For decades, the North Pacific loggerhead sea turtle was a most enigmatic species.  Known in Mexico as tortuga amarilla, or yellow turtle, it was found in large numbers along coastal habitats of Pacific Mexico, yet no nesting beaches were known to exist in the region. It wasn’t until 1987, when a solitary loggerhead bearing Japanese flipper tags wound up in waters off San Diego USA, that the notion of a transpacific migration was ever considered. With the Mexico-Japan connection confirmed with genetics and more tag returns in the mid-90s, and the story of Adelita—the most famous transpacific loggerhead—in 2000, there was an undeniable loggerhead linkage between the eastern Pacific and Japan—where the turtles are known as Akaumigame.  Equipped with this knowledge, scientists are now deciphering how loggerheads actually pull off such an amazing journey. Where are the migratory routes?  Which elements in their environment guide their behavior? A landmark study by our colleagues was conducted in 2021 that demonstrated the value of favorable sea water temperatures and the vast importance of ‘being at the right place at the right time’ for small loggerheads to access the perfect swim-way out of the Central Pacific and into Eastern Pacific waters of North America. Today, the emerging ‘Thermal Corridor Hypothesis’ sets the stage for our efforts to use of experimental oceanography and satellite tracking of loggerhead turtles strategically placed in Pacific high seas waters to test the “if”,  “where”, and “when” this oceanic gateway opens for eastbound loggerheads. Over the next four years, our Loggerhead Sea Turtle Research of the Thermal Corridor Hypothesis (hence our project’s name “STRETCH”) team will release 100 satellite-tag-equipped loggerheads to monitor their movements in relation to oceanographic conditions. By learning their transpacific tendencies, we will provide vital data for aiding the protection and conservation of this unique endangered species, a responsibility that, because of its migratory habits, is shared by three countries: Japan, USA, and Mexico. 

Adelita’s journey (Wallace J. Nichols)