View source for Green sea turtle

{{Short description|Species of large sea reptile}}
{{Redirect|Green turtle|the comic book character|Green Turtle (comics)}}
{{Redirect|Chelonia|the synonym of the order Testudines |Turtle}}
{{Speciesbox
| name = Green sea turtle
| fossil_range = {{Fossil range|0.21|0|ref=<ref>{{cite web|url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=173399|title=Chelonia mydas (green turtle)|website=Paleobiology Database}}</ref>}}
| image = Green sea turtle (Chelonia mydas) Moorea.jpg
| image_caption = Male Sea Turtle in [[Moorea]], [[French Polynesia]]
| image2 = Hawaii turtle 2.JPG
| image2_caption = Female Sea Turtle
| status = EN
| status_system = IUCN3.1
| status_ref = <ref name="iucn status 12 November 2021">{{cite iucn |author=Seminoff, J.A. |collaboration=Southwest Fisheries Science Center, U.S. |date=2004 |title=''Chelonia mydas'' |volume=2004 |page=e.T4615A11037468 |doi=10.2305/IUCN.UK.2004.RLTS.T4615A11037468.en |access-date=12 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
| parent_authority = [[Alexandre Brongniart|Brongniart]], 1800
| genus = Chelonia
| species = mydas
| authority = ([[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]])
| synonyms = {{collapsible list|bullets = true
 |title=<small>Species synonymy</small>
 |''Testudo mydas'' <br/>{{small|Linnaeus, 1758}}
 |''Testudo macropus'' <br/>{{small|[[Johann Julius Walbaum|Walbaum]], 1782}} <br/>(''[[nomen illegitimum]]'')
 |''Testudo viridis'' <br/>{{small|[[Johann Gottlob Theaenus Schneider|Schneider]], 1783}}
 |''Testudo japonica'' <br/>{{small|[[Carl Peter Thunberg|Thunberg]], 1787}}
 |''Testudo marina vulgaris'' <br/>{{small|[[Bernard Germain de Lacépède|Lacépède]], 1788}}
 |''Testudo viridisquamosa'' <br/>{{small|Lacépède, 1788}}
 |''Testudo mydas macropus'' <br/>{{small|[[Georg Adolf Suckow|Suckow]], 1798}}
 |''Chelonia mydas'' <br/>{{small|— [[Alexandre Brongniart|Brongniart]], 1800}}
 |''Testudo chloronotos'' <br/>{{small|[[Johann Matthäus Bechstein|Bechstein]], 1800}}
 |''Testudo cepediana'' <br/>{{small|[[François Marie Daudin|Daudin]], 1801}}
 |''Testudo rugosa'' <br/>{{small|Daudin, 1801}}
 |''Chelone mydas'' <br/>{{small|— Brongniart, 1805}}
 |''Chelonia japonica'' <br/>{{small|— [[August Friedrich Schweigger|Schweigger]], 1812}}
 |''Chelonia virgata'' <br/>{{small|Schweigger, 1812}}
 |''Caretta cepedii'' <br/>{{small|[[Blasius Merrem|Merrem]], 1820}}
 |''Caretta esculenta'' <br/>{{small|Merrem, 1820}}
 |''Caretta thunbergii'' <br/>{{small|Merrem, 1820}}
 |''Caretta mydas'' <br/>{{small|— [[Leopold Fitzinger|Fitzinger]], 1826}}
 |''Caretta virgata'' <br/>{{small|— Fitzinger, 1826}}
 |''Chelonia lachrymata'' <br/>{{small|[[Georges Cuvier|Cuvier]], 1829}}
 |''Chelonia maculosa'' <br/>{{small|Cuvier, 1829}}
 |''Chelonia midas'' [sic] <br/>{{small|[[Johann Georg Wagler|Wagler]], 1830}} <br/>(''[[ex errore]]'')
 |''Chelonia mydas ''var''. japonica'' <br/>{{small|— [[John Edward Gray|Gray]], 1831}}
 |''Chelonia esculenta'' <br/>{{small|— [[Arend Friedrich August Wiegmann|Wiegmann]] & [[Johann Fiedrich Ruthe|Ruthe]], 1832}}
 |''Chelonia bicarinata'' <br/>{{small|[[René Primevère Lesson|Lesson]], 1834}}
 |''Chelonia marmorata'' <br/>{{small|[[André Marie Constant Duméril|A.M.C. Duméril]] & [[Gabriel Bibron|Bibron]], 1835}}
 |''Chelonia'' (''Chelonia'') <br/>''cepedeana'' [sic] <br/>{{small|Fitzinger, 1835}} <br/>(''ex errore'')
 |''Chelonia viridis'' <br/>{{small|— [[Coenraad Jacob Temminck|Temminck]] & [[Hermann Schlegel|Schlegel]], 1835}}
 |''Mydas mydas'' <br/>{{small|— [[Jean Théodore Cocteau|Cocteau]], 1838}}
 |''Mydasea mydas'' <br/>{{small|— [[Paul Gervais|Gervais]], 1843}}
 |''Euchelonia mydas'' <br/>{{small|— [[Johann Jakob von Tschudi|Tschudi]], 1846}}
 |''Megemys mydas'' <br/>{{small|— [[Johannes von Nepomuk Franz Xaver Gistel|Gistel]], 1848}}
 |''Chelonia lacrymata'' [sic] <br/>{{small|Agassiz, 1857}} <br/>(''ex errore'')
 |''Chelonia formosa'' <br/>{{small|[[Charles Frédéric Girard|Girard]], 1858}}
 |''Chelonia tenuis'' <br/>{{small|Girard, 1858}}
 |''Euchelys macropus'' <br/>{{small|— Girard, 1858}}
 |''Chelone macropus'' <br/>{{small|— [[Alexander Strauch|Strauch]], 1862}}
 |''Chelone maculosa'' <br/>{{small|— Strauch, 1862}}
 |''Chelone marmorata'' <br/>{{small|— Strauch, 1862}}
 |''Chelone virgata'' <br/>{{small|— Strauch, 1862}}
 |''Chelone viridis'' <br/>{{small|— Strauch, 1862}}
 |''Chelonia albiventer'' <br/>{{small|[[Giovanni Domenico Nardo|Nardo]], 1864}}
 |''Thalassiochelys albiventer'' <br/>{{small|— [[Albert Günther|Günther]], 1865}}
 |''Chelonia agassizii'' <br/>{{small|[[Marie Firmin Bocourt|Bocourt]], 1868}}
 |''Mydas viridis'' <br/>{{small|— Gray, 1870}}
 |''Chelone midas'' <br/>{{small|— [[Edward Drinker Cope|Cope]], 1871}}
 |''Chelonia lata'' <br/>{{small|[[Rodolfo Amando Philippi|Philippi]], 1887}}
 |''Chelone mydas'' <br/>{{small|— [[George Albert Boulenger|Boulenger]], 1889}}
 |''Chelonia mydas mydas'' <br/>{{small|— [[Robert Mertens|Mertens]] & [[Lorenz Müller|L. Müller]], 1928}}
 |''Caretta thunbergi'' [sic] <br/>{{small|[[Hobart Muir Smith|H.M. Smith]], 1931}} <br/>(''ex errore'')
 |''Chelonia mydas agassizii'' <br/>{{small|— [[Archie Carr|Carr]], 1952}}
 |''Chelonia mydas agassizi'' [sic] <br/>{{small|[[Karl Patterson Schmidt|Schmidt]], 1953}} <br/>(''ex errore'')
 |''Chelonia mydas carrinegra'' <br/>{{small|[[David K. Caldwell|Caldwell]], 1962}}
 |''Chelonia agazisii'' [sic] <br/>{{small|[[Jorge L. Tamayo|Tamayo]], 1962}} <br/>(''ex errore'')
 |''Testudo nigrita'' <br/>{{small|Tamayo, 1962}}
 |''Chelonia agassizi'' <br/>{{small|— Carr, 1967}}
 |''Chelonia mydus'' [sic] <br/>{{small|[[Wirot Nutaphand|Nutaphand]], 1979}} <br/>(''ex errore'')
 |''Chelonia mydas carinegra'' [sic] <br/>{{small|Nutaphand, 1979}} <br/>(''ex errore'')
 |''Testudo chloronotus'' [sic] <br/>{{small|H.M. Smith & [[Rozella Pearl Beverly Blood Smith|R.B. Smith]], 1980}} <br/>(''ex errore'')
 |''Chelone albiventer'' <br/>{{small|— Márquez, 1990}}
 |''Caretta thumbergii'' [sic] <br/>{{small|[[Ramesh Chandra Sharma|Sharma]], 1998}} <br/>(''ex errore'')
 |''Chelonia mydas viridis'' <br/>{{small|— [[S.A. Karl|Karl]] & [[B.W. Bowen|Bowen]], 1999}}
 }}
| synonyms_ref = <ref name="Fritz 2007">{{Cite journal|journal=Vertebrate Zoology |title=Checklist of Chelonians of the World |year=2007 |author=Fritz, Uwe |author2=Peter Havaš |volume=57 |issue=2 |pages=165–167 |doi=10.3897/vz.57.e30895 |s2cid=87809001 |doi-access=free }}</ref>
}}

The '''green sea turtle''' ('''''Chelonia mydas'''''), also known as the '''green turtle''', '''black (sea) turtle''' or '''Pacific green turtle''',<ref>Swash, A. & Still, R. (2005). Birds, Mammals, and Reptiles of the Galápagos Islands. Second Edition. Hampshire, UK:WildGuides Ltd. p.116.</ref> is a [[species]] of large [[sea turtle]] of the [[Family (biology)|family]] [[Cheloniidae]]. It is the only [[species]] in the [[genus]] '''''Chelonia'''''.<ref name="ITIS">{{ITIS |id=173833 |taxon=''Chelonia mydas'' |access-date=February 21, 2007}}</ref> Its range extends throughout [[tropical]] and [[subtropical]] seas around the world, with two distinct populations in the [[Atlantic Ocean|Atlantic]] and [[Pacific Ocean]]s, but it is also found in the [[Indian Ocean]].<ref name="NGeo">{{cite web|url=http://www3.nationalgeographic.com/animals/reptiles/green-turtle.html|title=Green Sea Turtle (''Chelonia mydas'')|date=December 29, 2005|publisher=National Geographic Society|work=National Geographic – Animals|access-date=February 21, 2007|archive-url=https://web.archive.org/web/20070205055313/http://www3.nationalgeographic.com/animals/reptiles/green-turtle.html|archive-date=2007-02-05|url-status=dead}}</ref><ref name=":4">{{Cite book|title=Turtles & Tortoises|last=Ferri|first=Vincenzo|publisher=Firefly Books|year=2002|isbn=978-1-55209-631-4|location=Buffalo, New York|url-access=registration|url=https://archive.org/details/tortoisesturtles0000ferr}}</ref> The common name refers to the usually green [[fat]] found beneath its [[carapace]], due to its diet strictly being seagrass,<ref>{{cite journal |last1=Howell |first1=Lyndsey N |last2=Shaver |first2=Donna J. |title=Foraging habits of green sea turtles (Chelonia mydas) in the northwestern Gulf of Mexico |journal=Frontiers in Marine Science |date=2021|volume=8 |doi=10.3389/fmars.2021.658368 |doi-access=free |bibcode=2021FrMaS...858368H }}</ref> not to the color of its carapace, which is olive to black.

The [[Dorsoventral#Dorsal and ventral|dorsoventrally]] flattened body of ''C. mydas'' is covered by a large, teardrop-shaped carapace; it has a pair of large, [[paddle]]-like [[flipper (anatomy)|flippers]]. It is usually lightly colored, although in the eastern Pacific populations, parts of the carapace can be almost black. Unlike other members of its family, such as the [[hawksbill sea turtle]], ''C. mydas'' is mostly [[herbivore|herbivorous]]. The adults usually inhabit shallow [[lagoon]]s, feeding mostly on various species of [[seagrass]]es.<ref name="WildlifeofPakistan"/>  The green sea turtle is the only aquatic turtle species which is herbivorous when fully grown.   

Like other sea turtles, green sea turtles [[Migration (ecology)|migrate]] long distances between feeding grounds and hatching beaches. Many islands worldwide are known as [[Turtle Island (disambiguation)|Turtle Island]] due to green sea turtles nesting on their beaches. Females crawl out on beaches, dig nests, and lay eggs during the night. Later, hatchlings emerge, and scramble into the water. Those that reach [[Sexual maturity|maturity]] may live to 90 years in the wild.<ref name="NGeo"/>

''C. mydas'' is listed as [[endangered species|endangered]] by the [[IUCN]] and [[CITES]] and is protected from exploitation in most countries.<ref>{{Cite web|url=https://www.bbc.co.uk/nature/life/Green_sea_turtle|title=Green sea turtle}}</ref> It is illegal to collect, harm, or kill them. In addition, many countries have laws and ordinances to protect nesting areas. However, turtles are still in danger due to human activity. In some countries, turtles and their eggs are still [[turtling (hunting)|hunted]] for food. [[Pollution]] indirectly harms turtles at both population and individual scales. Many turtles die after being [[bycatch|caught]] in fishing nets. In addition, real estate [[Urban development|development]] often causes [[habitat loss]] by eliminating nesting beaches.

==Taxonomy==
The green sea turtle is a member of the [[tribe (biology)|tribe]] [[Cheloniini]].<ref>{{cite journal |last1=Aplin |first1=K.P. |last2=Smith |first2=L.A. |date=2001 |title=Checklist of the frogs and reptiles of Western Australia |url=https://museum.wa.gov.au/sites/default/files/3.%20Aplin,%20Smith.pdf |journal=Records of the Western Australian Museum Supplement |volume=6 |issue=3 |pages= 51–74 |doi=10.18195/issn.0313-122x.63.2001.051-074 |access-date=November 10, 2022}}</ref> A 1993 study clarified the status of [[genus]] ''Chelonia'' with respect to the other marine turtles. The [[carnivorous]] ''[[Eretmochelys]]'' (hawksbill), ''[[Loggerhead sea turtle|Caretta]]'' (loggerhead) and ''[[Lepidochelys]]'' (ridley) were assigned to the tribe [[Carettini]]. [[Herbivorous]] ''Chelonia'' warranted their status as a [[genus]], while ''[[Natator]]'' (flatback) was further removed from the other genera than previously believed.<ref name="MolecularPhylogeny">{{cite journal |last1 =Bowen |first1 =Brian W. |first2 =William S.|last2=Nelson|first3=John C.|last3=Avise |title =A Molecular Phylogeny for Marine Turtles: Trait Mapping, Rate Assessment, and Conservation Relevance |journal =Proceedings of the National Academy of Sciences of the United States of America |volume =90 |issue =12 |pages =5574–5577 |date =June 15, 1993 |doi = 10.1073/pnas.90.12.5574|pmid =8516304 |pmc =46763 |bibcode =1993PNAS...90.5574B |doi-access =free }}</ref>

The species was originally described by [[Carl Linnaeus]] in his landmark 1758 [[10th edition of Systema Naturae|10th edition of ''Systema Naturae'']] as ''Testudo mydas''.<ref name="ITISTM">{{ITIS |id=208662 |taxon=''Testudo mydas'' |access-date=February 23, 2007}}</ref> In 1868, [[Marie Firmin Bocourt]] named a particular species of sea turtle ''Chelonia agassizii'',<ref>''Chelonia agassizi'' is a commonly cited misspelling of this taxon.</ref><ref name="ITISCA1">{{ITIS |id=655934 |taxon=''Chelonia agassizi'' |access-date=February 23, 2007}}</ref> in honor of Swiss-American zoologist [[Louis Agassiz]].<ref>[[Richard Allen "Bo" Crombet-Beolens|Beolens B]], [[Michael Watkins (zoologist)|Watkins M]], [[Michael Grayson|Grayson M]] (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins University Press. xiii + 296 pp. {{ISBN|978-1-4214-0135-5}}. (''Chelonia mydas agasizii'', p. 2).</ref> This "species" was referred to as the "black sea turtle".<ref name="ITISCA2">{{ITIS |id=202103 |taxon=''Chelonia agassizii'' |access-date=February 23, 2007}}</ref> Later research determined Bocourt's "black sea turtle" was not genetically distinct from ''C. mydas'', and thus [[Taxonomy (biology)|taxonomically]] not a separate species.<ref name="BlackTurtleTaxonomy">{{cite journal |last =Karl |first =Stephen H. |author2=Brian W. Bowen |title =Evolutionary Significant Units versus Geopolitical Taxonomy: Molecular Systematics of an Endangered Sea Turtle (genus ''Chelonia'') |journal =Conservation Biology |volume =13 |issue =5 |pages =990–999 |doi=10.1046/j.1523-1739.1999.97352.x|year =1999|bibcode =1999ConBi..13..990K |s2cid =85192260 }}<!-- |access-date = September 9, 2007 --></ref> These two "species" were then united as ''Chelonia mydas'' and populations were given subspecies status: ''C. mydas mydas'' referred to the originally described population, while ''[[Galápagos green turtle|C. mydas agassizi]]'' referred only to the Pacific population known as the Galápagos green turtle.<ref name="ITISCMA">{{ITIS |id=208663 |taxon=''Chelonia mydas agassizi'' |access-date=February 23, 2007}}</ref><ref name="ITISCMM">{{ITIS |id=173834 |taxon=''Chelonia mydas mydas'' |access-date=February 23, 2007}}</ref> This subdivision was later determined to be invalid and all species members were then designated ''Chelonia mydas''.<ref name="ITIS"/> The oft-mentioned name ''C. agassizi'' remains an invalid [[junior synonym]] of ''C. mydas''.

The species' [[common name]] does not derive from any particular [[green]] external coloration of the turtle. Its name comes from the greenish color of the turtles' fat, which is only found in a layer between their inner organs and their shell.<ref name="MCSgreen">{{cite web|title=green turtle |work=Marine Turtles |publisher=Marine Conservation Society |year=2007 |url=http://www.mcsuk.org/marineworld/turtles/green+turtle |access-date=August 30, 2007 |archive-url=https://web.archive.org/web/20070822011514/http://www.mcsuk.org/marineworld/turtles/green%2Bturtle |archive-date=August 22, 2007 |url-status=dead }}</ref> As a species found worldwide, the green turtle has many local names. In the [[Hawaiian language]] it is called ''honu'',<ref>{{Hawaiian Dictionaries|honu|id=D4147}}</ref><ref name="Glick2005Smithsonian"/> and it is locally known as a symbol of good luck and longevity.<ref>{{Cite book|last1=Balazs|first1= G.H.|last2= Southwest Fisheries Center (U.S.)|year=1980|title=Synopsis of Biological Data on the Green Turtle in the Hawaiian Islands|series=NOAA-TM-NMFS-SWFC|volume=7|location=Honolulu, Hawaii|publisher=U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service}}</ref>

<gallery mode="packed" heights="160">
File:Green Sea Turtle, Curaçao.jpg|Green sea turtle swimming over the sand plateau at playa Grandi, [[Curaçao]]
File:Female Green Sea Turtle.jpg|Female returning to the sea after nesting in [[Redang Island]], [[Malaysia]]
File:Young Honu-Kahala.png|alt=Photo of two swimming turtles|Immature [[Hawaii]]an ''C. mydas''
File:Hawaii turtle 2.JPG|alt=Photo of swimming turtle|Swimming in Hawaii
File:Green Sea Turtles, Chelonia mydas is getting back to the ocean leaving a track.jpg|alt=Photo of turtle walking on beach|Heading for the ocean on a beach at the [[Pu'uhonua o Honaunau National Historical Park]]
File:Green sea turtle near Marsa Alam.JPG|Green sea turtle near [[Marsa Alam]], [[Egypt]]
File:Green sea turtle portrait.JPG|Green sea turtle near [[Marsa Alam]], [[Egypt]]
File:Total internal reflection of Chelonia mydas .jpg|Green sea turtle
File:Green Turtle taking a breath.jpg|Coming up for a breath
File:Green Sea Turtle, Maui.jpg|A green sea turtle at [[Key West]], US
File:Chelonia mydas at Punta Sal, Tumbes, Peru.jpg|Green sea turtle, found at [[Punta Sal]], Peru
</gallery>

== Description ==
[[File:Chelonia.svg|thumb|Escalation of [[carapace]] and [[plastron]]|alt=Drawing of turtle carapace and plastron showing respectively, vertebral, costal, marginal, and supracaudal and intergular, gular, pectoral, abdominal, humeral, femoral, anal, axillary (anterior inframarginal), and inguinal (posterior inframarginal) shields]]
[[File:Taxidermy of turtle shell (Chelonia mydas).jpg|thumb|Taxidermied shell of ''Chelonia mydas'']]
Its appearance is that of a typical [[sea turtle]]. ''C. mydas'' has a dorsoventrally flattened body, a beaked head at the end of a short neck, and paddle-like arms well-adapted for swimming.<ref name="FWS">{{cite web|url=https://www.fws.gov/northflorida/SeaTurtles/Turtle%20Factsheets/green-sea-turtle.htm|title=Green sea turtle (''Chelonia mydas'')|date=December 29, 2005|publisher=United States Fish and Wildlife Service|work=North Florida Field Office|access-date=February 21, 2007|archive-date=June 29, 2017|archive-url=https://web.archive.org/web/20170629221452/https://www.fws.gov/northflorida//SeaTurtles/Turtle%20Factsheets/green-sea-turtle.htm|url-status=dead}}</ref> Adult green turtles grow to {{convert|1.5|m|ft|0}} long.<ref name="Animal">{{cite book|title=Animal|last=Kindersley|first=Dorling|publisher=DK Publishing|year=2005|isbn=978-0-7894-7764-4|location=New York City}}</ref> The average weight of mature individuals is {{convert|68|-|190|kg|lb|abbr=on}} and the average carapace length is {{convert|78|-|112|cm|in|abbr=on}}.<ref>{{Cite web |url=http://www.seaworld.org/animal-info/info-books/sea-turtle/physical-characteristics.htm |title=SEA TURTLES - Physical Characteristics |access-date=2012-04-03 |archive-url=https://web.archive.org/web/20130728212355/http://www.seaworld.org/animal-info/info-books/sea-turtle/physical-characteristics.htm |archive-date=2013-07-28 |url-status=dead }}</ref> They are considered the second largest sea turtle in the United States, after the leatherback sea turtle.<ref>{{cite journal |last1=Sonmez |first1=Bektas |title="Morphological variations in the green turtle (Chelonia mydas): A field study on an eastern Mediterranean nesting population" |journal=Zoological Studies |date=2019|volume=58 |issue=58 |pages=e16 |doi=10.6620/ZS.2019.58-16 |pmid=31966317 |pmc=6875684 }}</ref>
Exceptional specimens can weigh {{convert|315|kg|lb|abbr=on}} or even more, with the largest known ''C. mydas'' having weighed {{convert|395|kg|lb|abbr=on}} and measured {{convert|153|cm|in|abbr=on}} in carapace length.<ref name="CCC">{{cite web|url=http://www.cccturtle.org/green.htm|title=Species Fact Sheet: Green Sea Turtle|date=December 29, 2005|publisher=Caribbean Conservation Corporation|work=Caribbean Conservation Corporation & Sea Turtle Survival League|access-date=February 22, 2007|url-status=dead|archive-url=https://web.archive.org/web/20070224150825/http://www.cccturtle.org/green.htm|archive-date=February 24, 2007}}</ref>

Anatomically, a few characteristics distinguish the green turtle from the other members of its family. Unlike its close relative the [[hawksbill turtle]], the green turtle's snout is very short and its [[beak]] is unhooked. The neck cannot be pulled into the shell.<ref>{{Cite web|url=http://animals.nationalgeographic.com/animals/reptiles/green-turtle/|archive-url=https://web.archive.org/web/20100123163239/http://animals.nationalgeographic.com/animals/reptiles/green-turtle|url-status=dead|archive-date=January 23, 2010|title=National Geographic|date=11 April 2010|website=Green Sea Turtle}}</ref> The sheath of the turtle's upper jaw possesses a denticulated edge, while its lower jaw has stronger, serrated, more defined denticulation. The dorsal surface of the turtle's head has a single pair of prefrontal scales. Its carapace is composed of five central [[scute]]s flanked by four pairs of lateral scutes. Underneath, the green turtle has four pairs of inframarginal scutes covering the area between the turtle's [[plastron]] and its shell. Mature ''C. mydas'' front appendages have only a single claw (as opposed to the hawksbill two), although a second claw is sometimes prominent in young specimens.<ref name="MarBioCmydas">{{cite web|url=http://marinebio.org/species.asp?id=51|title=Green Sea Turtle|date=May 21, 2007|publisher=MarineBio.org|access-date=September 2, 2007}}</ref>

The [[carapace]] of the turtle has various color patterns that change over time. Hatchlings of ''Chelonia mydas'', like those of other marine turtles, have mostly black carapaces and light-colored plastrons. Carapaces of juveniles turn dark brown to olive, while those of mature adults are either entirely brown, spotted or marbled with variegated rays. Underneath, the turtle's plastron is hued yellow. ''C. mydas'' limbs are dark-colored and lined with yellow, and are usually marked with a large dark brown spot in the center of each appendage.<ref name="NGeo" /><ref name="FaunaBritIndia">{{cite book|url=https://archive.org/details/in.ernet.dli.2015.207330 |title=The Fauna of British India, Including Ceylon and Burma: Reptilia and Batrachia |last=Boulenger|first=G. A.|publisher=Taylor & Francis|year=1890|isbn=978-0-548-96848-2|location=London|pages=[https://archive.org/details/in.ernet.dli.2015.207330/page/n561 541]}}</ref>

==Distribution==
[[File:Green turtle nesting sites.svg|thumb|Green sea turtle nesting populations (contradicted in article)]]
The [[Range (biology)|range]] of the green sea turtle extends throughout [[tropical]] and [[subtropical]] oceans worldwide. The two major [[subpopulation]]s are the Atlantic and the eastern Pacific subpopulations. Each <!--sub?-->population is genetically distinct, with its own set of nesting and feeding grounds within the population's known range.<ref name="NGeo"/> One of the genetic differences between the two subpopulations is the type of mitochondrial DNA found in individual's cells. Individuals from rookeries in the Atlantic Ocean and Mediterranean Sea have a similar type of mitochondrial DNA, and individuals from the Pacific and Indian Oceans have another type of mitochondrial DNA.<ref>Bowen, B.W., Meylan, A.B.; Ross, J.P.; Limpus, C.J.; Balazs, G.H.; Avise, J.C.. (1992) Global population structure and natural history of the green turtle (''Chelonia mydas'') in terms of matriarchal phylogeny. Evolution. International Journal of Organic Evolution. Vol. 46, No 4, pp. 865–881</ref> Their native range includes tropical to subtropical waters along continental coasts and islands between 30°N and 30°S. Since green sea turtles are a migrating species, their global distribution spans into the open ocean. The differences in mitochondrial DNA more than likely stems from the populations being isolated from each other by the southern tips of both South America and Africa with no warm waters for the green sea turtles to migrate through. The green sea turtle is estimated to inhabit coastal areas of more than 140 countries, with nesting sites in over 80 countries worldwide throughout the year. In the United States Atlantic coast, green sea turtles can be found from Texas and north to Massachusetts. In the United States Pacific coast, they have been found from southern California north to the southernmost tip of Alaska. The largest populations of green sea turtles within the United States coastline are in the Hawaiian Islands and [[Florida]]. Globally, the largest populations of sea turtles are in the [[Great Barrier Reef]] in Australia, and the [[Caribbean Sea]].<ref name=":2" />

===Atlantic subpopulation===
The green sea turtle can generally be found throughout the [[Atlantic Ocean]]. Although the species is most abundant in tropical climates, green sea turtles can also be found in [[temperate climate]]s, and individuals have been spotted as far north as [[Canada]] in the western Atlantic, and the [[Jutland|Cimbrian peninsula]] in the east. The subpopulation's southern range is known until past the southern tip of Africa in the east and [[Argentina]] in the western Atlantic. The major nesting sites can be found on various islands in the [[Caribbean]], along the Atlantic coast of [[Florida]] in the United States, the eastern coast of the [[South America|South American continent]] and most notably, on isolated [[North Atlantic]] islands.

In the Caribbean, major nesting sites have been identified on [[Aves Island]], the [[United States Virgin Islands|U.S. Virgin Islands]], [[Puerto Rico]], the [[Dominican Republic]], and [[Costa Rica]]. In recent years, there are signs of increased nesting in the Cayman Islands.<ref>{{cite news|last=Connolly|first=Norma|title=More turtles nesting in Cayman|url=http://www.compasscayman.com/caycompass/2011/06/02/More-turtles-nesting-in-Cayman/|newspaper=Caymanian Compass|date=June 2, 2011|quote=(Quoted Ebanks-Petrie, Gina and Blumenthal, Janice of the Department of the Environment, Cayman Islands)|access-date=April 9, 2012|archive-date=September 23, 2015|archive-url=https://web.archive.org/web/20150923205749/http://www.compasscayman.com/caycompass/2011/06/02/More-turtles-nesting-in-Cayman/|url-status=dead}}</ref> One of the region's most important nesting grounds is in [[Tortuguero Conservation Area|Tortuguero]] in Costa Rica.<ref name="Bjorndal1999CostaRica">{{cite journal |last =Bjorndal |first =Karen A. |author2=Jerry A. Wetherall |author3=Alan B. Bolten |author4=Jeanne A. Mortimer |title =Twenty-Six Years of Green Turtle Nesting at Tortuguero, Costa Rica: An Encouraging Trend |journal =Conservation Biology |volume =13 |issue =1 |pages =126–134 |date=February 1999 |doi =10.1046/j.1523-1739.1999.97329.x |bibcode =1999ConBi..13..126B |s2cid =86436582 }}</ref> In fact, the majority of the Caribbean region's ''C. mydas'' population hails from a few beaches in Tortuguero.<ref name="Lahanas1998">{{cite journal |last =Lahanas |first =P. N. |author2 =K. A. Bjorndal |author3 =A. B. Bolten |author4 =S. E. Encalada |author5 =M. M. Miyamoto |author6 =R. A. Valverde |author7 =B. W. Bowen |title =Genetic composition of a green turtle (''Chelonia mydas'') feeding ground population: evidence for multiple origins |journal =Marine Biology |volume =130 |issue =3 |pages =345–352 |year =1998 |url =http://accstr.ufl.edu/publications/Lahanas_et_al_1998_MarBiol.pdf |doi =10.1007/s002270050254 |bibcode =1998MarBi.130..345L |s2cid =30428806 |access-date =September 1, 2007 |url-status =dead |archive-url =https://web.archive.org/web/20070927092625/http://accstr.ufl.edu/publications/Lahanas_et_al_1998_MarBiol.pdf |archive-date =September 27, 2007 }}</ref> Within United States waters, minor nesting sites have been noted in the states of [[Georgia (U.S. state)|Georgia]], [[North Carolina]], and [[South Carolina]]. [[Florida]]'s east coast is the largest nesting site in the United States. [[Hutchinson Island, Florida|Hutchinson Island]] in particular is a major nesting area in Florida waters. Florida has several annual nesting periods when local beaches are closed or cordoned off to protect nesting sites. According to Green Sea Turtle Watch, in 2015 more than 37,000 green sea turtle nests were documented in Florida, a record number. In addition to sporadic distribution of nesting sites, feeding grounds are much more widely distributed throughout [[Florida]]. Important feeding grounds in [[Florida]] include [[Indian River Lagoon]], the [[Florida Keys]], [[Florida Bay]], [[Homosassa]], [[Crystal River (Florida)|Crystal River]], and [[Cedar Key]].<ref name="FWS"/><ref name="Audubon1897">{{cite book |last =Audubon |first =Maria R. |title =Audubon and His Journals: Dover Publications Reprint |publisher =Scribner's Sons |date =1986 |location =New York |pages = 373–375 |isbn = 978-0-486-25144-8}}</ref>

Notable locations in South America include secluded beaches in [[Suriname]] and [[French Guiana]].<ref name="Girondot1996">{{cite journal |last =Girondot |first =Marc |author2 =Jacques Fretey |title =Leatherback Turtles, ''Dermochelys coriacea'', Nesting in French Guiana, 1978–1995 |journal =[[Chelonian Conservation and Biology]] |volume =2 |pages =204–208 |year =1996 |url =http://www.ese.u-psud.fr/epc/conservation/Publi/texte/AE_CCB96.html |access-date =September 14, 2007 |archive-url =https://web.archive.org/web/20110721023118/http://www.ese.u-psud.fr/epc/conservation/Publi/texte/AE_CCB96.html |archive-date =July 21, 2011 |url-status =dead }}</ref> In the Southern Atlantic Ocean, the most notable nesting grounds for ''Chelonia mydas'' are found on the island of [[Ascension Island|Ascension]],<ref name="FWS"/> hosts 6,000–13,000 turtle nests.<ref name="Seminoff2002IUCN">{{cite book |last =Seminoff |first =Jeffrey A. |author-link =Marine Turtle Specialist Group |title =IUCN 2002 Red List Global Status Assessment: Green Turtle (''Chelonia mydas'') |publisher =of the World Conservation Union (IUCN) |year =2002 |url =http://www.seaturtle.org/PDF/Seminoff_2002_IUCNList.pdf |archive-url =https://wayback.archive-it.org/0/20081217092843/http://www.seaturtle.org/PDF/Seminoff_2002_IUCNList.pdf |url-status =dead |archive-date =2008-12-17 |page =93 }}</ref><ref name="Godley2001">{{cite journal |last =Godley |first =Brendan J. |author2=Annette C. Broderick |author3=[[Graeme Hays|Graeme C. Hays]] |title =Nesting of green turtles (''Chelonia mydas'') at Ascension Island, South Atlantic |journal =Biological Conservation |volume =97 |issue=2 |pages =151–158 |date=February 2001 |doi =10.1016/S0006-3207(00)00107-5|bibcode =2001BCons..97..151G }}</ref><ref name="Broderick2001">{{cite conference |last =Broderick |first =Annette C. |author2=Brendan J. Godley |author3=[[Graeme Hays|Graeme C. Hays]] |title =Monitoring and conservation of marine turtles of Ascension Island: a sustainable resource |book-title =Interim Report to Foreign and Commonwealth Office Environment Fund for the Overseas Territories |page =13 |year =2001 }}</ref>

===Indo-Pacific subpopulation===
[[File:Chelonia mydas is going for the air edit.jpg|thumb|About to break the surface for air at [[Kona District, Hawaii|Kona]], [[Hawaii]]|alt=Photo of turtle swimming towards surface with diver in background]]
In the [[Pacific Ocean|Pacific]], its range reaches as far north as the southern coast of [[Alaska]] and as far south as [[Chile]] in the east. The turtle's distribution in the western Pacific reaches north to [[Japan]] and southern parts of [[Russia]]'s Pacific coast, and as far south as the northern tip of [[New Zealand]] and a few islands south of [[Tasmania]]. Significant nesting grounds are scattered throughout the entire Pacific region, including [[Mexico]], the [[Hawaiian Islands]], the [[Oceania|South Pacific]], the northern coast of [[Australia]], and [[Southeast Asia]]. Major Indian Ocean nesting colonies include [[India]], [[Pakistan]], [[Sri Lanka]] and other coastal countries.<ref name="CCCDistMap"/>

The turtles can also be found throughout the [[Indian Ocean]]; the east coast of the [[Africa|African continent]] hosts a few nesting grounds, including islands in the waters around [[Madagascar]].<ref name="CCCDistMap">{{cite map |publisher =Caribbean Conservation Corporation |title =Green turtle nesting sites |url =http://www.cccturtle.org/sea-turtle-information.php?page=green |year =1961 |cartography =Center for Marine Conservation |access-date =August 31, 2007 |url-status =dead |archive-url =https://web.archive.org/web/20070928221334/http://www.cccturtle.org/sea-turtle-information.php?page=green |archive-date =September 28, 2007 }}</ref>

====Specific nesting grounds====
[[File:Karettschildkroete 01.jpg|thumb|left|Photo of swimming turtle at twilight in a  coral reef near [[Mexico]]]]
Nesting grounds are found all along the Mexican coast. These turtles feed in seagrass pastures in the [[Gulf of California]].<ref name="Seminoff2002">{{cite journal |last =Seminoff |first =Jeffrey A. |author2=Javier Alvarado |author3=Carlos Delgado |author4=Jose Luis Lopez |author5=Gabriel Hoeffer |title =First Direct Evidence of Migration by an East Pacific Green Seaturtle from Michoacan, Mexico to a Feeding Ground on the Sonoran Coast of the Gulf of California |journal =The Southwestern Naturalist |volume = 47 |issue = 2 |pages =314–316 |date=June 2002 |jstor = 3672922 |doi =10.2307/3672922|bibcode =2002SWNat..47..314S }}</ref> Green turtles belonging to the distinct Hawaiian subpopulation nest at the protected [[French Frigate Shoals]] some {{convert|800|km|mi|sp=us}} west of the Hawaiian Islands.<ref name="Glick2005Smithsonian">{{cite journal |last =Glick |first =Daniel |title =Back from the Brink |journal =Smithsonian Magazine |pages =54–55 |date=September 2005 |url=http://www.smithsonianmag.com/issues/2005/september/brink.php?page=1 |access-date = August 31, 2007}}</ref>

In the [[Philippines]], green turtles nest in the [[Turtle Islands, Tawi-Tawi|Turtle Islands]] along with closely related [[hawksbill turtle]]s.<ref name="OneOcean">{{cite web |title =Ocean Ambassadors – Philippine Turtle Islands |work =Coastal Resource & Fisheries Management of the Philippines |publisher =OneOcean.org |url =http://www.oneocean.org/ambassadors/track_a_turtle/tihpa/pti.html |access-date = February 6, 2007 }}</ref> 
In December 2007, fishermen using a ''hulbot-hulbot'' (a type of [[fish net]]) accidentally caught an {{convert|80|kg|lb|abbr=on}}, {{convert|93|cm|in|abbr=on}} long and {{convert|82|cm|in|abbr=on}} wide turtle off Barangay Bolong, [[Zamboanga City]], [[Philippines]]. December is breeding season near the Bolong beach.<ref>
[https://archive.today/20070709212017/http://www.abs-cbnnews.com/storypage.aspx?StoryId=103926 Abs-Cbn Interactive, Green sea turtle caught in Zamboanga].</ref>

An annual presence is recorded in the Gulf of Panama, on the Isla Parida island. Local activists also moving some turtle nests to the coast, in the vicinity of the small town of Malena, to save and increase the turtle population in the safe place.<ref>{{cite web|url=https://panamawildlife.org/sea-turtles/|title=Helping the Green Turtles in Panama|publisher=Panama Wildlife Conservation|access-date=2024-09-20}}</ref>

[[Indonesia]] has a few nesting beaches, one in the [[Meru Betiri]] National Reserve in [[East Java]].<ref name="WWFIndonesianCon">{{cite book |title =Indonesian Sea Turtle Conservation |publisher =World Wide Fund for Nature, Indonesia |location =Yayasan, Indonesia |url =http://assets.panda.org/downloads/brochureturtlecop7indonesiacbd.pdf |access-date=September 16, 2007 |page =4}}</ref>

Off the north-eastern and northern coasts of Australia, the [[Great Barrier Reef]] has two [[Population genetics|genetically distinct populations]]; one north and one south. Within the reef, 20 separate locations consisting of small islands and [[cays]] were identified as nesting sites for either population of ''C. mydas''. Of these, the most important is on [[Raine Island]].<ref name="Dobbs2007">{{cite book|last=Dobbs |first=Kirstin |title=Marine turtle and dugong habitats in the Great Barrier Reef Marine Park used to implement biophysical operational principles for the Representative Areas Program |publisher=Great Barrier Marine Park Authority |year=2007 |url=http://www.gbrmpa.gov.au/__data/assets/pdf_file/0007/18799/rap_turtle_and_dugong_bop.pdf |isbn=978-1-876945-58-9 |url-status=dead |archive-url=https://web.archive.org/web/20110718154323/http://www.gbrmpa.gov.au/__data/assets/pdf_file/0007/18799/rap_turtle_and_dugong_bop.pdf |archive-date=2011-07-18 }}</ref><ref name="Tucker2001">{{cite journal |last =Tucker |first =Anton D. |author2=Mark A. Read |title =Frequency of Foraging by Gravid Green Turtles (''Chelonia mydas'') at Raine Island, Great Barrier Reef |journal =Journal of Herpetology |volume = 35 |issue = 3 |pages =500–503 |date=September 2001 |jstor = 1565970 |doi =10.2307/1565970}}</ref> In the [[Torres Strait]] there is a large rookery on [[Bramble Cay]].<ref name=dawe>{{cite web | title=Melomys rubicola - Bramble Cay Melomys | website=Department of Agriculture, Water and the Environment, Australian Government | date=22 August 2021 | url=http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=64477 | access-date=22 August 2021}}</ref><ref name="Ellison">{{cite journal |title=Natural History of Bramble Cay, Torres Strait |journal=Atoll Research Bulletin |year=1998 |last=Ellison |first=Joanna |volume=455 |pages=1–31 |doi=10.5479/si.00775630.455.1 |url=http://stevespages.org.uk/melomys/docs/ellison-natural-1998.pdf |access-date=2019-03-02 }}</ref> The [[Coral Sea]] has nesting areas of world significance.<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>

Major nesting sites are common on either side of the [[Arabian Sea]], both in [[Ash Sharqiyah Region (Oman)|Ash Sharqiyah]], [[Oman]], and along the coast of [[Karachi]], [[Pakistan]]. Some specific beaches there, such as [[Hawke's Bay (Karachi)|Hawke's Bay]] and [[Sandspit Beach|Sandspit]], are common to both ''C. mydas'' and [[Olive ridley sea turtle|''L. olivacea'']] subpopulation. Sandy beaches along [[Sindh]] and [[Balochistan (Pakistan)|Balochistan]] are nesting sites. Some {{convert|25|km|mi|sp=us}} off the [[Geography of Pakistan|Pakistani coast]], [[Astola|Astola island]] is another nesting beach.<ref name="WildlifeofPakistan">{{cite web |title = Green Sea Turtle – ''Chelonia mydas japonica'' |work =Turtles of Pakistan |publisher =Wildlife of Pakistan |year =2003 |url= http://www.wildlifeofpakistan.com/ReptilesofPakistan/greenseaturtle.htm |access-date = February 21, 2007 }}</ref><ref name="Butler1977">{{cite journal |last =Butler |first =E. |author2=A. Astola |title =A summer cruise in the Gulf of Oman |journal =Stray Feathers |volume =5 |pages =283–304 |year =1877 }}</ref><ref name="MTNGroombridge">{{cite journal |last =Groombridge |first =Brian |author-link =Brian Groombridge |author2=Aban Marker Kabraji |author3=Abdul Latif Rao |title =Marine Turtles in Baluchistan (Pakistan) |journal =Marine Turtle Newsletter |volume =42 |pages =1–3 |year =1988 |url =http://www.seaturtle.org/mtn/archives/mtn42/mtn42p1.shtml |access-date = August 30, 2007 }}</ref>

====Galápagos green turtle ====
[[File:Green Sea Turtle Swimming in the Galápagos.jpg|thumb|Green Sea Turtle Swimming in the Galápagos]]
The population that has often been known as the Galápagos green turtle have been recorded and observed in the Galápagos as far back as the 17th century by [[William Dampier]].<ref name="green_1993">{{cite journal|last=Green|first=Derek|year=1993|title=Growth Rates of Wild Immature Green Turtles in the Galápagos Islands, Ecuador|journal=Journal of Herpetology|volume=27|issue=3|pages=338–341|doi=10.2307/1565159|jstor=1565159}}</ref> Not much attention has been paid to them due to the overwhelming research done on the [[Galápagos giant tortoise]]s.<ref name="pritchard_1971">{{cite journal|last=Pritchard|first=Peter C|year=1971|title=Galápagos Sea Turtles – Preliminary Findings|journal=Journal of Herpetology|volume=5|issue=1/2|pages=1–9|doi=10.2307/1562836|jstor=1562836}}</ref> Only over the last 30 years have extensive studies been performed covering the behaviors of the Galápagos green turtles. Much of the debate that has surrounded them recently is over the binomial classification of the species.<ref name="parham_1996">{{cite journal|last1=Parham|first1=J. F.|first2=G. R.|last2=Zug|year=1996|url=http://www.seaturtle.org/mtn/archives/mtn72/mtn72p2b.shtml|title=''Chelonia agassizii'' – Valid Or Not?|journal=Marine Turtle Newsletter|volume=72|pages=2–5}}</ref> At one point the name ''Chelonia agassizii'' was applied to this population as a separate species.<ref name="BlackTurtleTaxonomy"/> Analysis of [[Mitochondrial DNA|mitochondrial]] and [[nuclear DNA]] of 15&nbsp;nesting beaches,<ref name="parham_1996"/> however, has demonstrated that there is not only no significant distinction of this population but that it would be paraphyletic to recognise it. As such the species name ''Chelonia agassizzii'' is considered a junior synonym of ''Chelonia mydas'' <ref name="parham_1996"/> as such it is considered as a local variant of the populations of the East Pacific waters and those of other nesting areas.<ref name="parham_1996"/>

The morphological distinctiveness of the Galápagos green turtle has given rise to the debate,<ref name="BlackTurtleTaxonomy"/> but evidence of taxonomic distinctiveness is best served using the combination of multiple datasets. The two most notable morphological distinctions are the considerably smaller adult size and the much darker pigmentation of the carapace, plastron, and extremities.<ref name="BlackTurtleTaxonomy"/> Other distinctions are the curving of the carapace above each hind flipper, the more dome-shaped carapace, and the very long tail of adult males.<ref name="pritchard_1999">{{cite journal|last=Pritchard|first=Peter C. H.|year=1999|title=Status of the black sea turtle|journal=Conservation Biology|volume=13|issue=5|pages=1000–1003|doi=10.1046/j.1523-1739.1999.98432.x|bibcode=1999ConBi..13.1000P |s2cid=84867842}}</ref> 
Three possibilities have arisen from their unique characteristics: ''agassizii'' is a separate species from ''C. mydas'', it is a subspecies of green sea turtle, or it is simply a color mutation.<ref name="pritchard_1999"/> These facts have led to the debate over binomial separation however due to the significance of the DNA testing results there have been no distinctions made at this time.<ref name="parham_1996"/> At a meeting for sea turtle scientists and their collaborators in 2000, the evidence for the taxonomic position of the Galápagos green turtle was reviewed and a majority among the participants supported treating it as a population or subspecies of the green turtle (instead of a separate species).<ref>{{cite journal|author1=Bowen, B. W.|author2=Karl, S. A.|title=Status of the East Pacific Green Turtle (''Chelonia agassizii'')|url=http://www.seaturtle.org/mtn/archives/mtn89/mtn89p20.shtml|journal=Marine Turtle Newsletter|volume=89|pages=20–22}}</ref> However, this is possibly a case of political taxonomy. As such the three major international checklists that cover turtles of the world [[Reptile Database]]<ref>{{BioRef|reptileDB |genus=Chelonia|species=mydas|access-date=9 October 2019}}</ref> the checklist of Fritz and Havas (2007)<ref name="Fritz 2007" /> and the IUCN Checklist (TTWG 2017)<ref name=Rhodin2017>{{Cite book | author=Rhodin, A.G.J. | author2=Iverson, J.B. | author3=Bour, R. Fritz | author4= Georges, U. | author5= Shaffer, H.B. | author6=van Dijk, P.P. | name-list-style=amp | year=2017 | title=Turtles of the World: Annotated Checklist and Atlas of Taxonomy, Synonymy, Distribution, and Conservation Status | editor=Rhodin, A.G.J. | editor2=Iverson, J.B. | editor3=van Dijk, P.P. | editor4=Saumure, R.A. | editor5=Buhlmann, K.A. | editor6=Pritchard, P.C.H. | editor7=Mittermeier, R.A. | series=Conservation Biology of Freshwater Turtles and Tortoises: A Compilation Project of the IUCN/SSC Tortoise and Freshwater Turtle Specialist Group | edition=8th | journal=Chelonian Research Monographs | volume=7 | pages=1–292 | doi=10.3854/crm.7.checklist.atlas.v8.2017| isbn=9781532350269 }}</ref> all consider this a junior synonym.

== Habitat ==
[[File:Green turtle Chelonia mydas is basking on Punaluu Beach Big Island of Hawaii.jpg|thumb|Green sea turtle on [[Punaluu Beach|Punaluu black sand beach]] of Big Island, Hawaii.]]
Green sea turtles move across three [[habitat]] types, depending on their [[Biological life cycle|life stage]]. They lay eggs on beaches. Mature turtles spend most of their time in shallow, coastal waters with lush seagrass beds. Adults frequent inshore bays, lagoons, and shoals with lush [[seagrass meadow]]s. Entire generations often migrate between one pair of feeding and nesting areas.<ref name="FWS" /> Green sea turtles, ''Chelonia mydas'', are classified as an aquatic species and are distributed around the globe in warm tropical to subtropical waters. The environmental parameter that limits the distribution of the turtles is ocean temperatures below 7 to 10 degrees Celsius.<ref name=":3" /> Within their geographical range, the green sea turtles generally stay near continental and island coastlines. Near the coastlines, the green sea turtles live within shallow bays and protected shores. In these protected shores and bays, the green sea turtle habitats include coral reefs, salt marshes, and nearshore seagrass beds. The coral reefs provide red, brown, and green algae for their diet and give protection from predators and rough storms within the ocean. The salt marshes and seagrass beds contain seaweed and grass vegetation, allowing ample habitat for the sea turtles.<ref name=":2" />

Turtles spend most of their first five years in convergence zones within the bare open ocean that surround them.<ref name="WildlifeofPakistan" /><ref name="NOAAGT">{{cite web |title =Green Turtle, ''Chelonia mydas'' |work =Fisheries: Office of Protected Resources |publisher =U. S. National Oceanographic Atmospheric Administration |year =2007 |url =http://www.nmfs.noaa.gov/pr/species/turtles/green.htm |access-date = September 2, 2007 }}</ref> These young turtles are rarely seen as they swim in deep, [[pelagic]] waters.<ref name="Reich2007">{{cite journal|last=Reich |first=Kimberly J. |author2=Karen A. Bjorndal |author3=Alan B. Bolten |title=The 'lost years' of green turtles: using stable isotopes to study cryptic lifestages |journal=Biology Letters |volume=3 |issue=6 |pages=712–4 |date=September 18, 2007 |doi=10.1098/rsbl.2007.0394 |pmid=17878144 |pmc=2391226 }}</ref><ref name="LS20070918">{{cite news |last =Brynner |first =Jeanna |title =Sea Turtles' Mystery Hideout Revealed |work =LiveScience |publisher =Imaginova Corp. |date =September 19, 2007 |url = http://www.livescience.com/animals/070919_sea_turtle.html |access-date =September 20, 2007}}</ref> Green sea turtles typically swim at {{convert|2.5|-|3|km/h|abbr=on}}.<ref>P. Luschi, [[Graeme Hays|G. C. Hays]], C. Del Seppia, R. Marsh, and F. Papi. (1998) The navigational feats of green sea turtles
migrating from Ascension Island investigated by satellite telemetry. ''Proc. R. Soc. Lond. B''.</ref>

==Ecology and behavior==
[[File:Green turtle in Kona 2008.jpg|thumb|left|Swimming, Hawaii|alt=Turtle swimming toward surface]]
As one of the first sea turtle species studied, much of what is known of sea turtle ecology comes from studies of green turtles. The ecology of ''C. mydas'' changes drastically with each stage of its life history. Newly emerged hatchlings are [[carnivorous]], [[pelagic]] organisms, part of the open ocean mini[[nekton]]. In contrast, immature juveniles and adults are commonly found in [[seagrass]] meadows closer inshore as [[herbivorous]] grazers.

===Diet===
[[File:Green Sea Turtle grazing seagrass.jpg|thumb|Green sea turtle grazing on seagrass]] The diet of green turtles changes with age.<ref name=":1">{{Cite journal|url = http://researchonline.jcu.edu.au/19395/1/19395_Arthur_et_al_2008.pdf|title = Ontogenetic Changes in Diet and Habitat Use in Green Sea Turtle (''Chelonia mydas'') Life History|last1 = Arthur|first1 = Karen|date = June 30, 2008|journal = Mar Ecol Prog Ser|doi = 10.3354/meps07440|access-date = Dec 20, 2015|last2 = Boyle|first2 = Michelle|last3 = Limpus|first3 = Colin|volume=362|pages=303–311|bibcode = 2008MEPS..362..303A|doi-access = free}}</ref> Juveniles are carnivorous, but as they mature they become omnivorous.<ref name=":5">{{Cite book|title=On the Trail of Sea Turtles|last=Devaux|first=Bernard|publisher=Barron's Nature Travel Guides|year=2000|isbn=978-0-7641-1162-4|location=Paris, France|url-access=registration|url=https://archive.org/details/ontrailofseaturt00deva}}</ref> Young sea turtles eat [[fish]] and their [[egg]]s, [[Aplysia|sea hare]] eggs, [[hydrozoan]]s, [[bryozoan]]s, [[molluscs]], [[jellyfish]], small [[invertebrates]], [[echinoderm]]s, [[tunicate]]s, [[insect]]s, [[worm]]s, [[sponge]]s, [[algae]], [[Seagrass|sea grass]]es, [[leaves]], tree [[Bark (botany)|bark]], and [[crustacean]]s.<ref>{{Cite book|title=On the Trail of Sea Turtles|last=Devaux|first=Bernard|publisher=Barron's Nature Travel Guides|year=2000|isbn=978-0-7641-1162-4|url-access=registration|url=https://archive.org/details/ontrailofseaturt00deva}}</ref><ref name="auto">{{cite web | url=https://animaldiversity.org/accounts/Chelonia_mydas/ | title=Chelonia mydas (Green Turtle) | website=[[Animal Diversity Web]] }}</ref><ref name=":2" /><ref>{{Cite web|url=https://www.reptilesofecuador.com/chelonia_mydas.html|title=Green Sea Turtle (Chelonia mydas)|website=www.reptilesofecuador.com}}</ref> Green sea turtles have a relatively slow growth rate because of the low nutritional value of their diet. [[Body fat]] turns green because of the consumed [[vegetation]].<ref name=":5" /> This diet shift has an effect on the green turtle's skull morphology.<ref>http://www.nwf.org/wildlife/wildlife-library/amphibians-reptiles-and-fish/sea-turtles/green-sea-turtle.aspxNishizawa{{Dead link|date=June 2024 |bot=InternetArchiveBot |fix-attempted=yes }}, H., M. Asahara, N. Kamezaki, and N. Arai. 2010. Differences in the skull morphology between juvenile and adult green turtles: implications for the ontogenetic diet shift. Current Herpetology 29(2): 97–101. [http://www.bioone.org/doi/abs/10.3105/018.029.0205?journalCode=jche]</ref> Their serrated jaw helps them chew green and red algae (such as filamentous red alga (''[[Bostrychia (alga)|Bostrychia]]''), red moss (''Caloglossa''), freshwater red algae (''[[Compsopogon]]''), lobster horns (''[[Polysiphonia]]''), sea lettuce (''[[Ulva lactuca]]''), green seaweed (''[[Gayralia]]''), and crinkle grass (''[[Rhizoclonium]]'')) and sea grasses.<ref name="auto"/><ref>{{Cite web|url=https://www.nwf.org/Wildlife/Wildlife-Library/Amphibians-Reptiles-and-Fish/Sea-Turtles/Green-Sea-Turtle.aspx|title=Green Sea Turtle|website=National Wildlife Federation}}</ref> They also consume large quantities of wetland plants such as ''[[Avicennia]] schaueriana'' and ''[[Sporobolus alterniflorus]]'', which are commonly found in salt marshes.<ref name="auto"/> Most adult sea turtles are strictly herbivorous.<ref name=":5" />

===Predators and parasites===
Only some human beings and the larger [[shark]]s feed on ''C. mydas'' adults. Specifically, [[tiger shark]]s (''Galeocerdo cuvier'') hunt adults in Hawaiian waters.<ref name="MWANWR">{{cite web |title =Hawaiian Green Sea Turtle |publisher =Midway Atoll National Wildlife Refuge |date =September 5, 2002 |url =http://www.fws.gov/midway/wildlife/turtle.html |access-date = September 2, 2007 |archive-url = https://web.archive.org/web/20070816031529/http://www.fws.gov/midway/wildlife/turtle.html <!-- Bot retrieved archive --> |archive-date = August 16, 2007}}</ref> The tiger shark is the main predator of the green turtle as it will prey on green turtles of all sizes. The tiger shark has often been seen feeding on green turtles near their nesting beaches because they are restricted in the area of their nesting beaches and vulnerable to predation.<ref>{{cite journal |last1=Fitzpatrick |first1=Richard |last2=Thums |first2=Michele |last3=Bell |first3=Ian |last4=Meekan |first4=Mark |last5=Stevens |first5=John |last6=Barnett |first6=Adam |title=A Comparison of the Seasonal Movements of Tiger Sharks and Green Turtles Provides Insight into Their Predator-Prey Relationship |journal=PLOS ONE |year=2012 |volume=7 |issue=12 |pages=e51927 |doi=10.1371/journal.pone.0051927 |pmid=23284819 |pmc=3526478 |bibcode=2012PLoSO...751927F |doi-access=free }}</ref> Juveniles and new hatchlings have significantly more predators, including [[crab]]s, small [[marine mammal]]s and [[shorebird]]s.<ref name="NGeo"/> Additionally, their eggs are vulnerable to predation by scavengers like [[red fox]]es and [[golden jackal]]s.<ref>''Predation on green turtle ''Chelonia mydas'' nests by wild canids at Akyatan beach, Turkey'' by L. Brown and D. W. Macdonald, Biological Conservation, Volume 71, Issue 1, 1995, pp. 55–60.</ref>

Green sea turtles have a variety of parasites including [[barnacle]]s, [[leech]]es, [[protozoa]]ns, [[Cestoda|cestodes]], and [[nematode]]s. Barnacles attach to the carapace, and leeches to the flippers and skin of the turtles, causing damage to the soft tissues and leading to blood loss. Protozoans, cestodes and nematodes lead to many turtle deaths because of the infections in the liver and intestinal tract they cause. The greatest disease threat to the turtle population is [[Turtle fibropapillomatosis|fibropapilloma]], which produces lethal tumor growth on scales, lungs, stomach, and kidneys. Fibropapilloma is caused by a herpesvirus that is transmitted by leeches such as ''[[Ozobranchus branchiatus]]'', a species of leech which feeds almost entirely on green sea turtles.<ref name=":3">{{Cite book|title=Ruckdeschel, C. and Shoop, C. R. 2006. Sea Turtles of the Atlantic and Gulf Coasts of the United States. A Wormsloe Foundation nature book; Wormsloe Foundation nature book. Athens: University of Georgia Press.}}</ref><ref name=McGowin>{{cite journal |author1=McGowin, A.E. |author2=Truong, T.M. |author3=Corbett, A.M. |author4=Clark, Dave |year=2011 |title=Genetic barcoding of marine leeches (''Ozobranchus'' spp.) from Florida sea turtles and their divergence in host specificity |journal=Molecular Ecology Resources |volume=11 |issue=2 |pages=271–278 |doi=10.1111/j.1755-0998.2010.02946.x |pmid=21429133 |bibcode=2011MolER..11..271M |s2cid=34067696 }}</ref>

===Life cycle===
[[File:Baby Chelonia mydas 20060319.jpg|thumb|right|Hatchling|alt=Photo of newly hatched turtle held in human hand]]
Green sea turtles migrate long distances between feeding sites and nesting sites; some swim more than {{convert|2600|km|mi}} to reach their spawning grounds. Beaches in Southeast Asia, India, islands in the western Pacific, and Central America are where green sea turtles breed.<ref name=":4" /> Mature turtles often return to the exact beach from which they hatched. Females usually mate every two to four years. Males, on the other hand, visit the breeding areas every year, attempting to mate.<ref name="AuThreatenedSpecies">{{cite press release|title=Australian Threatened Species: Green turtle (''Chelonia mydas'') |publisher=Government of Australia |year=2006 |url=http://www.environment.gov.au/biodiversity/threatened/publications/pubs/tsd06green-turtle.pdf |access-date=August 15, 2007 |url-status=dead |archive-url=https://web.archive.org/web/20070911072001/http://www.environment.gov.au/biodiversity/threatened/publications/pubs/tsd06green-turtle.pdf |archive-date=September 11, 2007 }}</ref> Mating seasons vary between populations. For most ''C. mydas'' in the [[Caribbean]], mating season is from June to September.<ref name="FWS"/> The [[French Guiana]] nesting subpopulation nests from March to June.<ref name="Girondot1996"/> In the tropics, green turtles nest throughout the year, although some subpopulations prefer particular times of the year. In [[Pakistan]], [[Indian Ocean]] turtles nest year-round, but prefer the months of July to December.<ref name="Butler1977"/>
[[File:Green turtle nesting tracks.jpg|alt=Returning tracks from a female green sea turtle|left|thumb|Returning tracks from a female green sea turtle that had nested on  [[Ilha do Fogo, Mozambique]]]]
Sea turtles return to the beaches on which they were born to lay their own eggs. The reason for returning to native beaches may be that it guarantees the turtles an environment that has the necessary components for their nesting to be successful. These include a sandy beach, easy access for the hatchlings to get to the ocean, the right incubation temperatures, and low probability of predators that may feed on their eggs. Over time these turtles have evolved these tendencies to return to an area that has provided reproductive success for many generations. Their ability to return to their birthplace is known as [[natal homing]].<ref name="Wynekey, J. 2013. Pp 59-70">Wynekey, J.; Lohmann, J.K.; Musick, J.A. 2013. The biology of sea turtles. CRC Press. Vol 3. Pp 59–70</ref> The males also return to their birthplaces in order to mate. These males that return to their homes know they will be able to find mates because the females born there also return to breed. By doing this, the green sea turtles are able to improve their reproductive success and is why they are willing to expend the energy to travel thousands of miles across the ocean in order to reproduce.

Mating behaviour is similar to other marine turtles. Female turtles control the process. A few populations practice [[Polyandry in animals|polyandry]], although this does not seem to benefit hatchlings.<ref name="Lee2004">{{cite journal |last =Lee |first =Patricia L. M. |author-link =Patricia L. M. Lee |author2=[[Graeme Hays|Graeme C. Hays]] |title =Polyandry in a marine turtle: Females make the best of a bad job |journal =Proceedings of the National Academy of Sciences |volume =101 |issue =17 |pages =6530–6535 |date =April 27, 2004 |doi =10.1073/pnas.0307982101|pmid =15096623 |pmc =404079|bibcode =2004PNAS..101.6530L |doi-access =free }}</ref> After mating in the water, the female moves above the beach's high tide line, where she digs a hole {{convert|11|–|22|in|cm|order=flip}} in depth with her hind flippers and deposits her eggs. The hole is then covered up again.<ref name=":6">{{Cite book|title=Turtles of the World|last=Bonin|first=Franck|publisher=The Johns Hopkins University Press Baltimore|year=2006|isbn=978-0-8018-8496-2|location=Baltimore, Maryland|url-access=registration|url=https://archive.org/details/turtlesofworld0000boni}}</ref> Clutch size ranges between 85 and 200, depending on the age of the female. This process takes about an hour to an hour and a half. After the nest is completely covered, she returns to the sea. The female will do this 3 to 5 times in one season.<ref name=":4" />
[[File:PMNM - sea turtle hatchlings (28128852695).jpg|thumb|Green sea turtle hatchlings on the beach]]
The eggs are round and white, and about {{convert|45|mm|abbr=on}} in diameter. The hatchlings remain buried for days until they all emerge together at night.<ref name=":6" /> The temperature of the nest [[temperature-dependent sex determination|determines the sex]] of the turtles at around the 20–40 day mark. Green Sea Turtles are type 1a, meaning males develop at cooler temperatures while females are produced under hot temperatures.<ref>{{cite journal |last1=Standora |first1=Edward A |last2=Spotila |first2=James R. |title="Temperature dependent sex determination in sea turtles" |journal=Copeia |date=1985 |issue=3 |pages=711–722|doi=10.2307/1444765 |jstor=1444765 }}</ref><ref>Spotila, J. R. (2004). Sea turtles: a complete guide to their biology, behavior, and conservation. Baltimore: Johns Hopkins University Press.</ref> At around 50 to 70 days,<ref>{{Cite web|title = Green turtle|url = http://wwf.panda.org/what_we_do/endangered_species/marine_turtles/green_turtle/|website = wwf.panda.org|access-date = 2015-10-19}}</ref> the eggs hatch during the night, and the hatchlings [[instinct]]ively head directly into the water. This is the most dangerous time in a turtle's life. As they walk, predators, such as [[gull]]s and [[crab]]s, feed on them. A significant percentage never make it to the ocean. Little is known of the initial life history of newly hatched sea turtles.<ref name="FWS"/> Juveniles spend three to five years in the open ocean before they settle as still-immature juveniles into their permanent shallow-water lifestyle.<ref name="Reich2007"/><ref name="LS20070918"/> It is speculated that they take twenty to fifty years to reach [[sexual maturity]]. Individuals live up to eighty years in the wild.<ref name="NGeo"/> It is estimated that only 1% of hatchlings reach sexual maturity.

Each year on [[Ascension Island]] in the [[South Atlantic]], ''C. mydas'' females create 6,000 to 25,000 nests. They are among the largest green turtles in the world; many are more than {{convert|1|m}} in length and weigh up to {{convert|300|kg|lb}}.<ref name="AscensionGT">{{cite web |last =Fowler |first =Stephen |title =About The Green Turtle on Ascension |work =Turtles |publisher =Ascension Island Heritage Society |date =April 21, 2002 |url =http://www.heritage.org.ac/HS2right.htm |access-date =September 16, 2007 |archive-date =October 30, 2007 |archive-url =https://web.archive.org/web/20071030074741/http://www.heritage.org.ac/HS2right.htm |url-status =dead }}</ref>

===Breathing and sleep===
Sea turtles spend almost all their lives submerged, but must breathe air for the oxygen needed to meet the demands of vigorous activity. With a single explosive exhalation and rapid inhalation, sea turtles can quickly replace the air in their lungs. The lungs permit a rapid exchange of oxygen and prevent gases from being trapped during deep dives. Sea turtle blood can deliver oxygen efficiently to body tissues even at the pressures encountered during diving. During routine activity, green and loggerhead turtles dive for about four to five minutes, and surface to breathe for one to three seconds.

Turtles can rest or sleep underwater for several hours at a time, but submergence time is much shorter while diving for food or to escape predators. Breath-holding ability is affected by activity and stress, which is why turtles quickly drown in [[shrimp]] trawlers and other fishing gear.<ref name="MarBioCmydas"/> During the night while sleeping and to protect themselves from potential predators, the adults wedge themselves under rocks below the surface and under ledges in reefs and coastal rocks. Many green sea turtles have been observed in returning to the same sleeping location night after night.<ref name=":2" />

== Physiology and sensory modalities ==
[[File:Diving in Arraial do Cabo 05.JPG|thumb|Diver with a Green Sea Turtle at [[Arraial do Cabo]], Brasil]]
Green sea turtles tend to have good vision, well adapted to a life at sea. The turtles can see many colors, but are most sensitive to light from violet to yellow or wavelengths of 400 to 600 nanometers. They do not see many colors in the orange to red portion of the light spectrum. On land, however, the sea turtles are nearsighted because the lenses in the eyes are spherical and adjusted to refraction underwater.<ref name=":2" /> Sea turtles have no external ear and only one ear bone, called the columella. With one ear bone, the turtles can hear only low frequency sounds, from 200 to 700&nbsp;Hz. Sounds can also be detected through vibrations of the head, backbone, and shell. The nose of the turtle has two external openings and connects to the roof of the mouth through internal openings. The lower surface of the nasal passage has two sets of sensory cells called the Jacobson's organ. The turtle can use this organ to smell by pumping water in and out of its nose.<ref name=":3" />

Since green sea turtles migrate long distances during breeding seasons, they have special adaptive systems in order to navigate. In the open ocean, the turtles navigate using wave directions, sun light, and temperatures. The sea turtles also contain an internal magnetic compass. They can detect magnetic information by using magnetic forces acting on the magnetic crystals in their brains. Through these crystals, they can sense the intensity of Earth's magnetic field and are able to make their way back to their nesting grounds or preferred feeding grounds.<ref name=":3" />

[[Natal homing]] is an animal's ability to return to its birthplace in order to reproduce. Natal homing is found in all species of sea turtles and in other animals such as salmon. How these turtles are able to return to their birthplace is an interesting phenomenon. Many researchers believe that sea turtles use a process called imprinting, which is a special type of learning that occurs when turtles first hatch that allows them to recognize their native beach. There are two types of imprinting that are thought to be the reason turtles can find these beaches. The first is the chemical imprinting hypothesis. This hypothesis states that much like salmon, sea turtles are able to use olfactory cues and senses to smell their way home. However, a problem with this hypothesis is that some turtles travel thousands of miles to return to their native beaches, and the scents from that area are not likely to travel and be distinguishable from that distance.
The second hypothesis is the geomagnetic. This hypothesis states that as it hatches, a young turtle will imprint on the magnetic field of the beach they are born on. This hypothesis strongly correlates to the method which sea turtles use to navigate the earth.<ref name="Wynekey, J. 2013. Pp 59-70"/>

In order to tolerate the constant heat loss in the water, sea turtles have the ability to shunt blood away from tissues that are tolerant of low oxygen levels toward the heart, brain, and central nervous system. Other mechanisms include basking on warm beaches and producing heat through their activity and movements of their muscles. Basking turtles sometimes look like they are crying because behind the turtles eye is the lachrymal gland which stores excess salt from the sea water, which then expels through the turtles eye. In the winter months, turtles living at higher latitudes can hibernate for a short period in the mud.<ref>{{Cite book|title=Lutz, P. L., Musick, J. A., and Wyneken, J. 1997. The Biology of Sea Turtles. Marine Science series; Marine science series; CRC marine biology series. Boca Raton, FL: CRC Press.}}</ref>

== Unique characteristics and features ==
[[File:Green sea turtle coming up for air.jpg|thumb|Green Sea Turtle comes up for a breath]]
Green sea turtles can reach up to 40 miles per hour when swimming, making them the fastest sea turtle.<ref>{{cite journal |last1=Meylan |first1=Peter A. |last2=Meylan |first2=Anne B. |last3=Gray |first3=Jennifer A. |title=The ecology and migrations of sea turtles 8. Tests of the developmental habitat hypothesis. |journal=Bulletin of the American Museum of Natural History |date=2011 |volume=357 |pages=1–70|doi=10.1206/357.1 }}</ref> The green sea turtles exhibit sex differences by their development and appearance. As adult turtles, males are easily distinguishable from the females by having a longer tail (visibly extending past the shell) and longer claws on the front flippers. The hatching time and sex of the turtles are determined by the incubation temperature of the nest. Hatchings occur more quickly in nests that are warmer than nests that are in cooler conditions. Warm nesting sites above 30 degrees Celsius favor the development of females, whereas nesting sites below 30 degrees Celsius produce males. The position of the egg in the nest also affects sex-determination. Eggs in the center tend to hatch as females due to the warmer conditions within the nest.<ref name=":2">{{Cite book|last=Spotila|first=J.|year=2004|title=Sea Turtles: A Complete Guide to their Biology, Behavior, and Conservation|location=Baltimore, MD|publisher=Johns Hopkins University Press}}</ref>

Green sea turtles play an essential role in the ecosystem in which they live. In the seagrass beds, the turtles feed on the seagrass by trimming only the top and leaving the roots of the plant. Through their feeding technique, the turtles help to improve the health and growth of the seagrass beds. The healthy seagrass beds that the turtles provide give habitat and feeding grounds for many species of fish and crustaceans. On the nesting beaches, the green sea turtles provide key nutrients for the ecosystem through their hatched egg shells. In their coral reef habitat, the green sea turtles have a [[Symbiosis|symbiotic interaction]] with reef fish, including the yellow tang. The yellow tang fish swims along with the turtle and feeds on the algae, barnacles, and parasites on its shell and flippers. This species interaction provides food for the yellow tang and provides a necessary cleaning and smoothing of the turtle's shell. This cleaning helps the turtles swim by reducing the amount of drag and improves their health.<ref name=":3" />

==Importance to humans==
[[File:NSRW Turtles.png|thumb|left|Harvested green turtles on a wharf at [[Key West, Florida|Key West]], Florida|alt=Black-and-white photo of several turtles set on their backs]]
Historically, the turtles' skin was [[Tanning (leather)|tanned]] and used to make [[handbag]]s, especially in [[Hawaii]].<ref name="Glick2005Smithsonian"/> [[History of China#Ancient China|Ancient Chinese]] considered the flesh of sea turtles a culinary delicacy, including and especially ''C. mydas''.<ref name="EatingTurtlesChina">{{cite journal |last =Schafer |first =Edward H. |author-link =Edward H. Schafer |title =Eating Turtles in Ancient China |journal =Journal of the American Oriental Society |volume =82 |issue =1 |pages =73–74 |year =1962 |jstor= 595986 |doi = 10.2307/595986}}</ref> Particularly for this species, the turtle's [[body fat|fat]], [[cartilage]], and flesh, known as [[calipee]], are sought as ingredients for making [[turtle soup]], a popular 19th-century English and American dish.<ref>{{Cite book |last=Clarkson |first=Janet |title=Soup: a global history |date=2010 |publisher=Reaktion |isbn=978-1-86189-774-9| location=London| pages=115–118| oclc=642290114}}</ref><ref>''The Country Housewife and Lady's Director'', by Prof. R. Bradley, 1728</ref><ref name="MCSgreen"/>

In [[Java]], [[Indonesia]], sea turtle eggs were a popular delicacy. However, the turtle's flesh is regarded as ''[[ḥarām]]'' or "unclean" under [[Sharia|Islamic law]] ([[Islam]] is Java's primary religion). In [[Bali]], turtle meat was a prominent feature at ceremonial and religious feasts. Turtles were harvested in the remotest parts of the [[List of islands of Indonesia|Indonesian archipelago]].<ref name="EcoJavaBali">{{cite book |last=Whitten |first=T |author2=Soeriaatmadja, R. E. |author3=Suraya A. A. |title=The Ecology of Java and Bali |publisher=Periplus Editions Ltd |year=1996 |location=Hong Kong |pages=756–760 |isbn=978-962-593-072-5}}</ref> Bali has been importing sea turtles since the 1950s, as its own turtle supplies became depleted.<ref name="Sumertha1974">
Sumertha, I.N. 1974. Perikanan penyu dan cara pengelolaan di Indonesia. ''Dokumen. Kom. IPB'' 8: 1–18. Cited in {{cite book |last=Whitten |first=T |author2=Soeriaatmadja, R. E. |author3=Suraya A. A. |title=The Ecology of Java and Bali |publisher=Periplus Editions Ltd |year=1996 |location=Hong Kong |page=757 |isbn=978-962-593-072-5}}</ref> The mostly Hindu [[Balinese people|Balinese]] do not eat the eggs, but sell them instead to local [[Muslim]]s.
[[File:Chelonia mydas Maison Franconie tortue 1.jpg|thumb|Green Sea Turtle skeleton in the collection of the museum, ''Maison Franconie'' (Franconia House Museum), [[French Guiana]] ]]
Commercial farms, such as the [[Cayman Turtle Farm]] in the [[West Indies]], once bred them for commercial sale of turtle meat, turtle oil (rendered from the fat), turtle shell, and turtle leather made from the skin. The farm's initial stock was in large part from "doomed" eggs removed from nests threatened by erosion, flooding, or in chemically hostile soil.<ref>{{cite book|last=Fosdick|first=Peggy & Sam|title=Last chance lost?: can and should farming save the green sea turtle?|year=1994|publisher=Irvin S. Naylor|location=York, PA, USA|pages=73, 90 }}</ref> The farms held as many as 100,000 turtles at any one time. When the international markets were closed by regulations that did not allow even farm-bred turtle products to be exported internationally, the surviving farm became primarily a tourist attraction, supporting 11,000 turtles.<ref name="Morriss">{{cite web |last =Morriss |first =Andrew |title =Survival of the Sea Turtle: Cayman Turtle Farm Starts Over |work =PERC Reports |publisher =Property and Environment Research Center |url =http://www.perc.org/articles/article825.php |access-date =September 16, 2007 |archive-url =https://web.archive.org/web/20120723061637/http://www.perc.org/articles/article825.php |archive-date =2012-07-23 |url-status =dead }}</ref> Initially started as Mariculture Ltd., then Cayman Turtle Farm Ltd and subsequently branded Boatswain's Beach, in 2010 the farm's brandname was changed to Cayman Turtle Farm: Island Wildlife Encounter.<ref>{{cite web|title=About Us: 2010 |url=http://www.turtle.ky/about-us |publisher=Cayman Turtle Farm |access-date=April 9, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120507094037/http://www.turtle.ky/about-us |archive-date=May 7, 2012 }}</ref>

Sea turtles are integral to the history and culture of the [[Cayman Islands]]. When the islands were first discovered by [[Christopher Columbus]] in 1503, he named them "Las Tortugas" because of the abundance of sea turtles in the waters around the islands.<ref name="Turtle release set">{{cite news|title=Turtle release set|url=http://www.compasscayman.com/caycompass/2007/10/24/Turtle-release-set/|newspaper=Caymanian Compass|date=October 23, 2007|access-date=April 9, 2012|archive-date=September 23, 2015|archive-url=https://web.archive.org/web/20150923205736/http://www.compasscayman.com/caycompass/2007/10/24/Turtle-release-set/|url-status=dead}}</ref> Many of the earliest visitors came to the [[Cayman Islands]] to capture the turtles as a source of fresh meat during long voyages. The green turtle is a national symbol displayed as part of the [[coat of arms of the Cayman Islands]], which also forms part of the national [[flag of the Cayman Islands]]. The country's currency uses a turtle as the watermark in its banknotes.<ref>{{cite news|title=Fresh, new banknotes ready|newspaper=Caymanian Compass|date=April 6, 2011|url=http://www.compasscayman.com/caycompass/2011/04/06/Fresh,-new-banknotes-ready/|access-date=April 9, 2012|archive-date=September 23, 2015|archive-url=https://web.archive.org/web/20150923205747/http://www.compasscayman.com/caycompass/2011/04/06/Fresh,-new-banknotes-ready/|url-status=dead}}</ref> A stylised sea turtle nicknamed "Sir Turtle" is the mascot of the national airline [[Cayman Airways]]<ref>{{cite news|last=McGowan|first=Cliodhna|title=Sir Turtle to keep flying|newspaper=Caymanian Compass|date=May 13, 2007|url=http://www.compasscayman.com/caycompass/2007/05/14/Sir-Turtle-to-keep-flying/}}</ref> and is part of the livery of its aircraft.

A ki'i pōhaku ([[petroglyph]]) of a green sea turtle (or honu) can be found on the [[Big Island of Hawaii]] in the Pu'u Loa lava fields. The green sea turtle has always held a special meaning for [[Hawaiians]] and this petroglyph shows its importance; it may date to when the [[Hawaiian Islands]] first became populated. The turtle symbolizes a navigator that can find his way home time after time. This symbol mirrors the real life of the green Hawaiian turtle as it will swim hundreds of miles to lay its eggs at its own place of birth. Though there are other myths as well, some Hawaiian legends say the honu were the first to guide the [[Polynesians]] to the Hawaiian Islands. Hawaiians revere the turtle and the legend of Kailua, a turtle who could take the form of a girl at will. In human form, she looked after the children playing on [[Punaluʻu Beach]].<ref>{{Cite web |url=http://www.hawaiianlife.com/content/hawaiian-honu-and-its-meaning |title=www.HawaiianLife.com |access-date=2014-12-29 |archive-date=2014-12-29 |archive-url=https://web.archive.org/web/20141229230203/http://www.hawaiianlife.com/content/hawaiian-honu-and-its-meaning |url-status=dead }}</ref>

==Conservation==
[[File:Suppenschildkröte.jpg|thumb|left|In a [[public aquarium]]|alt=Photo from front of swimming turtle]]

In recent [[decade]]s, sea turtles have moved from unrestricted exploitation to global protection, with individual countries providing additional protection, although serious threats remain unabated.
All populations are considered "threatened".<ref name=":0">{{Cite web|url=http://www.nmfs.noaa.gov/pr/species/turtles/green.htm|title=Green Turtle (''Chelonia mydas'') :: NOAA Fisheries|last=Fisheries|first=NOAA|website=www.nmfs.noaa.gov|language=en-us|access-date=2015-12-24}}</ref><ref name="UKBAP">{{cite web |title =Green Sea Turtles of Florida, Mexico No Longer Endangered |work =U.S. Fish and Wildlife Service |publisher =Discovery News |year =2016 |url =http://news.discovery.com/animals/endangered-species/green-sea-turtles-of-florida-mexico-no-longer-endangered-160405.htm |access-date =April 25, 2016}}</ref>

===Threats===
Human action presents both intentional and unintentional threats to the species' survival. Intentional threats include continued [[turtling (hunting)|hunting]], [[poaching]] and egg harvesting. More dangerous are unintentional threats, including boat strikes, fishermen's nets that lack [[turtle excluder device]]s, [[pollution]] and [[habitat destruction]]. Chemical pollution may create [[tumor]]s;<ref>{{cite web
|url=http://news.nationalgeographic.com/news/2010/11/101108-green-sea-turtles-tumors-pollution-science-environment/
|archive-url=https://web.archive.org/web/20101111154154/http://news.nationalgeographic.com/news/2010/11/101108-green-sea-turtles-tumors-pollution-science-environment/
|url-status=dead
|archive-date=November 11, 2010
|title=Sea Turtle Herpes Tumors Linked to Sewage?
|first=Rebecca |last=Kessler
|publisher=National Geographic News
|date=November 9, 2010
|access-date=November 9, 2010}}</ref> [[effluent]] from [[harbor]]s near nesting sites may create disturbances; and [[light pollution]] may disorient hatchlings. With chemical pollution present, there is a development of tar balls that is often eaten by green sea turtles in a confusion of their food. Tar balls cause the green sea turtle to ingest toxins that can block their guts and cause swelling of the tissue, displacing the liver and intestines.<ref>{{cite book |last1=Shigenaka |first1=Gary |last2=Milton |first2=Sarah |last3=Lutz |first3=Peter |last4=Shigenaka |first4=Gary |last5=Hoff |first5=Rebecca Z. |last6=Yender |first6=Ruth A. |last7=Mearns |first7=Alan J. |title=Oil and Sea Turtles: Biology, Planning, and Response |date=1 August 2003 |publisher=U.S. Department Of Commerce: National Oceanic and Atmospheric Administration |location=Florida |doi=10.13140/2.1.1774.0486 |pages=35–46 |edition=1 |url=https://www.reefrelief.org/wp-content/uploads/oil-turtle1.pdf |access-date=26 March 2021}}</ref> Habitat loss usually occurs due to human development of nesting areas. Beach-front construction, land "reclamation" and increased tourism are examples of such development.<ref name="NGeo"/><ref name="WildlifeofPakistan"/> An infectious [[tumor]]-causing disease, [[Turtle fibropapillomatosis|fibropapillomatosis]], is also a problem in some populations. The disease kills a sizeable fraction of those it infects, though some individuals seem to resist the disease.<ref name="Glick2005Smithsonian"/><ref name="Herbst2000">{{cite journal |last =Herbst |first =Lawrence H. |title =Marine Turtle Fibropapillomatosis: Hope Floats in a Sea of Ignorance |journal =Proceedings of the 19th Annual Symposium on Sea Turtle Conservation and Biology |volume =19 |pages = 39–40 |date=September 2000 |id =NOAA Technical Memorandum NMFS-SEFSC-443}}</ref><ref name="Moncade2000">{{cite journal |last =Moncada |first =Felix |author2=Adela Prieto |title =Incidence of Fibropapillomas in the Green Turtle (''Chelonia mydas'') in Cuban Waters |journal =Proceedings of the 19th Annual Symposium on Sea Turtle Conservation and Biology |volume =19 |pages = 40–41 |date=September 2000 |id =NOAA Technical Memorandum NMFS-SEFSC-443}}</ref> In addition, at least in the Southwestern Atlantic (Río de la Plata, Uruguay), exotic invasive species such as the rapa whelk [[Rapana venosa]], were reported massively bio-fouling immature green turtles, reducing buoyancy, increasing drag, and causing severe injuries to the carapace.<ref>Lezama, C., Carranza, A., Fallabrino, A., Estrades, A., Scarabino, F., & López-Mendilaharsu, M. (2013). Unintended backpackers: bio-fouling of the invasive gastropod Rapana venosa on the green turtle ''Chelonia mydas'' in the Río de la Plata Estuary, Uruguay. Biological invasions, 15(3), 483–487</ref> Because of these threats, many populations are in a vulnerable state.

[[File:Chelonia mydas (poached).jpg|thumb|right|A poached green turtle in [[Costa Rica]]]]
Pacific green turtles' foraging habitats are poorly understood and mostly unknown.<ref name="Seminoff et al, 2002">{{cite journal | last1 = Seminoff | year = 2002 | title = Home range of green turtles ''Chelonia mydas'' at a coastal foraging area in the Gulf of California, Mexico | journal = Mar Ecol Prog Ser | volume = 242 | pages = 253–265 | doi=10.3354/meps242253|bibcode=2002MEPS..242..253S | doi-access = free }}</ref> These foraging grounds are most likely along the coast of Baja California, Mexico and southern California,<ref name="National Marine Fisheries Service and U.S. Fish and Wildlife Service (Greens), 1998">National Marine Fisheries Service and U.S. Fish and Wildlife Service. 1998. Recovery Plan for U.S. Pacific Populations of the East Pacific Green Turtle (''Chelonia mydas''). National Marine Fisheries Service, Silver Spring, MD.</ref> in which these turtles have a high risk of incidental capture by coastal fisheries. The main mortality factor for these turtles is the shrimp trawlers in Mexico, in which many of these turtles go undocumented.<ref name="National Marine Fisheries Service and U.S. Fish and Wildlife Service (Greens), 1998"/> The only foraging area that has been identified is San Diego Bay, but it is heavily polluted with metals and PCBs.<ref name="National Marine Fisheries Service and U.S. Fish and Wildlife Service (Greens), 1998"/> These contaminants have a negative effect on the ocean environment, and have been shown to cause lesions and sometimes mortality.<ref name="National Marine Fisheries Service and U.S. Fish and Wildlife Service (Greens), 1998"/> Green turtles also are threatened by entanglement and ingestion of plastic.<ref name="National Marine Fisheries Service and U.S. Fish and Wildlife Service (Greens), 1998"/> In San Diego Bay, an adult green turtle was found dead with monofilament netting tightly packed in its esophagus.<ref name="National Marine Fisheries Service and U.S. Fish and Wildlife Service (Greens), 1998"/> In addition there are indications that global climate change is affecting the ability of green turtle populations in Australia to produce males due to their [[temperature-dependent sex determination]] and the rising temperatures in the northern [[Great Barrier Reef]] region.<ref>{{Cite web | url=https://arstechnica.com/science/2018/01/some-great-barrier-reef-turtle-populations-produce-nothing-but-females/ | title=Some Great Barrier Reef turtle populations produce nothing but females| year=2018}}</ref> Construction of new [[thermal power station]]s 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>

Green sea turtles are the most commonly traded species along Java's south coast and are sold in the form of whole, stuffed animals or turtle oil, locally known as "minyak bulus".<ref>{{Cite journal|last=Nijman|first=Vincent|year=2015|title=Decades long open trade in protected marine turtles along java's south coast|url=https://www.researchgate.net/publication/273321727|journal=Marine Turtle Newsletter|via=ResearchGate}}</ref>

The geographer James J. Parsons' book titled ''The Green Turtle and Man'' played a special role in the conservation movement to save the species from extinction.<ref>William M. Denevan. "James J. Parsons, 1915-1997". in Patrick H. Artmstrong and Geoffrey J. Martin. editors on behalf of the Commission on the History of Geographical Thought of the International Union of the History and Philosophy of Science. (2000). ''Geographers : biobibliographical studies, v. 19''. Strand, London; New York, NY : Mansell Publishing Limited. p. 90. {{ISBN|0720123771}}.</ref>

===Global initiatives===
[[File:Confiscated musical instrument made from green turtle.jpg|thumb|right|A confiscated musical instrument made from the shell of a green turtle, on display at [[Narita International Airport]], Tokyo.]]
The [[International Union for Conservation of Nature]] (IUCN) has repeatedly listed green sea turtles in its [[IUCN Red List of Threatened Species|Red List]] under differing criteria. In 1982, they officially classified it as an [[endangered species]].<ref name="IUCNGroombridge1982">{{cite book |last =Groombridge |first =B. |title =The IUCN Amphibia-Reptilia Red Data Book, Part 1: Testudines, Crocodylia, Rhynocehapalia |publisher =IUCN |year =1982 |location =Gland, Switzerland }}</ref> The 1986,<ref name="IUCN1986">{{cite book |author = IUCN Conservation Monitoring Centre |author-link =IUCN |title =1986 IUCN Red List of Threatened Animals |publisher =IUCN |year =1986 |location =Gland, Switzerland and Cambridge, UK |isbn = 978-2-88032-605-0 }}</ref> 1988,<ref name="IUCN1988">{{cite book |author = IUCN Conservation Monitoring Centre |author-link =IUCN |title =1988 IUCN Red List of Threatened Animals |url = https://archive.org/details/1988iucnredlisto88wilc |publisher =IUCN |year =1988 |location =Gland, Switzerland and Cambridge, UK |isbn =9782880329358 }}</ref> 1990,<ref name="IUCN1990">{{cite book |author = IUCN |author-link =IUCN |title =1990 IUCN Red List of Threatened Animals |publisher =IUCN |year =1990 |location =Gland, Switzerland and Cambridge, UK.}}</ref> 1994,<ref name="IUCN1994">{{cite book |last =Groombridge |first =B. |title =1994 IUCN Red List of Threatened Animals |publisher =IUCN |year =1994 |location =Gland, Switzerland |isbn =978-2-8317-0194-3}}</ref> and the landmark 1996 edition of the [[IUCN Red List]], retained the listing.<ref name="IUCN1996">{{cite book |last =Groombridge |first =B. |author2=Baillie|title =1996 IUCN Red List of Threatened Animals |publisher =IUCN |year =1996 |location =Gland, Switzerland}}</ref>

In 2001, Nicholas Mrosovsky filed a delisting petition, claiming some green turtle populations were large, stable and in some cases, increasing. At the time, the species was listed under the strict EN A1abd criteria. The IUCN Standards and Petitions Subcommittee ruled that visual counts of nesting females could not be considered "direct observation" and thus downgraded the species' status to EN A1bd—retaining the turtle's endangered status.<ref name="IUCNPetition">{{cite web|author1=Red List Standards |author2=Petitions Subcommittee |author-link=IUCN |title=Ruling of the IUCN Red List Standards and Petitions Subcommittee on Petitions against the 1996 Listings of Four Marine Turtle Species, 18 October 2001 |publisher=International Union for Conservation of Nature and Natural Resources |date=October 18, 2001 |url=http://intranet.iucn.org/webfiles/doc/SSC/RedList/MarineTurtleDecisions_18_Oct_01.pdf |access-date=February 5, 2007 |url-status=dead |archive-url=https://web.archive.org/web/20061206095751/http://intranet.iucn.org/webfiles/doc/SSC/RedList/MarineTurtleDecisions_18_Oct_01.pdf |archive-date=6 December 2006 }}</ref>

In 2004, the IUCN reclassified ''C. mydas'' as endangered under the EN A2bd criteria, which essentially states the wild populations face a high risk of [[extinction]] because of several factors. These factors include a probable population reduction of more than 50% over the past decade as estimated from abundance indices and by projecting exploitation levels.<ref name="iucn status 12 November 2021" />

On 3 May 2007, ''C. mydas'' was listed on Appendix I of the [[Convention on International Trade in Endangered Species]] (CITES) as a member of the family [[Cheloniidae]].<ref name="CITESAPP">{{cite web|author=CITES |author-link=CITES |title=Appendices |publisher=Convention on International Trade in Endangered Species of Wild Flora and Fauna |date=May 3, 2007 |url=http://www.cites.org/eng/app/appendices.shtml |format=SHTML |access-date=August 31, 2007 |url-status=dead |archive-url=https://web.archive.org/web/20071229054904/http://www.cites.org/eng/app/appendices.shtml |archive-date=December 29, 2007 }}</ref> The species was originally listed on Appendix II in 1975. The entire family was moved to Appendix I in 1977, with the exception of the [[Australia]]n population of ''C. mydas''. In 1981, the Australian population joined the rest. The Appendix I listing prohibits commercial international trade in the species (including parts and derivatives).<ref name="CITES">{{cite web |author =UNEP-WCMC |author-link =UNEP-WCMC |title =''Chelonia mydas'' A-301.003.002.002 |work =UNEP-WCMC Species Database: CITES-Listed Species |publisher =United Nations Environment Programme – World Conservation Monitoring Centre |url =http://sea.unep-wcmc.org/isdb/CITES/Taxonomy/tax-species-result.cfm?displaylanguage=eng&Genus=Chelonia&Species=mydas&source=animals&Country=&tabname=all |access-date =August 31, 2007 |url-status =dead |archive-url =https://web.archive.org/web/20070929150449/http://sea.unep-wcmc.org/isdb/CITES/Taxonomy/tax-species-result.cfm?displaylanguage=eng&Genus=Chelonia&Species=mydas&source=animals&Country=&tabname=all |archive-date =September 29, 2007 }}</ref> The [[Zoological Society of London]] has listed the reptile as an [[EDGE species]].<ref>{{cite web | title=Green Turtle | website=EDGE of Existence | date=11 April 2018 | url=https://www.edgeofexistence.org/species/green-turtle/ | access-date=23 June 2020}}</ref>

The [[Mediterranean]] population is listed as critically endangered.<ref name="NGeo"/><ref name="MCSgreen"/> The eastern Pacific, Hawaiian and Southern California subpopulations are designated threatened. Specific Mexican subpopulations are listed as endangered. The Florida population is listed as endangered. The [[World Wide Fund for Nature]] has labeled populations in Pakistan as "rare and declining".<ref name="MTNGroombridge"/>

Since 1999, the [[Florida Aquarium]] has led extensive sea turtle rehabilitation efforts and visitor and community education & conservation platforms to advance sea turtle protection. Over a 20-year period, the aquarium received 200 sea turtles, and while not all could be released due to the nature of their injuries or illnesses, 180 were successfully released. In 2019, they opened a state-of-the-art Sea Turtle Rehabilitation Center in [[Apollo Beach]], Florida. In the first year, The Florida Aquarium Animal Response Team managed the care of 21 sea turtles, initiated new foraging-readiness testing for release candidates in deep-dive tank, and released 14 animals. In 2020, they also initiated a study to better understand how micro-plastics are impacting the sea turtles in their care. In 2016, [[Florida]] enacted extensive protection measures. Florida statutes (F.A.C. Rule 68E-1) restrict the take, possession, disturbance, mutilation, destruction, selling, transference, molestation, and harassment of marine turtles, nests or eggs. Protection is also afforded to marine turtle habitat. A specific authorization from commission staff is required to conduct scientific, conservation, or educational activities that directly involve marine turtles in or collected from [[Florida]], their nests, hatchlings or parts thereof, regardless of applicant's possession of any federal permit.

In the State of [[Hawaii]], specifically on the Island of Hawai'i (Hawaii County), state representative [[Faye Hanohano]], a Native Hawaiian rights activist, pressed for a measure to delist ''C. mydas'' from protected status so that Native Hawaiians could legally harvest the turtles and possibly their eggs as well. The bill, HCR14, was largely overlooked by the media since at that point it was only a local issue. While the bill was passed in the [[United States House of Representatives]], the [[United States Senate|United States Senate's]] Committee on Energy and Environment refused to hear it, which meant that the bill did not go on to be heard by the Senate.<ref name=bill>{{cite web|last=Callis |first=Tom |url=https://www.hawaiitribune-herald.com/2013/04/04/hawaii-news/turtle-report-months-away/ |title=Turtle report months away |website=Hawaii Tribune Herald |date=4 April 2013 |access-date=25 March 2017}}</ref>

===Country-specific initiatives===
[[File:OsakaAquarium SeaTurtle.jpg|thumb|left|At the [[Osaka Kaiyukan Aquarium|Osaka Aquarium]], profile photo of turtle resting on bottom]]
In addition to management by global entities such as the [[IUCN]] and [[CITES]], specific countries around the world have undertaken conservation efforts.

The [[Indonesia]]n island of [[Bali]] has traditional uses that were considered sustainable, but have been questioned considering greater demand from the larger and wealthier human population. The harvest was the most intensive in the world.<ref name="EcoJavaBali"/> In 1999, Indonesia restricted turtle trade and consumption because of the decreasing population and threat of a tourist boycott. It rejected a request made by Bali Governor [[I Made Mangku Pastika]] in November 2009 to set a quota of 1,000 turtles to be killed in [[Hindu]] religious ceremonies. While conservationists respect the need for turtles in rituals, they wanted a smaller quota.<ref>{{cite news|last=Karmini |first=Niniek |title=Indonesia rejects Bali plan for turtle sacrifices |url=https://www.google.com/hostednews/ap/article/ALeqM5j-i33PUryNTSZ6x2r55UA_RetEVgD9C7RT8O0 |agency=[[Associated Press]] |date=November 27, 2009 |archive-url=https://www.webcitation.org/5lbCBnXAs?url=http://www.google.com/hostednews/ap/article/ALeqM5j-i33PUryNTSZ6x2r55UA_RetEVgD9C7RT8O0 |archive-date=November 27, 2009 |access-date=November 27, 2009 |url-status=dead}}</ref>

Multiple [[List of protected areas of the Philippines|protected areas of the Philippines]] have significant green sea turtle nesting and feeding sites. The most notable is [[Turtle Islands, Tawi-Tawi|Turtle Islands Wildlife Sanctuary]], an [[UNESCO]] tentative site which encompasses an entire municipality and one of Southeast Asia's most important green sea turtle nesting sites.<ref>{{Cite web|url=https://whc.unesco.org/en/tentativelists/6008/|title = Turtle Islands Wildlife Sanctuary}}</ref> Other notable sites include the [[UNESCO]] tentative site of El Nido-Taytay Management Resource Protected Area and the [[UNESCO]] [[World Heritage Site]] of Tubbataha Reefs Natural Park. The species is protected under Republic Act 9147 or the Wildlife Resources Conservation and Protection Act, while the sites where they live and nest are protected under the National Integrated Protected Areas System Act.<ref>{{Cite web|url=https://businessmirror.com.ph/2017/10/15/protecting-the-endangered-pawikan/|title=Protecting the endangered 'pawikan' &#124; Jonathan L. Mayuga|website=[[BusinessMirror]] |date=15 October 2017}}</ref>

[[Ecotourism]] is one initiative in [[Sabah]], [[Malaysia]]. The island of [[Pulau Selingan]] is home to a turtle [[hatchery]]. Staff people place some of the eggs laid each night in a hatchery to protect them from predators. Incubation takes around sixty days. When the eggs hatch, [[tourists]] assist in the release of the baby turtles into the sea.<ref name="SelinganIsland">{{cite web |title =Selingan Turtle Island |work =Borneo: Journey Malaysia |publisher =Dolphin Diaries Travel Sdn Bhd. |year =2007 |url =http://www.journeymalaysia.com/MI_selinganturtleisland.htm |access-date =September 16, 2007 |archive-date =July 22, 2015 |archive-url =https://web.archive.org/web/20150722094434/http://www.journeymalaysia.com/MI_selinganturtleisland.htm |url-status =dead }}</ref>

The [[Hawaii]]an subpopulation has made a remarkable comeback and is now one focus of ecotourism and has become something of a state [[mascot]]. Students of [[Hawaii Preparatory Academy]] on [[Hawaii (island)|the Big Island]] have tagged thousands of specimens since the early 1990s.<ref name="Glick2005Smithsonian" />

In the [[United Kingdom]] the species is protected by a [[Biodiversity Action Plan]], due to excess harvesting and [[marine pollution]].<ref name="UKBAP2">{{cite web |title =Grouped Species Action Plan: Grouped plan for marine turtles |work =UK Biodiversity Action Plan |publisher =UK Joint Nature Conservation Committee |year =2006 |url =http://www.ukbap.org.uk/ukplans.aspx?ID=335 |access-date =September 16, 2007 |url-status =dead |archive-url =https://web.archive.org/web/20070805232805/http://www.ukbap.org.uk/UKPlans.aspx?ID=335 |archive-date =August 5, 2007}}</ref> The Pakistani-branch of the [[World Wide Fund for Nature]] has been initiating projects for secure turtle hatching since the 1980s. However, the population has continued to decline.<ref name="WildlifeofPakistan" />

In the Atlantic, conservation initiatives have centered around Caribbean nesting sites. The Tortuguero nesting beaches in [[Costa Rica]] have been the subject of egg-collection limits since the 1950s. The [[Tortuguero National Park]] was formally established in 1976, in part, to protect that region's nesting grounds.<ref name="Bjorndal1999CostaRica"/> On [[Ascension Island]], which contains some of the most important nesting beaches, an active conservation program has been implemented.<ref name="AscensionConservation">{{cite web |title =Ascension Conservation |work =Ascension Conservation, Wildlife |publisher =Ascension Conservation |year =2007 |url =http://www.ascensionconservation.org.ac/wildlife.htm |access-date =September 16, 2007 |url-status =dead |archive-url =https://web.archive.org/web/20070928054657/http://www.ascensionconservation.org.ac/wildlife.htm |archive-date =September 28, 2007 }}</ref> Karumbé has been monitoring foraging and developmental areas of juvenile green turtles in Uruguay since 1999.<ref>{{Cite web|url=http://www.karumbe.org/|title=Karumbé &#124; Centro de Tortugas marinas|website=www.karumbe.org}}</ref>

In Mozambique, there are a number of initiatives to protect sea turtles. In the [[Primeiras and Segundas Archipelago|Primeiras e Segundas]], [[World Wildlife Fund|WWF]] Mozambique has established a turtle tagging and protection program. The archipelago is a vital nesting area for green turtles, including [[Ilha do Fogo, Mozambique|Ilha do Fogo]] where Fire Island Conservation<ref>{{Cite web |title=Fire Island Conservation {{!}} Saving Sea Turtles |url=https://fireislandconservation.com/saving-sea-turtles/ |website=Fire Island Conservation|date=23 October 2023 }}</ref> manage a turtle monitoring programme, and at Celdeira Island, where several nesting females have been tagged.

[[Cayman Turtle Farm]] located in Grand Cayman in the northwest Caribbean Sea is the first farm to have achieved the second generation of green sea turtles bred, laid, hatched, and raised in captivity.<ref>{{cite web|title=History: 1989|url=http://www.turtle.ky/history-history|publisher=Cayman Turtle Farm|access-date=April 9, 2012|archive-date=June 12, 2015|archive-url=https://web.archive.org/web/20150612155633/http://www.turtle.ky/history-history|url-status=dead}}</ref> Since its beginning in 1968, the farm has released over 31,000 turtles into the wild,<ref name="Turtle release set"/> and each year more captive-bred turtles are released into the [[Caribbean Sea]] from beaches around the island of [[Grand Cayman]].<ref>{{cite news|last=Fuller|first=Brent|title=Little turtles swimming for it|url=http://www.compasscayman.com/caycompass/2011/11/18/Little-turtles-swimming-for-it/|newspaper=Caymanian Compass|date=November 18, 2011|access-date=April 9, 2012|archive-date=September 23, 2015|archive-url=https://web.archive.org/web/20150923205753/http://www.compasscayman.com/caycompass/2011/11/18/Little-turtles-swimming-for-it/|url-status=dead}}</ref> Captive-bred turtles released from the farm as hatchlings or yearlings with "living tags," have now begun to return to nest on Grand Cayman as adults.<ref>{{cite journal|last=Bell|first=Catherine|author2=Parsons J |author3=Austin TJ |author4=Broderick AC |author5=Ebanks-Petrie G |author6=Godley GJ |title=Some of them came home: the Cayman Turtle Farm headstarting project for the green turtle ''Chelonia mydas''|journal=Oryx|date=25 April 2005|volume=39|pages=137–148|doi=10.1017/S0030605305000372|issue=2|doi-access=free}}</ref><ref>{{cite news|last=Connolly|first=Norma|title=More turtles nesting in Cayman|url=http://www.compasscayman.com/caycompass/2011/06/02/More-turtles-nesting-in-Cayman/|newspaper=Caymanian Compass|date=June 2, 2011|quote=five turtles with tags from the Cayman Turtle Farm were observed nesting on Seven Mile Beach|access-date=April 9, 2012|archive-date=September 23, 2015|archive-url=https://web.archive.org/web/20150923205749/http://www.compasscayman.com/caycompass/2011/06/02/More-turtles-nesting-in-Cayman/|url-status=dead}}</ref> On February 19, 2012 the farm released the first 2nd-generation captive-bred green sea turtle equipped with a Position Tracking Transponder, or PTT<ref>{{Cite web|url=http://www.seaturtle.org/tracking/index.shtml?tag_id=112227&full=1|title=seaturtle.org - Satellite Tracking|website=www.seaturtle.org}}</ref> (also known as a satellite tag).<ref>{{cite web|title=Cayman Turtle Farm Green Sea Turtle Releases|url=http://www.seaturtle.org/tracking/index.shtml?tag_id=112227|publisher=SeaTurtle.org|access-date=April 9, 2012|author=Cayman Turtle Farm}}</ref> In addition, the farm provides turtle meat products to the local population for whom turtle has been part of the traditional cuisine for centuries. In so doing, the farm curtails the incentive to take turtles from the wild,<ref>{{cite news|last=Brammer|first=Jeff|title=What if the turtle farm went belly up?|url=http://www.compasscayman.com/caycompass/blogs/whatifcolumn/What-if-the-turtle-farm-went-belly-up-/|newspaper=Caymanian Compass|date=October 16, 2011|quote=presenting disincentives to poachers due to the commercial availability of turtle meat|access-date=April 9, 2012|archive-date=September 23, 2015|archive-url=https://web.archive.org/web/20150923205911/http://www.compasscayman.com/caycompass/blogs/whatifcolumn/What-if-the-turtle-farm-went-belly-up-/|url-status=dead}}</ref> which over the years in addition to the Cayman Turtle Farm's release of captive-bred turtles has enabled an increase in the number of turtles sighted in the waters around the island of [[Grand Cayman]] and nesting on its beaches.<ref>{{cite news|last=Connolly|first=Norma|title=More turtles nesting in Cayman|url=http://www.compasscayman.com/caycompass/2011/06/02/More-turtles-nesting-in-Cayman|newspaper=Caymanian Compass|date=June 2, 2011|quote=(Quoted Ebanks-Petrie, Gina and Blumenthal, Janice of Department of the Environment, Cayman Islands)|access-date=April 9, 2012|archive-date=September 23, 2015|archive-url=https://web.archive.org/web/20150923205749/http://www.compasscayman.com/caycompass/2011/06/02/More-turtles-nesting-in-Cayman/|url-status=dead}}</ref>
[[File:Nest 2 Measurements (7537662374).jpg|thumb|United States Fish and Wildlife Service measures sea turtle eggs]]
In the Pacific, green sea turtles nest on the ''motu'' ([[islets]]) in the [[Funafuti Conservation Area]], a marine conservation area covering 33 square kilometers (12.74 square miles) of reef, lagoon and ''motu'' on the western side of [[Funafuti]] atoll in [[Tuvalu]].<ref name=TTO>{{cite web|title=Tuvalu Funafuti Conservation Area |publisher=Ministry of Communication, Transport and Tourism – Government of Tuvalu |url=http://www.timelesstuvalu.com/tuvalu/export/sites/TTO/Attractions/funafuti_conservation_area.html |access-date=28 Oct 2011 |url-status=dead |archive-url=https://web.archive.org/web/20111102071017/http://www.timelesstuvalu.com/tuvalu/export/sites/TTO/Attractions/funafuti_conservation_area.html |archive-date=2011-11-02 }}</ref>

On [[Raine Island]], up to 100,000 nesting females have been observed in a season, with the cay producing 90% of the region's green turtles. However, the hatching rate declined in the 1990s, and a further decline in the population was threatened by the deaths of thousands of females as they struggled to climb the small sandy cliffs. In addition, as the shape of the island had changed over time, the spread of the beaches outwards had led to greater risk of inundation of the turtle nests. Between 2011 and 2020, a collaborative project by the [[Queensland Government]], [[BHP]] (as corporate sponsor), the Great Barrier Reef Marine Park Authority, Great Barrier Reef Foundation, and [[Wuthathi]] and [[Meriam people|Meriam]] [[traditional owners]], reshaped the island using heavy machinery in a way that gave the female turtles a smoother passage and reduced the risk of nest inundation. A sophisticated monitoring and research system, using [[3D modelling]], [[satellite]] technology and [[Unmanned aerial vehicle|drone]]s was employed, and monitoring continues.<ref>{{cite news | title=Green turtle rookery on Raine Island brought back from brink, but scientists' fight not over yet|first1= Sharnie |last1=Kim |first2 =Mark |last2 =Rigby | website=ABC News |publisher =Australian Broadcasting Corporation | date=12 June 2020 | url=https://www.abc.net.au/news/2020-06-13/saving-raine-island-worlds-largest-green-sea-turtle-rookery/12344046 | access-date=13 June 2020}}</ref>

{{as of|June 2020}}, a project called "The Turtle Cooling Project" is being undertaken by scientists from the [[World Wildlife Fund]] Australia, [[University of Queensland]], [[Deakin University]] and the [[Queensland Government]]. It is looking at the effect of [[global warming]] on northern green turtle breeding, in particular the effect of producing more male turtles owing to the higher temperatures. They are working in the area around Raine Island, [[Heron Island (Queensland)|Heron Island]] and Moulter Cay.<ref>{{cite news | title=Turning female: The race to save the northern green turtle| website=ABC News|publisher= Australian Broadcasting Corporation|first=Nick|last=Kilvert| date=12 June 2020 | url=https://www.abc.net.au/news/science/2020-06-12/green-turtle-save-science-gender/12300164 | access-date=15 June 2020}}</ref>

==Genetics==
The [[genome]] of ''Chelonia mydas'' was sequenced in 2013 to examine the development and evolution of the turtle body plan.<ref name="Wang2013">{{cite journal |author1=Wang Z. | author2= Pascual-Anaya, J. |author3=Zadissa A.|title=The draft genomes of the soft-shell turtle and green sea turtle yield insights into the development and evolution of the turtle-specific body plan |journal=Nature Genetics |year=2013 |volume=45 |pages=701–706 |doi=10.1038/ng.2615 |issue=6 |pmid=23624526|pmc=4000948}}</ref>

==See also==
{{Portal|marine life}}
* [[Sea Turtle Association of Japan, Kuroshima Research Station]]
* [[T. K. Bellis|T.K. Bellis]] The "Turtle King".

==References==<!-- BiodiversConserv17:2037. PacificScience61:36. -->
{{Reflist|20em}}

==External links==
*{{ITIS |id=173833|taxon=''Chelonia mydas ''|access-date=February 21, 2007}}
*{{cite iucn|author=Seminoff|year=2004|url=https://www.iucnredlist.org/species/4615/11037468|title=''Chelonia mydas'' |access-date=9 May 2006}}
{{Commons and category|Chelonia mydas|Chelonia mydas}}
{{Wikispecies|Chelonia mydas}}
* [https://web.archive.org/web/20060320213011/http://www.arkive.org/species/GES/reptiles/Chelonia_mydas/ Images and movies (''Chelonia mydas'')] — ARKive (archived 20 March 2006)
*[http://www.nmfs.noaa.gov/pr/species/turtles/green.htm US National Marine Fisheries Service green sea turtle page]
*[http://www.nmfs.noaa.gov/pr/species/turtles/green.html Floridian and Mexican populations]—US Fish and Wildlife Service
*[http://fohn.net/green-turtles-facts-pictures/ Desktop wallpaper & fun green turtle facts]
*[http://macaulaylibrary.org/video/59485 Green turtle video] – Macaulay Library
*[https://www.youtube.com/watch?v=pWZ0KKofPmw Baby green sea turtles] – Open Water 859 (video on [[YouTube]])
*{{SealifePhotos|137206}}

{{Cheloniidae}}
{{Taxonbar |from=Q199458}}
{{Authority control}}

[[Category:Chelonia]]
[[Category:Sea turtles]]
[[Category:Fauna of the Pantropical realm]]
[[Category:Fauna of Ascension Island]]
[[Category:Marine fauna of Northern Australia]]
[[Category:Natural history of Balochistan, Pakistan]]
[[Category:Reptiles of the Dominican Republic]]
[[Category:Reptiles of New Zealand]]
[[Category:Turtles of South America]]
[[Category:Turtles of Brazil]]
[[Category:Reptiles described in 1758]]
[[Category:Species that are or were threatened by habitat loss]]
[[Category:Taxa named by Carl Linnaeus]]
[[Category:Habitats Directive species]]
[[Category:Fauna of Christmas Island]]