01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-06-0139 |
| Title of Abstract | Biogeography and Dispersal dynamics of dinoflagellate cysts in the Indian Ocean deep-sea sediments: implications for deep-sea ecology and resource exploration |
| Authors | Pranoy Paul*, Jagadish S Patil |
| Organisation | CSIR-National Institute of Oceanography, Goa |
| Address | SR-17, NIO Colony Hostel, Dona Paula Panaji, Goa, India Pincode: 403004 E-mail: pranoy.paul80@gmail.com |
| Country | India |
| Presentation | Poster |
| Abstract | This study assesses dinoflagellate cyst assemblages (DCA) from deep-sea sediments (200 m ⿿ 5400 m depth) of the Indian Ocean (IO), focusing on their biogeographic distribution and ecological-environmental indicators. The DCA exhibits distinct geographic patterns influenced by both large- and small-scale lateral transport processes. Notably, the highest richness and concentration of DC species, many of which are potential harmful algal bloom (HAB) species, were recorded in the ecologically significant northern Indian Ocean (NIO), characterized by high productivity, the presence of oxygen minimum zones, and upwelling phenomena. In contrast, the economically substantial (e.g., mineral deposits and shipping routes regions) Equatorial and South Tropical IO regions demonstrated lower species diversity. Among the identified cyst types, 21 are cosmopolitan, including one HAB species, while 27 are exclusive to the NIO. Notable NIO-specific five potential HAB species include Polysphaeridium zoharyi, Lingulodinium machaerophorum, Polykrikos hartmannii, cysts of Alexandrium, and Gonyaulax. Conversely, Operculodinium centrocarpum is widespread in IO. Among cosmopolitan taxa, N. labyrinthus, Nematosphaeropsis, O. centrocarpum (a yessotoxin producer), S. mirabilis, S. hyperacanthus, and cysts of Protoperidinium could be crucial indicators for environmental, oceanic, and climatic changes. Furthermore, the morphometric variations of some cosmopolitan cysts between low- and high-salinity bioregions suggest the existence of different strains or influencing factors, highlighting the potential of morphometry as ecological-environmental indicators in IO and beyond. In summary, these findings significantly enrich our understanding of dinoflagellate biogeography and offer new perspective for biodiversity assessments and climate change monitoring in ecologically and economically vital regions. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Dinoflagellate cysts, Pelagic Indian Ocean, Arabian Sea, Equatorial Indian Ocean, Bay of Bengal, South tropical Indian Ocean |
| For Awards | yes |
| Date Of Birth | 10-10-1992 |
| ECSN Registration Number | IIOE2-ECSN-0121 |