DATE/TIME: Friday, October 31, 2025, 2:30 pm PLACE: ENR building, room 223 or this Remote Live option.
Salom Gnana Thanga Vincent
University of Kerala, Thiruvananthapuram, India; Fulbright Visiting Scholar, Department of Biochemistry and Microbiology, SEBS, Rutgers University
Environmental drivers of coastal sediment microbial activity. How do tropical coastal ecosystems become sources of greenhouse gases?
Coastal wetlands in tropical regions are under increasing anthropogenic pressure due to dense populations and rapidly expanding economic activities, resulting in the accelerated degradation of these vital ecosystems. Major stressors include land conversion for agriculture, intensive aquaculture, tourism development, transportation infrastructure, industrial waste discharge, untreated sewage inputs, and encroachment for urban construction. These alterations significantly impact the hydrological regimes and the physical, chemical, and biological functioning of coastal systems. Human-induced changes in the catchments of tropical estuaries often lead to nutrient over-enrichment, which stimulates excessive primary production, promotes eutrophication, and results in oxygen depletion and increased organic matter accumulation in sediments. In most coastal and eutrophic estuaries, where productivity is relatively high and detrital input to the bottom sediments is appreciable, the sediments are reduced and anoxic, and a considerable portion of the organic carbon mineralization occurs under anaerobic conditions. The sequence of terminal electron acceptors utilized in these sediments is largely determined by thermodynamic energy yield, but also influenced by microbial physiology and reaction kinetics. The dominant electron-accepting pathway plays a critical role in nutrient biogeochemistry and drives the production of key greenhouse gases from estuarine sediments. The associated heterotrophic microbial activity affects the biogeochemical processes on a short-term scale with regard to nutrient cycling and productivity, as well as on a long-term scale in terms of carbon sequestration or burial. This has implications for how the estuary behaves in terms of a sink or source of greenhouse gases like carbon dioxide, nitrous oxide and methane
Seminar Host:
Donna Fennell
Department of Environmental Sciences, SEBS, Rutgers University