- Dona Paula, Goa, India.
- +91-0832- 2450327
- iiosc2020[at]nio[dot]org
| Abstract Submission No. | ABS-2022-09-0132 |
| Title of Abstract | Seasonal analysis of benthic fluxes of dissolved inorganic nitrogen (DIN) and nitrous oxide (N2O) in Pulicat lagoon |
| Authors | Tanisha Nag*, Damodara Rao Valavala, Anitha Gera, M V Ramana Murthy |
| Organisation | National Centre for Coastal Research |
| Address | Zolo Classic, Kamakoti Nagar, Pallikaranai, Chennai Chennai, Tamil Nadu, India Pincode: 600100 Mobile: 8527041052 E-mail: tanisha@nccr.gov.in |
| Country | India |
| Presentation | Oral |
| Abstract | Pulicat lagoon is a shallow, transitional ecosystem connected with the coastal waters of the Bay of Bengal on the south-east coast of India. The lagoon receives most of its precipitation during the north-east (NE) monsoon. Benthic fluxes of nitrous oxide (N2O) and dissolved inorganic nitrogen (DIN) were investigated in North Pulicat in two seasons - the NE monsoon (December, 2020) and the south-west (SW) monsoon (September, 2021). The objective of the study was to understand the impacts of seasonally varying physical parameters (salinity and temperature) on benthic fluxes of DIN and N2O. Benthic N2O fluxes of -8.129 µmol/m2/d (during the SW monsoon) and -4.359 µmol/m2/d (during the NE monsoon) were observed. DIN fluxes of 41.378 mmol/m2/d (SW monsoon) and 1.305 mmol/m2/d (NE monsoon) were also observed. N2O fluxes were observed to be correlated with DIN fluxes and initial concentrations of DIN in the benthic water column. The DIN pool was dominated by ammonia (NH3-N) in both the seasons. Benthic water column salinity and temperature were observed to be correlated with N2O fluxes and DIN fluxes. Salinity (33 PSU) and temperature (32.7 °C) were greater during the SW monsoon compared to salinity (2.15 PSU) and temperature (26.94 °C) during the NE monsoon. Salinity and temperature likely impact fluxes of DIN and N2O through enhanced/reduced rates of sediment microbial activity, production/decomposition of organic matter, and enhanced/reduced benthic activity. Study of seasonal patterns of benthic fluxes of N2O and associated fluxes of DIN can help us determine the environmental parameters that control release/uptake of this greenhouse gas (GHG) in shallow, coastal ecosystems. Such studies are important in the context of climate change. |