Biomarkers of oxidative stress in an estuarine catfish species caught near a port complex on the Brazilian Amazon coast

Abstract

Biomonitoring studies in harbor areas are crucial for initiating timely interventions to minimize socioeconomic and environmental damage. This study aimed to analyze biomarkers of oxidative stress in Sciades herzbergii, an estuarine catfish species, caught near a port complex on the Brazilian Amazon coast. Water physicochemical parameters, fish biometric indices, superoxide dismutase, catalase, glutathione, glutathione S-transferase, and lipid peroxidation were analyzed in the dry and rainy periods of 2021 and 2022 in two regions, namely Porto Grande (PG, potentially impacted area) and Ilha dos Caranguejos (IC, conservation area). Lower levels of dissolved oxygen and higher concentrations of trace metals and polycyclic aromatic hydrocarbons were detected in PG sediments. PG fish showed delayed development, increased enzyme activities, and increased lipid peroxidation. Principal component analysis confirmed that biomarkers of oxidative stress showed higher expression during the rainy season, especially in 2022. Our findings showed that chemical contamination of estuaries directly influences the expression of oxidative stress enzymes in S. herzbergii, impairing fish health.