Mercury levels tend to build up more in larger fish, such as tuna and swordfish, than in smaller fish. Among the latter, sardines, anchovies, sea bream and sea bream are among the species that comply with the limit values recommended by the EU, alongside a mollusc: the squid, according to an analysis carried out at the IDEA Institute of the CSIC .
A scientific team from the Institute for Environmental Diagnosis and Water Studies (IDAEA) of the Higher Council for Scientific Research (CSIC) is analyzing the concentration of mercury in 58 species of fish and crustaceans intended for human consumption collected on local markets in Spain, Italy and France.
Of all of them, specimens of 13 species still had mercury concentrations below those recommended as safe by the European Union. Among them are sardines, anchovies, sea bream, sea bream and squid.
“Consuming these species minimizes our consumption of mercury, which is the price we pay by eating fish. In addition, these fish have a good amount of unsaturated fatty acids, which are more beneficial from a nutritional point of view.says Joan O. Grimalt, researcher at IDAEA-CSIC and lead author of the study.
Mercury is a toxic element that damages the kidneys, lungs, and cardiovascular and nervous systems, especially in pregnant women and children. Due to its physico-chemical properties, mercury can be transported over long distances and deposited in aquatic ecosystems, where it is taken up by fish and other organisms. Most of the mercury ingested by the human population comes precisely from the consumption of fish and shellfish.
Analysis of mercury levels in 1300 specimens in Mediterranean markets
The study, published in the journal Environmental pollutionanalyzed more than 1,300 specimens of 58 species of fish and shellfish intended for human consumption that were on sale in markets in Spain (Minorca, Majorca, Ibiza, Alicante, Ametlla de Mar and L’Ampolla), Italy (Genoa, Civitavecchia, Alghero) and France (Marseilles).
The results show that the specimens of 13 of the 58 species analyzed still have mercury levels below the limits recommended by the European Union: sardines, anchovies, blue whiting, caramel (or gerret), gilthead seabream, gilthead seabream, gallant, red mullet of rock, serrano, corvallo, salpa, dolphinfish and squid.
“Based on these results, health authorities should pay particular attention to the species of fish and shellfish highest in mercury and formulate appropriate preventive health recommendations, especially for pregnant women and children.Grimalt concludes.
In general, larger fish accumulate more of this toxic substance. Analyzes carried out by the Organization of Consumers and Users (OCU), for example, have detected higher concentrations of mercury in bluefin tuna, swordfish and some sharks.
Marco Capodiferro et al. “Wild Fish and Seafood Species in the Western Mediterranean with Safe Low Levels of Mercury”. Environmental pollution2022