The Brazilian government, through its Ministry of Agriculture, Livestock and Food Supply (MAPA), instituted a reference value of 0.5 mg kg1 for total Hg in fish farming and 1 mg kg1 for predator fish (Damin et al., 2013; PNCRC, 2009). Two of the five Brazilian samples (red porgy-1 and red porgy-2) were above the values recommended by the Brazilian government (Table 3). All Spanish samples had concentrations of total Hg below the maximum levelsset by EC Regulation No 1881/2006 (Commission Regulation (EC) No 1881/2006), except for tuna-3 and swordfish-1 samples (2.33 ± 0.03 mg kg1 and 1.04 ± 0.03 mg kg1, respectively). These data demonstrate the need to carry out speciation in seafood samples to discern the more toxic species.