Microbial responses on upwelling signature across reversal wind pattern in tropical coastal environment off Mumbai, India.

Upwelling promotes marine productivity through water column mixing. The process disturbs the ecosystem, causing oxygen depletion and thermal variability. This study analyses effect of upwelling processes on microbial signature in coastal waters off Mumbai. The coastal environment with seasonal reversal winds was analysed using data during ten cruises. Coastal metocean processes are examined using water quality parameters and the Ekman approximation with wind stress. This analysis explains oxygen depletion and coastal upwelling, influenced by seasonal reversal wind pattern. The study connects hypoxia in the coastal water column to wind-induced upwelling. Concurrently, microbial structure is assessed through metrics such as Total Viable Count, Total Bacterial Count, Sulfate Reducing Bacteria (SRB), and denitrifiers. Notably, high levels of SRB are observed during hypoxia associated with coastal upwelling. This study investigates microbial level with combined result of physical processes and water quality parameters.