Chronic toxicity after the oil spill on the Brazilian coast based on ecotoxicological biomarkers in the reef fish Stegastes fuscus (Cuvier, 1830).

Abstract

The Brazilian coast was affected by crude oil in 2019 that contaminated coral reef areas. Oil Polycyclic aromatic hydrocarbons (PAHs) are responsible for triggering sublethal toxicity in fish. This study aimed to evaluate chronic effects and recovery of the keystone damselfish Stegastes fuscus after exposure to crude oil in October 2019. Fish were sampled from seven oil affected reef areas and one non-affected, 17, 24 and 34 months after the oil spill. Analysis of biliary PAHs, biochemical and genotoxic biomarkers were carried out. Biliary PAHs in fish from Paiva and Suape areas were significantly reduced 17 months after the oil spill. Biliary PAHs and ethoxyresorufin-O-deethylase (EROD) activity in fish sampled from Janga, Paiva, Suape, Serrambi, Carneiros and Mamucabas reefs were higher than in specimens from Cupe reference area. Male and immature individuals presented higher activities than females for EROD, Glutathione S-transferase and catalase and lower values for superoxide dismutase and glutathione. Increased micronuclei frequencies were observed in Paiva, Suape, Serrambi and Carneiros samples. The results indicate that these reef areas are not being influenced by the 2019 oil spill. Contamination by PAHs occurs chronically in these locations such as the urbanized Janga reef area, where the highest bile PAH concentrations and EROD induction were detected. The integrated index of biomarker responses indicated changes in biochemical biomarkers in all reef areas related to Cupe, possibly reflecting exposure to other unmeasured contaminants. Continued monitoring with the species Stegastes fuscus is necessary to obtain information on the contamination status of these environments over the years.