Nutrients and contaminants in farmed Atlantic salmon (Salmo salar) fillet and fish feed from 2006 to 2021

Abstract

Nutrients and contaminants are monitored in commercially produced feed materials, fish feed and farmed Atlantic salmon (Salmo salar) in Norway. In this study, we present data for several nutrients such as fatty acids, vitamin D and selenium, and contaminants like dioxins, polychlorinated biphenyls (PCBs), organochlorine pesticides, mercury, cadmium, lead and arsenic in fish feed and fillet of Atlantic salmon for the years 2006–2021. The results showed co-occurring trends in concentrations of several of the nutrients and contaminants in fish feed and fillet of Atlantic salmon for the time period studied. The long-chain omega-3 fatty acids eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA) decreased in concentrations over the time period studied, while the concentrations of alpha-linolenic acid, linoleic acid and oleic acid increased in both feed and fillet. The concentration of several contaminants, including polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (dioxins) and dioxin-like PCBs (dl-PCBs), non-dioxin-like indicator PCBs (PCB-6), DDT and mercury, decreased in both feed and salmon fillet. The most pronounced changes in concentration were observed between 2006 and 2014, while the levels remained more stable from 2014 to 2021. Although the level of some of the nutrients decreased, a portion of Atlantic farmed salmon fillet remains a good source of EPA, DHA, vitamin D and selenium. The reduction in levels of contaminants, such as dioxins and dl-PCBs and mercury, in salmon fillets, has lowered the health risk associated with the presence of these contaminants in salmon.