科学美国人60秒 SSS Climate Change Might Shrink Fish（在线收听）

Climate Change Might Shrink Fish

气候变化会迫使鱼类变小

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

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 metabolic rate, meaning they have to consume more oxygen." Daniel Pauly, a fisheries scientist at the University of British Columbia. "Because essentially the whole metabolism, 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 intake? Pauly did the physiological math, and concluded that bigger gills won’t do the job. Because he says gills, being relatively 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。