| Session Details | |
| Section | OS - Ocean Sciences |
| Session Title | Physical Processes and Biogeochemistry of Coastal Ocean and Tropical Estuaries |
| Main Convener | Dr. Sarma Vedula V. S. S. (National Institute of Oceanography, Regional Center,, India) |
| Co-convener(s) | Dr. Murty Vadlamani (National Institute of Oceanography Regional Centre, India) Prof. Minhan Dai (Xiamen University, China) Dr. Jianping Gan (Hong Kong University of Science and Technology, Hong Kong) |
| Session Description | The coastal ocean, including estuaries, upstream rivers, is one of the most biogeochemically active zones at the surface of the Earth. This environment is a highly dynamic system controlled by complicated physical processes and impact to marine and continental influences. These regions are highly influenced by tides, direct interaction with sediments, and receive considerable amount of materials including contaminants from land and exchange with the open ocean. They play a key role as spawning grounds for fish and shellfish, and have been extensively exploited for aquaculture, fishing, tourism etc. Higher rates of biological production, in forms of plants and animals in coastal ecosystems are attributed to the enhanced nutrient inputs. Eutrophication is a naturally occurring process in several regions because of their function as a sink for nutrient inputs from land to sea. Besides the externally supplied organic carbon, the active biological pump in coastal regions contributes to significant accumulation of carbon in sediments. The fate of river-supplied organic carbon in coastal ecosystems depends on its characteristics that are not well understood. Estuaries exemplify the complexity of coastal ecosystems with very high variability with time and space. Despite the intense biological activity, estuaries are found typically source of carbon dioxide (CO2) to the atmosphere. Estuaries receive considerable amounts of freshwater, nutrients, dissolved and particulate organic matter, suspended matter, and contaminants from land and also exchange material and energy with the open ocean. According to current understanding of reactive nitrogen transport from land to sea, the estuaries of major rivers are thought to be sites of massive nitrate losses removing up to 50% of reactive nitrogen. Due to enhanced anthropogenic material inputs, some estuaries are turning into eutrophication leading to formation of suboxic to hypoxic or anoxic condition and have significant impact on fishery industry. Therefore, it is important to understand how do the changes in circulation, stratification, bathymetry, nutrient availability, and ecosystem structural change of the downstream river or estuary affect the ecosystem structure in the estuary as well as coastal biogeochemistry. The areas to be covered under this session are as follows: · Variability in physical processes in the coastal ocean and tropical estuaries · Influence of dams on the physical and biogeochemical processes in coastal ocean · Long-term changes in material fluxes through estuary to coastal ocean · Influence of climate change on coastal processes with reference to material flux and trace gases biogeochemistry. |