Research Projects

Ocean acidification, caused by increased CO2 emissions, has led to a decrease in the global ocean's pH by 0.1 units since the industrial revolution and is projected to further decrease by 0.3-0.4 units by the end of this century. This threatens life at the sediment water interface in highly productive intertidal zones, such as microphytobenthos (MPB), which are complex assemblages of unicellular eukaryotic algae and cyanobacteria that grow as thick mats on intertidal sediments. These MPBs not only fix CO2 but also sink aquatic toxicants. Coastal waters, particularly estuaries, support various human activities, but they are susceptible to pollution from solid waste discharge, industrial and agricultural effluents. As water pH decreases, metals that are currently fixed in sediments will be mobilized and solubilized in the water, leading to increased soluble metal concentrations in the future ocean water, facilitating biological uptake and trophic transfer. Intertidal MPBs have great potential to absorb heavy metals from the water and store them in their cellular structure. When buried in sediments, MPBs fix the metals back in the sediments, keeping marine and estuarine water clean of heavy metals. However, the adaptation mechanism and interaction with metals with increasing water pH are still unknown. To understand the future scenario, lab culture MPBs collected across salinity gradients from Sundarbans with different metal concentrations and varying pH.