Predicting the Potential Habitat Distribution of Scomber japonicus in the High Seas of the Northwest Pacific Ocean Using MaxEnt and GARP Models

Accurate prediction of the potential habitat distribution of Scomber japonicus, an important target species in China’s distant-water fisheries, is essential for fishing ground forecasting. Using catch data for S. japonicus collected from Chinese large-scale purse-seine and trawl fisheries in the Northwest Pacific Ocean from May to November during 2015–2024, this study applied the maximum entropy model (MaxEnt) and the genetic algorithm for rule-set production (GARP) model to predict the potential habitat distribution of S. japonicus in the Northwest Pacific Ocean. The area under the receiver operating characteristic curve (AUC) and the true skill statistic (TSS) were used to evaluate model performance. The MaxEnt model predicted a relatively concentrated highly suitable habitat, whereas the GARP model identified a broader highly suitable area. To reduce the bias and uncertainty associated with single-model predictions, the outputs of the MaxEnt and GARP models were integrated using a weighted ensemble approach, with the optimal weights for MaxEnt and GARP determined as 0.7:0.3. The ensemble model achieved higher predictive performance, with an AUC of 0.983 and a TSS of 0.840. The highly suitable habitat of S. japonicus was mainly concentrated within 147° E–156° E and 40° N–44° N. Chlorophyll concentration, sea surface temperature (SST), and temperatures at depths of 150 m and 200 m were the main environmental variables affecting the potential habitat distribution of S. japonicus in the MaxEnt model. These findings provide useful information for resource utilization, fishing ground forecasting, and sustainable management of S. japonicus in the high seas of the Northwest Pacific Ocean.