Since the moment they hatch, young loggerhead sea turtle turtles face a daunting journey across thousands of miles of open sea. Now scientists at the University of North Carolina at Chapel Hill reveal in a newly published study (November 2025) that these hatchlings use a hidden “touch” sense of Earth’s magnetic field to pinpoint their location, not just a magnetic compass.
Fast Facts
Study: New research shows young sea turtles use a magnetic “map sense” to navigate the open ocean.
Discovery: A short magnetic pulse disrupted the turtles’ ability to recognize learned magnetic cues.
Method: Researchers trained hatchlings to associate magnetic signatures with food, then tested their responses.
Why It Matters: Findings suggest human magnetic pollution may affect marine migration and conservation efforts.
Published By: Journal of Experimental Biology, 2025.
The core discovery turns on the difference between two magnetic senses: one gives direction (compass) and the other gives position (map). In past research scientists knew turtles had a magnetic compass but were unsure how they determined their position on the open ocean. This study shows the map sense relies at least partly on tiny magnetite particles inside the turtles meaning the turtles actually feel magnetic forces rather than just “seeing” them.
How did they prove it? Researchers trained hatchling turtles to associate a specific magnetic field signature with food. Then they exposed the turtles to a brief, strong magnetic pulse designed to disrupt the magnetite-based sensing system. After that pulse the turtles stopped showing their learned “dance” behaviour in the expected field — showing their map sense had been interrupted.
Why this matters is clear: knowing how sea turtles navigate helps wildlife biologists protect them. If turtles rely on magnetite-based sensing, then magnetic pollution (from undersea cables or human-made fields) might disrupt migrations. It also gives insight into how long-distance animal navigation works, which could influence conservation strategies and even robotics inspired by nature.
Lead author Alayna G. Mackiewicz and team say the findings “are consistent with the interpretation that the magnetic map sense of turtles is based at least partly on magnetite-based magnetoreceptors.” The Journal of Experimental Biology+1 Another expert outside the study noted this is “a significant advance” in understanding animal navigation. The tension here lies in that while direction sensing was known, the map sense mechanism was elusive — this study chips away at that mystery.
Connecting this to a larger issue: as the world faces increasing electromagnetic interference from subsea infrastructure, wind-farm cables and shipping traffic, this research suggests marine migrations may be more vulnerable than assumed. The finding links biology with technology, conservation with engineering — if animals depend on subtle forces in Earth’s field, human activities must account for them.
What happens next? Scientists will want to test whether other marine species use the same “feel-based” map sense. They will also explore how sensitive the system is to weaker magnetic disturbances, and whether human-caused changes in magnetic fields could misdirect migrating turtles. There remain open questions about how multiple navigation senses integrate in real ocean conditions.
In short, this study shows that baby loggerhead sea turtles don’t just use a magnetic compass — they feel Earth’s magnetic map to know where they are, and this insight opens new paths for protecting migrations, understanding navigation, and connecting biology with human impact.
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Journal Reference:
Alayna G. Mackiewicz, Abigail M. Glazener, Kayla M. Goforth, Dana S. Lim, Catherine M. F. Lohmann & Kenneth J. Lohmann. Disruption of the sea turtle magnetic map sense by a magnetic pulse. Journal of Experimental Biology, 2025. 228(22). DOI: 10.1242/jeb.251243