Microplastic occurrence and effects in commercially harvested North American finfish and shellfish: Current knowledge and future directions

Scientific Significance Statement As global seafood consumption rises, it is important to understand the mechanisms by which fisheries are affected by microplastic pollution. A growing body of literature describes the occurrence and effects of microplastics in commercial species, primarily from Europe, Asia, and South America; however, there are far fewer studies conducted in North America. In this article, we review the evidence available for the presence and effects of microplastics on commercially valuable fishery species of North America and possible consequences of human consumption. We identify key priorities for future research on this topic including geographic and taxonomic representativeness; physiological, organismal, and population level effects; microplastics as multiple stressors; human health risks; and standardization of field and lab protocols. Commercial fisheries yield essential foods, sustain cultural practices, and provide widespread employment around the globe. Commercially harvested species face a myriad of anthropogenic threats including degraded habitats, changing climate, overharvest, and pollution. Microplastics are pollutants of increasing concern, which are pervasive in the environment and can harbor or adsorb pollutants from surrounding waters. Aquatic organisms, including commercial species, encounter and ingest microplastics, but there is a paucity of data about those caught and cultured in North America. Additional research is needed to determine prevalence, physiological effects, and population-level implications of microplastics in commercial species from Canada, the United States, and Mexico. Investigations into possible human health effects of microplastic exposure from seafood are also greatly needed. This synthesis summarizes current knowledge, identifies data gaps, and provides future research directions for addressing microplastics effects in commercially valuable North American fishery species.