Loggerhead sea turtle

{{Short description|Species of marine reptile distributed throughout the world}} {{Redirect |Loggerhead turtle|}} {{Redirect |Caretta |the community in West Virginia |Caretta, West Virginia}} {{Featured article}} {{Speciesbox | name = Loggerhead sea turtle | fossil_range = {{Fossil range|40|0}}Eocene - Recent<ref name="spotila59"/> | image = Loggerhead sea turtle.jpg | image_alt = A loggerhead sea turtle in an aquarium tank swims overhead. The underside is visible. | status = VU | status_system = IUCN3.1 | status_ref = <ref name="iucn status 19 November 2021">{{cite iucn |author=Casale, P. |author2=Tucker, A.D. |date=2017 |title=''Caretta caretta'' |volume=2017 |article-number=e.T3897A119333622 |doi=10.2305/IUCN.UK.2017-2.RLTS.T3897A119333622.en |access-date=19 November 2021}}</ref> | status2 = CITES_A1 | status2_system = CITES | status2_ref = <ref>{{cite web|title=Appendices {{!}} CITES|url=https://cites.org/eng/app/appendices.php|access-date=2022-01-14|website=cites.org}}</ref> | display_parents = 2 | genus = Caretta | parent_authority = Rafinesque, 1814 | species = caretta | authority = (Linnaeus, 1758) | synonyms = | range_map = Cypron-Range Caretta caretta.svg | range_map_caption = Loggerhead sea turtle range according to the Food and Agriculture Organization {{collapsible list|bullets=true|title=Species synonymy | ''Testudo caretta'' Linnaeus, 1758 | ''Testudo cephalo'' Schneider, 1783 | ''Testudo nasicornis'' Lacépède, 1788 | ''Testudo caouana'' Lacépède, 1788 | ''Chelone caretta'' — Brongniart, 1805 | ''Chelonia caouanna'' Schweigger, 1812 | ''Caretta nasuta'' Rafinesque, 1814 | ''Chelonia cavanna'' Oken, 1816 | ''Caretta atra'' Merrem, 1820 | ''Caretta cephalo'' — Merrem, 1820 | ''Caretta nasicornis'' — Merrem, 1820 | ''Chelonia caretta'' — Bory de Saint-Vincent, 1828 | ''Testudo corianna'' Gray, 1831 | ''Chelonia pelasgorum'' Valenciennes ''in'' Bory de Saint-Vincent, 1833 | ''Chelonia cephalo'' — Gray, 1829 | ''Chelonia'' (''Caretta'') ''cephalo'' — Lesson ''in'' Bélanger, 1834 | ''Chelonia caouanna'' — A.M.C. Duméril & Bibron, 1835 | ''Chelonia'' (''Thalassochelys'') ''caouana'' — Fitzinger, 1836 | ''Chelonia'' (''Thalassochelys'') ''atra'' — Fitzinger, 1836 | ''Thalassochelys caretta'' — Bonaparte, 1838 | ''Chelonia'' (''Caouanna'') ''cephalo'' — Cocteau ''in'' Cocteau & Bibron ''in'' de la Sagra, 1838 | ''Halichelys atra'' — Fitzinger, 1843 | ''Caounana caretta'' — Gray, 1844 | ''Caouana elongata'' Gray, 1844 | ''Thalassochelys caouana'' — Agassiz, 1857 | ''Thalassochelys corticata'' Girard, 1858 | ''Chelonia corticata'' — Strauch, 1862 | ''Thalassochelys elongata'' Strauch, 1862 | ''Thalassochelys caouana'' Nardo, 1864 | ''Eremonia elongata'' — Gray, 1873 | ''Caretta caretta'' — Stejneger, 1873 | ''Thalassochelys cephalo'' — Barbour & Cole, 1906 | ''Caretta caretta caretta'' — Mertens & L. Müller, 1928 | ''Caretta gigas'' Deraniyagala, 1933 | ''Caretta caretta gigas'' — Deraniyagala, 1939 | ''Caretta caretta tarapacana'' Caldwell, 1962 | ''Chelonia cahuano'' — Tamayo, 1962 | ''Caretta careta'' [sic] Tamayo, 1962 (''ex errore'')<ref name="dodd1"/> }} {{collapsible list|bullets=true|title=Genus synonymy | ''Caretta'' Rafinesque, 1814 | ''Caretta'' (''Thalassochelys'') Fitzinger, 1835 | ''Thalassochelys'' Bonaparte, 1838 | ''Caouana'' Cocteau ''in'' de la Sagra, 1838 | ''Halichelys'' Fitzinger, 1843 | ''Eremonia'' Gray, 1873 | ?''Pliochelys'' Portis, 1890 | ?''Proganosaurus'' Portis, 1890<ref name="dodd2"/> }} }} The '''loggerhead sea turtle''' ('''''Caretta caretta'''''), '''loggerhead turtle''' or '''loggerhead''', is a species of sea turtle distributed throughout the world. It is a marine reptile, belonging to the family Cheloniidae. The average loggerhead measures around {{convert|90|cm|in|abbr=on}} in carapace length when fully grown. The adult loggerhead sea turtle weighs approximately {{convert|135|kg|lb|abbr=on}}, with the largest specimens weighing about {{cvt|200|kg}}. The skin ranges from yellow to brown in color, and the shell is typically reddish brown. No external differences in sex are seen until the turtle becomes an adult, the most obvious difference being the adult males have thicker tails and shorter plastrons (lower shells) than the females.

The loggerhead sea turtle is found in the Atlantic, Pacific, and Indian Oceans, as well as the Mediterranean Sea. It spends most of its life in saltwater and estuarine habitats, with females briefly coming ashore to lay eggs. The loggerhead sea turtle has a low reproductive rate; females lay an average of four egg clutches and then become quiescent, producing no eggs for two to three years. The loggerhead reaches sexual maturity within 17–33 years and has a lifespan of 47–67 years.

The loggerhead sea turtle is omnivorous, feeding mainly on bottom-dwelling invertebrates. Its large and powerful jaws serve as an effective tool for dismantling its prey. Young loggerheads are exploited by numerous predators; the eggs are especially vulnerable to terrestrial organisms. Once the turtles reach adulthood, their formidable size limits predation to large marine animals, such as large sharks.

The loggerhead sea turtle is considered a vulnerable species by the International Union for Conservation of Nature. In total, nine distinct population segments are under the protection of the Endangered Species Act of 1973, with four population segments classified as "threatened" and five classified as "endangered".<ref name="NOAA">{{cite web| url=http://www.nmfs.noaa.gov/pr/species/turtles/loggerhead.html| title=Loggerhead Turtle (''Caretta caretta'')| website=NOAA Fisheries| publisher=NOAA| date=22 February 2017| access-date=20 April 2018}}</ref> Commercial international trade of loggerheads or derived products is prohibited by CITES Appendix I. Untended fishing gear is responsible for many loggerhead deaths. The greatest threat is loss of nesting habitat due to coastal development, predation of nests, and human disturbances (such as coastal lighting and housing developments) that cause disorientations during the emergence of hatchlings.<ref>{{cite web|url=https://conserveturtles.org/information-sea-turtles-loggerhead-sea-turtle/|title=Information About Sea Turtles: Loggerhead Sea Turtle – Sea Turtle Conservancy|language=en-US|access-date=2019-05-29}}</ref> Turtles may also suffocate if they are trapped in fishing trawls. Turtle excluder devices have been implemented in efforts to reduce mortality by providing an escape route for the turtles. Loss of suitable nesting beaches and the introduction of exotic predators have also taken a toll on loggerhead populations. Efforts to restore their numbers will require international cooperation, since the turtles roam vast areas of ocean and critical nesting beaches are scattered across several countries.

==Taxonomy== Carl Linnaeus gave the loggerhead its first binomial name, ''Testudo caretta'', in 1758.<ref name="dodd1"/><ref name="seaturtlebook7"/> Thirty-five other names emerged over the following two centuries, with the combination ''Caretta caretta'' first introduced in 1873 by Leonhard Stejneger.<ref name="dodd2"/> The English common name "loggerhead" refers to the animal's large head.<ref name="noaa"/><ref name="dodd4"/> The loggerhead sea turtle belongs to the family Cheloniidae, which includes all extant sea turtles except the leatherback sea turtle.<ref name="turtleguide97"/> The subspecific classification of the loggerhead sea turtle is debated, but most authors consider it a single polymorphic species.<ref name="marquez14"/> Molecular genetics has confirmed hybridization of the loggerhead sea turtle with the Kemp's ridley sea turtle, hawksbill sea turtle, and green sea turtles. The extent of natural hybridization is not yet determined; however, second-generation hybrids have been reported, suggesting some hybrids are fertile.<ref name="hybrid581"/>

===Evolution=== Although evidence is lacking,<ref name="Witherington12"/> modern sea turtles probably descended from a single common ancestor during the Cretaceous period. Like all other sea turtles except the leatherback, loggerheads are members of the ancient family Cheloniidae, and appeared about 40 million years ago.<ref name="spotila59"/> Of the six species of living Cheloniidae, loggerheads are more closely related to the Kemp's ridley sea turtle, olive ridley sea turtle, and the hawksbill turtle than they are to the flatback turtle and the green turtle.

Around three million years ago, during the Pliocene epoch, Central America emerged from the sea, effectively cutting off currents between the Atlantic and Indo-Pacific Oceans. The rerouting of ocean currents led to climatic changes as the Earth entered a glacial cycle. Cold water upwelling around the Cape of Good Hope and reduction in water temperature at Cape Horn formed coldwater barriers to migrating turtles. The result was a complete isolation of the Atlantic and Pacific populations of loggerheads.<ref name="spotila167"/> During the most recent ice age, the beaches of southeastern North America were too cold for sea turtle eggs. As the Earth began to warm, loggerheads moved farther north, colonizing the northern beaches. Because of this, turtles nesting between North Carolina and northern Florida represent a different genetic population from those in southern Florida.<ref name="spotila167"/>

The distinct populations of loggerheads have unique characteristics and genetic differences. For example, Mediterranean loggerheads are smaller, on average, than Atlantic Ocean loggerheads.<ref name="spotila166"/> North Atlantic and Mediterranean loggerhead sea turtles are descendants of colonizing loggerheads from Tongaland, South Africa. South African loggerhead genes are still present in these populations today.<ref name="spotila167"/>

==Description== {{multiple image | align = left | direction = vertical | width = 200 | header = | image1 = Loggerhead turtle.jpg | alt1 = Photo of the carapace of a loggerhead sea turtle | caption1 = The carapace of this loggerhead is reddish brown; five vertebral scutes run down the turtle's midline bordered by five pairs of costal scutes | image2 = Caretta caretta 3d scan Natural History Museum University of Pisa B 32.stl | alt2 = 3d model of the skeleton | caption2 = 3d model of the skeleton | image3 = Caretta caretta skull 3d scan Natural History Museum University of Pisa B 32.stl | alt3 = 3d model of the skull | caption3 = 3d model of the skull }} The loggerhead sea turtle is the world's largest hard-shelled turtle, slightly larger at average and maximum mature weights than the green sea turtle and the Galapagos tortoise. It is also the world's second largest extant turtle after the leatherback sea turtle.<ref name="ernst37"/>{{sfn|Dodd|1988}}<ref name=Wood>{{cite book |last=Wood |first=Gerald |title=The Guinness Book of Animal Facts and Feats |year=1983 |isbn=978-0-85112-235-9 |url=https://archive.org/details/guinnessbookofan00wood |publisher=Enfield, Middlesex : Guinness Superlatives }}</ref> Adults have an approximate weight range of {{convert|80|to|200|kg|lb|abbr=on}}, averaging around {{convert|135|kg|lb|abbr=on}}, and a straight-line carapace length range of {{convert|70|to|95|cm|in|abbr=on}}.<ref name="ernst37"/> The maximum reported weight is {{convert|545|kg|lb|abbr=on}} and the maximum (presumed total) length is {{convert|213|cm|in|abbr=on}}.<ref name="ernst37"/> The head and carapace (upper shell) range from a yellow-orange to a reddish brown, while the plastron (underside) is typically pale yellow.<ref name="turtleguide104"/> The turtle's neck and sides are brown on the tops and yellow on the sides and bottom.<ref name="noaa"/>

The turtle's shell is divided into two sections: carapace and plastron. The carapace is further divided into large plates, or scutes.<ref name="turtleguide104"/> Typically, 11 or 12 pairs of marginal scutes rim the carapace.<ref name="seaturtlebook7"/> Five vertebral scutes run down the carapace's midline, while five pairs of costal scutes border them.<ref name="turtleguide110"/> The nuchal scute is located at the base of the head.<ref name="turtleguide110"/> The carapace connects to the plastron by three pairs of inframarginal scutes forming the bridge of the shell.<ref name="turtleguide110"/> The plastron features paired gular, humeral, pectoral, abdominal, femoral, and anal scutes.<ref name="seaturtlebook7"/> The shell serves as external armor, although loggerhead sea turtles cannot retract their heads or flippers into their shells.<ref name="anatomy"/>

Sexual dimorphism of the loggerhead sea turtle is only apparent in adults. Adult males have longer tails and claws than females. The males' plastrons are shorter than the females', presumably to accommodate the males' larger tails. The carapaces of males are wider and less domed than the females', and males typically have wider heads than females.<ref name="valente22"/> The sex of juveniles and subadults cannot be determined through external anatomy, but can be observed through dissection, laparoscopy (an operation performed on the abdomen), histological examination (cell anatomy), and radioimmunological assays (immune study dealing with radiolabeling).<ref name="valente22"/>

Lachrymal glands located behind each eye allow the loggerhead to maintain osmotic balance by eliminating the excess salt obtained from ingesting ocean water. On land, the excretion of excess salt gives the false impression that the turtle is crying.<ref name="peaker231"/> The urea content is high in ''Caretta caretta'' tears.<ref>{{Cite journal|last1=Oriá|first1=Arianne P.|last2=Lacerda|first2=Ariane de J.|last3=Raposo|first3=Ana Cláudia S.|last4=Araújo|first4=Nayone L. L. C.|last5=Portela|first5=Ricardo|last6=Mendonça|first6=Marcos A.|last7=Masmali|first7=Ali M.|date=2020|title=Comparison of Electrolyte Composition and Crystallization Patterns in Bird and Reptile Tears|journal=Frontiers in Veterinary Science|language=en|volume=7|article-number=574|doi=10.3389/fvets.2020.00574|pmid=32903625|pmc=7438592|s2cid=221104904|issn=2297-1769|doi-access=free}}</ref>

The skull is most easily distinguished from other sea turtles by having maxillae that meet in the mid-line of the palate.<ref name="Frazier1985">{{Cite journal|last=Frazier|first=J|title=Misidentifications of Sea Turtles in the East Pacific: ''Caretta caretta'' and ''Lepidochelys olivacea''|journal=Journal of Herpetology|year=1985|volume=19|issue=1|pages=1–11|doi=10.2307/1564414|jstor=1564414}}</ref><ref name="Jonesetal2012">{{Cite journal|last1=Jones|first1=MEH|last2=Werneburg|first2=I|last3=Curtis|first3=N|last4=Penrose|first4=RN|last5=O'Higgins|first5=P|last6=Fagan|first6=M|last7=Evans|first7=SE|date=2012 |title=The head and neck anatomy of sea turtles (Cryptodira: Chelonioidea) and skull shape in Testudines|journal=PLOS ONE|volume=7|issue=11|article-number=e47852|doi=10.1371/journal.pone.0047852|pmid=23144831|pmc=3492385|bibcode=2012PLoSO...747852J|doi-access=free}}</ref> The portion of skull behind the eyes is also relatively large and bulbous due to the extensive jaw muscles.<ref name="Jonesetal2012"/>

==Distribution== [[File:Loggerhead turtle.png|thumb|left|upright=1.25|alt=A map of the range of a loggerhead sea turtle covering the Atlantic, Pacific, and Indian Oceans, and the Mediterranean Sea|Range of the loggerhead sea turtle according to the National Oceanic and Atmospheric Administration]]

The loggerhead sea turtle has a cosmopolitan distribution, nesting over the broadest geographical range of any sea turtle. It inhabits the Atlantic, Indian, and Pacific Oceans and the Mediterranean Sea.<ref name="spotila164"/>

In the Atlantic Ocean, the greatest concentration of loggerheads is along the southeastern coast of North America and in the Gulf of Mexico. Very few loggerheads are found along the European and African coastlines.<ref name="spotila165"/> Florida is the most popular nesting site, with more than 67,000 nests built per year. Nesting extends as far north as Virginia, as far south as Brazil, and as far east as the Cape Verde Islands. The Cape Verde Islands are the only significant nesting site on the eastern side of the Atlantic. Loggerheads found in the Atlantic Ocean feed from Canada to Brazil.<ref name="spotila164"/>

In the Indian Ocean, loggerheads feed along the coastlines of Africa, the Arabian Peninsula, and in the Arabian Sea.<ref name="spotila166"/> Along the African coastline, loggerheads nest from Mozambique's Bazaruto Archipelago to South Africa's St Lucia estuary.<ref name="seaturtlebook8"/> The largest Indian Ocean nesting site is Oman, on the Arabian Peninsula, which hosts around 15,000 nests, giving it the second largest nesting population of loggerheads in the world. Western Australia is another notable nesting area, with 1,000–2,000 nests per year.<ref name="spotila166"/>

Pacific loggerheads live in temperate to tropical regions.<ref name="seaturtlebook8"/> They forage in the East China Sea, the southwestern Pacific, and along the Baja California Peninsula. Eastern Australia and Japan are the major nesting areas, with the Great Barrier Reef deemed an important nesting area.<ref>C.Michael Hogan. 2011. [http://www.eoearth.org/article/Coral_Sea?topic=49523 ''Coral Sea''. Encyclopedia of Earth. Eds. P. Saundry & C.J.Cleveland. National Council for Science and the Environment. Washington DC]</ref> Pacific loggerheads occasionally nest in Vanuatu and Tokelau. Yakushima Island is the most important site, with three nesting grounds visited by 40% of all nearby loggerheads.<ref name="spotila166"/> After nesting, females often find homes in the East China Sea, while the Kuroshio Current Extension's Bifurcation region provides important juvenile foraging areas.<ref name="seaturtlebook8"/> Eastern Pacific populations are concentrated off the coast of Baja California, where upwelling provides rich feeding grounds for juvenile turtles and subadults. Nesting sites along the eastern Pacific Basin are rare. mtDNA sequence polymorphism analysis and tracking studies suggest 95% of the population along the coast of the Americas hatch on the Japanese Islands in the western Pacific.<ref name="Bowen3731"/> The turtles are transported by the prevailing currents across the full length of the northern Pacific, one of the longest migration routes of any marine animal.<ref name="Bowen3731"/> The return journey to the natal beaches in Japan has been long suspected, although the trip would cross unproductive clear water with few feeding opportunities.<ref name="Bowen3733"/> Evidence of a return journey came from an adult female loggerhead named Adelita, which in 1996, equipped with a satellite tracking device, made the {{convert|14,500|km|mi|abbr=on}} trip from Mexico across the Pacific. Adelita was the first animal of any kind ever tracked across an ocean basin.<ref name="PBSNature" />

The Mediterranean Sea is a nursery for juveniles, as well as a common place for adults in the spring and summer months.<ref name="spotila165"/><ref name="seaturtlebook20"/> Almost 45% of the Mediterranean juvenile population has migrated from the Atlantic.<ref name="spotila165"/> Loggerheads feed in the Alboran Sea and the Adriatic Sea,<ref name="spotila165"/> with tens of thousands of specimens (mainly sub-adult) seasonally present in the North-Eastern portion of the latter, above all in the area of the Po Delta.<ref>{{cite magazine |last1=Vecchio |first1=S. |title=Tartarughe dell'Adriatico |journal=Storie Naturali |date=2014 |volume=8 |pages=45–51 |publisher=Regione Emilia Romagna| url=https://ambiente.regione.emilia-romagna.it/it/parchi-natura2000/consultazione/pubblicazioni/immagini%20e%20allegati/TartarugheMarine_articolorivista.pdf}}</ref> Greece is the most popular nesting site along the Mediterranean, with more than 3,000 nests per year.<ref name="spotila166"/> Zakynthos hosts the largest Mediterranean nesting with the second one being in Kyparissia Bay.<ref>{{Harvnb|Spotila|2004|pp=165–66}}; {{cite web |url=http://ec.europa.eu/environment/life/project/Projects/index.cfm?fuseaction=search.dspPage&n_proj_id=311&docType=pdf |title=''Caretta caretta''/Kiparissia – Application of Management Plan for ''Caretta caretta'' in southern Kyparissia Bay |last=Dimopoulos |first=D |website=ec.europa.eu |publisher=European Commission |page=1 |archive-url=https://web.archive.org/web/20170825145326/http://ec.europa.eu/environment/life/project/Projects/index.cfm?fuseaction=search.dspPage&n_proj_id=311&docType=pdf |archive-date=August 25, 2017 |url-status=live |access-date=2017-11-18}}</ref> Because of this, Greek authorities do not allow planes to take off or land at night in Zakynthos due to the nesting turtles.<ref name="flighttimes"/> In addition to the Greek coast, the coastlines of Cyprus and Turkey are also common nesting sites.<ref name="spotila166"/>

One record of this turtle was made in Ireland when a specimen washed ashore on Ballyhealy Beach in County Wexford in 2013.<ref>{{cite journal | last1 = Murray | first1 = T. | last2 = Doyle | first2 = T. | year = 2013 | title = Loggerhead turtle (''Caretta caretta'' (L.)) in Co. Wexford | journal = Irish Naturalists' Journal | volume = 32 | pages = 153–154 |jstor=i24392898}}</ref> Another records one specimen being washed up on a beach in County Donegal, Ireland, in 2019.<ref>{{cite web|url=https://www.donegaldaily.com/2019/03/13/rare-turtle-found-in-donegal-doing-swimmingly-in-new-aquarium-home/|title=Rare turtle found in Donegal doing swimmingly in new aquarium home – Donegal Daily|first=Stephen|last=Maguire|website=www.donegaldaily.com|date=13 March 2019 }}</ref> They are not native to UK waters, but have been increasingly seen, most recently in 2026.<ref>{{cite news|title=Rare loggerhead turtle washed up during storm|last=Burchell|first=Helen|work=BBC News|date=10 February 2026|url=https://www.bbc.co.uk/news/articles/cx202gl4pqko|access-date=14 February 2026}}</ref>

==Habitat== Loggerhead sea turtles spend most of their lives in the open ocean and in shallow coastal waters. They rarely come ashore besides the females' brief visits to construct nests and deposit eggs. Hatchling loggerhead turtles live in floating mats of ''Sargassum'' algae.<ref name="spotila172"/> Adults and juveniles live along the continental shelf as well as in shallow coastal estuaries.<ref name="spotila174"/> In the northwestern Atlantic Ocean, age plays a factor in habitat preference. Juveniles are more frequently found in shallow estuarine habitats with limited ocean access compared to non-nesting adults.<ref name="seaturtlebook11"/> Loggerheads occupy waters with surface temperatures ranging from {{convert|13.3|-|28|C|F|0}} during non-nesting season. Temperatures from {{convert|27|-|28|C|F}} are most suitable for nesting females.<ref name="ernst39"/>

Juvenile loggerheads share the ''Sargassum'' habitat with a variety of other organisms. The mats of ''Sargassum'' contain as many as 100 different species of animals on which the juveniles feed. Prey found in ''Sargassum'' mats may include barnacles, crab larvae, fish eggs, and hydrozoan colonies. Some prey, such as ants, flies, aphids, leafhoppers, and beetles, are carried by the wind to the mats.<ref name="spotila172"/> Marine mammals and commercial fishes, including tuna and mahi-mahi, also inhabit the ''Sargassum'' mats.<ref name="sargassum"/>

==Behavior== thumb|left|alt=A loggerhead sea turtle resting under a rock with its eyes open|A resting loggerhead sea turtle

Loggerhead sea turtles observed in captivity and in the wild are most active during the day. In captivity, the loggerheads' daily activities are divided between swimming and resting on the bottom. While resting, they spread their forelimbs to about midstroke swimming position. They remain motionless with eyes open or half-shut and are easily alerted during this state. At night, captives sleep in the same position with their eyes tightly shut, and are slow to react.<ref name="ernst39"/> Loggerheads spend up to 85% of their day submerged, with males being the more active divers than females. The average duration of dives is 15–30 min, but they can stay submerged for more than ten hours, longer than any other air-breathing marine vertebrate.<ref>{{Cite journal |last1=Broderick |first1=Annette C |last2=Coyne |first2=Michael S |last3=Fuller |first3=Wayne J |last4=Glen |first4=Fiona |last5=Godley |first5=Brendan J |date=2007-06-22 |title=Fidelity and over-wintering of sea turtles |journal=Proceedings of the Royal Society B: Biological Sciences |language=en |volume=274 |issue=1617 |pages=1533–1539 |doi=10.1098/rspb.2007.0211 |issn=0962-8452 |pmc=2176160 |pmid=17456456}}</ref><ref name="ernst44"/> Juvenile loggerheads and adults differ in their swimming methods. A juvenile keeps its forelimbs pressed to the side of its carapace, and propels itself by kicking with its hind limbs. As the juvenile matures, its swimming method is progressively replaced with the adult's alternating-limb method. They depend entirely on this method of swimming by one year old.<ref name="ernst43"/>

Water temperature affects the sea turtle's metabolic rate.<ref name="ernst39"/> Lethargy is induced at temperatures between {{convert|13|and|15|C|F}}. The loggerhead takes on a floating, cold-stunned posture when temperatures drop to around {{convert|10|C|F}}.<ref name="ernst39"/> However, younger loggerheads are more resistant to cold and do not become stunned until temperatures drop below {{convert|9|C|F}}. The loggerheads' migration helps to prevent instances of cold-stunning.<ref name="ernst40"/> Higher water temperatures cause an increase in metabolism and heart rate. A loggerhead's body temperature increases in warmer waters more quickly than it decreases in colder water; their critical thermal maximum is currently unknown.<ref name="ernst40"/> In February 2015, a live loggerhead turtle was found floating in British Columbian waters of {{convert|10.5|C|F}} with extensive algal growth on its carapace.<ref>{{Cite journal|last1=Halpin|first1=Luke R|last2=Seminoff|first2=Jeffrey A|last3=Hanke|first3=Gavin F|date=2018-03-01|title=First Photographic Evidence of a Loggerhead Sea Turtle (''Caretta caretta'') in British Columbia|journal=Northwestern Naturalist|volume=99|issue=1|pages=73–75|doi=10.1898/NWN17-26.1|s2cid=90237643|issn=1051-1733|url=https://repository.library.noaa.gov/view/noaa/53335 }}</ref>

Female-female aggression, which is fairly rare in other marine vertebrates, is common among loggerheads. Ritualized aggression escalates from passive threat displays to combat. This conflict primarily occurs over access to feeding grounds. Escalation typically follows four steps.<ref name="aggression"/> First, initial contact is stimulated by visual or tactile cues. Second, confrontation occurs, beginning with passive confrontations characterized by wide head-tail circling. They begin aggressive confrontation when one turtle ceases to circle and directly faces the other. Third, sparring occurs with turtles snapping at each other's jaws. The final stage, separation, is either mutual, with both turtles swimming away in opposite directions, or involves chasing one out of the immediate vicinity.<ref name="aggression"/> Escalation is determined by several factors, including hormone levels, energy expenditure, expected outcome, and importance of location. At all stages, an upright tail shows willingness to escalate, while a curled tail shows willingness to submit. Because higher aggression is metabolically costly and potentially debilitating, contact is much more likely to escalate when the conflict is over access to good foraging grounds.<ref name="aggression"/> Further aggression has also been reported in captive loggerheads. The turtles are seemingly territorial, and will fight with other loggerheads and sea turtles of different species.<ref name="ernst44"/>[[File:Moon jelly - adult (rev2).jpg|thumb|alt=Translucent moon jelly on black blackground: The jelly contains a solid white mass extending through about two-thirds of its body|An adult Aurelia jellyfish which loggerheads eat during migration through the open sea]]

===Feeding=== thumb|Feeding on Portuguese men o'war The loggerhead sea turtle is omnivorous, feeding mainly on bottom-dwelling invertebrates, such as whelks, conchs, bivalves, and horseshoe crabs.<ref>{{cite web|last=Duermit |first=Liz |url=https://animaldiversity.org/accounts/Caretta_caretta/ |title=ADW: Caretta caretta: INFORMATION |publisher=Animaldiversity.org |date=2006-10-07 |access-date=2022-10-01}}</ref> It has a greater list of known prey than any other sea turtle. Other food items include sponges, corals, sea pens, polychaete worms, tube worms, sea anemones, cephalopods, barnacles, brachiopods, amphipods, isopods, Portuguese men o' war, insects, bryozoans, hydrozoans, sea urchins, sand dollars, sea cucumbers, starfish, tunicates, fish (eggs, juveniles, and adults), hatchling turtles (including members of its own species), algae, and vascular plants.<ref name="ernst50"/><ref>{{cite web | url=https://www.reptilesofecuador.com/caretta_caretta.html | title=Loggerhead (Caretta caretta) }}</ref> During migration through the open sea, loggerheads eat jellyfish, floating molluscs, floating egg clusters, squid, and flying fish.<ref name="noaa"/>

Loggerheads crush prey with their large and powerful jaws.<ref name="noaa"/><ref name="ernst52"/> Projecting scale points on the anterior margin of the forelimbs allow manipulation of the food. These points can be used as "pseudo-claws" to tear large pieces of food in the loggerhead's mouth. The loggerhead will turn its neck sideways to consume the torn food on the scale points.<ref name="ernst52"/> Inward-pointing, mucus-covered papillae found in the fore region of the loggerhead's esophagus filter out foreign bodies, such as fish hooks. The next region of the esophagus is not papillated, with numerous mucosal folds. The digestion rate in loggerheads is temperature-dependent; it increases as temperature increases.<ref name="ernst52"/> {{Clear}}

===Predators=== [[File:110127 Running ghost crab O ceratophtalma prey Loggerhead hatchling Gnaraloo Bay Rookery.JPG|thumb|A horned ghost crab (''Ocypode ceratophthalma'') preying on a loggerhead hatchling in Gnaraloo, Western Australia. Ghost crabs are one of the chief causes of egg and hatchling mortality in sea turtles.<ref>{{Cite thesis |title= Health assessment and hatching success of two Western Australian loggerhead turtle (''Caretta caretta'') populations|type=Ph.D. |url=http://researchrepository.murdoch.edu.au/18114/2/02_Whole.pdf |author=Sabrina Trocini |year= 2013|publisher=Murdoch University }}</ref><ref>{{Cite thesis |title=Cascading effects of predator removal on the ecology of sea turtle nesting beaches |url= http://etd.fcla.edu/CF/CFE0002667/Brown_Justin_R_200905_MS.pdf|author= Brandon T. Barton|year=2009|publisher=University of Idaho }}</ref><ref name="W1">{{cite web|url=http://conservationmagazine.org/2008/09/dont-tread-on-me/|title=Don't Tread On Me|author=Nick Atkinson|date=September 27, 2008|publisher=Conservation, University of Washington|access-date=November 14, 2013}}</ref>]] [[File:Fox up a tree.jpg|thumb|right|alt=A red fox walking along a fallen tree|The red fox is a predator of loggerhead nests in Australia.]] Loggerheads have numerous predators, especially early in their lives. Egg and nestling predators include ghost crabs, oligochaete worms, some beetles, flesh fly larvae, some ants, flesh flies, snakes, gulls, corvids, opossums, bears, rats, armadillos, mustelids, skunks, canids like coyotes, dingos, the Red foxes in Australia, Jackals and feral dogs, procyonids, Feral cats, Feral pigs, and humans. During their migration from their nests to the sea, hatchlings are preyed on by dipteran larvae, crabs, toads, lizards, snakes, seabirds such as frigatebirds, and other assorted birds and mammals. In the ocean, predators of the loggerhead juveniles include portunid crabs and various fishes, such as parrotfishes and moray eels. Adults are more rarely attacked due to their large size, but may be preyed on by large sharks (such as bull sharks, oceanic whitetip sharks, tiger sharks, and great white sharks), monk seals, and killer whales. Nesting females are attacked by flesh flies, feral dogs, and humans. Salt marsh mosquitos can also pester nesting females.<ref name="ernst52"/><ref name="ernst53"/>

In Australia, the introduction of the red fox (''Vulpes vulpes'') by British settlers in the 19th century led to significant reductions in loggerhead sea turtle populations. In one coastal section in eastern Australia during the 1970s, predation of turtle eggs destroyed up to 95% of all clutches laid.<ref name="spotila171"/> Aggressive efforts to destroy foxes in the 1980s and 1990s has reduced this impact; however, it is estimated that it will be the year 2020 before populations will experience complete recovery from such dramatic losses.{{update inline|date= September 2025}}<ref name="council62"/>

Along the southeastern coast of the United States, the raccoon (''Procyon lotor'') is the most destructive predator of nesting sites. Mortality rates of nearly 100% of all clutches laid in a season have been recorded on some Florida beaches.<ref name="spotila171"/> This is attributed to an increase in raccoon populations, which have flourished in urban environments. Aggressive efforts to protect nesting sites by covering them with wire mesh has significantly reduced the impact of raccoon predation on loggerhead sea turtle eggs.<ref name="council62"/>

Up to 40% of nesting females around the world have wounds believed to come from shark attacks.<ref name="ernst53"/>

===Disease and parasites=== Infectious bacteria such as ''Pseudomonas'' and ''Salmonella'' attack loggerhead hatchlings and eggs. Fungi such as ''Penicillium'' infect loggerhead sea turtle nests and cloacae.<ref name="ernst53"/>

Fibropapillomatosis disease caused by a form of the herpes-type virus threatens loggerheads with internal and external tumors. These tumors disrupt essential behaviors and, if on the eyes, cause permanent blindness.<ref name="threats"/> Trematodes of the family Spirorchiidae inhabit tissues throughout the body of the loggerhead, including vital organs, such as the heart and the brain.<ref name="trematodes"/> Trematode infection can be highly debilitating. For example, inflammatory trematode lesions can cause endocarditis and neurological disease.<ref name="trematodes"/> A nematode, ''Angiostoma carettae'', also infects loggerheads,<ref name="lungworm"/> causing histologic lesions in the respiratory tract.<ref name="lungworm"/>

More than 100 species of animals from 13 phyla, as well as 37 kinds of algae, live on loggerheads' backs.<ref name="spotila177"/> These parasitic organisms, which increase drag, offer no known benefit to the turtle, although the dulling effect of organisms on shell color may improve camouflage.<ref name="spotila177"/>

In 2018, researchers from Florida State University examined 24 individual turtle carapaces and found an average of 33,000 meiofauna with one turtle having 150,000 organisms living on the shell. A collection of 7,000 nematodes from 111 genera were found on the turtles studied.<ref>{{cite news |last=Keartes |first=Sarah |url=https://www.hakaimagazine.com/news/the-infinitesimal-life-aboard-sea-turtles/ |title=The Infinitesimal Life Aboard Sea Turtles |work=Hakai Magazine |date=2020-07-15 |access-date=2020-07-16 }}</ref>

==Life history==

===Early life=== thumb|Hatchling running to sea thumb|A pair of hatchlings to scale with a human hand

Hatchlings range in color from light brown to almost black, lacking the adult's distinct yellows and reds.<ref name="turtleguide104"/> Upon hatching, they measure about {{convert|4.6|cm|in|abbr=on}} and weigh about {{convert|20|g|oz|1|abbr=on}}.<ref name="noaa"/> The eggs are typically laid on the beach in an area above the high-tide line. The eggs are laid near the water so the hatchlings can return to the sea.<ref name="biologyandconservation10"/> The loggerhead's sex is dictated by the temperature of the underground nest. Incubation temperatures generally range from {{convert|26|–|32|C|F}}. Sea turtle eggs kept at a constant incubating temperature of 32 °C become females. Eggs incubating at 28 °C become males. An incubation temperature of 30 °C results in an equal ratio of male to female hatchlings.<ref name="yntema1013"/> Hatchlings from eggs in the middle of the clutch tend to be the largest, grow the fastest, and be the most active during the first few days of sea life.<ref name="spotila171"/>

After incubating for around 80 days, hatchlings dig through the sand to the surface, usually at night, when darkness increases the chance of escaping predation and damage from extreme sand surface temperatures is reduced.<ref name="biologyandconservation10"/> Hatchlings enter the ocean by navigating toward the brighter horizon created by the reflection of the moon and starlight off the water's surface.<ref name="artificiallighting"/>

Hatchlings can lose up to 20% of their body mass due to evaporation of water as they journey from nest to ocean.<ref name="spotila21"/> They initially use the undertow to push them five to 10 m away from the shore.<ref name="spotila21"/> Once in the ocean, they swim for about 20 hours, taking them far offshore.<ref name="turtleguide104"/> An iron compound, magnetite, in their brains allows the turtles to perceive the Earth's magnetic field,<ref name="spotila22"/> for navigation. Many hatchlings use ''Sargassum'' in the open ocean as protection until they reach {{convert|45|cm|in|abbr=on}}.<ref name="turtleguide104"/> Hatchling loggerheads live in this pelagic environment until they reach juvenile age, and then they migrate to nearshore waters.<ref name="turtleguide104"/>

===Maturation=== thumb|left|alt= Photo of a loggerhead swimming above a reef|A mature loggerhead sea turtle

When ocean waters cool, loggerheads must migrate to warmer areas or hibernate to some degree. In the coldest months, they submerge for up to seven hours at a time, emerging for only seven minutes to breathe. Although outdone by freshwater turtles, these are among the longest recorded dives for any air-breathing marine vertebrate.<ref name="divetimes"/> During their seasonal migration, juvenile loggerheads have the ability to use both magnetic and visual cues.<ref name="orientation cues"/> When both aids are available, they are used in conjunction; if one aid is not available, the other suffices.<ref name="orientation cues"/> The turtles swim at about {{convert|1.6|km/h|kn m/s|1|abbr=on}} during migration.<ref>{{cite journal|title=The relationship between loggerhead turtle (''Caretta caretta'') movement patterns and Mediterranean currents |vauthors=Bentivegna F, Valentino F, Falco P, Zambianchi E, Hochscheid S |journal=Marine Biology |date=2007 |volume=151 |issue=5 |pages=1605–1614 |doi=10.1007/s00227-006-0600-1 |bibcode=2007MarBi.151.1605B |s2cid=85864707 }}</ref>

Like all marine turtles, the loggerhead prepares for reproduction in its foraging area. This takes place several years before the loggerhead migrates to a mating area.<ref name="biologyandconservation4"/> Female loggerheads first reproduce at ages 28–33 in Southeastern United States and Australia, and at ages 17–30 in South Africa. Age at first reproduction in the Mediterranean, Oman, Japan, and Brazil are unknown.<ref name="spotila16"/> Nesting loggerheads have a straight carapace length of {{convert|70|-|109|cm|in|abbr=on}}. Because of the large range, carapace length is not a reliable indicator of sexual maturity.<ref name="biologyandconservation9"/> Their estimated maximum lifespan is 47–67 years in the wild.<ref name="ernst50"/> {{Clear}}

===Reproduction=== thumb|right|Loggerhead turtle track on a beach thumb|right|alt=A female loggerhead sea turtle from the back, laying eggs into the hole it has dug|A loggerhead sea turtle laying eggs Female loggerheads first reproduce between the ages of 17 and 33,<ref name="spotila16"/> and their mating period may last more than six weeks.<ref name="biologyandconservation4"/> They court their mates, but these behaviors have not been thoroughly examined.<ref name="biologyandconservation6"/> Male forms of courtship behavior include nuzzling, biting, and head and flipper movements.<ref name="biologyandconservation6"/> Studies suggest females produce cloacal pheromones to indicate reproductive ability.<ref name="biologyandconservation6"/> Before mating, the male approaches a female and attempts to mount her, while she resists. Next, the male and female begin to circle each other. If the male has competitors, the female may let the males struggle with each other. The winner then mounts the female; the male's curved claws usually damage the shoulders of the female's shell during this process. Other courting males bite the male while he is attempting to copulate, damaging his flippers and tail, possibly exposing bones. Such damage can cause the male to dismount and may require weeks to heal.<ref name="biologyandconservation6"/> While nesting, females produce an average of 3.9 egg clutches, and then become quiescent, producing no eggs for two to three years.<ref name="biologyandconservation4"/><ref name="spotila170"/> Unlike other sea turtles, courtship and mating usually do not take place near the nesting beach, but rather along migration routes between feeding and breeding grounds.<ref name="biologyandconservation6"/> Recent evidence indicates ovulation in loggerheads is mating-induced.<ref name="induced"/> Through the act of mating, the female ovulates eggs which are fertilized by the male. This is unique, as mating-induced ovulation is rare outside of mammals.<ref name="induced"/> In the Northern Hemisphere, loggerheads mate from late March to early June. The nesting season is short, between May and August in the Northern Hemisphere and between October and March in the Southern Hemisphere.<ref name="biologyandconservation9"/>

Loggerheads may display multiple paternity.<ref name="paternity"/> Multiple paternity is possible due to sperm storage. The female can store sperm from multiple males in her oviducts until ovulation.<ref name="sperm storage"/> A single clutch may have as many as seven fathers, each contributing sperm to a portion of the clutch.<ref name="GApaternity"/> Multiple paternity and female size are positively correlated.<ref name="paternity"/><ref name="GApaternity"/> Two hypotheses explain this correlation. One posits that males favor large females because of their perceived higher fecundity (ability to reproduce).<ref name="paternity"/> The other states, because larger females are able to swim more quickly to mating grounds, they have longer mating periods.<ref name="paternity"/>

All sea turtles have similar basic nesting behaviors. Females return to lay eggs at intervals of 12–17 days during the nesting season, on or near the beach where they hatched.<ref name="biologyandconservation6"/><ref name="spotila170"/> They exit the water, climb the beach, and scrape away the surface sand to form a body pit. With their hind limbs, they excavate an egg chamber in which the eggs are deposited. The females then cover the egg chamber and body pit with sand, and finally return to the sea.<ref name="biologyandconservation13"/> This process takes one to two hours, and occurs in open sand areas or on top of sand dunes, preferably near dune grasses that the females can use to camouflage the nest.<ref name="spotila170"/> The nesting area must be selected carefully because it affects characteristics such as fitness, emergence ratio, and vulnerability to nest predators.<ref name="biologyandconservation10"/> Loggerheads have an average clutch size of 112.4 eggs.<ref name="biologyandconservation17"/>

==Conservation== Many human activities have negative effects on loggerhead sea turtle populations. The prolonged time required for loggerheads to reach sexual maturity and the high mortality rates of eggs and young turtles from natural phenomena compound the problems of population reduction as a consequence of human activities.<ref name="spotila178"/>

===Threats=== [[File:Loggerhead nesting area.jpg|thumb|left|alt=An orange diamond sign with the words "Loggerhead Turtle Nesting Area" is blocking off a roped-off area on the beach where a loggerhead has laid eggs.|Loggerhead sea turtle nest roped off as part of the Sea Turtle Protection Project on Hilton Head Island]] [[File:Loggerhead turtle attempted poaching.jpg|alt=Loggerhead lying upside down in a traditional fishing dhow after artisanal fishers poached it|thumb|Artisanal fishers attempted to poach this loggerhead turtle in Mozambique. It was rescued and released by the Ilha do Fogo conservation team.]] Loggerhead sea turtles were once intensively hunted for their meat and eggs; consumption has decreased, however, due to worldwide legislation. Despite this, turtle meat and eggs are still consumed in countries where regulations are not strictly enforced.<ref name="eatingturtles"/> In Mexico, turtle eggs are a common meal; locals claim the egg is an aphrodisiac.<ref name="eatturtleeggs"/> Eating turtle eggs or meat can cause serious illness due to harmful bacteria, such as ''Pseudomonas aeruginosa'' and ''Serratia marcescens'', and high levels of toxic metals that build up through bioaccumulation.<ref name="eatingturtles"/><ref name="seaturtlebacteria"/>

The US West Coast is a critical migratory corridor for the Pacific loggerheads, in which these turtles swim across the Pacific to California's coast from breeding grounds in Japan. Important foraging habitats for juveniles in the central North Pacific have been revealed through telemetry studies.<ref name="peckham"/> Along with these foraging habitats, high levels of bycatch from industrial-scale fisheries have been found to overlap; with drift gillnets in the past and longline fisheries presently.<ref name="peckham"/> Many juvenile loggerheads aggregate off the coast of Baja California Sur, Mexico, where small coastal fisheries  increase these turtles' mortality risk; fishers have reported catching dozens of loggerheads with bottom-set gear per day per boat.<ref name="peckham"/> The most common commercial fishery that accidentally takes loggerheads are bottom trawls used for shrimp vessels in the Gulf of California.<ref name="NMF"/> In 2000, between 2,600 and 6,000 loggerheads were estimated to have been killed by pelagic longlining in the Pacific.<ref name="peckham"/>

Fishing gear is the biggest threat to loggerheads in the open ocean. They often become entangled in longlines or gillnets. According to the 2009 status review of loggerheads by the Fisheries Service, drowning from entanglement in longline and gillnet fishing gear is the turtles' primary threat in the North Pacific.<ref name="NMF"/> They also become stuck in traps, pots, trawls, and dredges.<ref name="noaa"/> Caught in this unattended equipment, loggerheads risk serious injury or drowning. Turtle excluder devices for nets and other traps reduce the number being accidentally caught.

Nearly 11 million metric tons of plastic are released into the ocean annually. A number that is projected to increase to 29 million metric tons by 2040.<ref name="Plastic Pollution"/> Turtles ingest a wide array of this floating debris, including bags, sheets, pellets, balloons and abandoned fishing line.<ref name="council114"/> Loggerheads may mistake the floating plastic for jellyfish, a common food item. The ingested plastic causes numerous health concerns, including intestinal blockage, reduced nutrient absorption and malnutrition, suffocation, ulcerations, or starvation. Ingested plastics release toxic compounds, including polychlorinated biphenyls, which may accumulate in internal tissues. Such toxins may lead to a thinning of eggshells, tissue damage, or deviation from natural behaviors.<ref name="council115"/>

Artificial lighting discourages nesting and interferes with the hatchlings' ability to navigate to the water's edge. Females prefer nesting on beaches free of artificial lighting. On developed beaches, nests are often clustered around tall buildings, perhaps because they block out the man-made light sources.<ref name="biologyandconservation10"/> Loggerhead hatchlings are drawn toward the brighter area over the water which is the consequence of the reflection of moon and star light. Confused by the brighter artificial light, they navigate inland, away from the protective waters, which exposes them to dehydration and predation as the sun rises.<ref name="artificiallighting"/> Artificial lighting causes tens of thousands of hatchling deaths per year.<ref name="lorne23"/>

Destruction and encroachment of habitat by humans is another threat to loggerhead sea turtles. Optimum nesting beaches are open-sand beaches above the high-tide line. However, beach development deprives them of suitable nesting areas, forcing them to nest closer to the surf.<ref name="spotila170"/> Urbanization often leads to the siltation of sandy beaches, decreasing their viability.<ref name="spotila170"/> Construction of docks and marinas can destroy near-shore habitats. Boat traffic and dredging degrades habitat and can also injure or kill turtles when boats collide with turtles at or near the surface.<ref name="threats"/>

Annual variations in climatic temperatures can affect sex ratios, since loggerheads have temperature-dependent sex determination. High sand temperatures may skew gender ratios in favor of females. Nesting sites exposed to unseasonably warm temperatures over a three-year period produced 87–99% females.<ref>{{cite journal |author=N. Mrosovsky |author2=Jane Provancha |name-list-style=amp |year=1992 |title=Sex ratio of hatchling loggerhead sea turtles: data and estimates from a 5-year study |journal=Canadian Journal of Zoology |volume=70 |issue=3 |pages=530–538 |doi=10.1139/z92-080|bibcode=1992CaJZ...70..530M }}</ref> This raises concern over the connection between rapid global temperature changes and the possibility of population extinction.<ref name="janzen7489"/> A more localized effect on gender skewing comes from the construction of tall buildings, which reduce sun exposure, lowering the average sand temperature, which results in a shift in gender ratios to favor the emergence of male turtles.<ref name="spotila170"/> Construction of new thermal power stations can raise local water temperature, which is also said to be a threat.<ref>{{Cite news|date=15 June 2020 |title=Coal-fired plant project threatens endangered sea turtles on Turkey's Mediterranean shores|work=bianet|url=http://bianet.org/english/environment/225733-coal-fired-plant-project-threatens-endangered-sea-turtles-on-turkey-s-mediterranean-shores}}</ref>

The increase of temperature and food availability will increase reproduction output of loggerhead turtles. Many researchers agree that temperature increases due to climate change has a complicated impact on turtles. At breeding sites when a loggerhead turtle lays multiple clutches in a season, a higher temperature will cause the duration of time between laying two different nests to become shorter. The amount of food availability makes a difference in reproductive output because when there is a greater amount of food available, the turtles will grow to a larger size. The larger a turtle is, the more likely they will have a greater reproductive output. The amount of food also has a relationship to temperature. Researchers have found that an increase of temperature causes feeding grounds to produce more food.<ref>{{cite journal|last1=Marn|first1=Nina|first2=Marko|last2=Jusup|first3=Tarzan|last3=Legović|first4=S. A. L. M.|last4=Kooijman|first5=Tin|last5=Klanjšček|title=Environmental effects on growth, reproduction, and life-history traits of loggerhead turtles|journal=Ecological Modelling|volume=360|year=2017|pages=163–178|doi=10.1016/j.ecolmodel.2017.07.001|bibcode=2017EcMod.360..163M |s2cid=90100832 |url=http://fulir.irb.hr/5855/7/2017-Marnetal-ECOMOD.pdf}}</ref>

Tropical Cyclones have a significant impact on hatchling loss. The associated storm surges push water higher up the beach, flooding nest and drowning the embryos. Strong wave action may eroded away sand, exposing the eggs to drying and predation. The current trend of rising sea surface temperatures and the increase in both numbers and intensities of tropical cyclones as a result of climate change pose a growing threat to turtle populations.<ref name="Stormy Oceans"/>

===Conservation efforts=== [[File:logger ted 01.jpg|thumb|right|alt=A loggerhead sea turtle escapes a circular fisherman's net via a TED|Loggerhead sea turtle escapes from fishing net through a turtle excluder device]]

Since the loggerhead occupies such a broad range, successful conservation requires efforts from multiple countries.<ref name="noaa"/>

Loggerhead sea turtles are classified as vulnerable by the International Union for Conservation of Nature and are listed under Appendix I of the Convention on International Trade in Endangered Species, making commercial international trade prohibited.<ref name="noaa"/> In the United States, the Fish and Wildlife Service and National Marine Fisheries Service classify them as a threatened species under the Endangered Species Act.<ref name="noaa"/> Loggerheads are listed as endangered under both Australia's Environment Protection and Biodiversity Conservation Act 1999 and Queensland's Nature Conservation Act 1992. The Convention on Migratory Species works for the conservation of loggerhead sea turtles on the Atlantic coast of Africa, as well as in the Indian Ocean and southeast Asia.<ref name="southafricaconservation"/><ref name="southeastasiaconservation"/> Throughout Japan, the Sea Turtle Association of Japan aids in the conservation of loggerhead sea turtles.<ref name="japanconservation"/> Greece's ARCHELON works for their conservation.<ref name="greececonservation"/> The Marine Research Foundation works for loggerhead conservation in Oman.<ref name="omanconservation" /> Annex 2 of the Specially Protected Areas and Wildlife Protocol of the Cartagena Convention, which deals with pollution that could harm marine ecosystems, also protects them.<ref name="noaa"/><ref name="cartagenaconvention"/> Conservation organizations worldwide have worked with the shrimp trawling industry to develop turtle exclusion devices (TEDs) to exclude even the largest turtles. TEDs are mandatory for all shrimp trawlers.<ref name="noaa"/>

In many places during the nesting season, workers and volunteers search the coastline for nests,<ref name="volunteerwork" /> and researchers may also go out during the evening to look for nesting females for tagging studies and gather barnacles and tissues samples. Volunteers may, if necessary, relocate the nests for protection from threats, such as high spring tides and predators, and monitor the nests daily for disturbances. After the eggs hatch, volunteers uncover and tally hatched eggs, undeveloped eggs, and dead hatchlings. Any remaining live hatchlings are released or taken to research facilities. Typically, those that lack the vitality to hatch and climb to the surface die.<ref name="seaturtlebook13"/>

To provide information on the demographic history, effects of climate change, and for informing the conservation of the species the chromosome scale genome and methylomes were assembled from turtles from the globally important Cape Verde rookery.<ref>{{Cite journal |last1=Yen |first1=Eugenie C |last2=Gilbert |first2=James D |last3=Balard |first3=Alice |last4=Taxonera |first4=Albert |last5=Fairweather |first5=Kirsten |last6=Ford |first6=Heather L |last7=Thorburn |first7=Doko-Miles J |last8=Rossiter |first8=Stephen J |last9=Martín-Durán |first9=José M |last10=Eizaguirre |first10=Christophe |date=2025-01-01 |title=Chromosome-level genome assembly and methylome profile yield insights for the conservation of endangered loggerhead sea turtles |journal=GigaScience |volume=14 |article-number=giaf054 |doi=10.1093/gigascience/giaf054 |issn=2047-217X |pmc=12143204 |pmid=40478729}}</ref> Using ONT nanopore direct-DNA sequencing the blood methylome profile was also derived. The researchers finding the microchromosomes are particularly useful for monitoring functional genetic and epigenetic diversity.

==== United States ==== The National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), the U.S. Fish and Wildlife Services (USFWS), and the Department of the Interior ruled four distinct population segments as threatened (Northwestern Atlantic Ocean, South Atlantic Ocean, Southeast Indo-Pacific Ocean, and Southwest Indian Ocean) and five as endangered (Mediterranean Sea, North Indian Ocean, North Pacific Ocean, Northeast Atlantic Ocean, and South Pacific Ocean) effective on October 24, 2011.<ref name=":0">{{Cite news |date=2011-09-22 |title=Endangered and Threatened Species; Determination of Nine Distinct Population Segments of Loggerhead Sea Turtles as Endangered or Threatened |work=Federal Register |url=https://www.federalregister.gov/documents/2011/09/22/2011-23960/endangered-and-threatened-species-determination-of-nine-distinct-population-segments-of-loggerhead |access-date=2017-03-16}}</ref>

Off the coast of southern California NMFS, NOAA, and Department of Commerce prohibited fishing with large drift gillnet (DGN) gear in the loggerhead conservation area during the presence of El Niño conditions in order to protect the endangered North Pacific Ocean loggerhead DPS.<ref name=":2">{{Cite news |date=2014-07-25 |title=Fisheries Off West Coast States; the Highly Migratory Species Fishery; Closure |work=Federal Register |url=https://www.federalregister.gov/documents/2014/07/25/2014-17644/fisheries-off-west-coast-states-the-highly-migratory-species-fishery-closure |access-date=2017-03-16}}</ref> This ruling effective July 23, 2014 was intended to prevent bycatch of loggerhead sea turtles.<ref name=":2" /> A team including sea turtle biologists and oceanographers determined the presence of El Niño conditions based on the El Niño watch issued by the Climate Prediction Center (CPC), anomalies found in sea surface temperature (SST) charts published by NOAA's Coast Watch Program, the presence of loggerhead sea turtles in the Pacific loggerhead conservation area, and reports of loggerhead strandings.<ref name=":2" /> The SST data showed higher than average temperatures during summer months off the coast of southern California.<ref name=":2" /> This same fisheries closure ruling due to El Niño conditions was again implemented May 29, 2015, and then again June 1, 2016.<ref>{{Cite news |date=2015-06-03 |title=Fisheries Off West Coast States; the Highly Migratory Species Fishery; Closure |work=Federal Register |url=https://www.federalregister.gov/documents/2015/06/03/2015-13601/fisheries-off-west-coast-states-the-highly-migratory-species-fishery-closure |access-date=2017-03-16}}</ref><ref>{{Cite news |date=2016-06-03 |title=Fisheries Off West Coast States; the Highly Migratory Species Fishery; Closure |work=Federal Register |url=https://www.federalregister.gov/documents/2016/06/03/2016-13137/fisheries-off-west-coast-states-the-highly-migratory-species-fishery-closure |access-date=2017-03-16}}</ref>

Critical habitat designation for the Northwest Atlantic Ocean DPS of loggerhead sea turtles specified 38 marine areas that include nearshore reproductive habitat, breeding areas, winter area, constricted migratory corridors, and ''Sargassum'' habitat.<ref name=":3">{{Cite news |date=2014-07-10 |title=Endangered and Threatened Species: Critical Habitat for the Northwest Atlantic Ocean Loggerhead Sea Turtle Distinct Population Segment (DPS) and Determination Regarding Critical Habitat for the North Pacific Ocean Loggerhead DPS |work=Federal Register |url=https://www.federalregister.gov/documents/2014/07/10/2014-15748/endangered-and-threatened-species-critical-habitat-for-the-northwest-atlantic-ocean-loggerhead-sea |access-date=2017-03-16}}</ref> This ruling was made the NMFS, NOAA, and Department of Commerce effective August 11, 2014.<ref name=":3" /> Nesting beaches were identified as critical terrestrial habitat by Fish and Wildlife Services and the Department of the Interior within the Atlantic Ocean and Gulf of Mexico, effective August 11, 2014.<ref>{{Cite news |date=2014-07-10 |title=Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Northwest Atlantic Ocean Distinct Population Segment of the Loggerhead Sea Turtle |work=Federal Register |url=https://www.federalregister.gov/documents/2014/07/10/2014-15725/endangered-and-threatened-wildlife-and-plants-designation-of-critical-habitat-for-the-northwest |access-date=2017-03-16}}</ref> The 2012 BiOp is an integral component to managing the shallow-set fishery, because the one-year incidental take statement (ITS, including reasonable and prudent management measures, and terms and conditions) forms the basis for regulations that specify the annual limits on leatherback and North Pacific loggerhead sea turtle interactions with the fishery that are necessary to manage the impacts of the fishery on sea turtles.<ref name=":6">{{Cite news |date=2011-03-11 |title=Western Pacific Pelagic Fisheries; Hawaii-Based Shallow-set Longline Fishery; Court Order |work=Federal Register |url=https://www.federalregister.gov/documents/2011/03/11/2011-5664/western-pacific-pelagic-fisheries-hawaii-based-shallow-set-longline-fishery-court-order |access-date=2017-03-16}}</ref>

Effective January 11, 2010 the NMFS, NOAA, and Department of Commerce removed the limit on the number of fishing gear deployments for the Hawaii-based pelagic shallow-set longline fisheries and simultaneously increased the number of incidental interactions allowed with loggerhead sea turtles.<ref name=":4">{{Cite news |date=2009-12-10 |title=International Fisheries Regulations; Fisheries in the Western Pacific; Pelagic Fisheries; Hawaii-based Shallow-set Longline Fishery |work=Federal Register |url=https://www.federalregister.gov/documents/2009/12/10/E9-29444/international-fisheries-regulations-fisheries-in-the-western-pacific-pelagic-fisheries-hawaii-based |access-date=2017-03-16}}</ref> This ruling stated that longline fisheries may not interact with over 46 loggerhead sea turtles a year, a number thought to not interfere with survival and recovery of loggerhead sea turtles.<ref name=":4" /> This ruling was revised March 10, 2011 to reduce the number of allowed interactions from 46 a year to 17, a revision aimed to protect the loggerheads and maintain fishery yield.<ref name=":6"/> November 18, 2011 the pelagic shallow-set longline fisheries in Hawaii reached the annual limit on physical interactions with turtles and was closed by NMFS.<ref>{{Cite news |date=2011-11-25 |title=Western Pacific Pelagic Fisheries; Closure of the Hawaii Shallow-Set Pelagic Longline Fishery Due To Reaching the Annual Limit on Sea Turtle Interactions |work=Federal Register |url=https://www.federalregister.gov/documents/2011/11/25/2011-30386/western-pacific-pelagic-fisheries-closure-of-the-hawaii-shallow-set-pelagic-longline-fishery-due-to |access-date=2017-04-14}}</ref> Incidental interaction limit for loggerhead turtles was increased from 17 to 34 interactions a year starting November 5, 2012.<ref>{{Cite news |date=2012-10-04 |title=Western Pacific Pelagic Fisheries; Revised Limits on Sea Turtle Interactions in the Hawaii Shallow-Set Longline Fishery |work=Federal Register |url=https://www.federalregister.gov/documents/2012/10/04/2012-24536/western-pacific-pelagic-fisheries-revised-limits-on-sea-turtle-interactions-in-the-hawaii |access-date=2017-04-14}}</ref>

==Symbols==

The loggerhead sea turtle appears on the $1000 Colombian peso coin. In the United States, the loggerhead sea turtle is the official state reptile of South Carolina and also the state saltwater reptile of Florida.<ref name="Florida"/><ref name="Shearer323">{{Harvnb|Shearer|Shearer|1994|p=323}}</ref>

==See also== * Adelita, the first sea turtle tracked across an ocean basin. * İztuzu Beach, one of the prime nesting habitats of the loggerhead turtle in the Mediterranean * Sea turtle threats {{Clear}}

==References== === Footnotes === {{Reflist|colwidth=30em|refs= <ref name="NMF">{{cite web|url=http://www.nmfs.noaa.gov/pr/pdfs/recovery/turtle_loggerhead_pacific.pdf |title=Recovery Plan for U.S. Pacific Populations of the Loggerhead Turtle (''Caretta caretta'') |author=Pacific Sea Turtle Recovery Team |year=1998 |publisher=National Marine Fisheries Service |location=Silver Spring, MD. |page=23 |archive-url=https://web.archive.org/web/20101207013732/http://www.nmfs.noaa.gov/pr/pdfs/recovery/turtle_loggerhead_pacific.pdf |archive-date=2010-12-07 |access-date=2010-10-25 }}</ref> <ref name="dodd1">{{Harvnb|Dodd|1988|p=1}}</ref> <ref name="dodd2">{{Harvnb|Dodd|1988|p=2}}</ref> <ref name="dodd4">{{Harvnb|Dodd|1988|p=4}}</ref> <ref name="turtleguide97">{{Harvnb|Wynne|Schwartz|1999|p=97}}</ref> <ref name="turtleguide104">{{Harvnb|Wynne|Schwartz|1999|p=104}}</ref> <ref name="turtleguide110">{{Harvnb|Wynne|Schwartz|1999|p=110}}</ref> <ref name="biologyandconservation4">{{Harvnb|Miller|Limpus|Godfrey|2003|p=125}}</ref> <ref name="biologyandconservation6">{{Harvnb|Miller|Limpus|Godfrey|2003|p=127}}</ref> <ref name="biologyandconservation9">{{Harvnb|Miller|Limpus|Godfrey|2003|p=126}}</ref> <ref name="biologyandconservation10">{{Harvnb|Miller|Limpus|Godfrey|2003|p=128}}</ref> <ref name="biologyandconservation13">{{Harvnb|Miller|Limpus|Godfrey|2003|p=131}}</ref> <ref name="biologyandconservation17">{{Harvnb|Miller|Limpus|Godfrey|2003|p=133}}</ref> <ref name="spotila16">{{Harvnb|Spotila|2004|p=16}}</ref> <ref name="spotila21">{{Harvnb|Spotila|2004|p=21}}</ref> <ref name="spotila22">{{Harvnb|Spotila|2004|p=22}}</ref> <ref name="spotila59">{{Harvnb|Spotila|2004|p=59}}</ref> <ref name="spotila164">{{Harvnb|Spotila|2004|p=164}}</ref> <ref name="spotila165">{{Harvnb|Spotila|2004|p=165}}</ref> <ref name="spotila166">{{Harvnb|Spotila|2004|p=166}}</ref> <ref name="spotila167">{{Harvnb|Spotila|2004|p=167}}</ref> <ref name="spotila170">{{Harvnb|Spotila|2004|p=170}}</ref> <ref name="spotila171">{{Harvnb|Spotila|2004|p=171}}</ref> <ref name="spotila172">{{Harvnb|Spotila|2004|p=172}}</ref> <ref name="spotila174">{{Harvnb|Spotila|2004|p=174}}</ref> <ref name="spotila177">{{Harvnb|Spotila|2004|p=177}}</ref> <ref name="spotila178">{{Harvnb|Spotila|2004|p=178}}</ref> <ref name="seaturtlebook7">{{Harvnb|Conant|Dutton|Eguchi|Epperly|2009|p=7}}</ref> <ref name="seaturtlebook8">{{Harvnb|Conant|Dutton|Eguchi|Epperly|2009|p=8}}</ref> <ref name="seaturtlebook11">{{Harvnb|Conant|Dutton|Eguchi|Epperly|2009|p=11}}</ref> <ref name="seaturtlebook13">{{Harvnb|Conant|Dutton|Eguchi|Epperly|2009|p=13}}</ref> <ref name="seaturtlebook20">{{Harvnb|Conant|Dutton|Eguchi|Epperly|2009|p=20}}</ref> <ref name="Bowen3731">{{Harvnb|Bowen|Abreu-Grobois|Balazs|Kamezaki|1995|p=3731}}</ref> <ref name="Bowen3733">{{Harvnb|Bowen|Abreu-Grobois|Balazs|Kamezaki|1995|p=3733}}</ref> <ref name="ernst37">{{Harvnb|Ernst|Lovich|2009|p=37}}</ref> <ref name="ernst39">{{Harvnb|Ernst|Lovich|2009|p=39}}</ref> <ref name="ernst40">{{Harvnb|Ernst|Lovich|2009|p=40}}</ref> <ref name="ernst43">{{Harvnb|Ernst|Lovich|2009|p=43}}</ref> <ref name="ernst44">{{Harvnb|Ernst|Lovich|2009|p=44}}</ref> <ref name="ernst50">{{Harvnb|Ernst|Lovich|2009|p=50}}</ref> <ref name="ernst52">{{Harvnb|Ernst|Lovich|2009|p=52}}</ref> <ref name="ernst53">{{Harvnb|Ernst|Lovich|2009|p=53}}</ref>  <ref name="valente22">{{Harvnb|Valente|2007|p=22}}</ref> <ref name="peaker231">{{Harvnb|Peaker|Linzell|1975|p=231}}</ref> <ref name="yntema1013">{{Harvnb|Yntema|Mrosovsky|1982|p=1013}}</ref> <ref name="lorne23">{{Harvnb|Lorne|Salmon|2007|p=23}}</ref> <ref name="council62">{{Harvnb|Committee on Sea Turtle Conservation, National Research Council|1990|p=62}}</ref> <ref name="council114">{{Harvnb|Committee on Sea Turtle Conservation, National Research Council|1990|p=114}}</ref> <ref name="council115">{{Harvnb|Committee on Sea Turtle Conservation, National Research Council|1990|p=115}}</ref> <ref name="marquez14">{{Harvnb|Márquez|1990|p=14}}</ref> <ref name="hybrid581">{{Harvnb|James|Martin|Dutton|2004|p=581}}</ref> <ref name="janzen7489">{{Harvnb|Janzen|1994|p=7489}}</ref> <ref name="Witherington12">{{Harvnb|Witherington|2006|p=12}}</ref>

<ref name="threats">{{cite web|author=NOAA Fisheries |title=Threats to Marine Turtles |work=Endangered marine animal preservation |publisher=NOAA Fisheries Office of Protected Resources |year=2010 |url=http://www.nmfs.noaa.gov/pr/species/turtles/threats.htm |access-date=February 7, 2010 |archive-url=https://web.archive.org/web/20100528012252/http://www.nmfs.noaa.gov/pr/species/turtles/threats.htm |archive-date=May 28, 2010 }}</ref>

<ref name="eatingturtles">{{cite journal | title = Hazards Associated with the Consumption of Sea Turtle Meat and Eggs: A Review for Health Care Workers and the General Public | journal = EcoHealth |date = September 2006| first = A. | last = Aguirre |author2=Susan C. Gardner |author3=Jesse C. Marsh |author4=Stephen G. Delgado |author5=Colin J. Limpus |author6=Wallace J. Nichols | volume = 3 | issue = 3 | pages = 141–53| doi = 10.1007/s10393-006-0032-x | bibcode = 2006EcoH....3..141A | s2cid = 26439580 }}</ref>

<ref name="eatturtleeggs">{{cite news|last=Dellios |first=Hugh |title=Mexico Cracks Open Myth of Sea Turtle Eggs |newspaper=Chicago Tribune |date=September 18, 2005 |url=http://www.redorbit.com/news/science/243267/mexico_cracks_open_myth_of_sea_turtle_eggs/index.html |access-date=March 16, 2010 |archive-url=https://archive.today/20100527011957/http://www.redorbit.com/news/science/243267/mexico_cracks_open_myth_of_sea_turtle_eggs/index.html |archive-date=May 27, 2010 }}</ref>

<ref name="seaturtlebacteria">{{cite web|last1=Craven |first1=Kathryn |last2=Taylor |first2=Judy |title=Marine Turtle Newsletter: Identification of Bacterial Isolates from Unhatched Loggerhead (''Caretta caretta'') Sea Turtle Eggs in Georgia, USA |publisher=Armstrong Atlantic State University, Dept. Biology |date=September 11, 2007 |url=http://www.seaturtle.org/mtn/archives/mtn115/mtn115p9.shtml |access-date=March 16, 2010 |archive-url=https://web.archive.org/web/20160116012442/http://www.seaturtle.org/mtn/archives/mtn115/mtn115p9.shtml |archive-date=January 16, 2016 }}</ref>

<ref name="noaa">{{cite web|url=http://www.nmfs.noaa.gov/pr/species/turtles/loggerhead.htm |title=Loggerhead Turtle (''Caretta caretta'') |last1=Bolten |first1=A.B. |year=2003 |work=NOAA Fisheries |access-date=January 31, 2010 |archive-url=https://web.archive.org/web/20100514085206/http://www.nmfs.noaa.gov/pr/species/turtles/loggerhead.htm |archive-date=May 14, 2010 }}</ref>

<ref name="divetimes">{{cite journal|last1=Hochscheid |first1=S. |first2=F. |author3-link=Graeme Hays |last2=Bentivegna |first3=G.C. |last3=Hays |year=2005 |title=First records of dive durations for a hibernating sea turtle |journal=Biology Letters |volume=1 |issue=1 |pages=82–6 |pmid=17148134 |pmc=1629053 |doi=10.1098/rsbl.2004.0250 }}</ref>

<ref name="artificiallighting">{{cite web|author=Fish and Wildlife Research Institute |title=Artificial Lighting and Sea Turtle Hatchling Behavior |work=Florida Fish and Wildlife Conservation Commission |publisher=Coastal Carolina University |date=September 2009 |url=http://research.myfwc.com/features/view_article.asp?id=2156 |access-date=April 12, 2010 |archive-url=https://web.archive.org/web/20100717164447/http://research.myfwc.com/features/view_article.asp?id=2156 |archive-date=July 17, 2010 }}</ref>

<ref name="flighttimes">{{cite web|url=http://www.e-zakynthos.com/zakynthos.zante.airport.php |title=Zakynthos Airport |publisher=Zakynthos Internet Services |year=2010 |quote=Night flights are banned on Zakynthos, so as not to disturb the endangered ''Caretta Caretta'' turtles which nest their eggs on the beaches of Zante. |access-date=April 12, 2010 |archive-url=https://web.archive.org/web/20100706071439/http://www.e-zakynthos.com/zakynthos.zante.airport.php |archive-date=July 6, 2010 }}</ref>

<ref name="paternity">{{cite journal |last1=Zbinden |first1=Judith A. |last2=Largiadèr |first2=Carlo R. |last3=Leippert |first3=Fabio |last4=Margaritoulis |first4=Dimitris |last5=Arlettaz |first5=Raphaël |title=High frequency of multiple paternity in the largest rookery of Mediterranean loggerhead sea turtles |journal=Molecular Ecology |date=2007 |volume=16 |issue=17 |pages=3703–3711 |doi=10.1111/j.1365-294X.2007.03426.x |pmid=17845442|bibcode=2007MolEc..16.3703Z |s2cid=10168400 }}</ref>

<ref name="aggression">{{Cite journal | last1 = Schofield | first1 = Gail | last2 = Katselidis | first2 = KA | last3 = Pantis | first3 = JD | last4 = Dimopoulos | first4 = P | author5-link = Graeme Hays | last5 = Hays | first5 = GC | title = Female-female aggressions: structure of interaction and outcome in loggerhead sea turtles|journal=Marine Ecology Progress Series | volume = 336 | issue = 1 | page = 267 |publisher = Inter-Research | issn = 1616-1599 | doi = 10.3354/meps336267 | year = 2007 | bibcode = 2007MEPS..336..267S | doi-access = free | hdl = 10536/DRO/DU:30058367 | hdl-access = free }}</ref>

<ref name="trematodes">{{Cite journal|last=Flint |first=Mark |title=Postmortem diagnostic investigation of disease in free-ranging marine turtle populations: a review of common pathologic findings and protocols |journal=Journal of Veterinary Diagnostic Investigation |date=November 2009 |volume=21 |issue=6 |pages=733–59 |doi=10.1177/104063870902100601 |pmid=19901275 |bibcode=2009JVDI...21..733F |s2cid=17896270 |doi-access=free }}</ref>

<ref name="induced">{{Cite journal | last = Manire | first = Charles | title = Mating-induced ovulation in loggerhead sea turtles, ''Caretta caretta'' | journal = Zoo Biology | year = 2008 | volume = 27 | issue = 3 | pages = 213–25 | doi = 10.1002/zoo.20171 | pmid = 19360619 | url = http://apps.isiknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=11&SID=2DMN8o2JNghnf8I3mKe&page=1&doc=1&colname=WOS| url-access = subscription }} {{subscription required}}</ref>

<ref name="lungworm">{{Cite journal | last = Manire | first = Charles | title = Lungworm infection in three loggerhead sea turtles, ''Caretta caretta'' | journal = Journal of Zoo and Wildlife Medicine |date = March 2008| volume = 39 | issue = 1 | pages = 92–8 | doi = 10.1638/2007-0092.1 | pmid = 18432101 | s2cid = 2599545 | url = http://apps.isiknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=10&SID=2DMN8o2JNghnf8I3mKe&page=1&doc=1&colname=WOS| url-access = subscription }} {{subscription required}}</ref>

<ref name="orientation cues">{{Cite journal | last = Avens | first = Larisa | title = Use of multiple orientation cues by juvenile loggerhead sea turtles ''Caretta caretta'' |journal=The Journal of Experimental Biology|volume=206|issue=1|doi=10.1242/jeb.00657 | pmid = 14581601 | publisher =The Company of Biologists | year = 2003 | pages = 4317–4325| bibcode = 2003JExpB.206.4317A | doi-access = free }}</ref>

<ref name="sperm storage">{{Cite journal|last=Pearce |first=D.E. |title=Turtle Behavior Systems: Behavior, Sperm Storage, and Genetic Paternity |issue=2 |pages=206–211 |journal=The Journal of Heredity |volume=92 |year=2001 |doi=10.1093/jhered/92.2.206 |pmid=11396580 |doi-access=free }}</ref>

<ref name="volunteerwork">{{cite web|url=http://www.seaturtle.org/jobs/index.shtml?view=419 |title=Job Board |access-date=2010-05-27 |last=seaturtle.org |date=2009-12-11 |work=seaturtle.org |quote=collect biopsy samples for DNA studies, cage nests to prevent egg depredation, record location of nests and non-nesting emergences. |archive-url=https://web.archive.org/web/20160116012533/http://www.seaturtle.org/jobs/index.shtml?view=419 |archive-date=January 16, 2016 }}</ref>

<ref name="sargassum">{{cite web|last=Ross |first=Steve |title=''Sargassum'': A Complex 'Island' Community at Sea |publisher=NOAA |year=2009 |url=http://oceanexplorer.noaa.gov/explorations/03edge/background/sargassum/sargassum.html |access-date=May 27, 2010 |archive-url=https://web.archive.org/web/20100528184445/http://oceanexplorer.noaa.gov/explorations/03edge/background/sargassum/sargassum.html |archive-date=May 28, 2010 }}</ref>

<ref name="southafricaconservation">{{cite web|url=http://www.cms.int/species/africa_turtle/AFRICAturtle_bkgd.htm |title=Memorandum of Understanding concerning Conservation Measures for Marine Turtles of the Atlantic Coast of Africa |access-date=2010-05-26 |author=Convention on Migratory Species |year=2004 |work=Convention on Migratory Species |publisher=UNEP / CMS Secretariat |quote=The project aims to create a monitoring and protection network for nesting and feeding sites in close collaboration with local communities, fishermen, travel operators and coastal developers. |archive-url=https://web.archive.org/web/20100818173339/http://www.cms.int/species/africa_turtle/AFRICAturtle_bkgd.htm |archive-date=August 18, 2010 }}</ref>

<ref name="anatomy">{{cite web|url=http://www.cms.int/species/africa_turtle/AFRICAturtle_bkgd.htm |title=Sea Turtles: Physical Characteristics |access-date=2010-05-26 |author=SeaWorld Parks |author2=Entertainment |name-list-style=amp |year=2010 |publisher=SeaWorld/Busch Gardens Animals |quote=A sea turtle cannot retract its limbs under its shell as a land turtle can. |archive-url=https://web.archive.org/web/20100818173339/http://www.cms.int/species/africa_turtle/AFRICAturtle_bkgd.htm |archive-date=August 18, 2010 }}</ref>

<ref name="japanconservation">{{cite web|url=http://www.umigame.org/E1/turtlepowerstyle2.html |title=What is the Sea Turtle Association of Japan? |access-date=2010-05-26 |last=Bullock |first=Dusty |year=2008 |work=Sea Turtle Association of Japan |quote=Our most important activities are counting nesting turtles, and marking them to enable discrimination, using consistent methods throughout Japan. |archive-url=https://web.archive.org/web/20090227092526/http://www.umigame.org/E1/turtlepowerstyle2.html |archive-date=February 27, 2009 }}</ref>

<ref name="southeastasiaconservation">{{cite web|url=http://www.cms.int/species/iosea/IOSEAturtle_bkgd.htm |title=Memorandum of Understanding concerning Conservation Measures for Marine Turtles of the Indian Ocean and South-East Asia |access-date=2010-05-26 |author=Convention on Migratory Species |year=2004 |work=Convention on Migratory Species |publisher=UNEP / CMS Secretariat |quote=In the context of sustainable development, the conservation and management of marine turtles globally and within the Indian Ocean – South-East Asian region presents a formidable challenge. |archive-url=https://web.archive.org/web/20091209045719/http://www.cms.int/species/iosea/IOSEAturtle_bkgd.htm |archive-date=December 9, 2009 }}</ref>

<ref name="greececonservation">{{cite web|url=http://www.britishcheloniagroup.org.uk/testudo/v6/v6n2reesarchelon.htm |title=Archelon, the Sea Turtle Protection Society of Greece: 21 Years Studying and Protecting Sea Turtles |access-date=2010-05-27 |last=Rees |first=Alan |year=2005 |work=Archelon |publisher=British Chelonia Group |quote=Archelon is involved with the turtles, not only through nest management and turtle rehabilitation, but also with stakeholders |archive-url=https://web.archive.org/web/20120306080056/http://www.britishcheloniagroup.org.uk/testudo/v6/v6n2reesarchelon.htm |archive-date=March 6, 2012 }}</ref>

<ref name="omanconservation">{{cite web|url=http://mrf-asia.org/projects_view.cfm?THE_ID=34 |title=Ongoing Conservation Initiatives |access-date=2010-05-29 |author=Marine Research Foundation |year=2004 |work=Marine Research Foundation |quote=This project aimed to continue to build on Oman's programme to conduct surveys, develop survey protocols and provide equipment and material and personnel support for Government rangers |archive-url=https://archive.today/20100530225945/http://mrf-asia.org/projects_view.cfm?THE_ID=34 |archive-date=May 30, 2010 }}</ref>

<ref name="PBSNature">{{cite web | url = https://www.pbs.org/wnet/nature/voyage-of-the-lonely-turtle-interview-wallace-j-nichols/2508/ | title = Voyage of the Lonely Turtle – Interview: Wallace J. Nichols | access-date = 2010-05-30 | last = Wallace J. | first = Nichols | year = 2008 | work = PBS | publisher = Educational Broadcasting Corporation | archive-url = https://web.archive.org/web/20100426223737/http://www.pbs.org/wnet/nature/episodes/voyage-of-the-lonely-turtle/interview-wallace-j-nichols/2508/ | archive-date = 2010-04-26 | url-status = live }}</ref>

<ref name="cartagenaconvention">{{cite web|url=http://rod.eionet.europa.eu/instruments/575 |title=Legislative instrument details: Cartagena Convention |access-date=2010-05-31 |author=European Environment Agency |year=2010 |work=European Environment Agency |quote=The Cartagena Convention requires Parties to adopt measures aimed at preventing, reducing and controlling pollution of the following areas: pollution from ships; pollution caused by dumping; pollution from sea-bed activities; airborne pollution; and pollution from land-based sources and activities. |archive-url=https://web.archive.org/web/20091016040751/http://rod.eionet.europa.eu/instruments/575 |archive-date=October 16, 2009 }}</ref>

<ref name="peckham">{{cite journal |last1=Peckham |first1=S. Hoyt |last2=Diaz |first2=David Maldanado |last3=Walli |first3=Andreas |last4=Ruiz |first4=Georgita |last5=Crowder |first5=Larry B. |last6=Nichols |first6=Wallace J. |editor-last=Allen |editor-first=Colin |date=October 2007 |article-number=e1041 |volume=2 |title=Small-scale fisheries bycatch jeopardizes endangered Pacific loggerhead turtles |journal=PLOS ONE |doi=10.1371/journal.pone.0001041 |pmid=17940605 |issue=10 |pmc=2002513 |bibcode=2007PLoSO...2.1041P |doi-access=free }}</ref>

<ref name="Florida">{{cite web|url=http://www.myfloridahouse.gov/Sections/Bills/billsdetail.aspx?BillId=37196& |title=State symbols/Fla. cracker horse/loggerhead turtle (SB 230) |access-date=2011-08-10 |year=2008 |publisher=Florida House of Representatives |archive-url=https://web.archive.org/web/20110721050008/http://www.myfloridahouse.gov/Sections/Bills/billsdetail.aspx?BillId=37196& |archive-date=2011-07-21 }}</ref>

<ref name="GApaternity">{{cite journal |last1=Lasala |first1=Jacob |last2=Harrison|first2=J.S. |last3=Williams |first3=K.L. |last4=Rostal |first4=D.C. |title=Strong male-biased operational sex ratio in a breeding population of loggerhead turtles (''Caretta caretta'') inferred by paternal genotype reconstruction analysis |journal=Ecology and Evolution |date=November 2013 |volume=3 |issue=14 |pages=4736–4747 |doi=10.1002/ece3.761|pmid=24363901 |pmc=3867908 |bibcode=2013EcoEv...3.4736L }}</ref>

<ref name="Stormy Oceans">{{cite journal|author=Kyle S. Van Houtan and Oron L. Bass |title=Stormy oceans associated with declines in sea turtle hatching. |journal=Current Biology |year=2007 |volume=17 |issue=15 |pages=R590-1 |doi=10.1016/j.cub.2007.06.021 |pmid=17686427 |s2cid=2672476 |doi-access=free |bibcode=2007CBio...17.R590V }}</ref>

<ref name="Plastic Pollution">{{cite web|author=John Briley |title=Confronting Ocean Plastic Pollution |work=Trust Magazine |publisher=The PEW Charitable Trust |year=2020 |url=https://www.pewtrusts.org/en/trust/archive/fall-2020/confronting-ocean-plastic-pollution}}</ref> }}

=== Bibliography === * {{Cite journal|last1=Bowen |first1=B.W. |last2=Abreu-Grobois |first2=F.A. |last3=Balazs |first3=G.H. |last4=Kamezaki |first4=N |last5=Limpus |first5=C.J. |last6=Ferl |first6=R.J. |title=Trans-Pacific migrations of the loggerhead turtle (''Caretta caretta'') demonstrated with mitochondrial DNA markers |journal=Proc. Natl. Acad. Sci. 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==Further reading== *Arnold EN, Burton JA (1978). ''A Field Guide to Reptiles and Amphibians of Britain and Europe''. London: Collins. 272 pp. {{ISBN|0-00-219318-3}}. (''Caretta caretta'', p. 95 + Figure 2 on p. 99). *Behler JL, King FW (1979). ''The Audubon Society Field Guide to North American Reptiles and Amphibians''. New York: Alfred A. Knopf. 743 pp., 657 color plates. {{ISBN|0-394-50824-6}}. (''Caretta caretta'', pp. 475–476 + Plate 265). *{{Cite book|ref=none |title=Loggerhead Sea Turtles |year=2003 |first1=Alan B.|last1=Bolten |first2=Blair E.|last2=Witherington |publisher=Smithsonian Books |location=Washington, District of Columbia |isbn=1-58834-136-4 }} *Boulenger GA (1889). ''Catalogue of the Chelonians, Rhynchocephalians, and Crocodiles in the British Museum (Natural History). New Edition.'' London: Trustees of the British Museum (Natural History). (Taylor and Francis, Printers). x + 311 pp. + Plates I-III. (''Thalassochelys caretta'', pp. 184–186). *Goin CJ, Goin OB, Zug GR (1978). ''Introduction to Herpetology, Third Edition''. San Francisco, California: W.H. Freeman and Company. xi + 378 pp. {{ISBN|0-7167-0020-4}}. (''Caretta caretta'', pp. 122, 124, 267). *Gulko D, Eckert KL (2004). ''Sea Turtles: An Ecological Guide''. Honolulu, Hawaiʻi: Mutual Publishing. {{ISBN|1-56647-651-8}}. *Linnaeus C (1758). ''Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio Decima, Reformata.'' Stockholm: L. Salvius. 824 pp. (''Testudo caretta'', new species, pp. 197–198). (in Latin). *{{Cite book|ref=none |title=The Biology of Sea Turtles, Volume I |first1=Peter L.|last1=Lutz |first2=John A.|last2=Musick |first3=Jeanette|last3=Wyneken |year=1997 |publisher=CRC Press |location=Boca Raton, Florida |isbn=0-8493-8422-2 }} *{{Cite book|ref=none |title=The Biology of Sea Turtles, Volume II |first1=Peter L.|last1=Lutz |first2=John A.|last2=Musick |first3=Jeanette|last3=Wyneken |year=2003 |publisher=CRC Press |location=Boca Raton, Florida |isbn=0-8493-1123-3 }} *Powell R, Conant R, Collins JT (2016). ''Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, Fourth Edition''. Boston and New York: Houghton Mifflin Harcourt. xiv + 494 pp., 47 plates, 207 figures. {{ISBN|978-0-544-12997-9}}. (''Caretta caretta'', p. 192 + Plate 14 + Figure 81 on p. 174). *Smith HM, Brodie ED Jr (1982). ''Reptiles of North America: A Guide to Field Identification''. New York: Golden Press. 240 pp. {{ISBN|0-307-13666-3}}. (''Caretta caretta'', pp. 36–37). *Stejneger L, Barbour T (1917). ''A Check List of North American Amphibians and Reptiles''. Cambridge, Massachusetts: Harvard University Press. 125 pp. (''Caretta caretta'', p. 123).

== External links == {{Wikispecies|Caretta caretta}} {{Commons and category|Caretta caretta|Caretta caretta}} *[https://sketchfab.com/models/c438e81e796d41d9a6ae4cc147ef8d4f A 3D animation of a sea turtle. ] * {{SealifePhotos|137205}} * [https://www.museumventure.com/items/4 Painting of a sea turtle], as presented at The Museum of Contemporary Art Chicago

loggerhead sea turtle loggerhead sea turtle Category:Cosmopolitan vertebrates Category:Symbols of Florida Category:Symbols of South Carolina Category:Turtles of South America Category:Turtles of Brazil Category:Endangered animals Category:Nature Conservation Act endangered biota loggerhead sea turtle loggerhead sea turtle Category:EPBC Act endangered biota Category:Habitats Directive species