Plastic pollution in Maldivian mangroves: emerging evidence of macroplastic accumulation

Mangrove ecosystems are among the most biologically, ecologically, and economically important coastal environments, providing services such as shoreline protection, biodiversity support, carbon sequestration, and fisheries enhancement. Their complex root structures and dense vegetation make them natural traps for marine debris, particularly plastics, with accumulation up to four times higher than on sandy beaches. Nevertheless, mangroves remain understudied in the context of macroplastic pollution, with less than 5% of marine debris research focusing on these habitats. In the Maldives, a Small Island Developing State, plastic pollution is an escalating concern due to limited waste management capacity. In 2020, an estimated 1.6 kilotons of plastic waste entered the marine environment, largely from landfill leakage, inadequate infrastructure, and maritime activities. Although mangroves occur on 108 islands, no previous study has documented plastic accumulation in these ecosystems. During three MaRHE Center expeditions in 2024, we surveyed 28 islands across ten atolls and recorded macroplastic debris in four mangrove forests (14% of sites). The most common items, single-use PET bottles, were entangled in stands of Ceriops tagal, Bruguiera cylindrica, Rhizophora mucronata, and Pemphis acidula (Figure 1). Accumulations were observed in low-lying, wave-exposed embayments with dense vegetation and shallow depressions, indicating that geomorphology and forest structure drive debris retention. Plastic waste may obstruct roots, hinder seedling development, and compromise ecosystem health. These findings represent the first evidence of macroplastic pollution in Maldivian mangroves. Given their recent classification as critically endangered by the IUCN, this underscores the need for targeted conservation measures, improved waste management, and integration of mangrove protection into national marine pollution strategies. As macroplastics degrade into microplastics, future work will assess their presence and distribution in Maldivian mangroves, where no data currently exist.