Blue carbon ecosystems (BCEs) typically exhibit elevated sediment accretion rates, facilitating effective sequestration of microplastics (MPs) in their sediments. However, the heterogeneity of BCEs and the complexity of environmental factors result in the accumulation and distribution patterns of MPs in BCEs remaining poorly understood. In this study, a meta-analysis was conducted with 374 observations from 54 articles to quantitatively assess the accumulation and capture effects of MPs by BCEs using Hedges’ d effect sizes and enrichment index (EI). We systematically evaluated the influence of vegetation characteristics, sediment properties, and hydrodynamic conditions on the MP accumulation in BCEs. A significant accumulation and burial of MPs in BCE sediments is observed compared to unvegetated tidal flats, with an overall effect size of 1.93 (p<0.001). Mangrove forests exhibit a more pronounced effect size of 2.46 compared to seagrass meadows (1.01) and salt marshes (1.70). The vegetated area and particulate organic carbon (POC) content are positively correlated with MP accumulation, while sediment composition displays variable relationships with MP retention. In BCEs, MP abundance and EI values in the seaward and landward fringes are significantly greater than those in the interior areas due to the fringe effect. Since the 1950s, the MP burial rate has increased exponentially by 2.7% per year, about double the rate observed in bare tidal flats (1.4% year^-1). These findings provide new insights into the environmental fate and impacts of MPs in coastal wetland ecosystems.

中文翻译：

---

蓝碳沉积物作为微塑料的有效汇：全球荟萃分析

蓝碳生态系统 （BCE） 通常表现出较高的沉积物增积率，有助于在其沉积物中有效封存微塑料 （MP）。然而，BCEs 的异质性和环境因素的复杂性导致 MP 在 BCE 中的积累和分布模式仍然知之甚少。在这项研究中，对 54 篇文章的 374 个观察结果进行了荟萃分析，以使用 Hedges 的 d 效应大小和富集指数 （EI） 定量评估 BCE 对 MP 的积累和捕获效应。我们系统评价了植被特征、沉积物特性和水动力条件对 BCE 中 MP 积累的影响。与未植被的潮滩相比，在 BCE 沉积物中观察到 MPS 的显着积累和掩埋，总体效应量为 1.93 （p<0.001）。与海草草甸 （1.01） 和盐沼 （1.70） 相比，红树林表现出更明显的效应量，为 2.46。植被面积和颗粒有机碳 （POC） 含量与 MP 积累呈正相关，而沉积物组成与 MP 保留呈可变关系。在 BCE 中，由于边缘效应，向海和向陆边缘的 MP 丰度和 EI 值显著大于内部区域。自 1950 年代以来，MP 埋葬率每年呈指数级增长 2.7%，大约是裸露潮滩涂（每年 ^-1 1.4%）的两倍。这些发现为 MP 对沿海湿地生态系统的环境归宿和影响提供了新的见解。