The State of Sea Turtles in the South Atlantic Ocean
This regional article is part of “An Atlas of Global Sea Turtle Status”. See the full atlas here.
The South Atlantic region encompasses eight regional management units (RMUs) of five sea turtle species: greens (one RMU), hawksbills (two), leatherbacks (two), loggerheads (one), and olive ridleys (two). On the west side of this region, these species inhabit the waters of the Lesser Antilles in the eastern Caribbean; northern South America and the Guianas (Guyana, French Guiana, and Suriname); the entire coastline of Brazil including the islands of Fernando de Noronha and Trindade; and south along the coast of Argentina. To the east, the South Atlantic region’s turtles inhabit the entire western coast of Africa, from Mauritania to South Africa, and are found on and around several Atlantic island groups, including Ascension Island (U.K.), the Bijagós Archipelago (Guinea-Bissau), Bioko (Equatorial Guinea), and São Tomé and Príncipe. At their northern edge, these RMUs overlap slightly with those of the North Atlantic (see “The State of Sea Turtles in the North Atlantic”), and to the south, their ranges end where the ocean temperatures become too cold.
A loggerhead crawls across the beach in northeast Brazil. Although their population is relatively small, decades of conservation efforts in Brazil have helped make South Atlantic loggerheads one of the world’s least threatened populations. © Fundação Projeto TAMAR
The South Atlantic is home to many long-running sea turtle conservation programs and numerous protected areas supporting key habitats. As a result, half of the region’s eight RMUs are currently classified as low risk, low threat. Only two populations face high threat levels—Southeast Atlantic leatherbacks and East Atlantic olive ridleys—both of which nest in the East Atlantic, where threats are higher and conservation capacity is lower overall. Fortunately, a growing conservation movement in West and Central Africa, along with increasing regional collaboration, offers promising momentum for the future of South Atlantic turtles.
Research and Conservation
Sea turtle research and conservation efforts have been active across the South Atlantic for decades. Some of the region’s earliest research began on Ascension Island in the 1950s, where green turtles had been overhunted for centuries. Tagging by Harold Hirth and Archie Carr in the early 1960s revealed that Ascension Island’s green turtles migrate to Brazil to feed, confirming the first documented long-distance open-ocean migrations for this species. Protection in Ascension since 1944, coupled with community-based conservation led by Projeto TAMAR in Brazil since the 1980s, helped this population rebound into a globally celebrated conservation success.
Early work included expeditions by Joop Schulz, Peter Pritchard, Jacques Fretey, and others to the Guianas in the 1960s. These expeditions confirmed significant nesting sites not only for leatherbacks, hawksbills, and green turtles (all part of North Atlantic populations, see “The State of Sea Turtles in the North Atlantic”), but also for a now-vanished olive ridley arribada in Eilanti, Suriname. Today, the remnants of the Eilanti ridleys nest at Montjoly, French Guiana, and are known to belong to the West Atlantic olive ridley RMU (one of the region’s two olive ridley RMUs), which also includes significant nesting rookeries in Brazil, mainly in Sergipe, where protections are strong. Overall, this RMU is considered low risk, low threat, though bycatch remains a concern.
In West and Central Africa, sea turtle conservation took shape in the 1980s and 1990s. A pivotal 1990 survey in Guinea-Bissau’s Bijagós archipelago revealed a major green turtle rookery, ultimately leading to the creation of two protected areas in 2000. Today Bijagós is home to one of the most globally important green turtle nesting populations, with as many as 62,000 nests recorded on Poilão Island in a single year.
It was more recently discovered that Bijagós’ green turtles are part of a broader South Atlantic green turtle RMU that includes rookeries at Ascension Island and in Brazil. Genetic and tagging studies by Karumbé in Uruguay show that green turtles from all three sites gather seasonally to feed in Uruguayan waters. The connectivity of turtle habitats across the South Atlantic has made international collaboration a hallmark of the region. In the western South Atlantic, networks such as RETOMALA (the Marine Turtle Network of Latin America, established 1997) and Red ASO–Tortugas (established 2003) have promoted regional cooperation, bycatch monitoring, and threat assessments.
In the eastern South Atlantic, dozens of national and local conservation programs partner with communities. The Regional Partnership for Coastal and Marine Conservation (PRCM, active since 2003) facilitates collaboration among several West African and Mediterranean institutions to conserve sea turtles and other marine resources. RASTOMA (the Regional Network for the Conservation of Marine Turtles in Central Africa, active since 2012) represents stakeholders in the Central African countries of Cameroon, the Democratic Republic of Congo, Equatorial Guinea, Gabon, the Republic of Congo, and São Tomé and Príncipe and advances sea turtle and habitat protection alongside coastal communities. Inspired by RASTOMA, the West African Sea Turtle Conservation Network (WASTCON) has promoted similar work in nations of Benin, Côte d’Ivoire, Ghana, Guinea, Liberia, Nigeria, Sierra Leone, and Togo since 2020.
Notable long-term conservation efforts in the South Atlantic region include the following:
Ascension Island, U.K. (1950s–present): The U.K. government and others helped to restore a major green turtle rookery that had been reduced by exceedingly high hunting pressure. The population has steadily recovered from fewer than 1,000 nests per year in the 1950s to more than 23,000 nests per year today.
French Guiana (1960s–present): Sea turtle research and conservation have a long history in French Guiana led by a range of institutions, including Association Kwata, the Worldwide Fund for Nature (WWF), the French Guiana Regional Fisheries Committee (CRPM Guyane), Reserve Naturelle de l’Amana, and the Réseau Tortues Marines Guyane.
Suriname (1963–present): A sea turtle research and conservation program was initiated by Joop Schulz and the Suriname Forest Service in response to historically extensive take of turtles and eggs in Suriname. The program was moved under the Foundation for Nature Preservation in Suriname (STINASU, from its Dutch name) in 1969, and continues to the present day in partnership with WWF-Suriname.
Brazil (1982–present): Projeto TAMAR has studied and protected sea turtles in collaboration with local communities throughout Brazil, employing fishers and their families and building social engagement through small businesses, training, job creation, tourism, and more. Beach protection increased annual nesting of sea turtles (all species) from 62 in 1982 to more than 30,000 in 2017.
Bioko Island, Equatorial Guinea (1998–present): The Bioko Biodiversity Protection Program (BBPP), established by researchers from Arcadia University and now part of Drexel University (both in Pennsylvania, U.S.A.), operates in partnership with the Universidad Nacional de Guinea Ecuatorial to protect three species of nesting turtles through research, education, and local community engagement.
Senegal (1996–present): The African Chelonian Institute is a one-of-a-kind facility in West Africa that manages a rehabilitation and care unit for injured sea turtles. The institute leads the Senegal Stranding Network and has begun construction of a tourist-oriented Turtle and Nature Park with the country’s National Parks Service and Marine Protected Areas Division.
Uruguay (1999–present): Karumbé is a local nonprofit that runs programs that target plastic pollution, sea turtle rescue and rehabilitation, and bycatch reduction at sea. Moreover, the organization oversees a stranding network, operates two rehabilitation centers, and leads public education programs.
Bijagós, Guinea-Bissau (2004–present): The Institute of Biodiversity and Protected Areas (IBAP) protects sea turtles in Bijagós, an archipelago with one of the largest green turtle nesting colonies in the world. A national action plan for the conservation of sea turtles has been in place there since the 1990s.
Gabon (2005–present): The Gabon Sea Turtle Partnership is a network of organizations committed to protecting the world’s largest leatherback population and the largest olive ridley population in the Atlantic. The network includes Aventures Sans Frontières, the Wildlife Conservation Society, and the World Wildlife Fund, among others.
A leatherback returns to the sea at sunrise after nesting on Bioko Island, Equatorial Guinea, where conservation efforts have been ongoing since 1989. Like most leatherback RMUs, Southeast Atlantic leatherbacks are considered high risk, high threat. © Samuel Riley/Thisiswhyicare.com
Progress in Addressing Threats
Encouragingly, six of the eight RMUs in this region are ranked as low threat in the 2025 Conservation Priorities Portfolio 2.0 (CPP) assessment. Five are low risk, and four fall into the most favorable category: low risk, low threat. All four of these RMUs—South Atlantic green turtles, Southwest Atlantic loggerheads, Southwest Atlantic hawksbills, and West Atlantic olive ridleys—nest either partially or exclusively in Brazil, where strong conservation programs have been in place for decades. Notably, the Southwest Atlantic hawksbills hold the lowest threat score of any sea turtle RMU globally.
The remaining four RMUs face greater challenges. Southeast Atlantic leatherbacks, which nest along the African coast—primarily in Gabon, as well as in Equatorial Guinea (Bioko Island), the Republic of Congo, and elsewhere—are the only RMU in the region (and one of just nine globally) classified as high risk, high threat. That RMU also includes the largest leatherback nesting rookery in the world, in Gabon. The other three RMUs are a mixed bag: East Atlantic hawksbills and Southwest Atlantic leatherbacks are high risk, low threat; East Atlantic olive ridleys are low risk, high threat.
Encouragingly, threat levels have declined for nearly all RMUs since 2011, with the exception of Southeast Atlantic leatherbacks (for which threats increased) and East Atlantic olive ridleys (whose threat level is unchanged). Bycatch remains the most significant threat to sea turtles across the region.
Despite status improvements in many of the region’s RMUs and long-term conservation efforts that have mitigated many threats overall, turtles in the eastern portion of the region still confront high threat. Bycatch, overharvest, and habitat loss—driven by urbanization, coastal development, and weak enforcement—are the primary concerns. Large-scale port projects and rapid urban growth in cities like Lagos (Nigeria) and Pointe-Noire (Republic of Congo) pose growing challenges to turtles because of habitat degradation, increased pollution, vessel traffic, and hunting pressure. Brazil has also seen a rise in coastal development in recent decades, causing similar concerns for sea turtles and their habitats.
Fortunately, most South Atlantic countries have enacted laws to protect sea turtles, though enforcement capacity varies widely. Additionally, intergovernmental agreements, such as the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and the Convention on Biological Diversity, provide broad frameworks for international cooperation. Regionwide policy efforts have also done much to improve collaboration at the government level. Examples include the Convention on Migratory Species Memorandum of Understanding Concerning Conservation Measures for Marine Turtles of the Atlantic Coast of Africa (the Abidjan MOU) as well as the Inter-American Convention for the Protection and Conservation of Sea Turtles. Those initiatives, along with a rising number of community-driven efforts, have yielded measurable improvements.
Important advances have also been made in the establishment of protected areas throughout the region. In Uruguay, Karumbé’s research and advocacy helped establish the Cerro Verde and La Coronilla Islands Marine Protected Area (MPA) in 2011, protecting a critical foraging and developmental habitat for green turtles from throughout the Atlantic. Brazil’s Fernando de Noronha Marine National Park (established 1988) protects critical habitat for green and hawksbill turtles. Guinea-Bissau’s João Vieira and Poilão Marine National Park and Orango National Park (both established 2000) safeguard globally important green turtle habitats, and Gabon has created sea turtle-focused national parks since 2002. New MPAs are underway in the Republic of Congo (Loango Bay), Cameroon (Manyange na Elombo-Campo Marine National Park), and Côte d’Ivoire (Grand Béréby).
Collaboration among local community stakeholders has been critical to conservation success in western Africa. For example, the Ghana Turtle Research Project supports community-based ecotourism and works with fishermen to reduce bycatch. In Côte d’Ivoire, the Sea Turtle Project has helped communities develop eco-friendly businesses as an alternative to poaching since 2001. Cameroon’s AMMCO (African Marine Mammal Conservation Organization) created the SIREN app to engage fishers in reporting bycatch and wildlife sightings. Gabon’s national observer program has monitored bycatch aboard industrial fishing vessels since 2012. In Nigeria and Gabon, turtle excluder devices have been adopted by shrimp trawling fleets to help reduce bycatch. And in Sierra Leone, the Reptile and Amphibian Program (RAP-SL) leads monitoring and bycatch reduction programs in partnership with coastal communities.
See the “Atlas User Guide” for definitions and tips for interpreting these figures. Data citations can be downloaded here.
This article originally appeared in SWOT Report, vol. 20 (2025). Download this entire article as a PDF.