Current status and future outlook of aquatic microplastic pollution in Malaysia

Microplastics (MP) are generated across the full life cycle of plastics, causing widespread environmental pollution. This review provides a comprehensive analysis of MPs research trend, and knowledge gaps in aquatic organisms in Malaysia. Comparative analyses reveal significant variation in MP ingestion and accumulation, with some fish species, such as sharks and mackerel, harbouring thousands of MPs, indicating widespread contamination. Moreover, bivalves, particularly oysters and blood cockles, act as bioindicators of marine pollution due to their filter-feeding habits, displaying MPs concentrations that threaten food safety. Gastropods, sea cucumbers, and crustaceans also exhibit MP presence, often dominated by fibres and polymers like polyethylene terephthalate (PET), with ingestion likely driven by sediment intake and diet. Data on lower trophic levels, such as zooplankton, polychaetes, and aquatic insects, remain limited, yet existing evidence suggests potential biomagnification and ecosystem disruption, which could exacerbate MP transfer to higher organisms, including humans. Thus, understanding these differential effects underscores the importance of investigating biota-MP interactions to better assess and mitigate the health impacts of environmental MPs pollution. Moreover, mechanistic and long-term toxicological studies remain limited, necessitating the urgency for comprehensive risk assessments. In this regard, enhanced pollutant monitoring, reduced plastic release, and development of safer alternative materials are some of the measures critical to mitigate macro- and microplastic toxicity in aquatic environments.