Feeding Ecology and Prey Interactions of Japanese Spanish Mackerel Scomberomorus niphonius (Teleostei: Scombridae) in Korean Coastal Waters

ABSTRACT The Japanese Spanish mackerel, Scomberomorus niphonius , in Korean coastal waters has exhibited a consistent increase in catches since the 1970s, peaking in 2023, driven by fishing effort, climate‐induced habitat shifts and biological factors. This study examines its trophic ecology and population dynamics, emphasizing the South Sea as a critical habitat, contributing 90.5% of catches, with a rising East Sea contribution since the 1990s due to warming sea temperatures. Stomach content analysis of 741 individuals confirms fish, particularly anchovy ( Engraulis japonicus ) and largehead hairtail ( Trichiurus japonicus ), as dominant prey, highlighting its role as a specialist top predator. Seasonal and size‐class analyses reveal dietary plasticity, with ontogenetic shifts towards larger, energy‐rich prey like largehead hairtail in autumn. Generalized additive model (GAM) analysis indicates nonlinear relationships between mackerel catches and prey availability, with anchovy exerting a positive bottom‐up effect. The species’ reliance on key prey underscores its vulnerability to environmental fluctuations and overfishing pressures. Recommendations include climate impact assessments, stable isotope analysis, multispecies modelling and regional migration studies to support ecosystem‐based fisheries management for sustainable Japanese Spanish mackerel populations.