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发表于 2017-8-6 16:29:46
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By 2012 their distribution was skewed towards the northern part of that sea.
到2012年，这些浮游生物的影响更倾向于北极海域的北部地区。
Stocks of capelin used to be concentrated south of Svalbard, at latitude 75°N.
以前，大量的毛鳞鱼—是鲟鱼的食物—集中于北纬75度的斯瓦尔巴群岛南部。
In 2012 this had moved to 78°N. Some found their way as far up as 80°N.
而2012年，发现它们已经迁移到了北纬78度。还有些人甚至发现它们已经远移至北纬80度。
Which all sounds most promising.
这些似乎让大多数人看到了希望。
But many researchers think it will not continue.
但是，许多研究者认为，这种情况不会再持续下去。
First, the central Arctic is too deep for some important species, such as the polar cod.
首先，对某些重要物种来说，比如，极地鲟鱼北极中心的海域太深。
Young polar cod are pelagic, meaning they live at or near the surface.
年幼的极地鲟鱼是海洋生物，也就是说他们生活在或者接近海平面。
Those one or more years old are benthic, meaning they live near the bottom. In the Beaufortthat bottom is 200 metres down.
那些一岁或者以上的鲟鱼是深海生物，他们生活的区域接近海底。
In the central Arctic it descends to about 4,000 metres, which is too deep for polar cod tosurvive.
在博福尔，最深处就是200米以下。而北极中心的海底是约4,000米以下，那里对鲟鱼来说太深了无法生存。
A second reason why there may be no bonanza is acidification of the ocean.
渔业没有发展前途的第二个原因是海洋的酸化。
When water absorbs carbon dioxide, it produces carbonic acid.
当水吸收二氧化碳时会产生碳酸。
More CO2 means oceans everywhere are becoming more acidic, but the phenomenon isparticularly marked at high latitudes because cold water absorbs CO2 more readily thanwarm water does.
更多的二氧化碳意味着海洋的各个地方都会变得更加酸化，但是这种现象在高纬度地区特别明显，因为寒冷的水会更易于吸收二氧化碳。
The retreat of the ice also exposes ever more sea to do the absorbing.
加上冰块的融化也暴露了更多的海水，加速了对二氧化碳的吸收。
Cruises by the United States Geological Survey and the University of South Florida over thepast three years have found rising carbonic-acid levels north of Alaska.
美国地质调查局和美国南佛罗里达大学在过去三年里的巡查发现，阿拉斯加北部海水的酸化程度在上升。
They have also discovered that the shells of many organisms in the area are short ofaragonite, a form of calcium carbonate that gives them strength, but whose formation aciddiscourages.
他们也发现，这里许多生物的外壳缺少文石—一种让这些生物产生力量的碳酸钙形式—但是，它们体内的酸性形式阻碍了这种物质的合成。
Weaker shells means fewer shelled organisms and less food for fish.
不够强硬的外壳就表示带壳生物和供鱼类食用的生物越来越少。
The most important reason, though, for thinking that global warming will not produce anArctic feeding frenzy is that it may increase ocean stratification.
但是，认为全球变暖不会使北极成为巨大“经济资源”最重要的原因是，它可能会加剧海洋的分层化。
This is the tendency of seawater to separate into layers, because fresh water is lighter thansalt and cold water heavier than warm. The more stratified water is, the less nutrients in itmove around.
这是一种海水分层的趋势，因为新鲜水比又咸又冷的水轻，而又比温暖的水重。海水分层程度越高，那么它的营养成分流动得就越少。
Most free-swimming sea creatures are pelagic.
大多数自由移动的海洋生物都是海面生物。
Algae need light, so must live near the surface—as must the zooplankton and other animalsthat need the phytoplankton.
海藻需要光线，所以必须生活在接近海面的区域—还有需要浮游植物的浮游动物和其它动物也同样如此。
When they die, all these organisms sink to the bottom, where they become food for benthiccreatures.
当它们死亡时，所有这些生物都会下沉到海底，在那里它们会成为底栖生物的食物。
Once they have been consumed their component molecules, including nutrients such asnitrates, phosphates and iron, are stuck in Davy Jones's locker.
一旦它们消耗掉这些成份分子，包括硝酸盐，磷酸盐和铁等营养成份，就会成为戴维-琼斯小柜子的装饰了。
For the surface to be productive, the locker must be opened and the nutrients lifted back up,so that they can feed the growth of phytoplankton.
因为要保持海面的多样性，小柜子必须要打开，滋养物会重新恢复生机，因此它们能够给浮游植物提供养份。
Walking the plankton
移动的浮游生物
One of the most important ways this happens is by upwellings of water from thebottom—great churning columns caused by the collision of cold and temperate waters.
产生这种情况最重要的一种方式是通过海底水的上升流—通过寒冷和温和水域的碰撞产生巨大的水柱。
Two of the most important are in the Arctic: south of Greenland on the Atlantic side and southof the Bering Strait on the Pacific side.
还有两种最重要方式的实现就在北极：大西洋岸格陵兰岛南部和太平洋一侧白令海峡南部。
Nitrates are abundant at the surface in both places, which is why they are among theworld's richest fishing grounds.
这两个地区的海面都有丰富的硝酸盐，这也是为什么这两处是世界上最大渔场的原因。
There are few upwellings in the tropics, which are thus nutrient-poor.
热带地区很少有上升流，因此缺乏硝酸盐。
Stratification threatens this recycling system by suppressing the vertical movement ofwater.
而海水分层会抵制水的垂直流动，从而威胁着这种再循环系统。
And global warming encourages stratification because it turns the ice into a layer of freshwater that sits on the surface.
而全球变暖却推动了海水分层，因为变暖会让冰融化成为覆盖着海面的新鲜水层。
Imagine the ocean as a Tequila sunrise sitting on a warm bar.
可以把海洋想象为坐落在一个温馨酒巴上的龙舌兰日出。
The ice cubes at the top are melting away and the orange juice is sinking to the bottom.
顶部的冰柱正在融化，桔汁慢慢滑到底部。
At the conference, a paper by Jean-eric Tremblay and Marcel Babin of Laval University, inQuebec, described the effect by reporting the density difference of water at the surface andat a depth of 100 metres in different oceans.
在这次会议上，魁北克拉瓦尔大学的让-埃里克-特伦布莱和马塞尔-巴宾提交的报告中，通过报告不同海洋海平面和100米深处不同的水密度，描述了这种效应。
This density difference is an index of ocean stratification.
这种水密度差就是海洋分层的标志。
Parts of the Arctic seem to be getting badly stratified.
北极部分地区的分层现象正越来越严重。
In winter, there is almost no density difference in the North Atlantic and the Barents Sea—asyou would expect given the upwelling there.
北大西洋和巴伦支海在冬天几乎不会出现水密度差—鉴于那里的上涌现象，人们会有所期待。
But in summer, the northern part of the Barents Sea is even more stratified than the tropicalAtlantic and Pacific.
但是在夏天，巴伦支海的北部比大西洋和太平洋热带区域的分层程度还严重。
And the Beaufort Sea's stratification is high in both summer and winter.
波弗特海在夏冬两季的分层都很活跃。
Dr Tremblay concludes that the replenishment of nutrients is already limited by stratification,especially at high latitudes, and that global warming will make things worse.
特伦布博士的结论是，养份的补充已经被分层抵制，特别是在高纬度地区，加上全球变暖会让这种现象更加严重。
For Arctic productivity, the consequences are likely to be dire.
考虑到北极地区的生产力，这种后果可能更加可怕。
Paul Wassmann of the University of Tromso looked at the production of organic matter byalgae in different parts of the European Arctic, and used a climate model to predict thefuture.
特罗姆瑟大学的保罗-威萨曼仔细研究了欧洲北极不同地区藻类产生有机物的过程，使用一种气候模型以预测未来的形式。
The area is divided into five economic zones.
这个区域会被区分为五个经济区。
By 2050, according to the model, primary production is likely to have fallen in three of them,to be flat in one and to rise only in the Russian zone.
根据这个模式，到2050年，其中三个经济区的初级生产量会下降，第四个会持平，只有俄罗斯经济区的初级生产量会上升。
Primary production is measured as the weight of carbon fixed by photosynthesis persquare metre of the Earth's surface.
初级生产量是衡量地球表面每平米光合作用固定的碳重量的指标。
At the moment, in the most productive area of the Arctic, the Norwegian Sea, that figure is142 grams a square metre a year.
目前，在北极最有生产力的区域-挪威海，这个数字为每平米年均142克。
The model predicts this will fall to 128 grams.
而根据模式预测，这个数字会跌至128克。
And by 2100, according to the model, things will be worse.
到2100年，情况会变得更糟。
By then, four of the five zones will have experienced a loss in primary production. OnlyRussia will benefit.
到那时，五个经济区的四个会发生初级生产量大幅减少的现象。届时，只有俄罗斯还会从中受益。
A warming Arctic will not, in other words, be full of fish.
换句话说，变暖的北极不会满眼是鱼。
It will simply be an ice-free version of the desert it already is.
它将还是现在看到的北方沙漠，不同的是浮在海面上的冰消失了。
词语解释
1.ice sheet 大冰原，冰盾，冰盖
The antarctic ice sheet waxed and waned, andglobal sea level rose and fell.
随着南极冰盖冰冻和消融，全球海平面也在降低和升高。
But it did not destabilise the ice sheet or provide anew reason to worry about rising sea levels.
但这并没有导致大冰盖发生不稳定现象，也无法为海平面上升的担忧提供新的依据。
2.global warming 全球变暖
Global warming dries out farmland.
全球变暖使农田干枯。
We talk about global warming.
我们谈到了全球变暖。
3.hope for 希望，希望得到
Detailed and public scrutiny and peer group pressure are the most we can hope for.
细致审查、公众监督、以及来自其他集团的压力，是我们所能企盼的最好结果。
You remain passive and convince yourself that you have nothing to hope for.
你消极被动，使自己确信你没有希冀的事。
4.begin to 开始
A younger generation will begin to take over.
年轻一代将会开始接管中国的事务。
You'll begin to recognize the triggers for each of you.
你就能开始认识到每个人的触发点在哪里。
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