01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-06-0127 |
| Title of Abstract | Environmental regulation of picophytoplankton assemblages in the eastern Arabian Sea during early winter monsoon |
| Authors | Garima Chaudhari*, Smita Mitbavkar, Jagadish S. Patil, Sarun TP, Aakash P, Syed Moosa Ali |
| Organisation | CSIR-NIO, Dona Paula, Goa |
| Address | SAS-12, National Institute of Oceanography Colony Dona Paula, Goa, India Pincode: 403004 E-mail: garima3798@gmail.com |
| Country | India |
| Presentation | Oral |
| Abstract | Picophytoplankton play a crucial role in marine ecosystems by contributing significantly to global primary production and driving carbon cycling processes. To understand their distribution and ecological dynamics during the early winter monsoon, a research cruise (SSK-161) was conducted in the Eastern Arabian Sea from 25 October to 10 November 2023, covering latitudes 10.49°N to 21.49°N and longitudes 67.99°E to 75.48°E. Environmental parameters revealed strong spatial gradients. The coastal station in the Southeastern Arabian Sea (SEAS-C) was characterized by the highest sea surface temperature, dissolved oxygen, and chlorophyll fluorescence, as well as the lowest sea surface salinity and the shallowest mixed layer depth (MLD). The nitrate, nitrite, and phosphate concentrations were below 1 μM in the MLD, while silicate remained below 10 μM, except at SEAS-C. Picophytoplankton community structure varied distinctly across regions. Synechococcus and picoeukaryotes were most abundant at SEAS-C, while Prochlorococcus dominated in the open ocean stations. Vertical distribution patterns indicated that Synechococcus thrived above the sub-chlorophyll maxima layer (SCML) under high temperature and low nutrient conditions, whereas Prochlorococcus and picoeukaryotes were more abundant at or below the SCML, correlating with moderate temperatures and nutrient-rich waters. A diverse suite of photosynthetic and accessory pigments, including zeaxanthin, divinyl chlorophyll-a, fucoxanthin, chlorophyll b, 19⿲-hexanoyloxyfucoxanthin, alloxanthin, and lutein, reflects a taxonomically rich picophytoplankton community with distinct spatial niches. These observations underscore the ecological importance of picophytoplankton in maintaining productivity and biogeochemical cycling in the Arabian Sea during early winter monsoon period. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Eastern Arabian Sea, Pigments, Synechococcus, Prochlorococcus, picoeukaryotes |
| For Awards | yes |
| Date Of Birth | 03-07-1998 |
| ECSN Registration Number | IIOE2-ECSN-0115 |