VOA常速英语2013--海洋中的塑料碎片上滋养大量细菌（在线收听）

Bacteria Thrive on Ocean Plastic Debris 海洋中的塑料碎片上滋养大量细菌

Plastic pollution in the ocean is harboring colonies of bacteria that could be harmful, not only to marine animals, but also to humans.

海洋中的塑料污染滋生大量细菌，这样不仅威胁到海洋动物的生存，也使得人类的生活环境受到影响。

Thoughtless habits and practices - a bottle dropped here, a bag thrown there - are creating garbage dumps in the world’s oceans. The flotilla of debris moves with the currents and harms fish and marine mammals that either ingest or get entangled in it.

这里丢个瓶子，那里丢个塑料袋，这些无意之举都会导致海洋污染。这些垃圾随着水流四处漂浮，海洋中的鱼类或是哺乳动物会将它们吞下或是被它们缠住，因而受到极大伤害。

But for some organisms, it's home. Scientists have discovered a wide diversity of microbes colonizing and thriving on plastic that is polluting the ocean in the so-called plastisphere. 

但对于一些微生物来说，这些垃圾却为它们提供了良好的生存环境。科学家们发现，这些塑料垃圾上布满了大量细菌和微生物，使得海洋污染更为严重。

Forever trash

永久性垃圾

It takes about six weeks for a plastic bag or bottle to ride the surface currents from the U.S. East Coast to the Sargasso Sea, in the center of the North Atlantic. The area is a gyre, essentially a big whirlpool that traps and swirls the debris which, unlike other types of trash in the ocean, never bio-degrades.

一个塑料袋或塑料瓶从美国东海岸漂到北大西洋中部的马尾藻海大约需要六周的时间。这片海域仿佛形成一个巨大的漩涡，将这些垃圾牢牢的困在里面，这也是为什么这些垃圾不能像其他垃圾一样自然降解。

This is where Tracy Mincer, a microbiologist with Woods Hole Oceanographic Institution, and colleagues from the Marine Biological Laboratory, joined students aboard a Sea Education Association vessel to sample plastic debris for microbes. 

因此伍兹霍尔海洋研究所的微生物学家翠西·明瑟和她来自海洋生物实验室的同事带领海洋教育协会的学生们一起来到这片海域采集这些携带大量微生物的塑料垃圾标本。

“We hypothesized that the microbes on plastic were specifically interacting with it, rather than just a random association," Mincer said. "It’s not just flypaper that is just grabbing on to anything. Things are actually specifically interacting with plastic for a reason.”

“我们推测这些微生物是专门附着在这些塑料上，而不是被海浪冲刷而随机沾上的，”明瑟说。“这不像是一张粘蝇纸，什么东西都会黏在那上面。这些微生物肯定是因为某种特定原因附着在这些塑料上。”

The team skimmed the surface with fine nets, collecting confetti size bits of plastic. They analyzed the plastic with electron scanning tools and gene sequencing techniques. They found rich colonies of bacteria, including some that they hadn’t expected, which they called 'pit formers.'

整个团队将采集到的样本表面覆盖上网格，将它们分成糖果大小，并用电子扫描工具和基因测序技术进行分析。他们发现这些塑料上覆盖有大量的细菌，有一些细菌甚至是他们之前完全没有预料到的。

“We were surprised when we saw microbes that appeared to be hydrolyzing [breaking down] the plastic and etching into it," said Mincer, "as well as just a whole other amazing ecosystem that was thriving on this plastic surface.”

“我们十分惊讶的看到这些微生物在塑料表面水解并永久留在塑料上面，仿佛是刻上去的一样，”明瑟说，“它们好像在塑料的表面上形成了一个新的生态系统。”

The organisms in this plastisphere were different from those in the surrounding nutrient-poor water, indicating that the plastic acts as an artificial microbial reef, one that could harbor disease-causing pathogens and other harmful algal species.

这些覆盖在塑料表面的微生物不同于那些再没什么营养的水源中生活的微生物，对于它们来说，这些塑料表面就是一个人造的生物礁，为病原体及一些有害藻类的生长繁衍提供庇护。

“It’s certainly possible. And a lot of time certain toxins are oily in nature and they will absorb on to the plastic, but when the microbes interact with it they could be releasing those toxins off of the plastics,” Mincer said.

“这是极有可能的。在大自然中，许多有毒物质都是呈油性的，它们会粘在塑料表面。但当这些微生物附着时，这些毒素会从塑料表面脱落，”明瑟说。

Hormonal effects

荷尔蒙效应

Some of those additives are known to have hormonal effects in humans.

其中的一些附着物会对人体产生荷尔蒙效应。

More than 90 percent of the trash floating on the ocean surface is plastic. The largest of the planet's five gyre sites is the Great Pacific Garbage Patch, which is twice the size of Texas. Mincer says with so much plastic out there, it is important to know how it impacts marine species and by extension, people.

超过90%的漂浮在海面上的垃圾都是塑料。地球上在海洋中形成的五个有垃圾回流形成的漩涡中，太平洋上的那个是最大的。它的面积是德克萨斯州的两倍。明瑟说海洋中的垃圾如此之多，人们应当认识到这些垃圾会对海洋生物甚至使人类本身造成怎样的影响。

“Fish are eating the plastic," Mincer said. "Are they picking up certain toxins from the plastic or not? And what does happen to plastic once it goes out into this environment? Does it eventually degrade into little tiny bits? And then what does it do? Do the microbes make it heavier and make it sink quicker? Does it go away? Is it a problem?”

“鱼把这些塑料吃进肚子里，”明瑟说。“这些毒素会从它们身体中排出还是永远留在它们身体中了呢？如果这些毒素被排入我们生存的环境中会发生生什么呢？它们最终是会降解成许多小块或是别的什么形式？这些微生物是会加快降解的过程还是阻止降解？这些毒素最后会消失吗？他们会造成严重的影响吗？”

The initial survey identified about 1,000 microbes that live on and interact with plastic. The next step is to sequence their genomes to get a better idea of whether or not they could be harmful pathogens.

有关人员在进行初步调查时已经研究了1000个附着在塑料表面的微生物。下一步将会用基因组测序来判定这些微生物是否有害。