Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-ku, Tokyo 108-8477, Japan.
Mar Pollut Bull. 2021 Jan;162:111887. doi: 10.1016/j.marpolbul.2020.111887. Epub 2020 Dec 8.
Microplastics (MPs) pollution surveys were conducted in Tokyo Bay using neuston nets (May 2019 and January 2020). Although the pollution level in Tokyo Bay was high (3.98 pcs/m, May), it was lower than reported in other semi-closed bays because of differences in the Enclosed Index. It was found that polyethylene fragments dominated the retrieved MPs; the mode of MPs size was 800 μm. As MPs abundance in rivers had the same seasonality as found in the inner bay, rivers were considered the main source of MPs. The seawater residence time is shorter than the time required for the density of MPs to become greater than that of seawater; therefore, it was considered that MPs are transported out of the bay instead of sinking. MPs were aggregated into a convergence zone by residual currents (the thermohaline front) in May (January). These findings will improve understanding of MPs pollution in other bays.
在东京湾使用表层网进行了微塑料 (MPs) 污染调查 (2019 年 5 月和 2020 年 1 月)。尽管东京湾的污染水平很高 (5 月为 3.98 个/米)，但由于封闭指数的差异，其污染水平低于其他半封闭海湾的报道。研究发现，回收的 MPs 中以聚乙烯碎片为主; MPs 尺寸的模式为 800μm。由于河流中 MPs 的丰度与内湾相同，因此河流被认为是 MPs 的主要来源。海水的停留时间短于 MPs 密度大于海水密度所需的时间;因此，认为 MPs 被运出海湾而不是下沉。在 5 月 (1 月)，残余流 (温盐锋) 将 MPs 聚集到一个汇聚区。这些发现将有助于更好地了解其他海湾的 MPs 污染情况。
