Abstract:Sthenoteuthis oualaniensis, a cephalopod species with significant economic value, is widely distributed and abundant in the Northwestern Indian Ocean. This region is characterized by rich and active mesoscale eddies influenced by various factors such as monsoons. Currently, the impacts of mesoscale eddies on S. oualaniensis in the Northwestern Indian Ocean are still unknown. Therefore, this study utilized data derived from the angular momentum eddy detection and tracking algorithm (AMEDA) for eddy detection and tracking and matched the eddies with fisheries data. The spatiotemporal distribution of mesoscale eddies in the Northwestern Indian Ocean was examined, and the relationships between different types of eddies and the abundance and distribution of S. oualaniensis were evaluated. Moreover, this study applied the generalized additive model (GAM) to assess the association between the fundamental characteristics of mesoscale eddies and the abundance and distribution of S. oualaniensis. The results revealed that high-frequency occurrences of mesoscale eddies were observed in the northern regions of the Northwestern Indian Ocean, exhibiting monthly and interannual variations. Mesoscale eddies with larger amplitudes and higher relative vorticity tended to enhance the abundance of S. oualaniensis. The abundance of S. oualaniensis resources within the inner and peripheral regions of the cyclonic eddies was higher than that in the anticyclonic eddies, with this distinction being more pronounced within the internal zones of the eddies. Our findings suggested that mesoscale eddies had significant impacts on the distribution of S. oualaniensis, and the underlying mechanism could be further elucidated in the future by analyzing the environmental conditions.