The green sea turtle (''Chelonia mydas''), also known as the green turtle, black (sea) turtle or Pacific green turtle, is a
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of large
sea turtle
Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerhe ...
of the
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
Cheloniidae
Cheloniidae is a family of typically large marine turtles that are characterised by their common traits such as, having a flat streamlined wide and rounded shell and almost paddle-like flippers for their forelimbs. They are the only sea turtles t ...
. It is the only
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
in the
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
''Chelonia''.
Its range extends throughout
tropical
The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in
the Southern Hemisphere at S. The tropics are also referred to ...
and
subtropical seas around the world, with two distinct populations in the
Atlantic
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...
and
Pacific Ocean
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contin ...
s, but it is also found in the
Indian Ocean
The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by t ...
.
The common name refers to the usually green
fat
In nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such compounds, most commonly those that occur in living beings or in food.
The term often refers specifically to triglycerides (triple est ...
found beneath its
carapace, not to the color of its carapace, which is olive to black.
The
dorsoventrally
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...
flattened body of ''C. mydas'' is covered by a large, teardrop-shaped carapace; it has a pair of large,
paddle
A paddle is a handheld tool with an elongated handle and a flat, widened distal end (i.e. the ''blade''), used as a lever to apply force onto the bladed end. It most commonly describes a completely handheld tool used to propel a human-powered w ...
-like
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
herbivorous
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpar ...
. The adults usually inhabit shallow
lagoon
A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') ...
s, feeding mostly on various species of
seagrass
Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the or ...
es.
The turtles bite off the tips of the blades of seagrass, which keeps the grass healthy.
Like other sea turtles, green sea turtles
migrate long distances between feeding grounds and hatching beaches. Many islands worldwide are known as
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
maturity may live to 90 years in the wild.
''C. mydas'' is listed as
endangered
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and in ...
by the
IUCN and
CITES
CITES (shorter name for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of interna ...
and is protected from exploitation in most countries. 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
hunted for food.
Pollution
Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the ...
indirectly harms turtles at both population and individual scales. Many turtles die after being
caught in fishing nets. In addition, real estate
development
Development or developing may refer to:
Arts
*Development hell, when a project is stuck in development
*Filmmaking, development phase, including finance and budgeting
*Development (music), the process thematic material is reshaped
* Photograph ...
often causes
habitat loss
Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...
by eliminating nesting beaches.
Taxonomy
The green sea turtle is a member of the
tribe
The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English is in the discipline of anthropology. This definition is contested, in part due to confli ...
Cheloniini. A 1993 study clarified the status of
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
''Chelonia'' with respect to the other marine turtles. The
carnivorous ''
Eretmochelys
The hawksbill sea turtle (''Eretmochelys imbricata'') is a critically endangered sea turtle belonging to the family Cheloniidae. It is the only extant species in the genus ''Eretmochelys''. The species has a global distribution, that is large ...
'' (hawksbill), ''
Caretta'' (loggerhead) and ''
Lepidochelys'' (ridley) were assigned to the tribe
Carettini.
Herbivorous
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpar ...
''Chelonia'' warranted their status as a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
, while ''
Natator
The Australian flatback sea turtle (''Natator depressus'') is a species of sea turtle in the family Cheloniidae. The species is endemic to the sandy beaches and shallow coastal waters of the Australian continental shelf. This turtle gets its ...
'' (flatback) was further removed from the other genera than previously believed.
The species was originally described by
Carl Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his Nobility#Ennoblement, ennoblement in 1761 as Carl von Linné#Blunt, Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalise ...
in his landmark 1758
10th edition of ''Systema Naturae'' as ''Testudo mydas''.
In 1868,
Marie Firmin Bocourt
Marie Firmin Bocourt (19 April 1819 – 4 February 1904) was a French zoologist and artist.
As a young man, he worked as a preparateur for the zoologist Gabriel Bibron (1805–1848), later serving as a museum artist. In 1861, he was sent to Tha ...
named a particular species of sea turtle ''Chelonia agassizii'',
in honor of Swiss-American zoologist
Louis Agassiz. This "species" was referred to as the "black sea turtle".
Later research determined Bocourt's "black sea turtle" was not genetically distinct from ''C. mydas'', and thus
taxonomically
In biology, taxonomy () is the scientific study of naming, defining ( circumscribing) and classifying groups of biological organisms based on shared characteristics. Organisms are grouped into taxa (singular: taxon) and these groups are given ...
not a separate species.
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 ''
C. mydas agassizi'' referred only to the Pacific population known as the Galápagos green turtle.
This subdivision was later determined to be invalid and all species members were then designated ''Chelonia mydas''.
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
Green is the color between cyan and yellow on the visible spectrum. It is evoked by light which has a dominant wavelength of roughly 495570 nm. In subtractive color systems, used in painting and color printing, it is created by a combi ...
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.
As a species found worldwide, the green turtle has many local names. In the
Hawaiian language it is called ''honu'',
and it is locally known as a symbol of good luck and longevity.
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
Redang Island ( ms, Pulau Redang / 中文:热浪岛) is an island in Kuala Nerus District, Terengganu, Malaysia. It is one of the largest islands off the east coast of Peninsular Malaysia and as well as one of the most beautiful islands in the ...
, Malaysia
Malaysia ( ; ) is a country in Southeast Asia. The federation, federal constitutional monarchy consists of States and federal territories of Malaysia, thirteen states and three federal territories, separated by the South China Sea into two r ...
File:Young Honu-Kahala.png, alt=Photo of two swimming turtles, Immature Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state ...
an ''C. mydas''
File:Karettschildkroete 01.jpg, alt=Photo of swimming turtle at twilight, Swimming in a Mexican coral reef
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
Marsa Alam ( ar, مرسى علم ' , Classical Arabic ) is a town in south-eastern Egypt, located on the western shore of the Red Sea. It is currently seeing fast increasing popularity as a tourist destination and development following the openi ...
, Egypt
Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Medit ...
File:Green sea turtle portrait.JPG, Green sea turtle near Marsa Alam
Marsa Alam ( ar, مرسى علم ' , Classical Arabic ) is a town in south-eastern Egypt, located on the western shore of the Red Sea. It is currently seeing fast increasing popularity as a tourist destination and development following the openi ...
, Egypt
Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Medit ...
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
Description
![Chelonia](https://upload.wikimedia.org/wikipedia/commons/6/6d/Chelonia.svg)
Its appearance is that of a typical
sea turtle
Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerhe ...
. ''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.
Adult green turtles grow to long.
The average weight of mature individuals is and the average carapace length is . Exceptional specimens can weigh or even more, with the largest known ''C. mydas'' having weighed and measured in carapace length.
Anatomically, a few characteristics distinguish the green turtle from the other members of its family. Unlike its close relative the
hawksbill turtle
The hawksbill sea turtle (''Eretmochelys imbricata'') is a critically endangered sea turtle belonging to the family Cheloniidae. It is the only extant species in the genus ''Eretmochelys''. The species has a global distribution, that is lar ...
, the green turtle's snout is very short and its
beak
The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for eating, preening, manipulating objects, killing prey, fighting, probing for foo ...
is unhooked. The neck cannot be pulled into the shell. 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
A scute or scutum (Latin: ''scutum''; plural: ''scuta'' "shield") is a bony external plate or scale overlaid with horn, as on the shell of a turtle, the skin of crocodilians, and the feet of birds. The term is also used to describe the anterior po ...
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.
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.
Distribution
![Green turtle nesting sites](https://upload.wikimedia.org/wikipedia/commons/2/2d/Green_turtle_nesting_sites.svg)
The
range
Range may refer to:
Geography
* Range (geographic), a chain of hills or mountains; a somewhat linear, complex mountainous or hilly area (cordillera, sierra)
** Mountain range, a group of mountains bordered by lowlands
* Range, a term used to i ...
of the green sea turtle extends throughout
tropical
The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in
the Southern Hemisphere at S. The tropics are also referred to ...
and
subtropical oceans worldwide. The two major
subpopulation
In statistics, a population is a Set (mathematics), set of similar items or events which is of interest for some question or experiment. A statistical population can be a group of existing objects (e.g. the set of all stars within the Milky Way g ...
s are the Atlantic and the eastern Pacific subpopulations. Each population is genetically distinct, with its own set of nesting and feeding grounds within the population's known range.
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. 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
The Great Barrier Reef is the world's largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over over an area of approximately . The reef is located in the Coral Sea, off the coast of Queensland, ...
in Australia, and the
Caribbean Sea
The Caribbean Sea ( es, Mar Caribe; french: Mer des Caraïbes; ht, Lanmè Karayib; jam, Kiaribiyan Sii; nl, Caraïbische Zee; pap, Laman Karibe) is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. It is bounded by Mexico ...
.
Atlantic subpopulation
The green sea turtle can generally be found throughout the
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...
. Although the species is most abundant in tropical climates, green sea turtles can also be found in
temperate climate
In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout ...
s, and individuals have been spotted as far north as
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
in the western Atlantic, and the
British Isles
The British Isles are a group of islands in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isles, ...
in the east. The subpopulation's southern range is known until past the southern tip of Africa in the east and
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...
in the western Atlantic. The major nesting sites can be found on various islands in the
Caribbean, along the Atlantic coast of
Florida
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
in the United States, the eastern coast of the
South American continent and most notably, on isolated
North Atlantic islands.
In the Caribbean, major nesting sites have been identified on
Aves Island, the
U.S. Virgin Islands,
Puerto Rico
Puerto Rico (; abbreviated PR; tnq, Boriken, ''Borinquen''), officially the Commonwealth of Puerto Rico ( es, link=yes, Estado Libre Asociado de Puerto Rico, lit=Free Associated State of Puerto Rico), is a Caribbean island and unincorporated ...
, the
Dominican Republic
The Dominican Republic ( ; es, República Dominicana, ) is a country located on the island of Hispaniola in the Greater Antilles archipelago of the Caribbean region. It occupies the eastern five-eighths of the island, which it shares with ...
, and
Costa Rica. In recent years, there are signs of increased nesting in the Cayman Islands. One of the region's most important nesting grounds is in
Tortuguero in Costa Rica.
In fact, the majority of the Caribbean region's ''C. mydas'' population hails from a few beaches in Tortuguero.
Within United States waters, minor nesting sites have been noted in the states of
Georgia
Georgia most commonly refers to:
* Georgia (country), a country in the Caucasus region of Eurasia
* Georgia (U.S. state), a state in the Southeast United States
Georgia may also refer to:
Places
Historical states and entities
* Related to the ...
,
North Carolina
North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia and ...
, and
South Carolina
)'' Animis opibusque parati'' ( for, , Latin, Prepared in mind and resources, links=no)
, anthem = " Carolina";" South Carolina On My Mind"
, Former = Province of South Carolina
, seat = Columbia
, LargestCity = Charleston
, LargestMetro = ...
.
Florida
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
's east coast is the largest nesting site in the United States.
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
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
. Important feeding grounds in
Florida
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
include
Indian River Lagoon, the
Florida Keys,
Florida Bay
Florida Bay is the bay located between the southern end of the Florida mainland (the Florida Everglades) and the Florida Keys in the United States. It is a large, shallow estuary that while connected to the Gulf of Mexico, has limited exchange o ...
,
Homosassa
Homosassa is a census-designated place (CDP) in Citrus County, Florida, United States. The population was 2,578 at the 2010 census.
History
Homosassa is derived from a Seminole Indian name meaning either "river of fishes" or "pepper ridge".
I ...
,
Crystal River, and
Cedar Key
Cedar Key is a city in Levy County, Florida, United States. The population was 702 at the 2010 census. The Cedar Keys are a cluster of islands near the mainland. Most of the developed area of the city has been on Way Key since the end of the 19th ...
.
Notable locations in South America include secluded beaches in
Suriname and
French Guiana
French Guiana ( or ; french: link=no, Guyane ; gcr, label=French Guianese Creole, Lagwiyann ) is an overseas department/region and single territorial collectivity of France on the northern Atlantic coast of South America in the Guianas. ...
.
In the Southern Atlantic Ocean, the most notable nesting grounds for ''Chelonia mydas'' are found on the island of
Ascension,
hosts 6,000–13,000 turtle nests.
Indo-Pacific subpopulation
![Chelonia mydas is going for the air edit](https://upload.wikimedia.org/wikipedia/commons/6/6e/Chelonia_mydas_is_going_for_the_air_edit.jpg)
In the
Pacific
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contine ...
, its range reaches as far north as the southern coast of
Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S. ...
and as far south as
Chile
Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...
in the east. The turtle's distribution in the western Pacific reaches north to
Japan and southern parts of
Russia
Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...
's Pacific coast, and as far south as the northern tip of
New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
and a few islands south of
Tasmania
)
, nickname =
, image_map = Tasmania in Australia.svg
, map_caption = Location of Tasmania in AustraliaCoordinates:
, subdivision_type = Country
, subdi ...
. Significant nesting grounds are scattered throughout the entire Pacific region, including
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
, the
Hawaiian Islands, the
South Pacific, the northern coast of
Australia, and
Southeast Asia
Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical south-eastern region of Asia, consisting of the regions that are situated south of mainlan ...
. Major Indian Ocean nesting colonies include
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
,
Pakistan
Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's fifth-most populous country, with a population of almost 243 million people, and has the world's second-lar ...
,
Sri Lanka and other coastal countries.
The turtles can also be found throughout the
Indian Ocean
The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by t ...
; the east coast of the
African continent hosts a few nesting grounds, including islands in the waters around
Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...
.
Specific nesting grounds
Nesting grounds are found all along the Mexican coast. These turtles feed in seagrass pastures in the
Gulf of California
The Gulf of California ( es, Golfo de California), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Bermejo''), is a marginal sea of the Pacific Ocean that separates the Baja C ...
.
Green turtles belonging to the distinct Hawaiian subpopulation nest at the protected
French Frigate Shoals
The French Frigate Shoals ( Hawaiian: Kānemilohai) is the largest atoll in the Northwestern Hawaiian Islands. Its name commemorates French explorer Jean-François de La Pérouse, who nearly lost two frigates when attempting to navigate the sh ...
some west of the Hawaiian Islands.
In the
Philippines
The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no),
* bik, Republika kan Filipinas
* ceb, Republika sa Pilipinas
* cbk, República de Filipinas
* hil, Republ ...
, green turtles nest in the
Turtle Islands along with closely related
hawksbill turtle
The hawksbill sea turtle (''Eretmochelys imbricata'') is a critically endangered sea turtle belonging to the family Cheloniidae. It is the only extant species in the genus ''Eretmochelys''. The species has a global distribution, that is lar ...
s.
In December 2007, fishermen using a ''hulbot-hulbot'' (a type of
fish net
A fishing net is a net used for fishing. Nets are devices made from fibers woven in a grid-like structure. Some fishing nets are also called fish traps, for example fyke nets. Fishing nets are usually meshes formed by knotting a relatively ...
) accidentally caught an , long and wide turtle off Barangay Bolong,
Zamboanga City
Zamboanga City, officially the City of Zamboanga (Chavacano and es, Ciudad de Zamboanga, Tausūg: ''Dāira sin Sambuangan'', fil, Lungsod ng Zamboanga, ceb, Dakbayan sa Zamboanga), is a city in the Zamboanga Peninsula region of the Philipp ...
,
Philippines
The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no),
* bik, Republika kan Filipinas
* ceb, Republika sa Pilipinas
* cbk, República de Filipinas
* hil, Republ ...
. December is breeding season near the Bolong beach.
Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...
has a few nesting beaches, one in the
Meru Betiri
Meru may refer to:
Geography Kenya
* Meru, Kenya, a city in Meru County, Kenya
** Meru County, created by the merger of
*** Meru Central District
*** Meru North District
*** Meru South District
* Meru National Park, a Kenyan wildlife park
T ...
National Reserve in
East Java
East Java ( id, Jawa Timur) is a Provinces of Indonesia, province of Indonesia located in the easternmost hemisphere of Java island. It has a land border only with the province of Central Java to the west; the Java Sea and the Indian Ocean bord ...
.
Off the north-eastern and northern coasts of Australia, the
Great Barrier Reef
The Great Barrier Reef is the world's largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over over an area of approximately . The reef is located in the Coral Sea, off the coast of Queensland, ...
has two
genetically distinct populations; one north and one south. Within the reef, 20 separate locations consisting of small islands and
cays
A cay ( ), also spelled caye or key, is a small, low-elevation, sandy island on the surface of a coral reef. Cays occur in tropical environments throughout the Pacific, Atlantic, and Indian Oceans, including in the Caribbean and on the Great ...
were identified as nesting sites for either population of ''C. mydas''. Of these, the most important is on
Raine Island
Raine Island is a vegetated coral cay in total area situated on the outer edges of the Great Barrier Reef off north-eastern Australia. It lies approximately north-northwest of Cairns in Queensland, about east-north-east of Cape Grenville on ...
.
In the
Torres Strait
The Torres Strait (), also known as Zenadh Kes, is a strait between Australia and the Melanesian island of New Guinea. It is wide at its narrowest extent. To the south is Cape York Peninsula, the northernmost extremity of the Australian mai ...
there is a large rookery on
Bramble Cay
Bramble Cay, also known as Maizab Kaur (also spelt Maizub Kaur) and Massaramcoer, is a small cay located at the northeastern edge of Australia and the Torres Strait Islands of Queensland and at the northern end of the Great Barrier Reef. Lying ...
.
[ ] The
Coral Sea has nesting areas of world significance.
Major nesting sites are common on either side of the
Arabian Sea
The Arabian Sea ( ar, اَلْبَحرْ ٱلْعَرَبِيُّ, Al-Bahr al-ˁArabī) is a region of the northern Indian Ocean bounded on the north by Pakistan, Iran and the Gulf of Oman, on the west by the Gulf of Aden, Guardafui Channel ...
, both in
Ash Sharqiyah,
Oman
Oman ( ; ar, عُمَان ' ), officially the Sultanate of Oman ( ar, سلْطنةُ عُمان ), is an Arabian country located in southwestern Asia. It is situated on the southeastern coast of the Arabian Peninsula, and spans the mouth of ...
, and along the coast of
Karachi
Karachi (; ur, ; ; ) is the most populous city in Pakistan and 12th most populous city in the world, with a population of over 20 million. It is situated at the southern tip of the country along the Arabian Sea coast. It is the former c ...
,
Pakistan
Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's fifth-most populous country, with a population of almost 243 million people, and has the world's second-lar ...
. Some specific beaches there, such as
Hawke's Bay
Hawke's Bay ( mi, Te Matau-a-Māui) is a local government region on the east coast of New Zealand's North Island. The region's name derives from Hawke Bay, which was named by Captain James Cook in honour of Admiral Edward Hawke. The region i ...
and
Sandspit, are common to both ''C. mydas'' and
''L. olivacea'' subpopulation. Sandy beaches along
Sindh and
Balochistan
Balochistan ( ; bal, بلۏچستان; also romanised as Baluchistan and Baluchestan) is a historical region in Western and South Asia, located in the Iranian plateau's far southeast and bordering the Indian Plate and the Arabian Sea coastline. ...
are nesting sites. Some off the
Pakistani coast,
Astola island
Astola Island ( ur, ) also known as ''Jezira Haft Talar'' (Urdu, ) ''Satadip'' or 'Island of the Seven Hills', is a small uninhabited Pakistani island in the Arabian Sea approximately south of the nearest part of the coast and southeast of the ...
is another nesting beach.
Galápagos green turtle
![Green Sea Turtle Swimming in the Galápagos](https://upload.wikimedia.org/wikipedia/commons/a/a2/Green_Sea_Turtle_Swimming_in_the_Gal%C3%A1pagos.jpg)
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
William Dampier (baptised 5 September 1651; died March 1715) was an English explorer, pirate, privateer, navigator, and naturalist who became the first Englishman to explore parts of what is today Australia, and the first person to circumnav ...
.
Not much attention has been paid to them due to the overwhelming research done on the
Galápagos giant tortoises.
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.
At one point the name ''Chelonia agassizii'' was applied to this population as a separate species.
Analysis of
mitochondrial and
nuclear DNA
Nuclear DNA (nDNA), or nuclear deoxyribonucleic acid, is the DNA contained within each cell nucleus of a eukaryotic organism. It encodes for the majority of the genome in eukaryotes, with mitochondrial DNA and plastid DNA coding for the rest. I ...
of 15 nesting beaches,
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''
as such it is considered as a local variant of the populations of the East Pacific waters and those of other nesting areas.
The morphological distinctiveness of the Galápagos green turtle has given rise to the debate,
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.
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.
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.
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.
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). However, this is possibly a case of political taxonomy. As such the three major international checklists that cover turtles of the world
Reptile Database
The Reptile Database is a scientific database that collects taxonomic information on all living reptile species (i.e. no fossil species such as dinosaurs). The database focuses on species (as opposed to higher ranks such as families) and has entrie ...
the checklist of Fritz and Havas (2007)
and the IUCN Checklist (TTWG 2017)
all consider this a junior synonym.
Habitat
Green sea turtles move across three
habitat
In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...
types, depending on their
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
A seagrass meadow or seagrass bed is an underwater ecosystem formed by seagrasses. Seagrasses are marine (saltwater) plants found in shallow coastal waters and in the brackish waters of estuaries. Seagrasses are flowering plants with stems and ...
s. Entire generations often migrate between one pair of feeding and nesting areas.
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.
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.
Turtles spend most of their first five years in convergence zones within the bare open ocean that surround them.
These young turtles are rarely seen as they swim in deep,
pelagic
The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or w ...
waters.
Green sea turtles typically swim at .
Ecology and behavior
![Green turtle in Kona 2008](https://upload.wikimedia.org/wikipedia/commons/0/0f/Green_turtle_in_Kona_2008.jpg)
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
The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or w ...
organisms, part of the open ocean mini
nekton
Nekton or necton (from the ) refers to the actively swimming aquatic organisms in a body of water. The term was proposed by German biologist Ernst Haeckel to differentiate between the active swimmers in a body of water, and the passive organisms t ...
. In contrast, immature juveniles and adults are commonly found in
seagrass
Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the or ...
meadows closer inshore as
herbivorous
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpar ...
grazers.
Diet
![Green Sea Turtle grazing seagrass](https://upload.wikimedia.org/wikipedia/commons/d/d7/Green_Sea_Turtle_grazing_seagrass.jpg)
The diet of green turtles changes with age.
Juveniles are carnivorous, but as they mature they become omnivorous.
Young sea turtles eat
fish egg
An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the a ...
s,
sea hare
The clade Anaspidea, commonly known as sea hares ('' Aplysia'' species and related genera), are medium-sized to very large opisthobranch gastropod molluscs with a soft internal shell made of protein. These are marine gastropod molluscs in the ...
eggs,
hydrozoan
Hydrozoa (hydrozoans; ) are a taxonomic class of individually very small, predatory animals, some solitary and some colonial, most of which inhabit saline water. The colonies of the colonial species can be large, and in some cases the specialize ...
s,
bryozoans,
molluscs
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estim ...
,
jellyfish
Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals with umbrell ...
, small
invertebrates
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordat ...
,
worm
Worms are many different distantly related bilateral animals that typically have a long cylindrical tube-like body, no limbs, and no eyes (though not always).
Worms vary in size from microscopic to over in length for marine polychaete wo ...
s,
sponge
Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate throug ...
s,
algae, and
crustacean
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can ...
s.
Green sea turtles have a relatively slow growth rate because of the low nutritional value of their diet.
Body fat
Adipose tissue, body fat, or simply fat is a loose connective tissue composed mostly of adipocytes. In addition to adipocytes, adipose tissue contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, vascular e ...
turns green because of the consumed
vegetation
Vegetation is an assemblage of plant species and the ground cover they provide. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic characte ...
.
This diet shift has an effect on the green turtle's skull morphology. Their serrated jaw helps them chew green and red algae (such as filamentous red alga (''
Bostrychia
''Bostrychia'' is a genus of ibises in the family Threskiornithidae. Member species are found in many countries throughout Africa.
It contains the following five species:
Conservation
Four of these species are evaluated as Least Concern stat ...
''), red moss (''Caloglossa''), freshwater red algae (''
Compsopogon''), lobster horns (''
Polysiphonia
''Polysiphonia'' is a genus of filamentous red algae with about 19 species on the coasts of the British Isles and about 200 species worldwide, including Crete in Greece, Antarctica and Greenland. Its members are known by a number of common names ...
''), sea lettuce (''
Ulva lactuca
''Ulva lactuca'', also known by the common name sea lettuce, is an edible green alga in the family Ulvaceae. It is the type species of the genus '' Ulva''. A synonym is ''U. fenestrata'', referring to its "windowed" or "holed" appearance.
Des ...
''), green seaweed (''
Gayralia
''Gayralia'' is a genus of green algae in the family Gayraliaceae
Gayraliaceae is a family of green algae in the order Ulotrichales.
References
Ulvophyceae families
Ulotrichales
{{Green algae-stub ....
References
External links
...
''), and crinkle grass (''
Rhizoclonium
''Rhizoclonium'' is a genus of green algae in the family Cladophoraceae.See the NCBI
The National Center for Biotechnology Information (NCBI) is part of the United States National Library of Medicine (NLM), a branch of the National Institut ...
'')) and sea grasses. They also consume large quantities of wetland plants such as ''Avicennia schaueriana'' and ''
Sporobolus alterniflorus
''Sporobolus alterniflorus'', or synonymously known as ''Spartina alterniflora'', the smooth cordgrass, saltmarsh cordgrass, or salt-water cordgrass, is a perennial deciduous grass which is found in intertidal wetlands, especially estuarine salt ...
'', which are commonly found in salt marshes. Most adult sea turtles are strictly herbivorous.
Predators and parasites
Only human beings and the larger
shark
Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachi ...
s feed on ''C. mydas'' adults. Specifically,
tiger shark
The tiger shark (''Galeocerdo cuvier'') is a species of requiem shark and the last extant member of the family Galeocerdonidae. It is a large macropredator, capable of attaining a length over . Populations are found in many tropical and tempera ...
s (''Galeocerdo cuvier'') hunt adults in Hawaiian waters.
Juveniles and new hatchlings have significantly more predators, including
crabs, small
marine mammal
Marine mammals are aquatic mammals that rely on the ocean and other marine ecosystems for their existence. They include animals such as seals, whales, manatees, sea otters and polar bears. They are an informal group, unified only by their ...
s and
shorebird
245px, A flock of Dunlins and Red knots">Red_knot.html" ;"title="Dunlins and Red knot">Dunlins and Red knots
Waders or shorebirds are birds of the order Charadriiformes commonly found wikt:wade#Etymology 1, wading along shorelines and mudflat ...
s.
Additionally, their eggs are vulnerable to predation by scavengers like
red foxes and
golden jackal
The golden jackal (''Canis aureus''), also called common jackal, is a wolf-like canid that is native to Southeast Europe, Southwest Asia, South Asia, and regions of Southeast Asia. The golden jackal's coat varies in color from a pale creamy ...
s.
Green sea turtles have a variety of parasites including
barnacles,
leeches,
protozoans,
cestodes
Cestoda is a class of parasitic worms in the flatworm phylum (Platyhelminthes). Most of the species—and the best-known—are those in the subclass Eucestoda; they are ribbon-like worms as adults, known as tapeworms. Their bodies consist of man ...
, and
nematodes. 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
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.
Life cycle
![Baby Chelonia mydas 20060319](https://upload.wikimedia.org/wikipedia/commons/4/42/Baby_Chelonia_mydas_20060319.jpg)
Green sea turtles migrate long distances between feeding sites and nesting sites; some swim more than to reach their spawning grounds. Beaches in Southeast Asia, India, islands in the western Pacific, and Central America are where green sea turtles breed.
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.
Mating seasons vary between populations. For most ''C. mydas'' in the
Caribbean, mating season is from June to September.
The
French Guiana
French Guiana ( or ; french: link=no, Guyane ; gcr, label=French Guianese Creole, Lagwiyann ) is an overseas department/region and single territorial collectivity of France on the northern Atlantic coast of South America in the Guianas. ...
nesting subpopulation nests from March to June.
In the tropics, green turtles nest throughout the year, although some subpopulations prefer particular times of the year. In
Pakistan
Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's fifth-most populous country, with a population of almost 243 million people, and has the world's second-lar ...
,
Indian Ocean
The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by t ...
turtles nest year-round, but prefer the months of July to December.
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
Natal homing, or natal philopatry, is the homing process by which some adult animals return to their birthplace to reproduce. This process is primarily used by aquatic animals, such as sea turtles and Pacific salmon. Scientists believe that the m ...
.
[Wynekey, J.; Lohmann, J.K.; Musick, J.A. 2013. The biology of sea turtles. CRC Press. Vol 3. Pp 59–70] 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
Polyandry (; ) is a form of polygamy in which a woman takes two or more husbands at the same time. Polyandry is contrasted with polygyny, involving one male and two or more females. If a marriage involves a plural number of "husbands and wives ...
, although this does not seem to benefit hatchlings.
After mating in the water, the female moves above the beach's high tide line, where she digs a hole 11-22 inches in depth with her hind flippers and deposits her eggs. The hole is then covered up again.
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.
The eggs are round and white, and about 45 mm in diameter. The hatchlings remain buried for days until they all emerge together at night.
The temperature of the nest
determines the sex of the turtles at around the 20-40 day mark. At around 50 to 70 days, the eggs hatch during the night, and the hatchlings
instinctively head directly into the water. This is the most dangerous time in a turtle's life. As they walk, predators, such as
gull
Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and only distantly related to auks, and even more distantly to waders. Until the 21st century ...
s and
crabs, 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.
Juveniles spend three to five years in the open ocean before they settle as still-immature juveniles into their permanent shallow-water lifestyle.
It is speculated that they take twenty to fifty years to reach
sexual maturity
Sexual maturity is the capability of an organism to reproduce. In humans it might be considered synonymous with adulthood, but here puberty is the name for the process of biological sexual maturation, while adulthood is based on cultural definit ...
. Individuals live up to eighty years in the wild.
It is estimated that only 1% of hatchlings reach sexual maturity.
Each year on
Ascension Island in the
South Atlantic
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...
, ''C. mydas'' females create 6,000 to 25,000 nests. They are among the largest green turtles in the world; many are more than a metre in length and weigh up to .
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.
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.
Physiology and sensory modalities
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.
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 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.
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.
Natal homing
Natal homing, or natal philopatry, is the homing process by which some adult animals return to their birthplace to reproduce. This process is primarily used by aquatic animals, such as sea turtles and Pacific salmon. Scientists believe that the m ...
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 aren't 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.
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.
Unique characteristics and features
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.
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
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.
Importance to humans
![NSRW Turtles](https://upload.wikimedia.org/wikipedia/commons/c/c8/NSRW_Turtles.png)
Historically, the turtles' skin was
tanned and used to make
handbag
A handbag, commonly known as a purse or pocketbook in North American English, is a handled medium-to-large bag used to carry personal items.
Purse, handbag or pouch
The term "purse" originally referred to a small bag for holding coins. In man ...
s, especially in
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state ...
.
Ancient Chinese considered the flesh of sea turtles a culinary delicacy, including and especially ''C. mydas''.
Particularly for this species, the turtle's
fat
In nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such compounds, most commonly those that occur in living beings or in food.
The term often refers specifically to triglycerides (triple est ...
,
cartilage, and flesh, known as
calipee, are sought as ingredients for making
turtle soup
Turtle soup, also known as Terrapin soup, is a soup or stew made from the meat of turtles. Differing versions of the soup exist in some cultures and are viewed as a delicacy.
Versions China
In China, and in several countries in Southeast A ...
, a popular 19th-century English and American dish.
In
Java
Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mos ...
,
Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...
, sea turtle eggs were a popular delicacy. However, the turtle's flesh is regarded as ''
ḥarām
''Haram'' (; ar, حَرَام, , ) is an Arabic term meaning 'Forbidden'. This may refer to either something sacred to which access is not allowed to the people who are not in a state of purity or who are not initiated into the sacred knowle ...
'' or "unclean" under
Islamic law
Sharia (; ar, شريعة, sharīʿa ) is a body of religious law that forms a part of the Islamic tradition. It is derived from the religious precepts of Islam and is based on the sacred scriptures of Islam, particularly the Quran and the ...
(
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
Indonesian archipelago
The islands of Indonesia, also known as the Indonesian Archipelago ( id, Kepulauan Indonesia) or Nusantara, may refer either to the islands comprising the country of Indonesia or to the geographical groups which include its islands.
History ...
.
Bali has been importing sea turtles since the 1950s, as its own turtle supplies became depleted.
[
Sumertha, I.N. 1974. Perikanan penyu dan cara pengelolaan di Indonesia. ''Dokumen. Kom. IPB'' 8: 1–18. Cited in ] The mostly Hindu
Balinese do not eat the eggs, but sell them instead to local
Muslims.
Commercial farms, such as the
Cayman Turtle Farm
The Cayman Turtle Centre is a conservation facility and tourist attraction located in the district of West Bay in Grand Cayman, Cayman Islands. First established in 1968 as "Mariculture Ltd" and later called "Cayman Turtle Farm" by a group of Am ...
in the
West Indies
The West Indies is a subregion of North America, surrounded by the North Atlantic Ocean and the Caribbean Sea that includes 13 independent island countries and 18 dependencies and other territories in three major archipelagos: the Greate ...
, 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. 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.
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.
Sea turtles are integral to the history and culture of the
Cayman Islands. When the islands were first discovered by
Christopher Columbus
Christopher Columbus
* lij, Cristoffa C(or)ombo
* es, link=no, Cristóbal Colón
* pt, Cristóvão Colombo
* ca, Cristòfor (or )
* la, Christophorus Columbus. (; born between 25 August and 31 October 1451, died 20 May 1506) was a ...
in 1503, he named them "Las Tortugas" because of the abundance of sea turtles in the waters around the islands.
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
The Cayman Islands’ coat of arms consists of a shield, a crested helm and the motto. Three green stars, representing each of the three inhabited Islands (Grand Cayman, Little Cayman and Cayman Brac), are set in the lower two-thirds of the shiel ...
, which also forms part of the national
flag of the Cayman Islands
The flag of the Cayman Islands consists of a Blue Ensign defaced with the British overseas territory's coat of arms. Adopted in 1959 to supplement the Union Jack and to replace the flag of the Colony of Jamaica, it has been the flag of the C ...
. The country's currency uses a turtle as the watermark in its banknotes. A stylised sea turtle nicknamed "Sir Turtle" is the mascot of the national airline
Cayman Airways
Cayman Airways is the flag carrier airline of the British Overseas Territory of the Cayman Islands. With its head office in Grand Cayman, it operates mainly as an international and domestic scheduled passenger carrier, with cargo services avai ...
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
Native Hawaiians (also known as Indigenous Hawaiians, Kānaka Maoli, Aboriginal Hawaiians, First Hawaiians, or simply Hawaiians) ( haw, kānaka, , , and ), are the indigenous ethnic group of Polynesian people of the Hawaiian Islands.
Hawaii ...
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
Punalu'u Beach.
Conservation
![Suppenschildkröte](https://upload.wikimedia.org/wikipedia/commons/f/f5/Suppenschildkr%C3%B6te.jpg)
In recent
decade
A decade () is a period of ten years. Decades may describe any ten-year period, such as those of a person's life, or refer to specific groupings of calendar years.
Usage
Any period of ten years is a "decade". For example, the statement that "du ...
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".
Threats
Human action presents both intentional and unintentional threats to the species' survival. Intentional threats include continued
hunting
Hunting is the human practice of seeking, pursuing, capturing, or killing wildlife or feral animals. The most common reasons for humans to hunt are to harvest food (i.e. meat) and useful animal products ( fur/ hide, bone/tusks, horn/antler, ...
,
poaching
Poaching has been defined as the illegal hunting or capturing of wild animals, usually associated with land use rights.
Poaching was once performed by impoverished peasants for subsistence purposes and to supplement meager diets. It was set a ...
and egg harvesting. More dangerous are unintentional threats, including boat strikes, fishermen's nets that lack
turtle excluder devices,
pollution
Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the ...
and
habitat destruction
Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...
. Chemical pollution may create
tumor
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
s;
effluent from
harbor
A harbor (American English), harbour (British English; see spelling differences), or haven is a sheltered body of water where ships, boats, and barges can be docked. The term ''harbor'' is often used interchangeably with ''port'', which is a ...
s near nesting sites may create disturbances; and
light pollution
Light pollution is the presence of unwanted, inappropriate, or excessive use of artificial Visible spectrum, lighting. In a descriptive sense, the term ''light pollution'' refers to the effects of any poorly implemented lighting, during the day ...
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 intake toxins that can block their guts, displace the liver and intestines causing swelling of the tissue. Habitat loss usually occurs due to human development of nesting areas. Beach-front construction, land "reclamation" and increased tourism are examples of such development.
An infectious
tumor
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
-causing disease,
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.
In addition, at least in the Southwestern Atlantic (Río de la Plata, Uruguay), exotic invasive species such as the rapa whelk
Rapana venosa
''Rapana venosa'', common name the veined rapa whelk or Asian rapa whelk, is a species of large predatory sea snail, a marine gastropod mollusc or whelk, in the family Muricidae, the rock shells.
This large sea snail has become an invasive speci ...
, were reported massively bio-fouling immature green turtles, reducing buoyancy, increasing drag, and causing severe injuries to the carapace. Because of these threats, many populations are in a vulnerable state.
![Chelonia mydas (poached)](https://upload.wikimedia.org/wikipedia/commons/6/6b/Chelonia_mydas_%28poached%29.jpg)
Pacific green turtles' foraging habitats are poorly understood and mostly unknown.
These foraging grounds are most likely along the coast of Baja California, Mexico and southern California,
[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.] 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.
The only foraging area that has been identified is the San Diego Bay, but it is heavily polluted with metals and PCBs.
These contaminants have a negative effect on the ocean environment, and have been shown to cause lesions and sometimes mortality.
Green turtles also are threatened by entanglement and ingestion of plastic.
In San Diego Bay, an adult green turtle was found dead with monofilament netting tightly packed in its esophagus.
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 Temperature-dependent sex determination (TSD) is a type of environmental sex determination in which the temperatures experienced during embryonic/larval development determine the sex of the offspring. It is only observed in reptiles and teleost fish ...
and the rising temperatures in the northern
Great Barrier Reef
The Great Barrier Reef is the world's largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over over an area of approximately . The reef is located in the Coral Sea, off the coast of Queensland, ...
region. Construction of new
thermal power station
A thermal power station is a type of power station in which heat energy is converted to electrical energy. In a steam-generating cycle heat is used to boil water in a large pressure vessel to produce high-pressure steam, which drives a stea ...
s can raise local water temperature, which is also said to be a threat.
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".
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.
Global initiatives
![Confiscated musical instrument made from green turtle](https://upload.wikimedia.org/wikipedia/commons/9/97/Confiscated_musical_instrument_made_from_green_turtle.jpg)
The
International Union for Conservation of Nature
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of nat ...
(IUCN) has repeatedly listed green sea turtles in its
Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biologi ...
under differing criteria. In 1982, they officially classified it as an
endangered species.
The 1986,
1988,
1990,
1994,
and the landmark 1996 edition of the
IUCN Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...
, retained the listing.
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.
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
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
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.
On 3 May 2007, ''C. mydas'' was listed on Appendix I of the
Convention on International Trade in Endangered Species
CITES (shorter name for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of interna ...
(CITES) as a member of the family
Cheloniidae
Cheloniidae is a family of typically large marine turtles that are characterised by their common traits such as, having a flat streamlined wide and rounded shell and almost paddle-like flippers for their forelimbs. They are the only sea turtles t ...
.
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
Australian 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).
The
Zoological Society of London
The Zoological Society of London (ZSL) is a charity devoted to the worldwide conservation of animals and their habitats. It was founded in 1826. Since 1828, it has maintained the London Zoo, and since 1931 Whipsnade Park.
History
On 29 ...
has listed the reptile as an
EDGE species
Evolutionarily Distinct and Globally Endangered (EDGE) species are animal species which have a high 'EDGE score', a metric combining endangered conservation status with the genetic distinctiveness of the particular taxon. Distinctive species have ...
.
The
Mediterranean
The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western Europe, Western and Southern Europe and Anatolia, on the south by North Africa ...
population is listed as critically endangered.
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
The World Wide Fund for Nature Inc. (WWF) is an international non-governmental organization founded in 1961 that works in the field of wilderness preservation and the reduction of human impact on the environment. It was formerly named the Wor ...
has labeled populations in Pakistan as "rare and declining".
Since 1999, The
Florida Aquarium
The Florida Aquarium is a 501(c)(3) non-profit organization, publicly operated institution located in downtown Tampa, Florida, United States. It is a large scale, aquarium and is accredited by the Association of Zoos and Aquariums. This means ...
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 deemed releasable 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
Apollo Beach is an unincorporated census-designated place in Hillsborough County, Florida, United States. The population was 14,055 at the 2010 census, up from 7,444 at the 2000 census.
Geography
Apollo Beach is located in southern Hillsborough ...
, 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
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
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
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
, their nests, hatchlings or parts thereof, regardless of applicant's possession of any federal permit.
In the State of
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state ...
, 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 House of Representatives, often referred to as the House of Representatives, the U.S. House, or simply the House, is the lower chamber of the United States Congress, with the Senate being the upper chamber. Together they ...
, the
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.
Country-specific initiatives
![OsakaAquarium SeaTurtle](https://upload.wikimedia.org/wikipedia/commons/7/71/OsakaAquarium_SeaTurtle.jpg)
In addition to management by global entities such as the IUCN and CITES, specific countries around the world have undertaken conservation efforts.
The
Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...
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.
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
Hindus (; ) are people who religiously adhere to Hinduism. Jeffery D. Long (2007), A Vision for Hinduism, IB Tauris, , pages 35–37 Historically, the term has also been used as a geographical, cultural, and later religious identifier for ...
religious ceremonies. While conservationists respect the need for turtles in rituals, they wanted a smaller quota.
Multiple
protected areas of the Philippines
This is a list of protected areas of the Philippines administered by the Department of Environment and Natural Resources (DENR)'s Biodiversity Management Bureau under the National Integrated Protected Areas System (NIPAS) Act of 1992. As of 202 ...
have significant green sea turtle nesting and feeding sites. The most notable is
Turtle Islands Wildlife Sanctuary
Turtle Islands Wildlife Sanctuary is a protected area in the municipality of Turtle Islands in Tawi-Tawi, Philippines.
Background
Together with three islands of neighbour country Malaysia and the surrounding coral waters, Turtle Islands are one ...
, an
UNESCO
The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations (UN) aimed at promoting world peace and security through international cooperation in education, arts, sciences and culture. It ...
tentative site which encompasses an entire municipality and one of Southeast Asia's most important green sea turtle nesting sites. Other notable sites include the
UNESCO
The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations (UN) aimed at promoting world peace and security through international cooperation in education, arts, sciences and culture. It ...
tentative site of El Nido-Taytay Management Resource Protected Area and the
UNESCO
The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations (UN) aimed at promoting world peace and security through international cooperation in education, arts, sciences and culture. It ...
World Heritage Site
A World Heritage Site is a landmark or area with legal protection by an international convention administered by the United Nations Educational, Scientific and Cultural Organization (UNESCO). World Heritage Sites are designated by UNESCO for h ...
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.
Ecotourism
Ecotourism is a form of tourism involving responsible travel (using sustainable transport) to natural areas, conserving the environment, and improving the well-being of the local people. Its purpose may be to educate the traveler, to provide fund ...
is one initiative in
Sabah
Sabah () is a state of Malaysia located in northern Borneo, in the region of East Malaysia. Sabah borders the Malaysian state of Sarawak to the southwest and the North Kalimantan province of Indonesia to the south. The Federal Territory o ...
,
Malaysia
Malaysia ( ; ) is a country in Southeast Asia. The federation, federal constitutional monarchy consists of States and federal territories of Malaysia, thirteen states and three federal territories, separated by the South China Sea into two r ...
. The island of
Pulau Selingan is home to a turtle
hatchery
A hatchery is a facility where eggs are hatched under artificial conditions, especially those of fish, poultry or even turtles. It may be used for ex-situ conservation purposes, i.e. to breed rare or endangered species under controlled cond ...
. 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
Tourism is travel for pleasure or business; also the theory and practice of touring, the business of attracting, accommodating, and entertaining tourists, and the business of operating tours. The World Tourism Organization defines tourism mo ...
assist in the release of the baby turtles into the sea.
The
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state ...
an subpopulation has made a remarkable comeback and is now one focus of ecotourism and has become something of a state
mascot
A mascot is any human, animal, or object thought to bring luck, or anything used to represent a group with a common public identity, such as a school, professional sports team, society, military unit, or brand name. Mascots are also used as fi ...
. Students of
Hawaii Preparatory Academy
Hawaii Preparatory Academy (also known as HPA) is a coeducational, private, day and international boarding school in Kamuela, Hawaii, providing K-12 education. The school has an annual day tuition at the Lower School (K-5) of $22,900, $25,300 at t ...
on
the Big Island have tagged thousands of specimens since the early 1990s.
In the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...
the species is protected by a
Biodiversity Action Plan, due to excess harvesting and
marine pollution.
The Pakistani-branch of the
World Wide Fund for Nature
The World Wide Fund for Nature Inc. (WWF) is an international non-governmental organization founded in 1961 that works in the field of wilderness preservation and the reduction of human impact on the environment. It was formerly named the Wor ...
has been initiating projects for secure turtle hatching since the 1980s. However, the population has continued to decline.
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
Tortuguero National Park is a national park in the Limón Province of Costa Rica. It is situated within the Tortuguero Conservation Area of the northeastern part of the country.
Despite its remote location, reachable only by airplane or boat, it ...
was formally established in 1976, in part, to protect that region's nesting grounds.
On
Ascension Island, which contains some of the most important nesting beaches, an active conservation program has been implemented.
Karumbé has been monitoring foraging and developmental areas of juvenile green turtles in Uruguay since 1999.
Cayman Turtle Farm
The Cayman Turtle Centre is a conservation facility and tourist attraction located in the district of West Bay in Grand Cayman, Cayman Islands. First established in 1968 as "Mariculture Ltd" and later called "Cayman Turtle Farm" by a group of Am ...
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. Since its beginning in 1968, the farm has released over 31,000 turtles into the wild,
and each year more captive-bred turtles are released into the
Caribbean Sea
The Caribbean Sea ( es, Mar Caribe; french: Mer des Caraïbes; ht, Lanmè Karayib; jam, Kiaribiyan Sii; nl, Caraïbische Zee; pap, Laman Karibe) is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. It is bounded by Mexico ...
from beaches around the island of
Grand Cayman
Grand Cayman is the largest of the three Cayman Islands and the location of the territory's capital, George Town. In relation to the other two Cayman Islands, it is approximately 75 miles (121 km) southwest of Little Cayman and 90 miles (1 ...
. 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. On February 19, 2012 the farm released the first 2nd-generation captive-bred green sea turtle equipped with a Position Tracking Transponder, or PTT (also known as a satellite tag). 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, 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
Grand Cayman is the largest of the three Cayman Islands and the location of the territory's capital, George Town. In relation to the other two Cayman Islands, it is approximately 75 miles (121 km) southwest of Little Cayman and 90 miles (1 ...
and nesting on its beaches.
In the Pacific, green sea turtles nest on the ''motu'' (
islets
An islet is a very small, often unnamed island. Most definitions are not precise, but some suggest that an islet has little or no vegetation and cannot support human habitation. It may be made of rock, sand and/or hard coral; may be permanent ...
) in the
Funafuti Conservation Area
The Funafuti Conservation Area is a marine conservation area covering 33 square kilometers (12.74 square miles) of reef, lagoon and ''motu'' (islets) on the western side of Funafuti atoll in Tuvalu. The marine environment of the 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
Funafuti is the capital of the island nation of Tuvalu. It has a population of 6,320 people (2017 census), and so it has more people than the rest of Tuvalu combined, with approximately 60% of the population. It consists of a narrow sweep of lan ...
atoll in
Tuvalu
Tuvalu ( or ; formerly known as the Ellice Islands) is an island country and microstate in the Polynesian subregion of Oceania in the Pacific Ocean. Its islands are situated about midway between Hawaii and Australia. They lie east-nor ...
.
On
Raine Island
Raine Island is a vegetated coral cay in total area situated on the outer edges of the Great Barrier Reef off north-eastern Australia. It lies approximately north-northwest of Cairns in Queensland, about east-north-east of Cape Grenville on ...
, 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
The Queensland Government is the democratic administrative authority of the Australian state of Queensland. The Government of Queensland, a parliamentary constitutional monarchy was formed in 1859 as prescribed in its Constitution, as amended f ...
,
BHP
BHP Group Limited (formerly known as BHP Billiton) is an Australian multinational mining, metals, natural gas petroleum public company that is headquartered in Melbourne, Victoria, Australia.
The Broken Hill Proprietary Company was founded ...
(as corporate sponsor), the Great Barrier Reef Marine Park Authority, Great Barrier Reef Foundation, and
Wuthathi
The Wuthathi, also known as the Mutjati, are an Aboriginal Australian people of the state of Queensland. Anthropologist Norman Tindale distinguished the Mutjati from the Otati, whereas AIATSIS treats the two ethnonyms as variants related to th ...
and
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
In 3D computer graphics, 3D modeling is the process of developing a mathematical coordinate-based representation of any surface of an object (inanimate or living) in three dimensions via specialized software by manipulating edges, vertices, an ...
,
satellite
A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioi ...
technology and
drone
Drone most commonly refers to:
* Drone (bee), a male bee, from an unfertilized egg
* Unmanned aerial vehicle
* Unmanned surface vehicle, watercraft
* Unmanned underwater vehicle or underwater drone
Drone, drones or The Drones may also refer to:
...
s was employed, and monitoring continues.
, a project called "The Turtle Cooling Project" is being undertaken by scientists from the
World Wildlife Fund
The World Wide Fund for Nature Inc. (WWF) is an international non-governmental organization founded in 1961 that works in the field of wilderness preservation and the reduction of human impact on the environment. It was formerly named the Wo ...
Australia,
University of Queensland
, mottoeng = By means of knowledge and hard work
, established =
, endowment = A$224.3 million
, budget = A$2.1 billion
, type = Public research university
, chancellor = Peter Varghese
, vice_chancellor = Deborah Terry
, city = B ...
,
Deakin University
Deakin University is a public university in Victoria, Australia. Founded in 1974, the university was named after Alfred Deakin, the second Prime Minister of Australia.
Its main campuses are in Melbourne's Burwood suburb, Geelong Waurn Ponds, ...
and the
Queensland Government
The Queensland Government is the democratic administrative authority of the Australian state of Queensland. The Government of Queensland, a parliamentary constitutional monarchy was formed in 1859 as prescribed in its Constitution, as amended f ...
. It is looking at the effect of
global warming
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
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 and Moulter Cay.
Genetics
The
genome
In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding g ...
of ''Chelonia mydas'' was sequenced in 2013 to examine the development and evolution of the turtle body plan.
See also
*
Sea Turtle Association of Japan, Kuroshima Research Station
Kuroshima Research Station started in 1973, under the name of the UnderwaterPark Foundation, Yaeyama Underwater Park Research Institute, for the purpose of managing and utilizing the underwater area in Sekisei(Jap. 石西) lagoon between Ishiga ...
*
T.K. Bellis The "Turtle King".
References
External links
*
*
Images and movies (''Chelonia mydas'')ARKive
US Fish and Wildlife Service
Desktop wallpaper & fun green turtle factsGreen turtle video– Macaulay Library
Baby green sea turtles– Open Water 859
*
{{Authority control
green sea turtle
green sea turtle
Pantropical fauna
Fauna of Ascension Island
Reptiles of the Dominican Republic
Marine fauna of Northern Australia
Natural history of Balochistan, Pakistan
Endangered species
Species endangered by habitat loss
green sea turtle
Taxa named by Carl Linnaeus