Total Mercury in Atlantic Chub Mackerel (Scomber colias Gmelin, 1789) from the Saronic Gulf: Contamination Patterns, Biological Drivers and Food Safety Implications

This study determined total mercury (THg) concentrations in the muscle tissue of Atlantic chub mackerel (Scomber colias) from the Saronic Gulf, evaluated temporal variation, and examined their relationship with biological parameters. THg was analyzed in 79 muscle samples, comprising 50 individual and 29 pooled samples derived from 179 Atlantic chub mackerel specimens, using cold vapor atomic absorption spectrometry (CVAAS). Method accuracy was verified by certified reference material analysis, with a mean recovery of 103%. THg concentrations ranged from 0.005 to 0.247 μg/g wet weight, with a mean value of 0.065 ± 0.053 μg/g. THg levels varied significantly among sampling periods, with the highest concentrations observed during the September sampling periods, particularly in September 2024. A strong positive correlation was found between THg concentration and fish size, both for fork length (p < 0.001) and dressed weight (p < 0.001), while a moderate positive association was also observed with Fulton’s condition factor (p < 0.001). All concentrations were below the European Union maximum permitted level for mercury in Scomber species (0.30 μg/g wet weight). Risk assessment indicated low concern at mean THg levels (HQ = 0.50), but potential concern under the maximum-exposure scenario (HQ = 1.9). These findings provide baseline data on THg contamination in Atlantic chub mackerel from the Saronic Gulf, demonstrate size-dependent THg accumulation, and contribute to the evaluation of its potential utility in mercury biomonitoring and seafood safety assessment.