The State of Sea Turtles in the East Indian Ocean and Southeast Asia
This regional article is part of “An Atlas of Global Sea Turtle Status”. See the full atlas here.
Stretching from the Indian Ocean in the west to the Pacific Ocean in the east, the Eastern Indian Ocean and Southeast Asia (EIO&SEA) region encompasses a mosaic of interconnected seas, including the Bay of Bengal and the Andaman, Arafura, East China, South China, Sulu, Sulawesi (Celebes), Philippine, and Java seas. This region provides a wide range of vital habitats for migrating, feeding, and foraging sea turtles. The EIO&SEA is home to eight regional management units (RMUs) of five sea turtle species: loggerheads (two RMUs), greens (one), leatherbacks (one), hawksbills (three), and olive ridleys (one). A sixth species, the flatback, is also found here but was not assessed by the Conservation Priorities Portfolio 2.0 (CPP) (see “The Conservation Status of the Flatback”). Nesting occurs in every coastal nation of the region, with major sites in India and its Andaman and Nicobar Islands, Sri Lanka, Indonesia, Malaysia, the Philippines, Vietnam, and Australia. Foraging grounds span the entire zone from as far west as the East African coast, to Western Australia, and all the way east to the West Pacific.
The status of sea turtles in this enormous region varies widely, from the Northeast Indian loggerhead, which has just a handful of nesting sites and faces significant threats, to the Northeast Indian olive ridley, which has dozens of nesting sites, including the mass nesting population in Odisha, India, and is rated as low risk, low threat. As in other regions, fisheries bycatch poses the greatest threat for all RMUs. Direct take also remains a serious concern for some RMUs, such as the Southeast Asia hawksbill, a pressure that dates back centuries. Thankfully, conservation efforts are active and growing, with some populations showing signs of improvement.
A green turtle dines on a jelly in Coral Bay, Ningaloo Reef, Western Australia. © Emilie Ledwidge/Ocean Image Bank
Research and Conservation
Early management efforts in this region sought primarily to support commercial turtle harvests. As early as 1927, the British North Borneo Company issued decrees protecting the egg trade in Sabah, Malaysia, and later (in 1951), a commercial hatchery was established in Sarawak. Licenses were also issued for sea turtle harvesting in Western Australia from the 1930s to 1973 and for egg harvesting in Odisha, India, from 1947 to 1975. Many of these efforts were ultimately deemed unsustainable and were supplanted by protective legislation enacted in India (1972), Malaysia (1977), the Philippines (1979), and elsewhere. The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) was also ratified in the 1970s by Malaysia, Indonesia, India, and Sri Lanka.
Many conservation programs have been active for decades, supporting significant population recoveries. In the early 1970s, work began in Odisha and Chennai, India, and by the late 1980s and early 1990s, efforts proliferated in Australia, Bangladesh, Brunei, China, Indonesia, the Philippines, Sri Lanka, and Taiwan, most of which are still active in some form today. Although uptake was slower in places such as Cambodia, Vietnam, Myanmar, Singapore, and Timor-Leste, numerous nonprofit, community, and government sea turtle conservation programs are now underway. Regional cooperation for sea turtle conservation got a major boost in 1997 from the (now defunct) Memorandum of Understanding on ASEAN Sea Turtle Conservation and Protection, with nine signatory states, and again in 2001 from the IOSEA-MOU (Memorandum of Understanding on the Conservation and Management of Marine Turtles and Their Habitats of the Indian Ocean and South-East Asia), which remains active. The IOSEA-MOU is an intergovernmental agreement that aims to protect, conserve, replenish, and recover sea turtles and their habitats and has been signed by 36 nations.
Many coastal and marine protected areas have also played an important role in recovering EIO&SEA turtles, including Barrow Island Nature Reserve in Australia (established 1908), Turtle Islands Heritage Protected Area in Malaysia and the Philippines (established 1996), Gahirmatha Marine Sanctuary in India (established 1997), and Con Dao National Park in Vietnam (established 1984).
Notable long-term conservation programs in the EIO&SEA region include the following:
Turtle Islands, Malaysia (1977–present): Formerly the site of a commercial turtle farm, Malaysia’s Turtle Islands Park was established to protect green and hawksbill turtles at Selingan, Bakkungan Kecil, and Gulisaan Islands.
The Philippines (1979–present): An executive order issued to protect sea turtles led to the establishment of marine turtle sanctuaries on seven Philippine islands across three provinces by 1982, some of the earliest protected areas for sea turtles in the region.
India (1970s–present): Significant long-term research and conservation work has been carried out all along this country’s coastline by numerous entities at sites including the Andaman and Nicobar Islands, home to important nesting beaches for leatherbacks, hawksbills, and greens; Odisha, where olive ridley mass nesting occurs at two sites; and Chennai, where monitoring and conservation have been carried out by civil society groups and the Forest Department since 1973.
Taiwan (1989–present): Nesting beach management, scientific research, public outreach, and turtle rehabilitation efforts focused on greens and other turtle species are led by the Council of Agriculture.
Sri Lanka (1990s–present): A national program protecting greens, olive ridleys, leatherbacks, loggerheads, and hawksbills, which includes nest monitoring, community awareness, and initiatives to reduce fisheries bycatch, is led by Sri Lanka’s government and local nonprofits.
China (1992–present): The country’s only mainland green turtle nesting site is protected at the Huidong Gangkou Sea Turtle National Nature Reserve, though most sea turtle nesting activity occurs in the Xisha Islands, where systematic monitoring has been ongoing since 2013.
Bangladesh (1996–present): Led by MarineLife Alliance, a local nongovernmental organization, sea turtle conservation efforts at Cox’s Bazar and elsewhere emphasize public education to reduce egg harvesting and outreach to ensure the long-term protection of important coastal habitats.
North West Cape, Australia (1987–present): Ningaloo Marine Park protects significant nesting rookeries of green, hawksbill, and loggerhead turtles (plus occasional flatbacks) in Australia’s North West Cape. Research and conservation have been underway since 2002 by the Ningaloo Turtle Program, with the cooperation of nonprofit, university, and government partners.
Tiwi Islands, Australia (2001–present): The Tiwi Islands Marine Rangers lead efforts to monitor nesting beaches and combat illegal fishing, while protecting important habitats for green, flatback, and olive ridley turtles. It is one of several Aboriginal-led marine conservation initiatives in Australia.
An olive ridley arribada at Rushikulya in Odisha, India, where olive ridleys have been legally protected since the 1970s. © Arghya Adhikary
Progress in Addressing Threats
Historical accounts reveal that sea turtles were once significantly more abundant throughout the EIO&SEA region, supporting trade in tortoiseshell from Ceylon (present-day Sri Lanka) and India with the Roman Empire since the first century BCE. But commercial exploitation and trade increased significantly after the 15th century CE, affecting many of the region’s turtle populations.
Green turtle eggs from Malaysia were traded with the Chinese since the 1600s, and Southeast Asian nations were major suppliers of hawksbill shells for Japanese bekko artisans since at least the 1700s. By the early 20th century, large-scale commercial harvests were underway in India, Indonesia, Malaysia, Western Australia, Vietnam, and elsewhere, with green turtles, hawksbills, and olive ridleys heavily affected.
The tide began to turn in the 1970s, spurred by local and international interventions, national wildlife laws, and international agreements such as CITES, though some legal trade in Bali and Vietnam continued until the early 2000s. Bans on harvest and trade of turtle products have yielded positive results overall, although illegal take and trade remain a major threat to the region’s largest hawksbill RMU (Southeast Asia) and a moderate threat to the region’s only green turtle RMU.
For other populations, the cessation of trade has been a major boon. In Odisha, India, the introduction of wildlife laws in the 1970s under Prime Minister Indira Gandhi stopped the annual harvest of tens of thousands of olive ridleys for shipment to Kolkata. The Northeast Indian olive ridley RMU is now ranked low risk, low threat, and it appears to be on the rise, though bycatch remains stubbornly high. This threat also affects green turtles, as well as the Northeast Indian loggerhead RMU, Southeast Asia hawksbill RMU, and, to a lesser extent, Southeast Indian hawksbill RMU.
From the 1930s to 1970s, tens of thousands of primarily green turtles were harvested in Western Australia for export as canned turtle soup, meat, skins, and eggs. Fortunately, the last turtle harvesting license expired in 1973, and now turtles are well protected throughout Australia. In Australia’s Northern Territory, green turtles belonging to the East Indian and Southeast Asia RMUs were spared from commercial exploitation, and these animals benefit from Aboriginal stewardship, including traditional, sustainable harvests that have been practiced for millennia. One noteworthy effort is led by the first indigenous marine ranger program in the Northern Territory, the Tiwi Islands Marine Rangers, active since 2001. In recent years, targeted efforts in Australia’s Northern Territory have also successfully reduced egg predation by feral pigs—a serious localized threat to nesting turtles. Collaborative programs involving Aboriginal rangers, scientists, and government agencies have used nest monitoring, exclusion fencing, and pig control to significantly increase hatchling survival, particularly on Cape York Peninsula.
Of particular concern in the EIO&SEA region is the Northeast Indian loggerhead RMU, which has fewer than 100 nesting females per year, has few nesting sites (mostly in Sri Lanka), and faces high levels of threat from both fisheries bycatch and direct take. Though data about its genetic composition and trends are limited, the population is considered to be one of the most at-risk and threatened RMUs globally. Even less is known about the Northeast Indian hawksbill RMU, which nests mainly in the Andaman and Nicobar Islands and Sri Lanka. Nearly every threat and most risks were classified as data deficient in the CPP assessment, highlighting the urgent need for baseline research.
Turtles belonging to the region’s sole leatherback RMU nest almost exclusively in India’s Andaman and Nicobar Islands (as well as in Sri Lanka and Sumatra, Indonesia) and range widely across the Indian Ocean. While this population faces some risk from its low genetic diversity, it has the lowest combined risk and threat score of any leatherback RMU worldwide, in part because of the remoteness and protected status of its nesting areas. The population was first surveyed by Satish Bhaskar in 1978, the same year that 94 of the islands were designated as sanctuaries. Today, more than 1,000 leatherbacks nest annually, making this RMU the largest leatherback population in the Indian Ocean.
Since the last CPP assessment in 2011, the EIO&SEA region has seen some encouraging progress. The status of three RMUs—Southeast Asia hawksbills, Northeast Indian leatherbacks, and Northeast Indian olive ridleys—has improved. Three others—East Indian Ocean and Southeast Asia green turtles, and both Northeast Indian and Southeast Indian loggerhead populations—have remained stable. However, not all trends are positive: the Southeast Indian hawksbill RMU has worsened over time. With an ever-growing conservation movement, protection of many critical habitats, reduction in some key threats, and strengthened regional coordination, there is much to be hopeful about for the region’s sea turtles.
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This article originally appeared in SWOT Report, vol. 20 (2025). Download this entire article as a PDF.