Loggerhead sea turtle (Caretta caretta):
the ocean wanderer
Among the most widespread sea turtles, the loggerhead turtle (Caretta caretta) is undoubtedly one of the most fascinating species, but also one of the most threatened. Getting to know it better is the first step toward protecting it.
Tireless Traveler of the Oceans
The loggerhead turtle (Caretta caretta) is a cosmopolitan species found in temperate and subtropical waters of all the world’s oceans. It is commonly seen along both the eastern and western coasts of the Atlantic, the western Pacific, and various regions of the Indian Ocean.
In the Americas, it is frequently observed from the coasts of Massachusetts to Brazil and throughout the Gulf of Mexico. It is regularly seen in Japan and eastern Australia, as well as in southern Africa and the eastern islands.
Females are known for their philopatric fidelity—that is, their tendency to return to the same beaches where they were born to lay their eggs. This migratory behavior exposes them to numerous risks, but it is also one of the keys to the species’ reproductive success.
Distribution in the Mediterranean
The Mediterranean Sea hosts a resident population of Caretta caretta and represents a crucial area for both feeding and reproduction.
Most nesting occurs along the coasts of Greece (especially in Zakynthos, the Peloponnese, and Crete), southwestern Turkey, and Libya. However, over the past thirty years, nesting areas have expanded toward southern Italy, particularly in Calabria, Sicily, and Campania.
The loggerhead populations in the Mediterranean are considered a distinct subspecies compared to their Atlantic counterparts. Having separated several tens of millions of years ago, they have developed genetic differences as well as slightly smaller body sizes.
Biology and Characteristics
The loggerhead turtle is an extraordinary animal: strong, powerful, and extremely resilient. Adapted to survive in some of the most challenging marine environments on Earth, this species possesses exceptional features that make it truly unique.
Structure and Distinctive Traits
The bony carapace is rigid, heart-shaped, and reddish-brown in color, often covered with algae and encrusting organisms. It has five costal scutes on each side—a distinctive feature of the species.
The head is large and robust, with powerful jaws well-suited for preying on hard-shelled organisms. The front flippers are elongated, while the rear ones aid in maneuvering and digging nests.
Size
Adult Caretta caretta typically have a carapace length ranging from 85 to 110 cm (33 to 43 inches), and weigh between 70 and 120 kg (154 to 265 pounds). Some exceptionally large individuals can exceed 150 kg (330 pounds).
Females are generally larger than males and develop a more robust body to facilitate egg production and nesting.
How long does a loggerhead turtle live?
In the wild, Caretta caretta can live between 50 and 70 years, although some individuals can easily surpass 80 years. However, due to numerous threats, many die before reaching sexual maturity.
How long can a loggerhead turtle hold its breath?
Several variables influence how long loggerhead turtles can stay underwater.
Temperature, depth, body size, and even stress can significantly affect the duration. During routine activities such as swimming or foraging, a loggerhead turtle can hold its breath for about 30–40 minutes.
However, while resting on the seabed, a large adult can remain submerged for over 2 hours, thanks to a slowed metabolism and specific physiological adaptations.
Loggerhead turtles can generally dive to depths of 20 to 50 meters (65 to 165 feet), but some individuals—tracked with modern technologies like data loggers—have been recorded diving to depths between 100 and 200 meters (330 to 660 feet).
What do they eat?
The loggerhead turtle is an omnivorous species, with a diet that changes depending on its life stage and habitat. Juveniles, during their pelagic phase, feed on zooplankton, hydrozoans, small crustaceans found on floating algae rafts, and especially jellyfish.
As adults, they shift to a benthic lifestyle and prefer larger, tougher prey: bivalve mollusks, crustaceans, sea urchins, and fish. Their powerful jaws allow them to crush the shells of their prey with ease and, in some cases, even break apart rocks to reach hidden marine organisms.
Reproduction
Reproduction in Caretta caretta is a particularly delicate phase, especially in the Mediterranean Sea. Increasing direct and indirect threats are seriously endangering the species—this is precisely why dozens of conservation programs are in place.
Mating
The reproductive period in the Mediterranean runs from May to August. Mating takes place in open water, near nesting beaches. Males compete with each other for females and may mate multiple times.
Males grasp the females using a specially hooked claw on their front flippers. Females can store sperm in a specific anatomical structure, allowing them to fertilize several clutches within the same season.
Egg-laying
Nesting occurs at night, when the sand is cooler and the environment less dangerous for the female. After leaving the water, the turtle carefully selects a quiet area of the beach—usually above the high tide line—to avoid the risk of the nest being submerged.
With slow and precise movements, she digs a funnel-shaped hole: she starts with her front flippers and finishes the excavation with her hind flippers, reaching a depth of about 40–50 cm (16–20 inches). Inside this chamber, she lays between 80 and 120 eggs, one at a time, in a process that can last more than two hours.
During egg-laying, she enters an almost trance-like state, becoming largely unresponsive to her surroundings. Once the eggs are laid, she carefully covers the nest with sand, camouflaging it to protect it from predators and the elements.
After completing the nesting process, she returns to the sea, leaving the nest completely unattended. A female may repeat this process up to 4 or 5 times in a single breeding season, at intervals of about two weeks.
Incubation
The eggs, similar in size and shape to ping-pong balls, have an incubation period of about 40 to 60 days, depending on temperature. The average temperature during incubation also determines the sex of the hatchlings: at an average of 28 °C (82 °F), an even ratio of males and females is produced.
Higher temperatures favor the development of females, while lower temperatures produce mostly males. If the temperature reaches 33 °C (91.4 °F), the embryo cannot survive. In Calabria, nests typically result in approximately 70% female hatchlings.
Hatching
After about 40–60 days, the hatchlings break out of their shells and begin to emerge from the sand, usually at night to avoid predators and extreme heat. They instinctively orient themselves toward the natural light reflecting off the sea, but artificial lighting often disorients them.
Newborns are about 5 cm (2 inches) long and weigh less than 20 grams (0.7 ounces). They have a dark, streamlined shell adapted for swimming. While they are immediately independent, they are also extremely vulnerable: 95% of hatchlings do not survive the first week of life, and fewer than 1 in 1,000 will reach adulthood.
Growth
During the first years of life, juveniles remain in the open ocean, hiding among floating seaweed like Sargassum.
Being highly vulnerable, they are protected by small spines called “keels” that grow on their carapace and gradually disappear as they mature. This pelagic phase can last up to 10 years and is crucial for growth and development.
Caretta caretta reaches sexual maturity between 20 and 30 years of age. At that point, females begin the migratory cycle that will eventually bring them back to the beaches where they were born to lay their eggs.
How they manage to practice this “philopatry” is still not fully understood, but some theories suggest they are able to navigate using the Earth’s magnetic field.
Threats
The loggerhead turtle (Caretta caretta) faces numerous threats that can be both direct and indirect. Direct threats include human activities that cause the immediate death of the animal, such as fishing and pollution. Indirect threats, on the other hand, are activities that do not directly kill individuals but still have a significant impact on the population as a whole.
A species at risk
The loggerhead turtle (Caretta caretta), like all other sea turtle species, is listed on the IUCN Red List (International Union for Conservation of Nature). Globally, the loggerhead is classified as EN (Endangered), while in the Mediterranean it is considered VU (Vulnerable).
In recent years, the conservation status of the species in the Mediterranean has improved significantly thanks to numerous protection programs. However, the future of Caretta caretta remains closely tied to the continuity of these efforts: if they were to cease, the situation could quickly worsen due to the multiple threats described in the following sections.
Fishing
Fishing is the leading cause of mortality for all species of sea turtles, especially Caretta caretta, due to its feeding habits.
Every year, in the Mediterranean Sea alone, approximately 150,000 sea turtles are accidentally caught. Of these, around 50,000 die during capture, while the rest—often injured—are thrown back into the sea, left to their fate, which in most cases means death.
Since they have no commercial value, turtles are discarded along with other marine animals considered “bycatch,” such as sharks, cetaceans, and non-target fish species.
Several fishing methods cause high levels of interaction with Caretta caretta, but two are particularly impactful: longline fishing and bottom trawling.
These techniques, widely used in the Mediterranean depending on the characteristics of the seabed, pose a serious threat to the survival of the species.
Pollution
Pollution is also a serious threat to sea turtles. All species feed on organisms such as jellyfish and salps, which often resemble floating plastic bags or fragments.
When ingested, plastic can accumulate in the stomach, causing intestinal blockages and preventing the animal from feeding, eventually leading to death.
However, the most severe issue related to plastic pollution is entanglement. Countless pieces of floating debris—often abandoned fishing gear—drift on the ocean’s surface.
These objects can host small marine organisms, attracting turtles in search of food. While attempting to feed, turtles can become entangled by their flippers or necks. In the best-case scenario, the affected individual may lose a limb. In the worst case, unable to reach the surface to breathe, it drowns.
Boat traffic
Another common threat, especially in heavily trafficked areas like the Strait of Messina, is boat collisions.
Sea turtles spend a lot of time at the surface to breathe and to regulate their body temperature by absorbing heat from the sun. During this time, they are particularly vulnerable and, unfortunately, are often struck by passing boats.
Indirect threats
There are also a number of silent threats—less publicized but highly impactful—not only to loggerhead turtle populations, but to the entire marine ecosystem.
Climate crisis
Global warming is the most silent threat of all. Sea turtles are ectothermic animals, meaning their lives depend on the planet’s climate balance.
From the earliest embryonic stages, temperature plays a fundamental role: the sex of hatchlings is determined by the average temperature inside the incubation chamber. As this temperature rises, so does the proportion of female hatchlings.
This is why global warming poses a serious threat to the species: in the future, we could see a significant imbalance in the population, with a sharp predominance of females.
Habitat loss
The construction of roads, seafronts, beach resorts, and tourist facilities on shorelines is rapidly erasing the natural habitats of sea turtles.
Moreover, beaches and dunes are among the most dynamic environments in nature: cement structures prevent the sea from naturally shaping these features, accelerating coastal erosion.
All of this poses a serious threat to Caretta caretta, especially in Italy, where natural coastal areas are becoming increasingly rare.
Heavy machinery on beaches
Bulldozers, tractors, and other machinery used for beach cleaning are a major problem—not only for sea turtles, but for all species living on beaches and dunes. In Italy, mechanical beach cleaning is a widespread practice, and in several cases, Caretta caretta nests have been accidentally destroyed.
Species Conservation
In Italy and around the world, numerous conservation programs are in place. Among them, Sea Turtle Rescue Centers are one of the most effective tools for protecting these animals. Blue Conservancy has been managing the Sea Turtle Rescue Center (CRTM) in Brancaleone for nearly twenty years.
Rescue Centers
A rescue center is essentially a hospital for sea turtles, dedicated to rescuing, treating, and releasing individuals found in distress, often as victims of fishing activities and pollution.
Thanks to the work of specialized veterinarians, injured turtles—caught in nets, hooks, or plastic—receive medical care with the goal of returning them to the wild. Sea Turtle Rescue Centers have played a crucial role not only in saving individual animals—treating and releasing thousands—but also in changing public awareness.
When we opened the CRTM in Brancaleone in 2006, there was very little public discourse about sea turtles. Today, nearly twenty years later, awareness has changed dramatically.
Blue Conservancy has been committed to sea turtle conservation since 2006 and now manages one of the most important rescue centers in Italy.
Beach Protection
Another key activity for the conservation of Caretta caretta, especially in Italy, is the management of nesting sites on Italian beaches. The organizations involved in this area of conservation monitor and protect the nests and hatchlings.
Volunteer groups work to fence off, guard, and protect nests from harm—whether by people or, in the most vulnerable areas, by predators. During hatching, they watch over the hatchlings to ensure they make it safely to the sea.
Further Insight
The Caretta caretta, commonly known as the loggerhead sea turtle or simply the loggerhead, belongs to the vast domain of Eukaryota, which includes all organisms with cells containing a nucleus.
It is part of the kingdom Animalia, encompassing all animals, and the phylum Chordata, which groups living beings possessing a dorsal nerve cord at least during some stage of development. From a class perspective, it belongs to Reptilia, a group of terrestrial and aquatic vertebrates characterized by scaly skin and lung-based respiration.
It falls under the order Testudines, which includes all turtles—both marine and terrestrial—distinguished by their characteristic hard shell.
Caretta caretta is classified in the family Cheloniidae, which includes marine turtles with elongated front flippers and a relatively flat shell. The genus Caretta is monotypic, containing only one species: Caretta caretta (Linnaeus, 1758).
| Level | Classificazione |
|---|---|
| Domain | Eukaryota |
| Kingdom | Animalia |
| Phylum | Chordata |
| Class | Reptilia |
| Order | Testudines |
| Family | Cheloniidae |
| Genus | Caretta |
| Species | Caretta caretta |
Conclusions
The Caretta caretta is much more than just a sea turtle: it is a symbol of balance and biodiversity in the Mediterranean. Its survival depends on our ability to protect habitats, reduce threats, and support conservation programs. Every action, no matter how small, can make a difference for these extraordinary creatures. Defending the Caretta caretta means caring for the sea and the future of our planet.
Filippo Armonio, attualmente Presidente di Blue Conservancy Ets, da oltre vent’anni si occupa della salvaguardia delle tartarughe marine in Calabria, come volontario. Fotografo di professione con una grande passione per l’ambiente e gli oceani, si batte ogni giorno per difendere il mare dalle attività umane.
