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科学美国人60秒 SSS 气候变暖为北极熊健康带来福音

时间:2017-07-06 08:34:14

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(单词翻译)

Rising Temps Lower Polar Bear Mercury Intake 气候变暖为北极熊健康带来福音

As climate change warms the Arctic, sea ice there is disappearing at record rates—sea ice that polar bears prefer to prowl. As a result, some bears are spending more time on solid land. And are thus switching up their diets, too. Instead of the ringed seals they ate out on the ice, the bears are foraging1 on bowhead whale carcasses, cast up on the beach.

随着气候变化使北极变暖,北极的海上浮冰(海冰)正在以创纪录的速度消失。然而,北极熊非常喜欢在海冰上徘徊。这一现象导致一些北极熊花费更多时间在陆地上逗留,也因此改变了它们的饮食习惯。与此前在冰上捕食环斑海豹不同,它们现在以觅食被冲到沙滩上的北极露脊鲸的尸体为生。

So what does this mean for them?

那么,这对它们来说意味着什么呢?

\"It's sort of good news/bad news." Melissa McKinney, an ecotoxicologist at the University of Connecticut. The bad news is that the bears are losing vital habitat. But the silver lining3 is that bears decamping to land have lower levels of toxic2 mercury due to their changes in diet.

“这既是一个好消息,也是一个坏消息。”康涅狄格大学的生态毒理学家梅丽莎·麦金尼(Melissa McKinney)说道。坏消息是,北极熊正在失去对它们至关重要的栖息地。但不幸中的万幸是,由于北极熊撤到陆地上生存导致其饮食发生变化,它们接触的有毒汞也随之减少。

McKinney and her team studied hair samples from one polar bear population in Alaska, from 2004 to 2011. In that time they saw a 65 percent drop in the bears' mercury levels—to concentrations below the known threshold for negative biological effects. And it looks like the different diet may be the reason.

2004年至2011年,麦金尼和她的团队研究了阿拉斯加某个北极熊种群的毛发样本。在此期间,她们发现北极熊身上的汞含量下降了65%——浓度达到了已知负面生物学效应的阈值以下。饮食的变化可能是其原因。

Bowhead whales feed on plankton4, while ringed seals eat fish and other animals in which mercury has had the chance to accumulate. "So if polar bears are feeding on prey5 items that are lower in the food chain, then they're likely experiencing a less mercury-contaminated food source than they would be otherwise."

露脊鲸以浮游生物为食,而环斑海豹则以鱼和其它体内会积聚汞的动物为食。“因此,如果北极熊捕食的是食物链中较低层的猎物,那么它们的食物来源可能会遭受较少的汞污染。反之则不然。”

The bears that feed on whales are also in better condition—higher body-mass index. And being well fed means their bodies don't need to break down fat and muscle energy stores, where a lot of whatever mercury they have consumed is locked up. The study is in the journal Environmental Science and Technology.

以鲸鱼为食的北极熊体质也似乎变得更好了——身体质量指数更高了。吃得好就意味着它们的身体不需要分解脂肪和肌肉能量储备,因而大量它们消费的汞均被冻结。这项研究发表在《环境科学与技术》杂志上。

“We see polar bears as a sentinel of climate change. And I think it's really important for us to remember that, either positively6 or negatively, climate change can shape the risks that are posed by other environmental stressors—in this case toxic pollutants7." Of course, it would be better to stop the warming and have less mercury in the environment. But the takeaway here is that climate change has multiple effects that go beyond disappearing ice.

“我们将北极熊视为气候变化的哨兵。我认为对我们来说谨记这一点非常重要,不管是积极的还是消极的,气候变化会影响其他环境压力因素造成的风险——这种情况下,是对有毒污染物的影响。”当然,最好的还是阻止气候变暖,减少环境中的汞含量。但此处得出的结论是,气候变化带来的影响不只是海冰消融,它还有多种影响。


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1 foraging 6101d89c0b474e01becb6651ecd4f87f     
v.搜寻(食物),尤指动物觅(食)( forage的现在分词 );(尤指用手)搜寻(东西)
参考例句:
  • They eke out a precarious existence foraging in rubbish dumps. 他们靠在垃圾场捡垃圾维持着朝不保夕的生活。 来自《简明英汉词典》
  • The campers went foraging for wood to make a fire. 露营者去搜寻柴木点火。 来自辞典例句
2 toxic inSwc     
adj.有毒的,因中毒引起的
参考例句:
  • The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
  • There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。
3 lining kpgzTO     
n.衬里,衬料
参考例句:
  • The lining of my coat is torn.我的外套衬里破了。
  • Moss makes an attractive lining to wire baskets.用苔藓垫在铁丝篮里很漂亮。
4 plankton B2IzA     
n.浮游生物
参考例句:
  • Plankton is at the bottom of the marine food chain.浮游生物处于海洋食物链的最底层。
  • The plankton in the sea feeds many kinds of animals. 海的浮游生物成为很多种动物的食物。
5 prey g1czH     
n.被掠食者,牺牲者,掠食;v.捕食,掠夺,折磨
参考例句:
  • Stronger animals prey on weaker ones.弱肉强食。
  • The lion was hunting for its prey.狮子在寻找猎物。
6 positively vPTxw     
adv.明确地,断然,坚决地;实在,确实
参考例句:
  • She was positively glowing with happiness.她满脸幸福。
  • The weather was positively poisonous.这天气着实讨厌。
7 pollutants 694861490fe64672170a0da250a277c7     
污染物质(尤指工业废物)( pollutant的名词复数 )
参考例句:
  • Pollutants are constantly being released into the atmosphere. 污染物质正在不断地被排放到大气中去。
  • The 1987 Amendments limit 301(g) discharges to a few well-studied nonconventional pollutants. 1987年的修正案把第301条(g)的普通排放限制施加在一些认真研究过的几种非常规污染物上。 来自英汉非文学 - 环境法 - 环境法

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