Africa, with its vast coastlines and diverse ecosystems, is home to a remarkable variety of turtle species. Bounded by the Atlantic and Indian Oceans, as well as the Mediterranean and Red Seas, the continent provides seemingly limitless turtle habitats. This article delves into the diversity of African turtle species, the challenges they face, and the conservation efforts aimed at protecting these ancient creatures.
Mating green turtles embrace near Europa Atoll in the Éparses Islands of the southwest Indian Ocean.
The Scale and Complexity of African Turtle Conservation
The principal challenge to fully understanding Africa’s sea turtles is the enormous scale and complexity of the task. Africa’s 54 countries (63 political territories) cover approximately one-third of the land surface of Earth-an area the size of China, India, the United States, and most of Europe combined. The African coastline stretches some 26,000 kilometers (16,150 miles) across 71 degrees of latitude (7,881 kilometers/4,897 miles) and 68 degrees of longitude (7,548 kilometers/4,690 miles). Africa also encompasses an enormous exclusive economic zone (EEZ), with an ocean footprint of approximately 6,023,900 square kilometers (3,743,100 square miles).
We have chosen to exclude the Mediterranean and Red Seas and to focus in this article and the maps below only on Africa’s continental shores, from the Straits of Gibraltar in Morocco to the Horn of Africa in Somalia, plus the offshore archipelagos and island nations, including the Canary Islands (Spain), Cabo Verde, Bijagós (Guinea-Bissau), Bioko (Equatorial Guinea), São Tomé and Príncipe, Madagascar, the Comoros, Mauritius, La Réunion (France), and the Seychelles, to name a few of the largest. This sizable area comprises 33 countries and their territories and is a zone of superlative global importance for sea turtles.
Sea Turtle Species in Africa
Five of the world’s seven sea turtle species (leatherbacks, olive ridleys, green turtles, hawksbills, and loggerheads) inhabit these waters and nest on Africa’s continental shores-from Mauritania south to Angola on Africa’s Atlantic coast, and from South Africa north to Somalia on the Indian Ocean coast, plus the aforementioned archipelagos. Even the Kemp’s ridley, endemic to the North Atlantic and the Gulf of Mexico, occasionally wanders into African waters. The only sea turtle species completely absent from Africa is the Australian flatback.
Read also: Property Practitioners Regulatory Authority
Sea turtles are among the most widely ranging creatures on Earth, and many sea turtles that nest outside Africa spend time in African waters as well. Those seasonal visitors may have hatched on distant shores in South America, the Caribbean, and the Central Atlantic (Ascension Island). Similarly, turtles born on West African beaches can be found throughout the Atlantic and Caribbean, and green and loggerhead turtles born on Africa’s Indian Ocean shores travel far north to the Arabian Peninsula. Leatherbacks that nest in South Africa and nearby Mozambique migrate through the frigid waters around the Cape of Good Hope to forage off Namibia.
Of the 58 sea turtle subpopulations worldwide (called regional management units, or RMUs), 18 overlap with Africa and its Indian and Atlantic Ocean islands.
Threats to African Sea Turtles
All African sea turtles are facing human-made threats, and pressure from humans has taken an enormous toll. The ecological footprint of all African countries increased by 240 percent from 1961 to 2008, according to the Global Footprint Network, due to growing populations and increased per capita consumption. By 2050, Africa’s population is projected to reach as high as 2.47 billion people, this compared to 1.02 billion in 2010 and 0.294 billion in 1961.
Turtles are an important component of local culture and practices for many African coastal communities and have provided food and other traditional uses for millennia. Over the centuries, human impacts to turtles have evolved from subsistence-level hunting to more severe and pervasive threats, often driven by widespread poverty and food shortages. Today, sea turtles in Africa face threats from fisheries, consumption of adults and eggs, boat strikes, pollution, and climate change. Moreover, many coastal areas of Africa are developing significant infrastructure that is fueling habitat loss, and deep-sea ports are springing up like mushrooms to meet the tremendous global demand for African resources.
The African helmeted turtle (Pelomedusa subrufa), also known commonly as the marsh terrapin, the crocodile turtle, or in the pet trade as the African side-necked turtle, is a species of omnivorous side-necked terrapin in the family Pelomedusidae.
Read also: Amazing Facts About Africa
The marsh terrapin is typically a rather small turtle, with most individuals being less than 20 cm (7.9 in) ranging from 15 to 21 centimeters in straight carapace length, but one has been recorded with a length of 32.5 cm (12.8 in). It has a black or brown carapace. A female tends to have a shorter tail and a broader carapace. A hatchling has a shell size of about 3 cm (1.2 in) in length, and is olive to black in color. Uniquely, the genus Pelomedusa does not have a hinged plastron (lower shell). All the other species in the family Pelomedusidae, however, do have this feature with which they can, using muscles, close the plastron to the carapace to cover the head and front limbs. Recent genetic research suggests that Pelomedusa comprises at least 10 different species, and not only one as previously thought.
The geographic range of P. subrufa covers a large portion of Africa, from the Cape Peninsula to Sudan. It can be found as far west as Ghana and as far south as Cape Town. Its preference seems to be for standing water, such as swamps, pans, dams, and lakes. However it is found to a lesser extent along rivers. The African helmeted turtle is an omnivorous eater and will eat almost anything mainly involving aquatic invertebrates, small fish, and vegetation. It may feed on carrion. The fine claws on its feet help it tear its prey apart. Groups of P. subrufa have been observed capturing and drowning larger prey such as doves that come to drink; the commotion caused by these group attacks is often mistaken for crocodiles.
Several large mammals, such as warthogs, Cape buffalo, and rhinoceroses, have recently been documented utilizing the turtles to remove parasites at popular wallowing holes. One such incident in Hluhluwe-iMfolozi park involved two African helmeted turtles removing ticks and blood-sucking flies from the body of a wallowing warthog. Though the turtles probably do not have a symbiotic relationship with these animals, it is very likely that the buffalo, rhinos, and warthogs seek them out and have learned to utilize them from past experiences.
During wet weather P. subrufa will often leave water bodies and embark on long overland journeys. During exceptionally dry weather when water bodies dry up, it will typically dig into the ground and bury itself until rains return; it has been known to spend months or even years in such a state.
Courtship of P. subrufa is held year round. The male will follow the female, nodding his head in front of hers. If she is not responsive, she will nip and snap and walk away. If she is willing, she responds by nodding her head or just standing still, so he can mount her. The female will lay two to ten eggs on average, normally during late spring and early summer. The eggs are placed in a flask-shaped nest about 4 to 7 in (10 to 18 cm) deep.
Read also: Discover Thula Thula
African Spurred Tortoise (Geochelone sulcata)
The African spurred tortoise (Geochelone sulcata) is the largest mainland tortoise species in the world. They are reported to grow to over two hundred pounds in weight and thirty-six inches in length. Sulcata come from the southern Sahara Desert region, an area of Africa which crosses the countries of Senegal, Mauritania, Mali, Chad, Sudan, and Ethiopia. Almost all the available information is on captive animals. From talking to people who either keep or know about sulcata and from discovering that the region of Africa they inhabit is semi-arid and in the tropical zone, I had a few clues to go on. Sulcata are vegetarians and most of their natural food is dried grasses and leaves from desert scrub. In the wild they have to walk and nibble to get their fill.
Sulcata like to be dry and warm. Unlike our desert tortoise they do not hibernate. (Being in the tropics, the southern Sahara doesn't cool down like the Mojave desert.)
Sea Turtles 101 | National Geographic
Table of African Sea Turtle Species and Their Conservation Status
| Species | Common Name | Conservation Status (IUCN) | Nesting Locations in Africa |
|---|---|---|---|
| Dermochelys coriacea | Leatherback | Vulnerable | South Africa, Mozambique, Mauritania, Senegal |
| Lepidochelys olivacea | Olive Ridley | Vulnerable | Guinea, Guinea-Bissau, Senegal |
| Chelonia mydas | Green Turtle | Endangered | Guinea-Bissau, Mauritania, The Gambia |
| Eretmochelys imbricata | Hawksbill | Critically Endangered | Guinea-Bissau, Coastal regions of West Africa |
| Caretta caretta | Loggerhead | Endangered | Cabo Verde, South Africa |
Conservation Efforts and Regional Networks
In response to growing threats and increasing environmental awareness, most coastal African countries have enacted laws specifically to protect sea turtles. All the coastal countries of Africa are also parties to the Convention on International Trade in Endangered Species of Wild Fauna and Flora and the Convention on Biological Diversity, and all but Namibia and Sierra Leone are parties to the Convention on Migratory Species.
In addition, two intergovernmental agreements focus on sea turtles on both sides of Africa: the Indian Ocean South East Asian Marine Turtle Memorandum of Understanding and the Memorandum of Understanding Concerning Conservation Measures for Marine Turtles of the Atlantic Coast of Africa.
Regional networks also play an increasingly important role in organizing the African sea turtle movement, including the Gold Coast Sea Turtle Conservation Network, the Sea Turtle Professional Network in Central Africa (Rastoma), and the Western Indian Ocean-Marine Turtle Task Force. Since 2014, the African Sea Turtle Newsletter, produced by the Ocean Ecology Network, has served as a multilingual communications tool among the continent’s far-flung sea turtle researchers.
Regional Overviews
Northwest Africa: Morocco to Guinea, and the Canary and Cabo Verde Archipelagos
The region from Morocco to Guinea on continental Africa straddles two major geomorphological domains: (a) the coastal dunes of the Sahel in Morocco and Senegal and (b) the vast river deltas from southern Senegal south to Guinea. The former is characterized by arid deserts that abut the coast, and the latter is a maze of deltas, cliffs, estuaries, and mangrove lagoons. The continental shelf in this zone extends 30 kilometers (19 miles) from the coast, except in Guinea-Bissau, where it broadens to 200 kilometers (124 miles). Cold, nutrient-rich upwellings support high levels of marine productivity in this region, and the main marine turtle foraging and nesting areas can be found in these rich waters at sites such as Banc d’Arguin National Park (Mauritania), the transboundary Biosphere Reserve of the Senegal River’s lower delta (Mauritania-Senegal), the Saloum Delta (Senegal), the Bolama Bijagós Archipelago Biosphere Reserve (Guinea-Bissau), and the Tristão-Alcatraz Marine Protected Area (Guinea).
In chronicles dating from the 15th century, explorers provide accounts of abundant sea turtles throughout West Africa and the nearby archipelagos of the Canary Islands (Spain) and Cabo Verde, as well as of their widespread exploitation at the time. Today, loggerheads nest predominantly in Cabo Verde; green turtles in GuineaBissau’s Bijagós Archipelago; and, sporadically, olive ridleys, leatherbacks, hawksbills, and loggerheads along the coast from Mauritania to Guinea-Bissau.
Southern Morocco reported large numbers of nesting turtles in the late 1950s, but more recent reports suggest a dramatic decline. In 2008, the Association for the Protection of Sea Turtles in Morocco was formed to address that dire situation. The presence of primarily juvenile loggerheads and leatherbacks in Moroccan waters suggests that the area may be an important foraging or developmental habitat or a migratory corridor.
Lying about 570 kilometers (350 miles) off the coast of Senegal, the Cabo Verde Archipelago boasts the third-largest loggerhead rookery in the world. Up to 20,000 nests are laid on Boa Vista Island alone in some seasons, representing 85 percent or more of the nesting in Cabo Verde. The Northeast Atlantic loggerhead RMU is listed as among the 11 most threatened sea turtle populations (see SWOT Report, vol. VII, 28). Despite national laws, active conservation projects, and some military protection, turtles are still hunted in Cabo Verde, and coastal construction and tourism pressures are also exacting a serious toll. On some beaches, poachers kill up to 90 percent of nesting females and harvest the eggs. To address the protection of this globally important sea turtle population, a Cabo Verdean sea turtle network called TAOLA was founded in 2009.
Loggerheads, green turtles, and leatherbacks are found in the waters around the Canary Islands, but hawksbills and Kemp’s ridleys are rare. The Canary Islands are of greatest significance as foraging and migratory habitats for sea turtles from both sides of the Atlantic Ocean. Young loggerheads often are observed between the Canaries and Madeira as well, likely migrants following the Gulf Stream from North American nesting beaches. Young green turtles also are observed during the summer months off Gran Canaria and Lanzarote.
Mauritania still harbors small numbers of nesting turtles, including an aggregation of green turtles, south of the capital, Nouakchott. A local project, Digmile, has worked with the Mauritanian Institute for Oceanographic Research and Fisheries (IMROP) at this site since 2014 and has noted sporadic loggerhead nesting. An alarming outcome of IMROP’s surveys has been the discovery of hundreds of stranded juvenile and adult loggerheads, presumably killed in fishing nets while foraging in the rich nearshore waters. Mauritania’s Banc d’Arguin National Park is an important foraging area for green turtles from the Bijagós Archipelago.
Despite 20th-century reports of nesting leatherbacks in Mauritania and Senegal, such sightings are extremely rare today, although the area seems to be an important foraging zone for leatherbacks from the Americas. Senegalese coastal waters are well known as a migratory corridor, and four East Atlantic species (green, loggerhead, olive ridley, and leatherback) are known to nest sporadically in the country. Very little is understood about their abundance and seasonality. Hawksbills appear to be even rarer.
The African Chelonian Institute (ACI) conducts beach surveys in northern Senegal from Dakar to St. Louis (a distance of 184 kilometers, or 114 miles) to assess sea turtle and cetacean mortality on those remote and little-developed shores. An astonishing 65 dead sea turtles of four species were found in the first of those surveys. Researchers believe that the massive mortality is a result of bycatch impacts from the very intensive offshore fishing in the region. ACI is now working with partners to find ways to reduce such tragic and unsustainable loss.
Green turtles also nest on the tiny coast of The Gambia between Bakau and Kartung, where the nongovernmental organization (NGO) Turtle SOS The Gambia monitors and protects the 27 kilometers (17 miles) of beach and conducts public awareness programs for communities and tourists. Noteworthy numbers of immature green turtles live in The Gambia’s nearshore waters.
Little is known about the frequency of olive ridley and hawksbill turtles in this subregion, although both species are known to nest in the Bijagós Archipelago (Guinea-Bissau) and on Katrack Island (Guinea). The National Center for Fisheries Science in Boussoura (CNSHB), the Guinean Kaloe Kurè Project, and the French Association Chélonée have been working together to learn more about sea turtles on Katrack and to do outreach with local communities there.
Guinea-Bissau has one of the most important nesting populations of green turtles in the world at Bijagós, a coastal archipelago comprising 88 islands and islets, covering an area of nearly 10,000 square kilometers (6,214 square miles). Five sea turtle species have been confirmed in Bijagós, including at Poilão Island where about 40,000 green turtle nests were recorded in 2014 and perhaps thousands more on nearby islands. The olive ridley is the second most abundant species in Bijagós, with roughly 90 nests annually on Orango Island. A few dozen hawksbill and leatherback nests have also been reported. Loggerhead nests are very rare, but a few carapaces have been found in the archipelago, indicating that it may be non-breedingoil habitat for the species.
A female leatherback turtle nests in front of Enokyi Village in western Ghana, an area monitored by the Bahari Karuna Project, www.wildseas.org.
West Africa: Guinea to Nigeria
The south-facing coastline of West Africa-encompassing the countries of Guinea, Sierra Leone, Liberia, Côte d’Ivoire, Ghana, Togo, Benin, and Nigeria-is a mosaic of high-energy beaches, mangrove estuaries, and pockets of coastal rainforest. The estuaries in this zone are nurseries for many important coastal fisheries, and the longshore current traveling through the Gulf of Guinea is a highway for migrating marine mammals and turtles. The region is rich in tradition and culture and is home to more than 100 ethnic groups that have managed their marine resources for centuries.
Historical records indicate that loggerheads, hawksbills, green turtles, leatherbacks, and olive ridleys (in order of increasing abundance) nest throughout this region. Political, economic, and social barriers, however, have prevented long-term research and conservation programs from fully understanding the biogeography and demography of sea turtles. There is little doubt that the region’s turtles face significant threats from poaching, fishery interactions, habitat degradation, and oil exploration. Those hazards underscore the importance of prioritizing baseline population and distribution studies for monitoring the long-term health of sea turtles and their habitats.
Guinea has a nesting population of olive ridleys, hawksbills, and green turtles, and the Kaloe Kurè Project supports community-based nest protection in the country’s Tristão Archipelago. Similar community-based work takes place in Sierra Leone and Liberia to protect nesting leatherbacks, green turtles,...
Popular articles:
tags: #Africa
