01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-01-0174 |
| Title of Abstract | Climatic Drivers and Oceanographic Factors Influencing Indian Oil Sardine Aggregation Along the West Coast of India |
| Authors | Sanjiba Kumar Baliarsingh *, Bhagyashree Dash, Dhanya M. Lal, Alakes Samanta, Sudheer Joseph, T.M. Balakrishnan Nair |
| Organisation | Indian National Centre for Ocean Information Services |
| Address | INCOIS Hyderabad, Telangana, India Pincode: 500090 E-mail: baliarsingh.s@incois.gov.in |
| Country | India |
| Presentation | Poster |
| Abstract | A detailed assessment was carried out to examine the environmental factors influencing the aggregation patterns of Indian Oil Sardine (IOS) during 2023-2024 along India⿿s west coast, specifically across Kerala, Karnataka, and Goa. Building on earlier studies, this investigation utilized a more extensive spatio-temporal dataset to find out additional drivers affecting IOS aggregation behaviour. The results signified the critical influence of climate-related phenomena, particularly persistent marine heatwaves (MHWs) and ENSO phases, on sea surface temperature (SST) anomalies, which may have limited IOS movements. All observed aggregation events coincided with SST anomalies, with eight instances recording temperatures above 29°C and one exceeding 30°C. These conditions surpass the optimal SST range for IOS. Such elevated thermal regimes are likely to induce stress, disrupt physiological functions, and alter migratory patterns, potentially contributing to beach stranding incidents. Although broader offshore waters remained anomalously warm, certain nearshore regions provided temporary thermal relief due to factors like enhanced chlorophyll levels, relative marginal surface cooling from rainfall-induced mixing, and subsurface upwelling. Furthermore, the transition from El Niño to La Niña intensified regional oceanographic dynamics, contributing to increased sardine abundance along the Malabar coast. Coast-ward or alongshore-directed ocean currents and wind might have further influenced IOS movement toward the shoreline. This study identifies evolving climate variability and chlorophyll concentrations as emerging key drivers, alongside established factors such as SST, currents, and wind patterns. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Indian Oil Sardine (IOS), Sea Surface Temperature (SST) Anomalies, Marine Heatwaves (MHWs), ENSO, Sardine Aggregation |
| For Awards | no |