About 15 Tg of plastic are estimated to enter the ocean yearly, with this figure growing exponentially every year. Assessments of floating marine plastic amount to 0.2% of the expected plastic stock, implying that 99.8% is stored in a sink yet to be identified. Marine sediments are believed to be the ultimate sink for oceanic plastic, however, there is currently no global estimate of the plastic load stored there. Here, we synthesize available estimates of micro- and mesoplastic stocks in marine sediments and, by integrating stocks across different habitats, we conservatively estimate a load of 170 Tg (25–900 Tg) of nonfibrous plastic globally accumulated in marine sediments from 1950 to 2010, most of which at intermediate depths (200–2000 m). This estimate, despite the uncertainty, is two to three orders of magnitude higher than the floating plastic stock and confirms marine sediments as a major plastic sink.

中文翻译：

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海洋沉积物作为海洋微塑料和中塑料的全球汇

据估计，每年约有 15 Tg 的塑料进入海洋，而且这个数字每年都呈指数增长。浮动海洋塑料的评估量占预期塑料存量的 0.2%，这意味着 99.8% 存储在尚未确定的水槽中。海洋沉积物被认为是海洋塑料的最终汇，然而，目前没有全球估计储存在那里的塑料负荷。在这里，我们综合了海洋沉积物中微塑性和中塑性储量的可用估计值，并通过整合不同栖息地的储量，我们保守地估计 1950 年至 2010 年全球在海洋沉积物中积累的非纤维塑料负荷为 170 Tg（25-900 Tg） ，其中大部分在中间深度（200-2000 m）。这一估计，尽管存在不确定性，