Marine Biology

, Volume 158, Issue 1, pp 101–112 | Cite as

Magnetic orientation by hatchling loggerhead sea turtles (Caretta caretta) from the Gulf of Mexico

  • Maria W. Merrill
  • Michael SalmonEmail author
Original Paper


Loggerhead sea turtle hatchlings emerge from nests on either the east or west coast of the South Florida peninsula and then migrate offshore in opposite directions. Under laboratory conditions, magnetic cues induce east coast hatchlings to swim in directions that promote their transport by oceanic surface currents, such as the North Atlantic gyre. However, the surface currents used by west coast hatchlings are unknown. We examined the responses of west (Sarasota) hatchlings to magnetic cues in the Gulf of Mexico, the Florida Straits, and the Gulf Stream to determine their (1) likely migratory routes (2) orientation where currents lead into the Atlantic Ocean, and (3) orientation adjacent to Florida’s east coast. The results suggest that migration inside Gulf waters may be circuitous, that the turtles respond appropriately to enter Atlantic waters, and that orientation along Florida’s east coast probably promotes transport by the Gulf Stream into the North Atlantic gyre.


Surface Current Gulf Stream Nest Beach National Geophysical Data Center Florida Current 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



This study was completed by MWM in partial fulfillment of the requirements for a Masters of Science degree in the Department of Biological Sciences, Florida Atlantic University (FAU). It was supported by several scholarship awards for students in Marine Biology and by generous contributions to the Nelligan Fund for Sea Turtle Research at FAU. We extend our special thanks to K. J. Lohmann for his advice and guidance and for allowing us to calibrate our old magnetometer against his new one. A. D. Tucker and his marine turtle group provided access to nests, while W. N. Tavolga provided laboratory space that made our work at the Mote Marine Laboratory possible. S. Kajiura and A. D. Tucker served on the thesis committee; their suggestions improved the thesis. J. Wyneken kindly reviewed the manuscript before submission. The comments of two referees improved the manuscript after submission. MWM extends her special thanks to family and friends for their encouragement and unwavering support. This study was carried out under permits issued by the Florida Fish and Wildlife Conservation Commission (TP 173) and by the FAU Institutional Animal Care Committee (Protocol A08-2a).


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Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  1. 1.Department of Biological SciencesFlorida Atlantic UniversityBoca RatonUSA
  2. 2.Florida Fish and Wildlife Conservation CommissionTallahasseeUSA

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