榕江入海口自然沙滩微型塑料污染调查研究

Micro-plastic pollution of unspoiled beaches around Rongjiang River estuary

1920s至今,塑料产业发展迅猛,海洋塑料污染问题日益严重.关于微型塑料(尺寸小于5 mm)对海洋生态系统的危害近年来受到国际社会的广泛关注.目前,我国关于河口和海岸带微型塑料的污染调查研究相对较少,开展相关研究将有利于海洋生态系统的管理、保护与健康.因此,本文以粤东第二大河流(榕江,汕头)入海口附近的自然沙滩为研究区域,选择榕江主干入海口、支流入海口和偏远海岸3个不同的区域,布设6个采样站位,调查和研究高潮线上部中小型塑料垃圾的组成、分布和来源.结果表明:榕江入海口自然沙滩废塑料的主要成分为塑料碎片(60%)、泡沫聚苯乙烯(27%)和前体颗粒(13%);各沙滩废塑料的平均密度为1067.67个·m-2,与世界其它地区同类的研究相比处于中等偏上的水平;废塑料的尺寸以直径小于5 mm的微型塑料为主,数量占总数的72%;微型塑料密度和塑料总密度在不同采样区域都呈现相同的趋势,即支流入海口附近海滩>主干入海口附近海滩>偏远海滩.对微型塑料的来源也作了初步探讨,河流上游塑料污染、河口附近城市的生活塑料垃圾排放及海上渔业活动是海滩微型塑料的主要潜在来源.

Since 1920,the pollution caused by plastics in the marine environment has become more serious due to the rapid development of plastic industry. Relevant study on harm generated by micro- plastics（ size in diameter 5 mm） in the marine ecosystem is very few in China. In this study,micro-plastics above high-tide line was collected at six unspoiled beaches in three typical areas（ Estuary of Rongjiang River,Estuary of its tributary and a remote region）. The results showed that plastics in three beaches were mainly composed of plastic fragments（ 60%）,polystyrene foam（ 27%）,and plastic resin pellets（ 13%）. Micro-plastics were dominant and accounted for 72% of the total plastics. The average density was 1067. 67 items·m- 2and the percentage contribution of the micro-plastics in three sites was in the following order： the tributary the mainstream the remote region. We speculated that the main potential sources of the micro-plastics in the beaches were degraded components of plastics from river upstream,mainly household garbage and aquaculture.