Monitoring heavy metal content on tissues of amberjacks captured in the Canary Islands

Abstract

The topic addressed in this undergraduate thesis titled "Monitoring heavy metal content in tissues of amberjacks captured in the Canary Islands" focuses on the assessment of heavy metal pollution in the tissues of the fish species Seriola spp., commonly known as amberjack, captured in the Canary Islands. This study is relevant due to the growing concern about food safety and public health, particularly regarding the consumption of seafood products. Fish consumption is considered one of the most recommended habits for obtaining animal protein. However, their tissues may contain heavy metals, as they are exposed to environmental contamination, which can affect human health. The recent Commission Regulation (EU) 2023/915 of 25 April 2023 derogating Regulation (EC) No 1881/2006 establishes maximum limits for certain contaminants in food, including fish meat: The maximum mercury level is 0.50 mg/kg, or 1 mg/kg for the species listed in Annex I (section 3.3.1.2). The maximum cadmium level is 0.050 mg/kg, or 0.10, 0.15, 0.25 mg/kg for species listed in Annex I (section 3.2.1.4.2, 3.2.1.4.3, 3.2.1.4.4). The maximum lead level is 0.30 mg/kg in fish meat (Annex I). Throughout the study, tissue samples from amberjacks are analysed to determine the concentration of heavy metals such as mercury, lead and cadmium. The results showed that 94.7% fishes had a mercury content above the legal limit of 0.5 mg/kg of mercury in muscle. The levels of cadmium (<0.020mg/kg) and lead (<0.05 mg/kg) in muscle were not relevant. In liver, 84.2% had mercury contents above 0.5 mg/kg and 100% had levels between 1.4 and 5 mg/kg of cadmium. Lead content in the liver was <0.05 mg/kg. The conclusions of this study reveal that amberjacks with an average weight of 30 kg accumulate mercury and cadmium in muscle and liver above the permitted value, although this species and the liver values are not referenced in the current legislation