North Pacific loggerhead turtles ( caretta caretta ) hatch off the coast of Japan and spend most of their time in the Pacific. However, they occasionally appear in Mexico, some 14,500 kilometers from the place where they originally nest. This spectacular journey would force them to cross potentially deadly cold waters, as these turtles need the heat of the environment to maintain their body temperature. However, scientists have discovered that turtles survive this migration thanks to a hidden corridor.
A mystery for decades
This mystery, according to Larry Crowder, professor of marine ecology and conservation at Stanford University (United States) had existed for decades. Along the Pacific coast of North America, seasonal winds push quality surface waters towards the coast. Thus, the cold water from the depths of the ocean rises to replace that warm water, carrying with it a large amount of nutrients.
Tropical species, such as loggerhead turtles, rarely venture into those cold waters of the open Pacific. In fact, most scientists considered them impassable for animals that depend on warm waters. But, according to this new research, the results of which have been published in the journal Frontiers in Marine Science, loggerhead turtles can reach the Mexican coast during ‘El Niño’, a phenomenon that shifts the warmer waters of the western Pacific to the east ( along the equator).
This, according to the study researchers, produces a thermal corridor that allows loggerheads to reach Mexico. However, this passage only takes place during ‘El Niño’.
Protect loggerhead turtles
This research not only provides information on the movement of turtles, but also helps protect a species that is listed as ‘vulnerable’ by the International Union for Conservation of Nature. In addition, according to scientists, conservation efforts may need to adapt as turtles react to warming marine waters due to climate change.
