01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-03-0176 |
| Title of Abstract | Decadal Trends in Phytoplankton Biomass and Size Structure with a Focus on Diatoms in the Western Bay of Bengal |
| Authors | Suchismita Srichandan*, Amit Kumar Jena, Alakes Samanta, Susmita Raulo, Sanjiba Kumar Baliarsingh, Amit Maharana, Kamal Kumar Barik |
| Organisation | Berhampur University |
| Address | Berhampur University, Bhanja Bihar Berhampur, Odisha, India Pincode: 760007 E-mail: suchismita.sima@gmail.com |
| Country | India |
| Presentation | Poster |
| Abstract | This study examines the seasonal and spatial variability of chlorophyll-a (chl-a) concentrations, diatom distributions, and phytoplankton size classes (PSCs) in the coastal waters off Gopalpur and Visakhapatnam, located along the western Bay of Bengal. Using MODIS-Aqua satellite data from 2003 to 2024, monthly climatologies of chl-a, diatom pixel counts, and PSCs (micro-, nano-, and picophytoplankton) were generated. The analysis revealed bimodal peaks in chl-a concentrations during the pre-southwest (Marchâ¿¿April) and post-southwest (Septemberâ¿¿October) monsoon seasons along both locations. Gopalpur, influenced by the Rushikulya River and relatively lower anthropogenic pressure, exhibited higher chl-a and more frequent algal bloom events, predominantly dominated by diatoms. In contrast, Visakhapatnam, despite experiencing strong upwelling, lacked recurrent bloom reports, likely due to limited freshwater input and port-associated material flux. Seasonal variation in PSCs showed dominance of microphytoplankton during post-southwest monsoon periods, with picophytoplankton prevailing during the peak monsoon season due to increased turbidity. Spatially, microphytoplankton dominated nearshore regions, while picophytoplankton were more prevalent in offshore. The East India Coastal Current (EICC) and upwelling processes emerged as key physical drivers influencing phytoplankton biomass distribution and bloom timing. Cyclonic events and monsoonal dynamics also modulated nutrient availability, further impacting bloom development. While satellite-based observations offer broad-scale insights, they face limitations under high turbidity and cloud cover. This study underscores the need for integrated bloom monitoring that combines satellite data with in situ measurements and modeling approaches. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Algal Blooms, Chlorophyll-a, Ocean Colour, MODIS-Aqua, Monsoon |
| For Awards | no |