Fig. 3

Monthly averages of covariates over the entire study area in the Indian Ocean for the four seasons, represented by January (summer), April (autumn), July (winter), and November (spring), for the years 2014 and 2022. The variables represented are: (a) SST (°C), (b) log (Chl-a) (mg/m\(^{3}\)), and (c) MSI (%). The red dots indicate the locations of the hydrophones used in this study.