Movement behavior of a blue whale between the Galapagos Archipelago and the Frontal System off Baja California Peninsula

Abstract

The movement behavior of blue whales in the Eastern Tropical Pacific (ETP) is not well understood, especially regarding the migration of Northeast (NEP) and Southeast (SEP) Pacific populations. This study presents tracking data from a satellite‐tagged blue whale recorded between the Galapagos Islands and the Baja California Frontal System. A Bayesian state‐space model (BSAM) estimated the whale's movement trajectory, and a hidden Markov model (HMM) classified behavioral states. Environmental factors like sea surface temperature, chlorophyll‐a concentration, primary productivity, and mesoscale eddies were analyzed to identify ecological drivers. The whale displayed foraging behavior in areas with lower temperatures, higher productivity, and elevated chlorophyll levels, with movements influenced by cyclonic and anticyclonic eddies. These findings improve understanding of blue whale migration and the potential overlap between NEP and SEP populations in key tropical regions. They suggest that areas like the Galapagos and Costa Rica Thermal Dome may serve as ecological corridors, influenced by eddies.