  Tuna and billfish are charismatic pelagic fishes attracting considerable
scientific attention due to their ecophysiological and socioeconomic
importance. However, the knowledge of their basin-wide spawning and larval
habitats, especially in a warming ocean, is limited. We use the largest
available dataset on tuna and billfish larvae in the Pacific Ocean to build a
geostatistical species-distribution model with high explanatory power. The
results reveal the spatial distribution of tuna and billfish larvae through all
seasons across the Pacific. The model also identifies the optimal temperature
ranges for nine major species and assesses the potential impact of ocean
warming on larval distributions. We additionally present evidence that
environmental variables, such as pH, phosphate concentration, and sea-surface
height, exert secondary effects on larval distributions that warrant further
investigation. Our findings make a quantum leap in understanding the
ecophysiology of tuna and billfish, providing valuable information for future
conservation efforts.
