漂洋過海的27萬噸塑料垃圾

 

漂洋過海的27萬噸塑料垃圾

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滿了各種塑料垃圾，這早已不是秘密。第一片漂浮的垃圾聚集物是在上世紀90年代發(fā)現(xiàn)的。不過，研究人員已經(jīng)開始對這個問題的規(guī)模和范圍有了更好的了解。

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.

據(jù)周三發(fā)布在雜志《公共科學圖書館·綜合》(PLoS ONE)上的一篇研究報告估計，世界各地的海洋——即便最偏遠的海域都不能避免——可以找到5.25萬億件共計26.9萬噸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.

進行這項研究的船只通過海洋航行，用網(wǎng)子收集小體積的塑料垃圾，并利用計算機模型對樣本進行分析，估算出了全世界的數(shù)值。這項工作的領(lǐng)導者、“五大環(huán)流”(5 Gyres Institute)的聯(lián)合創(chuàng)始人馬庫斯·埃里克森(Marcus Eriksen)說，從重量來看，最大的塑料廢棄物來源是廢棄的漁網(wǎng)和浮標。“五大環(huán)流”是一個非營利組織，既從事科學研究，也在進行反污染活動。

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，如果開展一個國際項目，向漁船支付回收漁網(wǎng)的費用，可能有助于解決這個問題。不過，這對于處理瓶子、牙刷、箱包，玩具等飄洋過海，并在水流匯集的“環(huán)流”處聚集的其他雜物并無幫助。因為水流和波浪作用，垃圾碎片相互碰撞，陽光使它們變得易碎，從而把這些漂浮的廢品堆變成了“粉碎機”，他說，制造出體積越來越小的塑料垃圾，散播到更遠更廣闊的地方。

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，調(diào)查隊在尋找沙粒般大小的水上漂浮塑料碎片時，驚奇地發(fā)現(xiàn)他們所找到的樣本比預(yù)計中要少得多——只是他們的模型所預(yù)測的碎片數(shù)量的百分之一。埃里克森說，這表明，體積較小的碎片可能被掃入了更深的海里，或者已經(jīng)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.

這個結(jié)果呼應(yīng)了《美國國家科學院院刊》(Proceedings of the National Academy of Sciences)今年發(fā)布的一篇文章的內(nèi)容。這篇文章也發(fā)現(xiàn)，小塑料垃圾的數(shù)量之少，令人震驚。這些研究者預(yù)計，共有多達3.5萬噸較小的碎片散布在世界各地的海洋，但他們曾經(jīng)估計會找到數(shù)百萬噸這樣的碎片。

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.”

加的斯大學(University of Cadiz)研究員安德列斯·科薩爾(Andrés Cózar)是這項研究的負責人，他在一封電子郵件中說，他和埃里克森關(guān)于塑料漂浮物數(shù)量的結(jié)論有所不同，但是，“很顯然，海洋里的塑料物質(zhì)太多了。”對于地球而言，塑料是一種相對較新的新增物，鑒于這里有這么多塑料垃圾，他說，“塑料材料目前的管理模式(在經(jīng)濟和生態(tài)方面)是不可持續(xù)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實絕不是什么好消息。事實上，它或許比塑料垃圾所造成的不堪入目的景象還要麻煩許多。塑料能夠吸引多氯聯(lián)苯和其他污染物等有毒物質(zhì)，然后外表被這些物質(zhì)包裹。研究人員擔心，吞食了這些塑料物質(zhì)的魚和其他生物可能會重新吸收這些有毒物質(zhì)，然后再傳遞給吃掉它們的食肉動物。“塑料就像是污染物混合體，在水生生物的棲息地四處飄浮，”加州大學戴維斯分校(University of California, Davis)的海洋生態(tài)學家切爾西·M·羅什曼(Chelsea M. Rochman)說。“這些污染物可能會在食物鏈中逐級放大。”