Advances in Remote Sensing-Based Studies on Environmental Characteristics and Formation Mechanisms of Purpleback Flying Squid Fishing Grounds

The purpleback flying squid (Sthenoteuthis oualaniensis) is an important commercially exploited cephalopod resource in tropical open oceans. The formation and spatial variability of its fishing grounds are jointly regulated by local marine environmental conditions, ocean dynamic processes, and multiscale climate variability. In recent years, substantial progress has been achieved in understanding the environmental characteristics and formation mechanisms of S. oualaniensis fishing grounds with the development of satellite remote sensing, multisource oceanographic observations, and ecological statistical models. However, due to differences in study regions, data sources, and modeling approaches, considerable discrepancies remain among studies regarding the mechanisms through which environmental factors and climate modes influence the distribution and abundance variations in S. oualaniensis resources. This review systematically summarizes recent advances in the application of remote sensing and multisource marine data in S. oualaniensis fishing ground studies and highlights the ecological significance of major environmental drivers. Current evidence indicates that the formation of S. oualaniensis fishing grounds is not controlled by a single environmental factor but results from the integrated effects of SST, Chl-a, oceanographic dynamic processes (e.g., mesoscale eddies, fronts, and upwelling), and subsurface environmental conditions such as thermocline structure and dissolved oxygen. Suitable thermal conditions and moderate productivity levels provide fundamental environmental prerequisites for resource aggregation, whereas mesoscale physical processes and three-dimensional ecological structures further regulate prey transport, habitat availability, and squid aggregation processes. Moreover, substantial regional differences exist in fishing ground formation mechanisms. In the northwestern Indian Ocean, fishing grounds are primarily controlled by monsoon-driven upwelling and large-scale circulation systems, exhibiting strong continuity and pronounced climate-related variability. In contrast, fishing grounds in the South China Sea are more strongly influenced by Kuroshio intrusion, island–reef topography, and regional circulation processes, resulting in greater spatial heterogeneity. With advances in analytical approaches, fishing ground prediction methods for S. oualaniensis have gradually evolved from empirical statistical analyses toward multifactor statistical modeling and machine-learning-based prediction frameworks. Nevertheless, resolving three-dimensional ecological processes, developing physical–biological coupled models, and improving model interpretability remain key challenges for future research. This review provides theoretical insights for remote sensing-based investigations of S. oualaniensis fishing ground formation mechanisms, resource assessment, and sustainable exploitation.