Genotoxicity Biomarkers for Environmental Health Assessment Towards Sustainable Management of Fish Genetic Resources

High industrialization, urbanization, and agricultural practices generate several types of chemicals, pesticides, microplastics, dusts, and heavy metal particles that are severely accumulating in the environment, including in water bodies, causing environmental pollution and genotoxicity in living organisms. Genotoxicity biomarkers play a dynamic role in assessing the impact of environmental stressors and are also considered instrumental in formulating strategies for sustainable management. Micronuclei, the small additional nuclei formed during cell division, resulting from chromosomal damage are widely used to assess the genotoxicity in fish populations exposed to pollutants. The comet assay is a very sensitive gel electrophoresis-based method that measures the DNA strand breaks and allows the detection of damaged DNA at the individual cell level. The sister chromatid exchange (SCE), indicative of the exchange of genetic material between the sister chromatids, is another method that provides information on chromosomal instability and genotoxic effects. The changes in the activity of antioxidant enzymes, such as SOD and CAT, indicate oxidative stress and potential genotoxic effects. Elevated levels of malondialdehyde (MDA) suggest damage to cell membranes due to oxidative stress. Regular monitoring of these biomarkers contributes to the conservation of fish genetic resources and the overall health of aquatic ecosystems. The future of genotoxicity biomarkers has great promise for evaluating and improving the health of both fish and humans. In the present chapter, we have discussed here the genotoxicological endpoints of various environmental pollutants in fish, highlighting the biomarkers for environmental health assessment towards the sustainable management of fish genetic resources.