Microplastic Toxicity in Aquatic Organisms and Aquatic Ecosystems: a Review

Microplastics are pervasive pollutants and have been found in all environmental compartments globally, including aquatic ecosystems. Ingestion and trophic transfer of microplastics through aquatic species have been widely reported. Although a plethora of studies have reported that microplastics can be transferred through higher trophic level food webs with the potential for accumulation and toxicity, most microplastic aquatic toxicity studies have been conducted in laboratory studies. This means that studies within entire ecosystems or at environmentally relevant concentrations are lacking, representing a critical knowledge gap for ecotoxicological impact of microplastics on aquatic species and higher trophic level consumers (including humans). Thus, an understanding of aquatic ecosystem toxicity is still relatively unknown. To address this knowledge gap, this study provides a non-exhaustive summary of microplastic transport pathways, ecotoxicology, food web transfer, and examples of toxic pollutants sorbed onto microplastics in aquatic food webs. This study will guide future research priorities to address microplastic toxicity through aquatic food webs.