A model to environmental risk assessment based on biochemical and morphological biomarkers in catfish

Abstract

In this research, we present a mathematical model to environmental risk assessment based on biochemical (glutathione S-transferase) and morphological (branchial lesions) biomarkers in catfish Sciades herzbergii from São Luís Island (harbor area) and Caranguejos Island (reference area) in São Marcos Bay, Brazil. The fish were sampled from a port known to be contaminated and from a protected area in Maranhão (North of Brazil). Glutathione S-transferase (GST) was measured spectrophotometrically, and branchial lesions were examined by light microscope. A non-linear model was used to analyze the dependence of the enzyme activity on the areas of sampling and on selected branchial lesions of the fish. Results from the mathematical model indicate that GST activity has a strong relationship with the occurrence of branchial lesions only at the polluted harbor site. This model based on two biomarkers (histological lesions and enzyme activity) in catfish provides a realistic approach to analyze stress induced by contaminants.