14 million tonnes of microplastics on seafloor

澳大利亚联邦科学与工业研究组织近日发布公报说,该机构已完成世界第一个评估全球海底微塑料污染总量的研究,结果表明,全球深海中约有1400万吨该类污染物,预计是海洋表面塑料污染总量的两倍以上。相关成果已发表在新一期《海洋科学前沿》杂志上。

该研究负责人巴雷特介绍,进入海洋的塑料污染物会分解,最终形成微塑料。“我们的研究对海底有多少微塑料进行了第一个全球性评估。结果表明,即使深海也容易受到塑料污染问题的影响。微塑料确实正在沉入海底。”

此次记录微塑料量 比以前记录量高25倍

此次研究中,澳洲研究人员使用潜水机器人在多个地点采集样本,潜水深度达3000米,采集范围最远处距该国南部的南澳州海岸380公里。他们发现,此次记录的微塑料量比以前深海研究记录量高25倍。研究人员将此次采样所获的深海微塑料密度按比例放大到全球海洋,估算出了全球海底微塑料总量。

该研究参与者哈迪斯蒂说,此次在偏远的深海发现高聚集的微塑料令人惊讶。研究发现,深海就像一个汇聚微塑料的“水槽”,因此迫切需要解决塑料污染的有效方案。

该公报介绍,尽管人们越来越关注塑料污染对海洋生态系统、野生动植物,以及人类健康带来的危害,但每年仍有数百万吨塑料污染进入海洋环境,并且其数量在未来几年还会增加。

哈迪斯蒂建议,每个人都可以减少海洋塑料污染,比如尽量避免使用一次性塑料物品,支持回收和废物处理行业等。各行业和社区须共同努力,从而显著减少在海滩和海洋中的垃圾数量。


CSIRO, Australia’s national science agency, has provided the first ever global estimate for microplastics on the seafloor, with results suggesting there are 14 million tonnes in the deep ocean.

This is more than double the amount of plastic pollution estimated to be on the ocean’s surface.

Justine Barrett from CSIRO’s Oceans and Atmosphere who led the study published on 5 Oct 2020 said the research extended our understanding of the amount of plastic pollution in our oceans and the impact of plastic items, both large and small.

“Plastic pollution that ends up in the ocean deteriorates and breaks down, ending up as microplastics,” Ms Barrett said.

“Our research provides the first global estimate of how much microplastic there is on the seafloor.

“Even the deep ocean is susceptible to the plastic pollution problem.

“The results show microplastics are indeed sinking to the ocean floor.”

Millions of tonnes of plastic enter the marine environment annually, and quantities are expected to increase in coming years, despite increased attention on the detrimental impacts of plastic pollution on marine ecosystems, wildlife and human health.

The samples used in this study were collected using a robotic submarine in depths to 3000 metres at sites up to 380 kilometres offshore from South Australia.

The amount of microplastics recorded was 25 times higher than previous deep-sea studies.

Based on the results of deep-sea plastic densities, and scaling up to the size of the ocean, we calculated a global estimate of microplastics on the seafloor.

Dr Denise Hardesty, Principal Research Scientist and co-author, said plastic pollution of the world’s oceans was an internationally recognised environmental issue, with the results indicating the urgent need to generate effective plastic pollution solutions.

“Our research found that the deep ocean is a sink for microplastics,” Dr Hardesty said.

The number of microplastic fragments on the seafloor was generally higher in areas where there was also more floating rubbish.

“We were surprised to observe high microplastic loads in such a remote location.

“By identifying where and how much microplastic there is, we get a better picture of the extent of the problem.

“This will help to inform waste management strategies and create behavioural change and opportunities to stop plastic and other rubbish entering our environment.

“We can all help to reduce plastic ending up in our oceans by avoiding single-use plastics, supporting Australian recycling and waste industries, and disposing of our rubbish thoughtfully so it doesn’t end up in our environment.

“Government, industry and the community need to work together to significantly reduce the amount of litter we see along our beaches and in our oceans.”


Source: Zaobao / CSIRO / Full Publication

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