ANTHROPOGENIC INFLUENCE ON MERCURY LEVELS IN A COMMERCIAL SNAPPER (LUTJANUS JOCU) FROM ESPIRITO SANTO COAST, BRAZIL

Resumo

INTRODUCTION: Mercury is a heavy metal toxic to humans and marine life, reported in tissues
of various aquatic species. Lutjanus jocu is a reef fish species with limited migration, making it a
good indicator of local contamination and an economically important species. OBJECTIVES: To
assess mercury contamination in Lutjanus jocu and potential anthropogenic influences in the
northern coastal region of Espírito Santo, Brazil. MATERIALS AND METHODS: Specimens
were collected from the São Mateus coast, ES, and, as a control with low anthropogenic activity,
from the coast of the Abrolhos Marine National Park, BA, between March 2022 and June 2023.
Total mercury concentration in the liver, gills, and muscle tissue of the collected fish was analyzed
by atomic absorption spectrophotometry after gold amalgamation, with absorbance readings at
253.7 nm. Concentration was determined by interpolation using a 7-point analytical curve ranging
from 0 to 11 ng of mercury (r² = 0.9987). Data were evaluated using unpaired t-tests for pairwise
comparisons and ANOVA with Tukey's test for multiple comparisons. RESULTS AND
CONCLUSION: The mean mercury concentration in liver (0.085±0.06 mg/kg, n = 59) was 1.6
times higher than in muscle tissue (0.053±0.02 mg/kg, n = 17, p = 0.0136) and 8.7 times higher than
in gills (0.0098±0.0073 mg/kg, n = 31, p < 0.0001), while muscle showed a 5.4 times higher
concentration compared to gills (p < 0.0001). Mercury concentration in livers of São Mateus fish
(0.085±0.06 mg/kg, n = 59), a coastal region, was 1.9 times higher than that in fish from the
Abrolhos archipelago (0.044±0.02 mg/kg, n = 30, p = 0.0008), a protected environmental area.
Bioaccumulation of mercury was observed in liver and muscle, while gills, which indicate acute
exposure, showed significantly lower levels. The results suggest anthropogenic influence on
mercury total levels in liver of fish collected along the northern coast of Espírito Santo (São
Mateus) when compared to the protected area. However, the mercury levels found were below the
maximum limit established by the Codex Alimentarius Commission (0.5 mg/kg).