Occurrence and Effects of Microplastics in Commercially Harvested Finfish and Shellfish in North America: Research Needs and Future Directions

Commercial fisheries feed the planet, support cultural practices, and provide widespread employment around the globe. Many commercially-harvested species face a myriad of anthropogenic threats such as overharvesting, degraded habitats, changing climate, and pollution. Microplastics, which are 5mm or smaller in length, are an aquatic pollutant of increasing concern that are now ubiquitous and persistent in nearly every ecosystem on the planet. Marine and freshwater organisms, including commercial species, encounter, ingest, and respire microplastics and increasingly microfibers, which harbor pollutants added during manufacturing or adsorbed from surrounding waters. Recent studies have identified widespread occurrence of microplastics in marine organisms ingested as seafood globally, but there is a paucity of data from species caught and cultured in North America. Additional research is necessary to determine the prevalence and impacts of microplastics on organisms harvested for human consumption in the United States of America (U.S.), Canada, and Mexico, as well as the population-level implications for wild and farmed species in these countries. Furthermore, estimates of human ingestion based on seafood consumption and investigations into the possibility of human health impacts are greatly needed. As the human population continues to grow and environmental stressors are amplified, the importance of investigating potential additive or synergistic effects of stressors occurring concomitantly with microplastics grows daily. Opportunities for closing critical knowledge gaps relating to microplastics in commercially important species in North America are discussed herein.