Comprehensive overview of feed‐to‐fillet transfer of new and traditional contaminants in Atlantic salmon and gilthead sea bream fed plant‐based diets

European fish farming drives the development of sustainable marine fish feed where marine ingredients are replaced by alternatives such as plant meals and vegetable oils. A new scenario emerges where noncurrent and/or new contaminants enter into the fish food chain as potential food safety and/or welfare concerns. Novel analytical methodologies must be developed to assess the large variety of contaminants from different families in feed ingredients, feeds based on these ingredients and fish farmed on the novel feeds. Of the novel contaminants identified in feed ingredients and feeds, the pesticides, such as chlorpyrifos‐methyl, pirimiphos‐methyl, boscalid and azoxystrobin, and the mycotoxins, such as deoxynivalenol and fumonisins (B1 + B2 + B3), were detected. Polyaromatic hydrocarbons, especially those with ≤4 ring, were found in all samples. Information of the transfer of contaminants from feed to public foodstuffs is essential for an appropriate human risk assessment of feed contaminants as well as for the harmonization of legislation of contaminants throughout the aquaculture production chain. However, the pesticides and mycotoxins found in feed were not detected in fish fillet, and hence, no transfer factor could be established. As a result, no apparent risk seems to be associated with these contaminants in fish fillets at the current background exposure levels by feeds