Incidental Detection of Polypropylene Microplastics in a Mangrove Propagule: Evidence of Surface-Associated Interaction with Marine Plastic Pollution

Mangrove ecosystems are increasingly recognized as sinks for marine plastic pollution; however, evidence of microplastic surface-associated embedding into mangrove reproductive structures remains scarce. The incidental detection of a polypropylene (PP) microplastic particle (∼200 μm) physically embedded within the structure of a Rhizophora sp . propagule collected from an estuarine environment is herein reported. The particle was identified during routine inspection for insect larvae ( Coccotrypes rhizophorae ) using a handheld optical microscope, without prior chemical or mechanical treatment, subsequently extracted and confirmed as PP by micro-Fourier Transform Infrared Spectroscopy (μFTIR). This observation suggests that microplastics may become physically embedded within propagule structures under environmental conditions. This observation highlights a potential but unverified interaction between microplastics and mangrove reproductive structures. Given that the finding is based on a single propagule and a single particle, no conclusions can be drawn regarding prevalence or ecological significance. However, it underscores the need for systematic investigation of early-life stage exposure to microplastics under controlled conditions.