concluded that bigger gills won’t do the job. Because he says gills, being relatively⁹ two-dimensional, simply can't keep up with the three-dimensional growth of the rest of a fish's body.

那么，通过长出较大的鱼鳃来增加氧气吸入量可好？保利就此进行了生理推算，得出结论是鱼鳃变大并不能达到这种效果。他表示，相对来说鱼鳃是二维的，因此它无法跟上鱼身其他部分的三维生长。

Instead, Pauly's calculations suggest that, to feed their increasing need for oxygen, fish of all kinds may actually shrink as a result of climate change. With decreased supply, they’ll need to lower demand. The study is in the journal Global Change Biology.

保利的计算表明，为了满足自身日益增长的氧气需求，鱼类们实际上反而可能会因气候变化而萎缩。随着供给减少，它们需要减少需求。这项研究发表在《全球变化生物学》杂志上。

One more detail bears mentioning: warmer water also holds less dissolved oxygen. "So the two effects, increased demand and the lowered supply are working towards making the fish smaller."

还有一个细节值得一提：较温暖的水温下含有的溶解氧也较少。“因此，在需求增长和供给减少的共同影响下，鱼类将朝着变小的方向发展。“”

Which means future fishermen might find a lot of lower-value small fry in their nets.

这意味着将来渔民们可能会在渔网中发现许多低价值的小鱼。