Microbial diversity analysis in the oxygen minimum zones of the Arabian Sea using metagenomics approach

Large oxygen-depleted areas known as oxygen minimum zones (OMZs) have been reported from the Arabian Sea, and recent reports indicate that these areas are expanding at an alarming rate. In marine waters, oxygen depletion may also be related to global warming and temperature rise. The acidification and deoxygenation due to OMZs can lead to major consequences wherein the plants, fish and other biota will struggle to survive in the ecosystem. The present study has identified the microbial community structure using next generation sequencing-based metagenomics analysis in water samples collected at different depths from the OMZs and non-OMZs of the Arabian Sea. Environmental variables such as depth, site of collection and oxygen concentration might influence species richness and evenness among microbial communities in these locations. Our observations suggest that population dynamics of microbes consisting of nitrate reducers accompanied by sulphate reducers and sulphur oxidizers influences the interconnected geochemical cycles of OMZs. In addition to providing baseline data related to the diversity and microbial community dynamics in waters in the OMZs; such analysis can provide insight into processes regulating productivity and ecological community structure of the ocean.