Microplastic particle impacts to the marine food web: Fish tissue analysis for the presence of plastic additives & persistent organic pollutants (POPs) and the extraction/identification of microplastics from the stomachs of freshwater and marine fish

Plastic marine debris and its devolution into microplastic particles impacts the food web. Our work describes some of the few field studies conducted on fish stomach contents and perhaps the only ones to also evaluate tissue of the same fish for plastic chemical additives and POPs. In addition, our exacting microplastic particle extraction and identification procedures represent the most promising approach for standardizing high-quality procedures for other field studies, addressing quality concerns for this emerging field. Outcomes of the work have direct benefits to microplastic programs and policies measuring and addressing microplastic pollution.

Microplastic particles in the marine environment may contain chemical additives and/or chemicals accumulated from seawater. In two open ocean field studies, we investigated fish exposure to contaminants associated with microplastic particles. Chemical analysis of Myctophid fish tissue samples from the North Pacific and South Atlantic oceans revealed the presence of plastic additives in all the tissue samples. Additionally, all fish tissue exhibited the presence of polychlorinated biphenyls (PCBs). In a subset of the Myctophids we identified microplastic particles in fish guts using optical and scanning electron microscopy and micro-spectroscopy. We compare chemical concentrations between fish with microplastic particle detections and those without. The field studies presented utilize chemical analysis in combination with microplastic particle identification using micro-spectroscopy.