Understanding recent variations in the zero year-class entries of Indian oil sardine and its impact on the fisheries of Kerala

The Indian oil sardine (IOS) fishery along the Kerala coast from 2021 to 2024 was assessed using an ecoregion approach, revealing a significant increase in recruitment in 2024 compared to previous years, and at varying scales.The ecosystem productivity indicators showed a stronger influence on recruitment dynamics than the biological indicator of spawning stock biomass.The relative contributions of micro-, pico-, and nanoplankton functional groups indicated linkages with the physio-biological dynamics of IOS and need further research.The present study highlights region-specific environment variability, especially during the prespawning and pre-recruitment periods, that needs to be adequately integrated into stock assessments and dynamic management frameworks.Development of species-specific, eco-physiological indicators for timely fisheries governance interventions to sustain the fishery of IOS under changing oceanographic conditions and supporting the development of short-term forecast models is recommended.