A critical synthesis of seagrass meadows as microplastic sinks: Current trends and research gaps

Seagrass meadows are increasingly being recognized as accumulation zones for microplastics. To critically evaluate this role, this systematic review analyzed 84 peer-reviewed studies published between 2015 and 2024, identified through the Scopus database using the PRISMA guidelines. These findings indicate that dense seagrass canopies attenuate hydrodynamic forces, and epiphytic biofilms enhance particle adhesion, leading to significantly higher microplastic concentrations in sediments (ranging from 1.3 to 17.6 times) than in adjacent unvegetated areas. This sequestration creates a scenario in which high biodiversity habitats overlap with elevated contaminant exposure, increasing the risk of ingestion by seagrass-associated fauna and facilitating trophic transfer into coastal food webs. However, seagrasses are not permanent sinks; storm-driven resuspension and detritus export can remobilize plastics, making meadows a secondary source. This review emphasizes the dual role of seagrasses as filters and vectors for microplastic pollution. Effective management must conserve these habitats to maintain their filtering function, while urgently addressing plastic inputs at their sources and exploring long-term impacts on seagrass health.