Giant manta rays travel thousands of miles but keep returning to familiar reefs

A new multi-year study tracked giant manta rays off Costa Rica and found a clear age-based split in behavior. Immature mantas stayed near shore in shallow coastal areas for years, while mature adults crossed into waters of five countries. Researchers led by Jeffry Madrigal-Mesén of Mantas Costa Rica, with CREMA and MigraMar, followed rays using acoustic tags and satellite transmitters from 2018 to 2025. Of 59 tagged with acoustic equipment, 42 produced data; 12 carried satellite tags. Juveniles about 10 feet across remained in Costa Rica waters for 108 and 64 days, traveling over 1,200 miles each along the shelf. Adults covered 13,555 miles total, with one crossing from deep water near Cocos Island to the continental shelf in five days.