At the stroke of a fin, Dianaabout 20 years old—the species can be over 60—has traveled more than 6,400 kilometers from Ceuta to the Caribbean, one of its nesting areas. Researchers following her rescued her in June last year, having approached her attracted by captured fish, an easy source of food. Back then, no one imagined that he would end up crossing the Atlantic. It left through the Strait of Gibraltar in September last year and reached the American coast this February, where it is still located.
After being released, she spent the summer in the Alboran Sea – the westernmost area of the Mediterranean –, like five other species found in the same nets. All the specimens returned to the sea, but equipped with a GPS firmly attached to the shell. The marking of these chelonians (Caretta caretta) is part of the Alma project of the Oceanographic Institute of Spain (IEO-CSIC) focused on the and the effects that climate change may have on them.
Diana It crossed the Strait of Gibraltar on September 18 of last year, crossed the Atlantic in just over four months and approached the mouth of the Amazon, in Brazil, but did not enter. It continued coasting and made landfall on at least two occasions, in Suriname and Trinidad and Tobago. The scientists who marked her believe she laid her eggs there, because female sea turtles only come out of the water to lay their eggs. Males spend their entire lives in the sea: even mating occurs in the water, near the areas where they nest.
Not all turtles marked with Diana They set out to cross the Atlantic. Two stayed in Cape Verde and two others, less travelers, continue in the Mediterranean, between the Balearic Islands and Algeria. “Each one has behaved in a different way, which indicates that in the Alboran Sea and in Spanish waters we cannot speak of a Mediterranean or Atlantic loggerhead turtle, but rather of a confluence of populations,” explains José Carlos Báez, IEO-CSIC researcher and head of the project.
The scientists released Diana on August 4, 2025 in Ceuta after spending a month in a recovery center. “We couldn’t let her go until the vet gave the go-ahead, because she arrived a little badly from the trap and was floating, she wasn’t able to sink, a sign that she had some problem,” explains Báez. Back in the water, he passed by drawing a chaotic tangle of lines on the map.
“It was feeding to head to the Atlantic and waiting for the necessary temperature conditions,” the scientist clarifies. Diana He finally crossed the Strait of Gibraltar on September 18. “From there the journey was quite straight, because the open ocean is like a desert, unlike the coastal areas, where there is more food. And they travel alone, not as many people imagine after watching the movie. Nemo in which loggerhead sea turtles are seen migrating together,” he adds.
Diana It arrived near the mouth of the Amazon on February 6 of this year, but did not enter. And that’s where it starts to coast towards the north. Finally, (in northern South America), at the height of the Marowijne River, where it may have laid eggs. It continued its path up the coast and may have made landfall again on the Venezuelan coast. “But we are not so clear about that,” says Báez.
“We are interested in knowing where the adult females go and, above all, where the males are, because fewer and fewer are born due to the increase in temperatures,” he adds. In turtles, sex is not determined by genes, but by the temperature of the sand in which they incubate their eggs. When the nest is kept at lower temperatures—between 26 and 28 degrees—more males are born; On the other hand, if the sand is warmer—between 29 and 32—females predominate.
The turtles rescued by scientists confirm this trend: of the six marked, only one is male, although they have doubts as to what sex is another of the specimens found between the Balearic Islands and Algeria. “We have named her Brumarlo, as if she were a male, but she is young and determining her sex is very complicated. A laparoscopy would have to be performed and it is a very invasive test,” explains Báez.
Alma, another of the tagged turtles, began crossing the Atlantic on the same dates as Dianabut its device stopped broadcasting on December 17, 2025, in the middle of the ocean. “We don’t know what happened, he may have died or lost the sensor.”
The transmitter records and stores data such as the position of the turtle, the depth it reaches ―Diana has reached 100 meters― or the temperature of the water. When the animal surfaces to breathe, the device sends the information to the satellite, from where scientists receive it. Sometimes they have little scares, for example, if the satellite passes by and cannot locate it because it is submerged. “If this happens three days in a row, you start to worry,” says the researcher.
Will they return to the Spanish coasts? “That’s the big question,” answers Báez. The loggerhead sea turtle performs complex migrations that connect continents. The same individual can be born in the Caribbean, grow up in the open Atlantic, feed in the Mediterranean and return to America to reproduce. As you seem to be doing Diana.
But climate change is changing these customs and there are already loggerhead turtles that make their nests on the Spanish coasts. (Almeria). Since then, the spawning has spread to other places in Andalusia, Valencia and Catalonia.
The most important traditional breeding areas in the Mediterranean are Greece, followed by the sandy beaches of Libya, Türkiye, Tunisia, Syria and Cyprus. Spain was not on that list, but it is beginning to be an emerging market area. “Sea turtles are very resilient, they appeared 150 million years ago and have survived the dinosaurs and several extinctions, so they will surely adapt,” concludes Báez.
