科學家稱氣候變化可能導致魚類萎縮

As the world's oceans heat up, salmon are migrating earlier. Plankton are shifting their range.

由於全球海洋升溫，所以鮭魚洄游的時間提前了。浮游生物也在改變它們的生存範圍。

But warmer water temperatures also mean warmer fish—and faster-running metabolisms.

而水溫升高也意味着魚類的體溫升高，新陳代謝也會加快。

"Fish that are in water of higher temperature have a higher metabolic rate, meaning they have to consume more oxygen," said Daniel Pauly, a fisheries scientist at the University of British Columbia.

英國哥倫比亞大學的漁業科學家丹尼爾·保利表示：“在高溫水中生活的魚類的新陳代謝率也較高，這表明它們要消耗更多氧氣。”

"Because essentially the whole metabolism, all the chemical reactions in your body, are accelerated."

“因爲從本質上說，體內整個新陳代謝和所有的化學反應都在加速。”

So, how about growing bigger gills to allow for more oxygen intake? Pauly did the physiological math, and concluded that bigger gills just won't do the job.

那要是通過長出更大的魚鰓來攝入更多氧氣呢？保利就此進行了生理學運算，結論是魚鰓變大並不能吸入更多氧氣。

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.

他表示，因爲相對來說魚鰓的結構是平面的，而其它部位是立體的，所以魚鰓變大跟不上身體增長的氧氣需求。

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.

相反，保利的計算表明，爲了滿足自身日益增長的氧氣需求，所有魚類的體型可能都會縮小，這就是氣候變化造成的後果。

With decreased supply, they'll need to lower demand. The study is in the journal Global Change Biology.

隨着供給減少，它們的需求也會減少。這項研究結果發表在《全球變化生物學》期刊上。

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."

還有一個細節值得一提：水溫升高會導致水中的溶解氧含量減少。“因此，需求增加和供給減少這兩種因素共同作用，會使魚類體型變小。”