Global marine fish trade networks track international pathways of nutrients and contaminants.

Marine fish trade globalizes nutrients and contaminants. Using trade data, human demographic information, and nutrient and contaminant exposure data, the estimated direct consumption of traded fish from Northeast Atlantic Ocean (NEAO) catches varied among 155 importer countries/regions. The associated trade pathways globalised high amounts of important nutrients including iodine, selenium, and eicosapentaenoic acid and docosahexaenoic acid (EPA + DHA) and contributed greatly to annual domestic EPA + DHA requirements for small-population importers (e.g., Lithuania: 62.8%) but not for high-population importers (e.g., Chinese mainland). Traded amounts of mercury, dioxin, and dioxin-like polychlorinated biphenyls (dl-PCBs) from the NEAO fish were low, and associated pathway contributions to total domestic mercury exposures were <4%. Changes in fish body size affected nutrient and contaminant fillet concentrations and subsequently trade dynamics of nutrients and contaminants. Our study provides valuable insights regarding seafood globalization and marine fish trade that can be used to support adaptive management strategies for contaminants and nutrition-sensitive policies.