01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-09-0309 |
| Title of Abstract | Understanding spatio-temporal variability in the ichthyoplankton abundance and distribution in the eastern Arabian Sea |
| Authors | Sonal R. Kalbande*, Kusum Komal Karati, Ajit Antony, Aneena Yesudas, Anusree A |
| Organisation | Centre for Marine Living Resources and Ecology, Kochi, India, Ke |
| Address | CMLRE Puthuvypin south, Kochi, India Pincode: 682508 E-mail: sonalkalbande123@gmail.com |
| Country | India |
| Presentation | Oral |
| Abstract | Seasonal dynamics of ichthyoplankton⿿fish eggs (FE) and larvae (FL)⿿offer key insights into spawning behavior and marine productivity, yet remain underexplored in the eastern Arabian Sea (EAS). This study presents a detailed assessment of ichthyoplankton abundance during two pivotal seasons: the Early Summer Monsoon (ESM) of 2023 and the Winter Monsoon (WM) of 2024. Sampling along west coast of India encompassed northern (Gujarat, Maharashtra), central (Goa, Karnataka), and southern (Kerala and southern tip of Tamil Nadu) coastal transects. Simultaneously, physicochemical parameters (temperature, dissolved oxygen, salinity, and nutrients) and biotic indicators (phytoplankton, zooplankton) were recorded to evaluate their impact on ichthyoplankton distribution. Ichthyoplankton occurred in all regions across both seasons, displaying pronounced spatial and temporal variation. Overall abundance was markedly higher during ESM (1145±5584 ind/100m³) than in WM (85±176ind/100m³). During ESM, high abundance weas observed in southern zone⿿from the southern tip of India through Kerala extending to central coastal Karnataka region. In contrast, WM saw elevated abundance in northern EAS, particularly Maharashtra, while Karnataka also showed high abundance, though lower than during ESM. Interestingly, Gujarat experienced a 3.5-fold increase in abundance in winter compared to summer, indicating WM as dominant spawning period for this region. Enhanced phytoplankton biomass, driven by nutrient-rich upwelling in southern EAS during ESM, likely created favorable spawning conditions there. Conversely, winter cooling and convective mixing enriched northern waters, boosting phytoplankton biomass that encouraged spawning in Gujarat and Maharashtra. Central Karnataka maintained moderate phytoplankton across both seasons, potentially supporting consistent ichthyoplankton abundance. Generalized Additive Models revealed strong influences of physical factors, nutrient levels, and phytoplankton biomass on ichthyoplankton distribution. These findings highlight the need for detailed, region-specific management strategies to safeguard fisheries by protecting habitat of critical early life stages within eastern Arabian Sea. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Ichthyoplankton, eastern Arabian Sea, Early Summer Monsoon, Winter Monsoon; spawning habitat mapping |
| For Awards | yes |
| Date Of Birth | 01-02-1996 |
| ECSN Registration Number | IIOE2-ECSN-0173 |