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25. Green Turtle

Chelonia mydas

About

The green turtle is a truly global species, occurring across the tropics and subtropics. Females show the incredible behaviour of natal homing, returning to the beaches where they hatched to lay their own eggs!

Females can lay more than 100 eggs in each nest, and all hatchlings will emerge from the nest at the same time, scurrying towards the sea in what is commonly known as a “nest explosion”. Unlike in human development, the sex of hatchling green turtles is dependent upon the temperature of the nest, and warmer nests tends to lead to a greater proportion of female hatchlings.

The green turtle is a unique and highly evolutionarily distinct species. The green turtle is the only species in its genus and diverged from all other living turtles more than 30 million years ago. This is around the time humans last shared a common ancestor with baboons!

Unfortunately, this species suffering a drastic population decline. This decline is driven by hunting, egg collection, bycatch in fisheries, and beach erosion, along with many other threats across their range.

The green turtle is listed as Critically Endangered by the IUCN Red List and is listed on CITES Appendix I. There are a number of conservation programmes running small schemes to protect their local nesting turtles, but there are also international treaties and agreements to stop hunting and trade, drive public awareness and establish marine protected areas.

  • Order: Testudines
  • Family: Cheloniidae
  • Population: Unknown
  • Trend: decreasing
  • Size: 1.5m
  • Weight: 130kg

EDGE Score

EDGE Score: 5.99 (?)
ED Score: 48.729 (?)
GE / IUCN Red List (?)
Not Evaluated Data Deficient Least Concern Near Threatened Vulnerable Endangered Critically Endangered Extinct in the Wild Extinct

Distribution

This species has a circumglobal distribution throughout tropical and subtropical waters of the Atlantic, Indian and Pacific Ocean. They nest in at least 80 countries.

Habitat and Ecology

Green Turtles nest on sandy beaches throughout the tropics and subtropics. Like other sea turtles, they are highly migratory and depend on a wide variety of regions and habitats during their lifetime. They consume large amounts of algae, reach sexual maturity around the age of 20 and live to around 80 years old.

Find out more

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Download the Survival Blueprint for this species below. Each survival blueprint is compiled by an EDGE Fellow working on the species with input from collaborators and stakeholders. The Survival Blueprint provides a status review (information on the distribution, protection status, habitat & ecology, threat and stakeholder analysis) and more information on the action programme listed here.

This Survival Blueprint is for the Action Programme for Sabah, Malaysia

Vision (30-50 years)

A sustainable population of green turtles in the waters of Mantanani through community-driven conservation efforts.

Goal (5-10 years)

Identify and minimise the threats to green turtles that are recruited to the foraging grounds of Mantanani.

Objectives

Priority
Facilitate a participatory drafting process of the management plan for the proposed MPA to be created in Mantanani, ensuring local communities are included appropriately in the process Critical
Extend ongoing aerial monitoring program to understand changes over time of the distribution and abundance of green turtles in the shallow waters of Mantanani High
Estimate the home range of green sea turtles in the coral reefs of Mantanani by 2025 High
Upskilling at least 20 local fishing community members to transition into ecotourism jobs by 2025 High
Identify and quantify main threats to foraging green turtles in the waters of Mantanani by the end of 2023 Medium

This Survival Blueprint is for the Action Programme for the Calamianes islands, Philippines 

Vision (30-50 years)

Viable and healthy nesting and foraging populations of Green Sea Turtles in the Calamianes islands

Goal (5-10 years)

Develop and implement a sustainable and collaborative conservation plan with Tagbanwa communities to increase and stabilize green sea turtle population in the Calamianes islands.

Objectives

Priority
Perform habitat assessments of nesting and foraging grounds of green sea turtles within the ancestral waters of the indigenous Tagbanwa and marine protected areas in the Calamianes Critical
Estimate population size and reproductive output of green sea turtles in the Calamianes Critical
Build capacity and provide support to create sea turtle local conservation areas Critical
Determine movement and habitat use of green sea turtles in the Calamianes High
Establish a sustainable community- managed programme that will both benefit the species and the members of the Tagbanwa communities High

Jonathan Phu Jiun Lang

  • Project name: Understanding population distribution of green turtles (Chelonia mydas)in Mantanani Island using Unmanned Aerial Vehicles (UAVs)
  • Project site: Mantanani, Sabah, Malaysia
  • Active: 2019 - ongoing
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Ginelle Gacasan

  • Project name: Integrating traditional ecological knowledge (TEK) of Tagbanwa communities into the conservation of green sea turtle, Chelonia mydas, in the Calamianes Islands
  • Project site: Calamianes Group of Islands, Palawan, Philippines
  • Active: 2019 - ongoing
Find out more