Seafood supply mapping reveals production and consumption mismatches and large dietary nutrient losses through exports in the United Kingdom.

Seafood can contribute towards healthy and sustainable food systems by improving public health and helping achieve net zero carbon emissions. Here, we provide a high-resolution perspective on UK seafood supplies and nutrient flows at the species level. We mapped seafood production (capture and aquaculture), trade (imports and exports), purchases (within and out of home) and seafood consumption between 2009 and 2020. UK dietary recommendations for finfish consumption were not achieved by domestic production nor national supplies. Mapping dietary nutrient flows revealed that the UK undergoes substantial losses of omega-3 fatty acids, vitamin B and vitamin D, which could contribute 73%, 46% and 7% towards UK-recommended nutrient intakes, respectively, through exports of oily fish such as salmon, herring and mackerel. Policies should consider promoting greater consumption of locally produced oily fish species to improve public health and seafood system resilience.