Characterisation of coastal aquaculture sites in the state of Rio de Janeiro, Brazil, using genotoxicity biomarkers

Mollusc aquaculture is highly dependent on environmental quality which, when impacted, can compromise cultivation. Genotoxicity biomarkers were applied to determine organism quality and environmental DNA damage capacity. The purpose of this study was to evaluate three coastal aquaculture areas with different contamination levels situated in the state of Rio de Janeiro, Brazil, where Perna perna mussels are cultivated for commercialisation and consumption. Mussel haemocytes were evaluated by genotoxic biomarkers at the DNA and chromosome levels. Organism sensitivity was tested after exposure to the carcinogen methyl methanesulfonate, which induced genetic damage when compared to the control organisms. Mussels sampled in aquaculture sites from the polluted Guanabara Bay showed the highest level of genetic damage compared to tourist areas with low urbanisation, which showed values close to zero. It can be concluded that genotoxic biomarkers, such as percentage of DNA in the comet (nucleoid) tail, obtained by the comet assay and micronucleus frequency are useful tools for recognising healthy sites for bivalve culture. (c) 2019 Elsevier B.V. All rights reserved.