Abstract:Albacore tuna (Thunnus alalunga) is an economically important fish in tuna fishery in the Indian Ocean. As a pelagic migratory fish, its distribution is significantly influenced by the marine environment. In this study, we used environmental data from the Indian Ocean spanning from 2001 to 2016 to construct a habitat model for different life history stages of albacore tuna and their corresponding environmental requirements. We validated the accuracy of the model by comparing the predicted suitable habitat locations with the actual distribution of catch quantities. We evaluated the model using the area under the receiver operating characteristic curve (area under curve, AUC) and analyzed the inter-annual variations of suitable habitat at different life history stages of albacore tuna to examine the impact of marine environmental changes on spatial-temporal habitat distribution. The results indicated that: (1) The high catch areas largely overlap with the model-predicted suitable habitat, with monthly average AUC values of 0.79 for immature and 0.73 for mature albacore tuna habitat models, showing high prediction accuracy. (2) The model predicted that suitable habitat for immature albacore tuna was located between 25°S and 40°S in the Indian Ocean from January to June and between 20°S and 40°S from July to December. For mature albacore tuna, the suitable habitat during the spawning period is located east of Madagascar Island between 10°S and 25°S, whereas during the non-spawning period, it is between 25°S and 45°S. (3) Both the suitable habitats for immature and mature albacore tuna showed a year-on-year trend of southward migration. The above results have significant scientific importance for understanding the population dynamics of albacore tuna and promoting sustainable resource utilization.