
Green Turtle
Chelonia mydas

Protected Status
Quick Facts

Green sea turtle. Credit: NOAA Pacific Islands Fisheries Science Center
About the Species

Green sea turtle. Credit: NOAA Pacific Islands Fisheries Science Center
The green sea turtle is the largest hard-shelled sea turtle. They are unique among sea turtles in that they are herbivores, eating mostly seagrasses and algae. This diet is what gives their fat a greenish color (not their shells), which is where their name comes from.
Green turtles are found throughout the world. They nest in over 80 countries and live in the coastal areas of more than 140 countries. Historically, green turtles were exploited for their fat, meat and eggs, causing global population declines. Many countries, including the United States, prohibit the killing of sea turtles and collection of their eggs. However, in some areas, the killing of green turtles for their meat or to supply shells to the wildlife trafficking trade remains a threat to their recovery. Bycatch in commercial and recreational fishing gear, vessel strikes, loss of nesting habitat from coastal development, and climate change are the biggest threats facing green turtles.
NOAA Fisheries and our partners are dedicated to protecting and recovering green turtle populations worldwide. We use a variety of innovative techniques to study, protect, and recover these threatened and endangered populations. We engage our partners as we develop measures and recovery plans that foster the conservation and recovery of green turtles and their habitats. And we fund research, monitoring, and conservation projects to implement priorities outlined in recovery plans.
Population Status
Green turtles are found worldwide with 11 distinct population segments (DPS) listed under the Endangered Species Act. The largest green turtle nesting populations in the world are found at:
- Tortuguero on the Caribbean coast of Costa Rica—30,000 females nest per season (on average)
- Raine Island on the Great Barrier Reef in Australia—During a peak nesting season, up to 60,000 females nest on this island and the surrounding reef
Green turtles nest in over 80 countries, but in the United States, nesting green turtles are primarily found in the Hawaiian Islands, U.S. Pacific Island territories (Guam, the Commonwealth of the Northern Mariana Islands, and American Samoa), Puerto Rico, the Virgin Islands, and Florida. Nesting also occurs annually in Georgia, South Carolina, North Carolina, and Texas.
The 2015 ESA status review of the green sea turtle provides additional information for this species.
Protected Status
ESA Endangered
- Central South Pacific DPS
ESA Endangered
- Central West Pacific DPS
ESA Endangered - Foreign
- Mediterranean DPS
ESA Threatened
- Central North Pacific DPS
ESA Threatened
- East Pacific DPS
ESA Threatened
- North Atlantic DPS
ESA Threatened
- South Atlantic DPS
ESA Threatened - Foreign
- East Indian-West Pacific DPS
ESA Threatened - Foreign
- North Indian DPS
ESA Threatened - Foreign
- Southwest Indian DPS
ESA Threatened - Foreign
- Southwest Pacific DPS
CITES Appendix I
- Throughout Its Range
SPAW Annex II
- Throughout the Wider Caribbean Region
Appearance
Green turtles are the largest of all the hard-shelled sea turtles, but have a comparatively small head. A typical adult is 3 to 4 feet long and weighs 300 to 350 pounds. They have dark brown, grey, or olive colored shells and a much lighter, yellow-to-white underside. Their shells have five scutes running down the middle and four scutes on each side. Other distinct characteristics of the green turtle are their serrated beak on the lower jaws and two large scales located between the eyes.
Behavior and Diet
Green turtles, like all sea turtles, are reptiles and must surface to breathe and lay their eggs on land. Green turtles migrate hundreds to thousands of kilometers each way between their foraging grounds and nesting beaches. They are solitary, night-time nesters.
The life history of green turtles involves a series of stages of development from hatchling to adult. After emerging from the nest, hatchlings swim to offshore areas, where they live for several years in pelagic habitat. Juveniles eventually leave the open ocean habitat and travel to nearshore foraging grounds in shallow coastal habitats, where they mature to adulthood and spend the remainder of their lives. Adults migrate every 2 to 5 years from their coastal foraging areas to the waters off the nesting beaches where they originally hatched to reproduce.
Green turtles are the only herbivorous species of sea turtle. Their diet mainly consists of algae and seagrasses, though they may also forage on sponges, invertebrates, and discarded fish. The East Pacific green turtle tends to eat more animal prey than other populations. Prior to recruiting to nearshore foraging areas, pelagic juveniles forage on plant and animal life found in oceanic drift communities (such as pelagic Sargassum communities).
Where They Live
Green turtles are found worldwide primarily in subtropical and temperate regions of the Atlantic, Pacific, and Indian Oceans, and in the Mediterranean Sea.
In U.S. Atlantic and Gulf of Mexico waters, green turtles are found in inshore and nearshore waters from Texas to Maine, the U.S. Virgin Islands, and Puerto Rico. Important feeding areas in Florida include the Indian River Lagoon, the Florida Keys, Florida Bay, the Dry Tortugas, Homosassa, Crystal River, Cedar Key, and St. Joseph Bay.
In the eastern North Pacific, green turtles have been sighted as far north as southern Alaska, but most commonly occur from southern California to northwestern Mexico. Elsewhere in the U.S. Pacific, green turtles occur in Hawaii, American Samoa, Guam, and the Commonwealth of the Northern Mariana Islands.
Green turtles occur in many countries, making it critical to work together for their protection and recovery.

Lifespan & Reproduction
Green turtles are long-lived and could live for at least 70 years or more. Female green turtles reach maturity at 25 to 35 years. Every 2 to 5 years they undertake reproductive migrations and return to nest on a beach in the general area where they hatched decades earlier.
In the United States, the breeding season begins in late spring. Males mate with females on foraging grounds, along migratory pathways, and off nesting beaches. Green turtles lay about 110 eggs per nest and will nest every 2 weeks over several months before leaving the nesting area and returning to their foraging grounds.
After about two months incubating in the warm sand, the eggs hatch and the hatchlings make their way to the water. Hatchlings orient seaward by moving away from the darkest silhouette of the landward dune or vegetation to crawl towards the brightest horizon. On undeveloped beaches, this is toward the open horizon over the ocean.
Threats
Bycatch in Fishing Gear
A primary threat to sea turtles is their unintended capture in fishing gear which can result in drowning or cause injuries that lead to death or debilitation (for example, swallowing hooks, or flipper entanglement). The term for this unintended capture is bycatch. Sea turtle bycatch is a worldwide problem. The primary types of gear that result in bycatch of green turtles include trawls, gillnets, longlines, hook and line, and pot/traps.
Direct Harvest of Turtles and Eggs
Historically, green turtles were killed in extraordinarily high numbers for their fat, meat, and eggs. This led to the catastrophic global decline of the species. While illegal in the United States, killing green turtles and collecting their eggs remains legal in some countries and this can disrupt regional efforts to recover this species.
Loss and Degradation of Nesting Habitat
Coastal development and rising seas from climate change are leading to the loss of nesting beach habitat for green turtles. Shoreline hardening or armoring (e.g., seawalls) can result in the complete loss of dry sand suitable for successful nesting. Artificial lighting on and near nesting beaches can deter nesting females from coming ashore to nest and can disorient hatchlings trying to find the sea after emerging from their nests.
Vessel Strikes
Various types of watercraft can strike green turtles when they are at or near the surface resulting in injury or death. Vessel strikes are a major threat to green turtles, in particular large juveniles and adults near ports, waterways, and developed coastlines throughout their range. High boat traffic areas such as marinas and inlets present a higher risk to green turtles. Adult green turtles, in particular nesting females, are more susceptible to vessel strikes when making reproductive migrations and while they are nearshore during the nesting season.
Ocean Pollution/Marine Debris
Increasing pollution of nearshore and offshore marine habitats threatens all sea turtles and degrades their habitats. The Deepwater Horizon oil spill was the largest offshore oil spill in U.S. history and affected nesting (including nesting females, eggs, and hatchlings), small juvenile, large juvenile, and adult sea turtles throughout the Gulf of Mexico. Ingestion of marine debris is another threat to all species of sea turtles. Green turtles may ingest marine debris such as fishing line, balloons, plastic bags, floating tar or oil, and other materials discarded by humans which they can mistake for food. They may also become entangled in marine debris, including lost or discarded fishing gear, and can be killed or seriously injured.
Climate Change
For all sea turtles, a warming climate is likely to result in changes in beach morphology and higher sand temperatures, which can be lethal to eggs or alter the ratio of male and female hatchlings produced. Rising seas and storm events cause beach erosion, which may flood nests or wash them away. Changes in the temperature of the marine environment are likely to alter the abundance and distribution of food resources, leading to a shift in the migratory and foraging range and nesting season of green turtles.
Disease
Fibropapillomatosis is a disease that causes external and internal tumors in green turtles. These tumors can significantly affect their ability to swim and feed and can lead to death. The disease is most prevalent in green turtles and some evidence has linked the disease prevalence to degraded marine habitats.
Scientific Classification
Kingdom | Animalia | Phylum | Chordata | Class | Reptilia | Order | Testudines | Family | Cheloniidae | Genus | Chelonia | Species | mydas |
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Last updated by NOAA Fisheries on 09/15/2022
What We Do
Conservation & Management
Since 1977, NOAA Fisheries and the U.S. Fish and Wildlife Service have shared jurisdiction of sea turtles listed under the ESA. A Memorandum of Understanding outlines our specific roles: NOAA Fisheries leads the recovery and conservation efforts for sea turtles in the marine environment, and the U.S. FWS leads the conservation and recovery efforts for sea turtles on nesting beaches.
We are committed to the protection and conservation of green turtles by:
- Working with partners to ensure compliance with national, state, and U.S. territory laws to protect sea turtles
- Cooperating with international partners to implement conservation measures and establish agreements, such as international treaties that protect sea turtles
- Researching, developing, and implementing changes to fishing gear practices and/or fishing gear modifications (e.g., turtle excluder devices), using large circle hooks in longline fisheries, and implementing spatial or temporal closures to avoid or minimize bycatch
- Designating critical habitat areas essential for the conservation of green turtles
- Protecting and monitoring green turtles in the marine environment and on nesting beaches
- Conducting research on threats and developing conservation measures that reduce threats and promote recovery
- Collecting information on the species biology and ecology to better inform conservation management strategies and to assess progress toward recovery
- Conducting and supporting education and outreach efforts to the general public by raising awareness on threats to sea turtles, highlighting the importance of sea turtle conservation, and sharing ways people can help sea turtles
- Working with partners to study and raise awareness about illegal sea turtle trade
Science
We conduct various research activities on the biology, behavior, and ecology of green sea turtles. The results of this research are used to evaluate population trends, inform conservation management strategies, and to assess progress toward recovery for this imperiled species. Our work includes:
- Monitoring populations through vessel-based or aerial surveys, nesting beach studies, satellite tracking, genetics, and mark-recapture (flipper tagging) studies
- Studying foraging and reproductive behavior to understand demographics, physiology, habitat use, and resource requirements
- Tracking individuals over time to understand important aspects of their life history such as growth and age to maturity
- Evaluating life history and population health information from stranding and fisheries bycatch datasets
- Understanding impacts of change in environmental and ocean conditions on sea turtle abundance, distribution, and demographics
- Estimating population abundance and analyzing trends
- Monitoring fisheries impacts and designing fishing gear to minimize bycatch during commercial and recreational fishing operations
- Capacity building and training to share the latest scientific techniques and tools to monitor sea turtle populations globally
Featured News



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Management Overview
Green turtles are protected under the Endangered Species Act. Eleven distinct population segments (DPS) are listed as endangered or threatened. This means that the green turtle is in danger of extinction, now or in the foreseeable future, throughout all or a significant portion of its range. NOAA Fisheries is working to protect this species in many ways, with the goal of conserving and recovering each of the DPSs.
In the United States, NOAA Fisheries and the U.S. Fish and Wildlife Service have joint jurisdiction for sea turtles, with NOAA having the lead in the marine environment and U.S. FWS having the lead on the nesting beaches. Both federal agencies, along with many state and U.S. territory agencies and international partners, are working together to conserve and recover sea turtles and have issued regulations to eliminate or reduce threats to sea turtles.
Regulatory History
The green turtle was first listed under the Endangered Species Act in 1978. In April 2016, the original listing was revised by listing eight distinct population segments (DPS) as threatened and three DPS as endangered. The 2015 ESA status review provided the scientific basis to revise the ESA listings.
In 1992, we finalized regulations to require turtle excluder devices (TEDs) in shrimp trawl fisheries to reduce sea turtle bycatch. Since then, we have updated these regulations as new information became available and TEDs were modified to improve their turtle exclusion rates.
We have also implemented other measures to reduce sea turtle bycatch in fisheries through regulations and permits under both the ESA and Magnuson-Stevens Act.These requirements include the use of large circle hooks in longline fisheries, time and area closures/mesh size restrictions for gillnets, and modifications to Virginia pound net leaders and Atlantic sea scallop dredges.
Key Actions and Documents
Incidental Take Permit to North Carolina Division of Marine Fisheries (Sea Turtles and Sturgeon)
Incidental Take Permit to Barney Davis, LLC.
Incidental Take Permit to North Carolina Division of Marine Fisheries for Sea Turtles
Last updated by NOAA Fisheries on 09/15/2022
Science Overview
NOAA Fisheries conducts research on the biology, behavior, and ecology of the green sea turtle. The results of this research are used to inform management decisions and enhance recovery efforts for the species.
Population Assessments
Sea turtle population assessments ideally include information on the species’ abundance and distribution, life history, and human impacts. This information can help NOAA Fisheries evaluate the effectiveness of conservation and recovery measures, and can help guide actions to enhance recovery. To estimate population abundance, researchers conduct aerial and vessel-based surveys of selected areas and capture and mark turtles in the water and on beaches. We also incorporate data collected on nesting beaches, via stranding networks, and from fisheries observer programs. Other information that informs sea turtle population assessments includes population structure (genetic analyses), age to maturity, survivorship of the various life stages (e.g., hatchling, juvenile, adult), foraging and reproductive behavior, movement and distribution, and habitat studies.

Tagging and Tracking Studies
Satellite telemetry allows researchers to track sea turtles as they migrate between and within foraging and nesting areas. Tags are designed and attached in a manner that minimizes disturbance and/or harm to the turtle. The data help us understand migration patterns, identify feeding areas, and identify where turtles overlap with their primary threats (e.g., fisheries, vessel traffic).
Research to Reduce Bycatch in Fishing Gear
We observe fisheries to understand the level of sea turtle bycatch and the ways in which turtles interact with fishing gear. We work with partners and industry to develop modifications to fishing gear and/or fishing practices to reduce sea turtle bycatch while at the same time retaining a sustainable catch of targeted species. These efforts include the development of Turtle Excluder Devices (TEDs) for use in trawl fisheries, use of circle hooks and certain bait types in longline fisheries, time and area closures/mesh size restrictions and low profile designs for gillnets, and modifications to Virginia pound net leaders and Atlantic scallop dredge gear.
Learn more about our fishing gear research
Sea Turtle Genetics
NOAA Fisheries’ National Sea Turtle Molecular Genetics Center serves as a worldwide central repository for sea turtle tissue and DNA samples and constitutes a major area of research supporting sea turtle conservation. For example, a turtle’s genetic “fingerprint” can be used to determine which nesting population it originated from.
Learn more about our turtle genetics and isotope studies
Life History Studies
Life history studies include gathering information on such things as migration patterns, where turtles nest and forage, growth rates, age to maturity, and sex ratios. This information is important in understanding key biological parameters that influence population trends and inform the conservation status.
More Information
- Green Turtle Research and Conservation in Southern California
- Sea Turtle Research in the Pacific
- Sea Turtle Ecology and Population Dynamics in the Northeast
- Southwest Fisheries Science Center Marine Turtle Research Program
- Scientific Research and Enhancement Permits
- Cooperative Marine Turtle Tagging Program
Recent Science Blogs
Last updated by NOAA Fisheries on 09/15/2022
Documents
Northern Gulf of Mexico Sea Turtle Strandings: A Summary of Findings and Analyses from 2015–2019
The Technical Memo presents information, analyses, and conclusions related to the study of sea…
Biological Opinion on the Federally Regulated Oil and Gas Program Activities in the Gulf of Mexico
Programmatic biological opinion on the Gulf of Mexico oil and Gas Program in federal waters…
Integrated Bayesian models to estimate bycatch of sea turtles in the Gulf of Mexico and southeastern U.S. Atlantic coast shrimp otter trawl fishery
Elizabeth A. Babcock, Michael Barnette, James Bohnsack, John Jeffery Isely, Clay Porch, Paul M…
Report of the Technical Expert Workshop: Developing Recommendations for Field Response, Captive Management, and Rehabilitation of Sea Turtles with Fibropapillomatosis
NOAA and USFWS hosted a workshop in St. Petersburg, Florida on September 6, 2017 to seek input on…
Data & Maps
Recovery Action Database
Tracks the implementation of recovery actions from Endangered Species Act (ESA) recovery plans.
Last updated by NOAA Fisheries on 09/15/2022