Fulfer Victoria M, Nguyen-Ngoc L, Walsh J P
Graduate School of Oceanography, University of Rhode Island, Narragansett, RI, USA; 5 Gyres Institute, Santa Monica, CA, USA.
Institute of Oceanography, Vietnam Academy of Science and Technology, Nha Trang, Viet Nam.
Mar Pollut Bull. 2025 Sep;218:118156. doi: 10.1016/j.marpolbul.2025.118156. Epub 2025 May 22.
Marine debris mostly originates from land, but the wide variety of sources, types, and transport pathways make understanding of their flow and fate difficult. Vietnam is a developing country with high production and emission of plastic to the sea, and better understanding of shoreline areas as sources, sinks or ephemeral storage areas is needed to inform management. Using the city of Nha Trang, Vietnam as a case study location, four shorelines were surveyed every 4 to 7 days to track the amount of marine debris present. Over a four-month time series, nearly 74,000 marine debris items were documented on the shorelines of Nha Trang. Tracking marine debris concentrations across space and time, and comparing against environmental parameters gave insights into how tides, river discharge, or storms influence shoreline debris deposition and removal. Measurements illustrated that sandy shorelines, at least temporarily, accumulated more marine debris than hardened shorelines, and cleaned beaches appeared to have only partially dampened the marine debris signals over time. Large storm and wind events, as well as tidal cycles, caused transfer of marine debris signals and impact our ability to clean a system. This work highlighted the many complexities likely influencing shoreline debris and emphasized how beach cleanups cannot be the only mitigation solution - plastic inputs must be addressed. The comparison of hardened and non-hardened shores highlighted differing behavior that yielded a conceptual model emphasizing that source to sink dynamics of debris is governed by not only anthropogenic input but also human alterations of the shoreline.
海洋垃圾大多源自陆地，但由于其来源、类型和运输途径多种多样，很难了解它们的流动和归宿情况。越南是一个塑料产量高且向海洋排放量大的发展中国家，因此需要更好地了解海岸线区域作为来源地、汇或临时储存区的情况，以便为管理工作提供依据。以越南芽庄市为案例研究地点，每4至7天对四条海岸线进行一次调查，以追踪现存海洋垃圾的数量。在四个月的时间序列中，芽庄市海岸线记录了近7.4万个海洋垃圾物品。通过跨时空追踪海洋垃圾浓度，并与环境参数进行比较，了解潮汐、河流流量或风暴如何影响海岸线垃圾的沉积和清除。测量结果表明，沙质海岸线至少在短期内积累的海洋垃圾比硬化海岸线更多，而且随着时间的推移，清理过的海滩似乎只是部分减弱了海洋垃圾信号。大型风暴和风力事件以及潮汐周期导致海洋垃圾信号转移，并影响我们清理系统的能力。这项工作突出了可能影响海岸线垃圾的诸多复杂性，并强调海滩清理不能是唯一的缓解解决方案——必须解决塑料输入问题。对硬化海岸和非硬化海岸的比较突出了不同的行为，得出了一个概念模型，强调垃圾从源到汇的动态不仅受人为输入的影响，还受海岸线人类改造的影响。
