An integrated approach to study the biomarker responses in marine gastropod Nerita chamaeleon environmentally exposed to polycyclic aromatic hydrocarbons
Keywords:Integrated biomarker response, oxidative stress, genotoxic damage, polycyclic aromatic hydrocarbon, comet assay
Ecological risk assessment using multiple biomarkers produce a large amount of data that is hard to interpret and the result are often contradictory. In this context, Integrated Biomarker Response (IBR) index was used to integrate the biomarkers effects to assess the impact of environmental contaminants in marine gastropod Nerita chamaeleon from Goa, India. Genotoxic (DNA damage as measured by comet assay and alkaline unwinding assay) and biochemical [superoxide dismutase, catalase, glutathione S-transferase, lipid peroxidation and acetylcholinesterase] biomarkers were measured in snails collected from different sites (Arambol, Anjuna, Sinquerim, Dona Paula, Velsao, Betul and Palolem). Total polycyclic aromatic hydrocarbons in snail tissue were in the range from 5.29 - 12.14 μg/g wet weight. Standardized values of biomarker response were visualized using star plots, which show unique patterns for different biomarkers. The mean IBR value was found to be highest at Dona Paula (8.07 ± 0.91) followed by Sinquerim (6.95 ± 0.91), Velsao (4.48 ± 0.68), Anjuna (3.28 ± 1.05), Palolem (2.53 ± 0.73), Arambol (1.81 ± 0.21) and Betul (0.88 ± 0.77). Additionally, the IBR values were found to be positively correlated with PAH concentration in snail tissues. These results suggest that integration of biomarkers effects using IBR along with chemical analysis can be a useful tool for the assessment of environmental pollution and to identify spatial patterns of contamination in the aquatic ecosystem.