Enzymatic (glutathione S-transferase, GST and catalase, CAT) and histological biomarkers in S. herzbergii are important for the analysis of impacted estuaries in port regions of the Brazilian Amazon coast. Fish specimens were collected in two areas in the rainy and dry seasons: Porto Grande (potentially impacted region) and Ilha dos Caranguejos (less impacted region). Sediment samples were collected for chemical analysis. Morphometric, histological, and enzymatic biomarker analyzes were performed. The analysis of the sediments collected in the potentially impacted region showed levels of iron, aluminum and polycyclic aromatic hydrocarbons above the limits allowed by CONAMA legislation. Histological changes in the gills and liver, as well as GST and CAT activities, were high in fish collected at the port. Analyzes suggest that fish in the potentially impacted region are subject to pollutants that compromise their health.