Abstract:The habitat distribution of chub mackerel Scomber japonicus, an economically important pelagic fish species, is strongly susceptible to climate variability. In this study, we calculated the habitat suitability index (HSI) for the fishing ground of S. japonicus in the East China Sea during 1950?2015, based on the environmental data of vertical water temperature at depths of 2.5 m, 25 m, and 50 m, as well as the Ni?o3.4 index. The spatio-temporal distributions of potential habitats for S. japonicus were compared among La Ni?a years of varying intensity. The habitat suitability was found to be higher during the La Ni?a years than during the years of normal climate conditions. During the weak and moderate La Ni?a years, water temperatures were cold at different depths, leading to a higher proportion of areas with suitable water temperatures and increasing the habitat suitability. However, during the strong La Ni?a years, water temperature at different depths increased, resulting in a decrease in the proportion of areas with suitable water temperatures at different depths. Therefore, the habitat suitability declined. Weak and moderate La Ni?a events resulted in an eastward shift of the longitudinal gravity center of suitable habitat and a southward shift in the latitudinal gravity center relative to its position during strong La Ni?a events. In contrast, the longitudinal gravity center of unsuitable habitat shifted westward, while the latitudinal gravity center of unsuitable habitat shifted northward. During July?September during strong La Ni?a events, the distribution of the most suitable water temperatures at different depths shifted northwestward. Variations in the spatial distribution of S. japonicus habitat under La Ni?a events with different intensities may be due to the monthly difference in distribution of the most suitable water temperature at different depths. Our findings indicated that La Ni?a events with different intensities significantly affected the habitat of S. japonicas in the East China Sea.