Cadmium content in commercial fishes of the Barents Sea (based on long-term data)

The aim: to study the amount of cadmium found in muscle tissue and liver of the main commercial fish species of the Barents Sea. Research material was comprised of fish samples collected during the expeditions of N.M. Knipovich «PINRO» in the Barents Sea in 2009–2021. The study was based on muscle and liver samples taken from cod , haddock, long rough dab, Greenland halibut, plaice and spotted catfish. Over 1500 samples were analyzed. Novelty: for the first time a comparative analysis of Cd concentration in six commercial fish species of the Barents Sea was run and background readings were provided using such a big amount of data. Methods used: the content of Cd in fish samples was measured using Shimadzu (Japan) Atomic Absorption Spectrophotometer (AAS). Statistical data processing and charting were done using MS Excel and application software package of Statistica 13. The results show that the average content of Cd in muscle and liver of the examined fish did not exceed the established sanitary standard for the maximal concentrations of 0.2 and 0.7 mg/kg of wet weight, respectively. No evidence of anthropogenic contamination of the studied species by cadmium was found. The cadmium concentrations in liver was 11–17 times higher than in muscle. The total content of Cd in muscle and liver demonstrated a high variability (dispersion). The main reason for this variability is differences in the diet and feeding habits of the fishes. The cadmium content in muscle tissues is species-specific. The liver is capable of removing Cd from the body actively. The study also found other factors influencing the cadmium concentrations, such as taxonomic affiliation and regional peculiarities (particularly, habitats and fishing areas). Practical significance: the acquired results were used to determine whether the commercial fishes meet the sanitary standards used in Russia.