Loggerhead sea turtle – Caretta caretta

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This is the most common species of sea turtle in the Mediterranean and nests mainly on the beaches of Greece, Turkey and Libya. However, an important part of the specimens present in Catalan waters comes from the nesting beaches of Florida (USA). In recent years, some individuals of this species have been detected also on the Catalan coasts and other beaches on the northern shores of the western Iberian Mediterranean. However, it does not seem that there has ever been a high historical breeding density of the species on the Catalan coast. The breeding season begins at the end of May and ends at the beginning of September, and during this period a turtle can lay one to three clutches. Using their later fins, they lay their nests about 40 centimeters deep in sandy beaches. Each nest can have up to 120 eggs and the incubation lasts about 60 days. As in all turtles, the sex of the offspring is determined by the temperature of the nest: those from hottest temperatures producing females, and from the coldest temperate, males. Currently, Catalan beaches produce basically males. The species feeds on jellyfish during their juvenile oceanic phase and invertebrates from the sea bottom from 50 cm in length.

Due to the tourist development and urbanization of the coast, there is a lack of adequate nesting sites for the species and the few available are threatened. Climate change can reduce breeding performance on the beaches of the eastern Mediterranean, but improve it in the western Mediterranean.

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Green turtle – Chelonia mydas

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The green turtle is found mainly in tropical waters and to a lesser extent in subtropical waters of the entire planet. In the Mediterranean, nest on the most eastern area and occupies the warmest areas of the Mediterranean. The green turtles that travel through the Western Mediterranean are young individuals from the Atlantic and not from the Eastern Mediterranean. In the juvenile stage they are oceanic and carnivorous. When reaching 30-50 cm, they become benthic and change diet preferences, first being omnivores and then herbivores, although they can occasionally capture some invertebrate. Due to this diet this species is the turtle with a slower growth rate. The species is currently classified as threatened by IUCN, although many populations are increasing. The main threats to the species are the exploitation of eggs and the capture of adults by humans, accidental capture in fishing gear and the loss of suitable places for breeding.

more info at CRAM