GRE阅读材料大补充 海洋生态新视角之塑料星球
- 2016年06月10日09:00 来源：小站整理
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SINCE 2008 geologists have been mulling over the idea of the Anthropocene, a proposed newepoch in the history of the Earth that would encompass the years in which people have hadprofound effects on the planet's workings.Most often, discussion of theAnthropocene revolves around how atmospheric chemistry has changed since the beginning ofthe industrial revolution.Sometimes the effects of new terrestrial ecosystems, in the form of fields, pastures andplantations, are also considered.To date, though, how the Anthropocene has created new ecosystems in the oceans as well ason land has not been much examined.
自2008年以来,地质学家一直在研究人类纪这一理念，人类纪是在地球历史上提出的新纪元，其囊括了人们深刻地影响地球的运作的年代。大多数时候,人类纪的讨论大多是围绕着从工业革命开始大气化学有何种变化进行的。有时新型陆地系统所产生的影响也考虑在内。到目前为止,然而人类纪是如何创造新型海洋及陆地生态系统并未做过多的研究。
Such ecosystems are, nevertheless, emerging—as Tracy Mincer of the Woods HoleOceanographic Institution,in Massachusetts, and Linda Amaral-Zettler of the Marine Biological Laboratory, also in WoodsHole, describe in Environmental Science and Technology.The malign effect of floating plastic debris on seabirds, turtles and other sea creatures is wellknown.But, as Dr Mincer and Dr Amaral-Zettler have discovered, plastic debris also provides a newhabitat for organisms small enough to take advantage of it.
不过这样的生态系统在《环境科技》杂志中有所描述，是由马萨诸塞州伍兹霍尔海洋学研究所的特蕾西·明瑟以及伍兹霍尔海洋学研究所海洋生物研究室的琳达阿玛拉尔-特勒联合提出的。众所周知，漂浮的塑料碎片对海鸟海龟以及其他海洋生物有负面影响。但是,正如明瑟及阿玛拉尔-特勒两位博士已经发现的一样，塑料碎片还给有机体提供了一个小型足以充分利用全新的栖息地。
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The two researchers collected pieces of plastic from various sites in the North Atlantic.They then examined each using DNA analysis, and also an electron microscope, to see whatwas living on it.Lots of things were.Altogether, they discovered about 50 species of single-celled plant, animal and bacterial life.Each bit of debris was, in effect, a tiny ecosystem.As with many ecosystems, the bottom of the food chain was occupied by things thatphotosynthesise.These included unicellular algae called diatoms and dinoflagellates, and photosynthetic bacteriaknown as cyanobacteria.
两位研究员从北大西洋的不同地点收集塑料碎片。他们然后用DNA分析仪、电子显微镜检测每一个，观测其上生活着何种生物。有很多生物。总之,他们发现约50种单细胞植物、动物和细菌的踪迹。确切地说，每块碎片是一个小型的生态系统。正如诸多生态系统一样，食物链的底层被光合作用的生物占据着。这些包括名为硅藻和甲藻的单细胞藻类和蓝藻的光合细菌。
Usually, such creatures swim freely in the ocean.They therefore have to work hard to stay near the surface, where light for photosynthesis isabundant.By hitching a ride on a piece of floating plastic, they can stay near the surface without effort.Where plants abound, herbivores will not be far behind.These, Dr Mincer and Dr Amaral-Zettler found in the form of dinoflagellates,some of which liketo snack on smaller creatures to supplement their photosynthesis.They also found predators on the herbivores, in the form of ciliates and predator bacteria,which feed on other bacteria.
通常,这些生物在海洋里自由自在地游荡。因此他们必须努力保持在表层水域，因为那里的进行光进行光合所需的阳光是充裕的。通过搭乘漂浮塑料这一顺风车,他们可以毫不费力地呆在表层。植物比比皆是的地方食草动物的出现也不会落后。明瑟及阿玛拉尔-特勒两位博士以甲藻的形式发现了食草动物的存在,一些甲藻喜欢吃小型生物作为他们光合作用的补充。他们还发现食草动物的捕食者，如纤毛虫以及以其他细菌为食的捕食细菌。
Except for top predators—the type that themselves prey on predators—the two researchersthus discovered a classic web of food chains of the sort familiar from ecology text books.And they also, and perhaps most pertinently from the human point of view, found evidence forone other part of such a food web: the decomposers.Plastics are energy-rich substances, which is why many of them burn so readily.Any organism that could unlock and use that energy would do well in the Anthropocene.Terrestrial bacteria and fungi which can manage this trick are already familiar to experts in thefield.
除了顶级捕食者外，两位研究人员发现了一个与生态学课本上相似的经典的食物网。或许从人类的观点来看最为适切的他们还发现了食物网的另一部分：分解者。塑料是能源丰富的物质,这就是为什么他们中的许多容易燃烧的原因。任何可以分解和使用那些能源的生物在人类纪将会取得先机。掌握这种技能的陆地上的细菌及真菌是这个领域的专家。
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Dr Mincer and Dr Amaral-Zettler found evidence of them on their marine plastic, too.They noticed many of their pieces of debris sported surface pits around two microns across.Such pits are about the size of a bacterial cell. Closer examination showed that some of thesepits did, indeed, contain bacteria,and that in several cases these bacteria were dividing and thus, by the perverse arithmetic ofbiological terminology, multiplying.Though the two researchers have not yet proved the bugs in the pits are actually eating theplastic, that hypothesis seems a good bet.And if they are, it suggests plastic pollution in the ocean may not hang around as long as hasoften been feared.
明瑟及阿玛拉尔-特勒两位博士在海洋塑料上也发现了它们的踪迹。他们发现很多塑料碎片的运动表面周围有大约两微米的凹坑。凹坑与细菌一般大小。进一步的研究显示这些凹坑中的一部分确实含有细菌，在部分状况下细菌正在分裂，因此根据生物学的反常计算其数量正在递增。尽管两位研究员至今未找到凹坑中的细菌是以塑料为食的证据，那个假说就好像是一场赌博。如果假说是正确的，这就意味着海洋塑料污染可能不如担心的那么持久。
Less encouragingly, Dr Mincer and Dr Amaral-Zettler also found cholera-like bacteria in theirtiny floating ecosystems.Both fish and seabirds act as vectors for cholera,so anywhere that such creatures might pick upcholera bugs is something worth keeping an eye on.The researchers paint an intriguing picture of the adaptability of nature, and provide anotherpiece of the jigsaw that is the Anthropocene.Conservationists intent on preserving charismatic megafauna have reason to lament thespread of plastics through the ocean.But those interested in smaller critters have been given a whole, new sphere—theplastisphere—to study.
令人扫兴的是，明瑟及阿玛拉尔-特勒两位博士在漂浮的小型生态系统中发现了类似于霍乱的细菌。鱼类或者是海鸟都充当着霍乱病菌的载体，所以任何使这些生物可能携带霍乱病菌的地区都值得密切关注。研究者就大自然的适应性描绘了一幅耐人寻味的画面，并提供了人类纪的另一块拼图。致力于保护引人好奇的大型动物的环保人士有理由担心海洋塑料污染的蔓延。但是却给了那些对小型生物感兴趣的环保人士一个全新的视角——塑料星球。
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