Beyond Boundaries—Satellite telemetry reveals regional movements and partial protection of oceanic manta rays (Mobula birostris) in the Mexican Pacific

Abstract The oceanic manta ray ( Mobula birostris ) is a wide-ranging pelagic species threatened due to its low reproductive output and high susceptibility to anthropogenic pressures, particularly fisheries. Satellite telemetry data from 12 individuals tracked between 2017 and 2024 in Revillagigedo National Park, a no-take marine protected area (MPA) in Mexico, were used to investigate space use, seasonal movements, and overlap with industrial fishing activity. Individuals were tagged at Socorro Island (18.78° N, 110.95° W) and San Benedicto Island (19.30° N, 110.82° W). A Random Forest machine learning model was trained using state-space telemetry tracks and associated environmental data to predict spatial occurrence. Occurrence was primarily associated with warm surface waters (> 25.5 °C), low chlorophyll concentrations (< 0.1 mg m⁻³), weak surface currents, and offshore environments. Predicted occurrence was highest within the protected area but extended well beyond its boundaries, with seasonal expansion toward the Gulf of California during summer and autumn. Over one-third of estimated positions occurred outside the park, where high occurrence probability overlapped with intense tuna purse-seine effort along MPA boundaries. Individuals varied substantially in space use, with the longest recorded movement exceeding 1,300 km. These findings underscore both the conservation value of Revillagigedo National Park and the limitations of static protected areas, highlighting that effective conservation will require regional cooperation, targeted bycatch mitigation in adjacent buffer zones, and the establishment of a mosaic of larger, connected protected areas across the Eastern Tropical Pacific. This is the first study to use satellite telemetry and distribution models to characterize the spatial ecology of oceanic manta rays in the Mexican Pacific.