Liu Huijun, Zhang Yuntao, Wang Qisheng, Liu Mengyang, Yang Chenghu, Cai Minggang, Li Zhiheng, Li Xuchun, Fang Zhiguo, Cheng Kaiming, Zhao Wenlu
School of Environmental Science and Engineering, Key Laboratory of Solid Waste Treatment and Recycling of Zhejiang Province, International Science and Technology Cooperation Platform for Low-Carbon Recycling of Waste and Green Development, Zhejiang Gongshang University, Hangzhou 310018, PR China.
State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong 999077, PR China.
Mar Pollut Bull. 2025 Oct;219:118284. doi: 10.1016/j.marpolbul.2025.118284. Epub 2025 Jun 16.
The presence of sedimentary microplastics (MPs) remains a significant concern due to their substantial contribution to the "missing" MPs in marine environments and their crucial role in the global MP cycle. In this study, we investigated MPs in sediments from three representative bays in the Zhejiang Great Bay Area, China, and examined their sources and mass budgets within these bay systems. High spatial similarities were observed among these regions. In Hangzhou Bay, sedimentary MPs primarily originated from textile and fishing activities, while local mariculture and coastal tourism significantly influenced MP levels in Sanmen Bay. In Wenzhou Bay, packaging and agricultural sources contributed to the presence of MPs. Riverine discharges are crucial for MP mass budget in the three bays, accounting for 41.5 %-96.7 % of the total. Hydrodynamic conditions and topographic features significantly influence oceanic inflow/outflow patterns that affect both water column and sediment MPs. The estimated retention time suggests that these bay systems serve as temporary reservoirs, facilitating the migration of part of MPs from land to open sea. Importantly, the continuous transport pathways, whether through offshore-bound MPs in the water or sediment-resuspended particles, create persistent mobilization mechanisms that may enhance ecological risks in marine ecosystems. These findings emphasize the need for timely action to reduce MP pollution in bay environments and provide valuable information for future policy development regarding MPs.
沉积微塑料（MPs）的存在仍然是一个重大问题，因为它们对海洋环境中“失踪”的微塑料有很大贡献，并且在全球微塑料循环中起着关键作用。在本研究中，我们调查了中国浙江大湾区三个代表性海湾沉积物中的微塑料，并研究了这些海湾系统中微塑料的来源和质量收支。这些区域之间存在高度的空间相似性。在杭州湾，沉积微塑料主要源自纺织和渔业活动，而当地海水养殖和沿海旅游业对三门湾的微塑料水平有显著影响。在温州湾，包装和农业来源导致了微塑料的存在。河流排放对这三个海湾的微塑料质量收支至关重要，占总量的41.5%-96.7%。水动力条件和地形特征显著影响海洋的流入/流出模式，进而影响水柱和沉积物中的微塑料。估计的滞留时间表明，这些海湾系统充当临时储存库，促进部分微塑料从陆地向公海迁移。重要的是，持续的运输途径，无论是通过水中向近海的微塑料还是沉积物再悬浮颗粒，都形成了持续的迁移机制，这可能会增加海洋生态系统中的生态风险。这些发现强调需要及时采取行动减少海湾环境中的微塑料污染，并为未来有关微塑料的政策制定提供有价值的信息。
