Microplastic Impacts on Seafood: A Global Synthesis of Experimental Findings

ABSTRACT Plastic pollution is a growing global concern, with plastic and microplastic particles now widespread in aquatic environments. Microplastics are frequently ingested by marine organisms, including commercially important seafood species. Ingestion can lead to a range of biological effects, influenced by the size, type and quantity of plastic, as well as the species impacted. Despite rising concern, and an escalating body of literature, there has been limited synthesis of how microplastics effect seafood species and what this means for the fishing, aquaculture and seafood sectors. To address this, we conducted a systematic review of experimental studies assessing the effects of microplastics on seafood species. We identified 1107 relevant studies, with microplastics found to effect 95.2% of all specimens tested, though exposure conditions (e.g., polymer type and size, concentration and duration of exposure) varied widely. Reported effects included changes in behaviour, growth and development, immune and reproductive function, biomarker expression and mortality. This review provides a comprehensive overview of the current evidence base, offering insight into the experiments conducted on seafood species such as bivalves, crustaceans and finfish, and their findings related to microplastic uptake, accumulation and health effects. By identifying patterns and gaps in existing research, we highlight opportunities to improve the design and focus of future studies. With a large body of research already established, it is critical that future experiments build strategically on existing knowledge, moving beyond understanding individual level effects to population and ecosystem consequences, to support the sustainable management of seafood resources and our broader marine environment.