南海与周边海域表层塑料颗粒交换的拉格朗日示踪研究

Exchanges of surface plastic particles in the South China Sea through straits using Lagrangian method

塑料污染已成为国际海洋界关注的海洋环境问题之一。文章探讨海洋环流对南海及其周边海域表层塑料颗粒交换的影响。在南海周边多个海域,分别在4个季节投放塑料颗粒。一年后,用拉格朗日颗粒示踪方法考察投放颗粒的运动轨迹和最终停留位置。结果表明,在秋、冬季,大部分塑料颗粒会进入南海和爪哇海,极少部分颗粒北输送到太平洋;在春、夏季,仅有部分颗粒进入南海和爪哇海,而多数颗粒流到太平洋。南海洋流具有季节特征,塑料颗粒轨迹特征与之较为符合。

Plastics have caused serious pollution in the ocean,and become one of the marine environmental issues of concern to the international marine community.The South China Sea is a major area of marine plastic pollution.The areas around the South China Sea are major sources of plastic pollution,and previous studies have focused on the offshore environment.In this study,we discuss the exchange of plastic particles in the surface of the South China Sea and surrounding waters by ocean circulations.First,the particles were placed at the junction of the South China Sea and its adjacent seas,and were released at the initial time of every season Using Lagrangian particle tracing method,we analyzed the trajectories and final locations of the particles within one year after release.The results show that plastic particles enter the South China Sea mainly through the southern strait.The transport of particles at the same starting point varies a lot with season.During autumn and winter,most particles will enter the South China Sea and Java Sea,and little particles will be transported to the Pacific Ocean.However,only a few particles enter the South China Sea and Java Sea during spring and summer,while most of them are transported to the Pacific Ocean.The South China Sea current is mainly affected by monsoon and has significant seasonal characteristics.This research will help understand the impact of surface plastics around the South China Sea on the plastic pollutant in the South China Sea.