漂洋过海的27万吨塑料垃圾

 

漂洋过海的27万吨塑料垃圾

It is no secret that the world’s oceans are swimming with plastic debris — the first floating masses of trash were discovered in the 1990s. But researchers are starting to get a better sense of the size and scope of the problem.

世界各地的海洋上漂满了各种塑料垃圾，这早已不是秘密。第一片漂浮的垃圾聚集物是在上世纪90年代发现的。不过，研究人员已经开始对这个问题的规模和范围有了更好的了解。

A study published Wednesday in the journal PLOS One estimated that 5.25 trillion pieces of plastic, large and small, weighing 269,000 tons, could be found throughout the world’s oceans, even in the most remote reaches.

据周三发布在杂志《公共科学图书馆·综合》(PLoS ONE)上的一篇研究报告估计，世界各地的海洋——即便最偏远的海域都不能避免——可以找到5.25万亿件共计26.9万吨大大小小的塑料碎片。

The ships conducting the research traveled the seas collecting small bits of plastic with nets and estimated worldwide figures from their samples using computer models. The largest source of plastic by weight comes from discarded fishing nets and buoys, said Marcus Eriksen, the leader of the effort and co-founder of the 5 Gyres Institute, a nonprofit group that combines scientific research with antipollution activism.

进行这项研究的船只通过海洋航行，用网子收集小体积的塑料垃圾，并利用计算机模型对样本进行分析，估算出了全世界的数值。这项工作的领导者、“五大环流”(5 Gyres Institute)的联合创始人马库斯·埃里克森(Marcus Eriksen)说，从重量来看，最大的塑料废弃物来源是废弃的渔网和浮标。“五大环流”是一个非营利组织，既从事科学研究，也在进行反污染活动。

Dr. Eriksen suggested that an international program that paid fishing vessels for reclaimed nets could help address that issue. But that would do nothing to solve the problem of bottles, toothbrushes, bags, toys and other debris that float across the seas and gather at “gyres” where currents converge. The pieces of garbage collide against one another because of the currents and wave action, and sunlight makes them brittle, turning these floating junkyards into “shredders,” he said, producing smaller and smaller bits of plastic that spread far and wide.

埃里克森表示，如果开展一个国际项目，向渔船支付回收渔网的费用，可能有助于解决这个问题。不过，这对于处理瓶子、牙刷、箱包，玩具等飘洋过海，并在水流汇集的“环流”处聚集的其他杂物并无帮助。因为水流和波浪作用，垃圾碎片相互碰撞，阳光使它们变得易碎，从而把这些漂浮的废品堆变成了“粉碎机”，他说，制造出体积越来越小的塑料垃圾，散播到更远更广阔的地方。

When the survey teams looked for plastics floating in the water that were the size of grains of sand, however, they were surprised to find far fewer samples than expected — one-hundredth as many particles as their models predicted. That, Dr. Eriksen said, suggests that the smaller bits may be swept deeper into the sea or consumed by marine organisms.

然而，调查队在寻找沙粒般大小的水上漂浮塑料碎片时，惊奇地发现他们所找到的样本比预计中要少得多——只是他们的模型所预测的碎片数量的百分之一。埃里克森说，这表明，体积较小的碎片可能被扫入了更深的海里，或者已经被海洋生物吞食。

The result echoed that of a paper published this year in Proceedings of the National Academy of Sciences that found a surprisingly low amount of small plastic debris. Those researchers estimated as much as 35,000 tons of the smaller debris were spread across the world’s oceans, but they had expected to find millions of tons.

这个结果呼应了《美国国家科学院院刊》(Proceedings of the National Academy of Sciences)今年发布的一篇文章的内容。这篇文章也发现，小塑料垃圾的数量之少，令人震惊。这些研究者预计，共有多达3.5万吨较小的碎片散布在世界各地的海洋，但他们曾经估计会找到数百万吨这样的碎片。

Andrés Cózar, a researcher from the University of Cadiz who headed that study, said in an email that he and Dr. Eriksen came to somewhat different conclusions about the amount of plastic afloat, but that “it is evident that there is too much plastic in the ocean.” With so much debris from materials that are a relatively recent addition to the planet, he said, “The current model of management of plastic materials is (economically and ecologically) unsustainable.”

加的斯大学(University of Cadiz)研究员安德列斯·科萨尔(Andrés Cózar)是这项研究的负责人，他在一封电子邮件中说，他和埃里克森关于塑料漂浮物数量的结论有所不同，但是，“很显然，海洋里的塑料物质太多了。”对于地球而言，塑料是一种相对较新的新增物，鉴于这里有这么多塑料垃圾，他说，“塑料材料目前的管理模式(在经济和生态方面)是不可持续的。”

The fact that the small plastics are disappearing is hardly good news. In fact, it could be far more troubling than the unsightly mess the plastics cause. Plastics attract and become coated with toxic substances like PCBs and other pollutants. Researchers are concerned that fish and other organisms that consume the plastics could reabsorb the toxic substances and pass them along to other predators when they are eaten. “Plastics are like a cocktail of contaminants floating around in the aquatic habitat,” said Chelsea M. Rochman, a marine ecologist at the University of California, Davis. “These contaminants may be magnifying up the food chain.”

小塑料垃圾正在消失的事实绝不是什么好消息。事实上，它或许比塑料垃圾所造成的不堪入目的景象还要麻烦许多。塑料能够吸引多氯联苯和其他污染物等有毒物质，然后外表被这些物质包裹。研究人员担心，吞食了这些塑料物质的鱼和其他生物可能会重新吸收这些有毒物质，然后再传递给吃掉它们的食肉动物。“塑料就像是污染物混合体，在水生生物的栖息地四处飘浮，”加州大学戴维斯分校(University of California, Davis)的海洋生态学家切尔西·M·罗什曼(Chelsea M. Rochman)说。“这些污染物可能会在食物链中逐级放大。”