Analysis of Environmental Factors Influencing Regional Yellowfin Tuna Fishing Using Multi‐Strategy Generalized Additive Model

Yellowfin tuna ( Thunnus albacares ) distribution is regulated by multidimensional oceanic environmental factors. However, the biophysical mechanisms associated with subsurface ocean parameters remain unclear. Here, we elucidated environmental factors influencing catch per unit effort in the South China Sea and adjacent waters, evaluated hyperparameter optimization for generalized additive models, and provided recommendations for fisheries management. Bayesian optimization outperformed other methods across all metrics, with the lowest AIC, highest fitted‐model pseudo‐ R 2 , and shortest training time. The factors most affecting catch per unit effort were water depth at 12°C, surface height, surface salinity, sea level anomaly, and thermocline upper boundary temperature. Extreme survival depth 450–520 m, surface height 0.4–0.6 m, surface salinity 32.3–32.8 psu, sea level anomaly 0.15–0.22 m, and thermocline upper boundary temperature 28.5°C–30.2°C were suitable. These findings support the development of environmental indicators for dynamic fishing advice and provide insights for ecosystem‐based management of yellowfin tuna fisheries.