01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-06-0291 |
| Title of Abstract | Is the Bay of Bengal Primary and Secondary Productivity within the Euphotic Zone Co-Limited by Silicate and dissolved Nitrogen ? |
| Authors | Inakonda Veera Ganga Bhavani*, Faseela Hamza, Vinu Valsala |
| Organisation | Indian National Centre for Ocean Information Services (INCOIS) |
| Address | INCOIS Hyderabad, Telangana, India Pincode: 500090 E-mail: vgb.inakonda-p@incois.gov.in |
| Country | India |
| Presentation | Oral |
| Abstract | A single-column coupled physical and biological model based on the North Pacific Ecosystem Model for Understanding Regional Oceanography (NEMURO) with nitrogen and silicon cycles is adapted for the Bay of Bengal (BoB) environment. The model simulated plankton biomass and nutrients along the track of Bio-Argos over East and West BoB (from 2016 to 2017) are validated with the observations. The model fairly simulates the perennial structure of subsurface chlorophyll maximum (SCM). Further, three experiments are carried out to know the limitations in primary and secondary production in terms of nitrogen (NO3 + NH4) and silicate (Si(OH)4) in the open ocean BoB. In a ⿿no-NO3⿿ experiment, the nitrate limiting term [i.e., NO3/(NO3 + KNO3)] is set to zero so that the difference from the control case gives the role of ⿿regenerated production⿿ in the total primary and secondary production. Similarly, a no-NH4 experiment was conducted to infer the role of ⿿new production⿿. The new (regenerated) production fuels 85±1% (28±6%) of the living biomass in the East part of open ocean BoB (East BoB). The corresponding values for the west part (West BoB) are 86±1% (42±2%). Among the primary producers, the new (regenerated) production contributed 72±1% (24±6%) in the East BoB and 74±1% (37±2%) in the West BoB. The silicate limits the diatom production by 46±22% (45±27%) of the actual amount of diatom in the East BoB (West BoB) diatom. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Ecosystem modeling, primary production, secondary production, nitrate, silicate, nutrient limitation |
| For Awards | no |