This is Scientific American — 60-Second Science. I'm Christopher Intagliata.
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.
"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."
So, how about growing bigger gills to allow for more oxygen intake? Pauly did the physiological math, and concluded that bigger gills just 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.
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.
One more detail bears mentioning: that is the warmer water also holds less dissolved oxygen. "So the two effects, increased demand and the lowered supply are working towards making the fish smaller."
Which means future fishermen might find a lot of lower-value small fry in their nets.
Thanks for listening for Scientific American — 60-Second Science Science. I'm Christopher Intagliata.
因为全球海洋升温，所以鲑鱼洄游的时间提前了 。浮游生物也在改变它们的生存范围 。而水温升高也意味着鱼类的体温升高，新陈代谢也会加快 。
“在高温水中生活的鱼类的新陈代谢率也较高，这表明它们要消耗更多氧气 。”英国哥伦比亚大学的渔业科学家丹尼尔·保利说道 。“因为从本质上说，体内整个新陈代谢和所有的化学反应都在加速 。”
那要是通过长出更大的鱼鳃来摄入更多氧气呢？保利就此进行了生理学运算，结论是鱼鳃变大并不能吸入更多氧气 。他表示，因为相对来说鱼鳃的结构是平面的，而其它部位是立体的，所以鱼鳃变大跟不上身体增长的氧气需求 。
相反，保利的计算表明，为了满足自身日益增长的氧气需求，所有鱼类的体型可能都会缩小，这就是气候变化造成的后果 。随着供给减少，它们的需求也会减少 。这项研究结果发表在《全球变化生物学》期刊上 。
还有一个细节值得一提：水温升高会导致水中的溶解氧含量减少 。“因此，需求增加和供给减少这两种因素共同作用，会使鱼类体型变小 。”
谢谢大家收听科学美国人——60秒科学 。我是克里斯托弗·因塔利亚塔 。
1. heat up 变热；
例句：In the summer her mobile home heats up like an oven.
2. how about （用于提出建议或邀请）怎么样好吗；
例句：How about going shopping and seeing a show in London?
3. keep up with 跟上（变化等）；
例句：If you want to keep up with the times, you have to get a large amount of information.
4. as a result of 结果；后果；成果；效果；
例句：As a result of this conflict he lost both his home and his means of livelihood.