Microplastic Pollution in Deep-Sea Sediments From the Great Australian Bight
Microplastic Pollution in Deep-Sea Sediments From the Great Australian Bight
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DOI：
10.3389/fmars.2020.576170
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发表时间：
2020-10-05
影响因子：
3.7
通讯作者：
Wilcox, Chris
中科院分区：
文献类型：
--
作者：
Barrett, Justine;Chase, Zanna;Wilcox, Chris
在全球范围内，人们对了解塑料，特别是微塑料污染程度的兴趣有所增加。然而，我们仍然对有多少塑料污染进入世界海洋深处知之甚少。深海沉积物中微塑料污染的程度仍然很难量化，但这一知识对于预测全球塑料污染的分布和潜在影响至关重要。为了解决这一知识缺口，我们使用经过调整的密度分离和染料荧光技术对大澳大利亚湾深海沉积物中的微塑料进行了定量。我们分析了来自六个地点（每个地点1-6个岩心，共16个样本）的沉积物岩心，深度从1，655到3，062米不等，离岸距离从288到356公里不等。微塑料计数范围为0 - 13.6碎片/g干沉积物（平均值1.26 +/- 0.68; n = 51）。我们发现微塑料计数比深海沉积物的其他分析中记录的要高得多。总体而言，沉积物中微塑料碎片的数量随着表面塑料计数的增加而增加，并且随着海底坡度角的增加而增加。然而，微塑料计数变化很大，同一地点沉积物芯之间的异质性大于采样点之间的差异。根据我们的经验数据，我们保守估计有1400万吨微塑料存在于海底。
Interest in understanding the extent of plastic and specifically microplastic pollution has increased on a global scale. However, we still know relatively little about how much plastic pollution has found its way into the deeper areas of the world's oceans. The extent of microplastic pollution in deep-sea sediments remains poorly quantified, but this knowledge is imperative for predicting the distribution and potential impacts of global plastic pollution. To address this knowledge gap, we quantified microplastics in deep-sea sediments from the Great Australian Bight using an adapted density separation and dye fluorescence technique. We analyzed sediment cores from six locations (1-6 cores each, n = 16 total samples) ranging in depth from 1,655 to 3,062 m and offshore distances ranging from 288 to 356 km from the Australian coastline. Microplastic counts ranged from 0 to 13.6 fragments per g dry sediment (mean 1.26 +/- 0.68; n = 51). We found substantially higher microplastic counts than recorded in other analyses of deep-sea sediments. Overall, the number of microplastic fragments in the sediment increased as surface plastic counts increased, and as the seafloor slope angle increased. However, microplastic counts were highly variable, with heterogeneity between sediment cores from the same location greater than the variation across sampling sites. Based on our empirical data, we conservatively estimate 14 million tonnes of microplastic reside on the ocean floor.