01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-06-0018 |
| Title of Abstract | Influence of Oceanic Fronts and Mid-Oceanic Islands on Coccolithophore Biogeography and Carbonate Production in the Southwest Indian Ocean |
| Authors | Shramik Patil*, Rahul Mohan, Melena Soares |
| Organisation | National Centre for Polar and Ocean Research |
| Address | National Centre for Polar and Ocean Research Vasco da Gama, Goa, India Pincode: 403804 E-mail: shramikpatil@gmail.com |
| Country | India |
| Presentation | Oral |
| Abstract | Coccolithophores, a group of calcifying phytoplankton, play a vital role in oceanic carbon cycling through both organic carbon fixation and calcium carbonate production. Although well-studied in many oceanic regions, their distribution and ecological functioning in the Southern Ocean remain relatively underexplored. This study investigates the spatial variability of coccolithophore abundance and diversity in the Southwest Indian Ocean, using surface water and sediment samples collected during the CROTALE expedition (FebruaryâżżMarch 2019). Sampling across the Subtropical Gyre, Agulhas Return Frontal Zone (ARFZ), Subtropical Zone (STZ), and Subantarctic Zone (SAZ), we observed strong regional contrasts influenced by oceanic fronts, mesoscale eddies, and physical properties such as temperature, salinity, and nutrient availability. Notably, coccolithophore abundance and diversity were significantly lower in waters surrounding mid-oceanic islands (e.g., Crozet Islands), suggesting that island-driven topographic and hydrographic features modulate phytoplankton communities, potentially creating localized zones of suppressed carbonate production within the broader Great Calcite Belt (GCB). These findings underscore the importance of mid-oceanic islands in shaping the distribution of siliceous and calcareous phytoplankton and highlight their potential role in regulating regional biogeochemical cycles, especially under projected climate-driven shifts in ocean circulation and frontal dynamics. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Coccolithophores, Oceanic fronts, Mid-oceanic islands, Great Calcite Belt, Marine biogeochemical cycling |
| For Awards | no |