BaselinePollutant levels in discarded fish species by Spanish trawlers operating in the Great Sole Bank and the Atlantic coast of the Iberian Peninsula

•Pollutants were monitored in discarded species of North West Spanish trawlers fleet.•Among the evaluated metals, only Cd frequently exceeded legal limits in some species.•Interspecies variation was detected for Cd and Hg, while season only influences Pb.•Pollutant levels determine the valorization processes for the different species.

Organic and inorganic pollutant levels were determined for the most discarded species from trawlers operating in Great Sole and Spanish coastal fishing grounds. Results for heavy metals indicated that Cd can reach values higher than legal limits for some species and tissues, while Hg and Pb concentrations are below established values. No significant variation was noticed with fishing grounds, but both season influences in the case of Pb and interspecies variation for Hg and Cd have been detected. Valorization recommendations could be therefore established according to the levels found in the different species.