‘I feel obligated to protect them’: A lifelong love affair with Guinea-Bissau’s turtles

  • Biologist Castro Barbosa has spent his career working to protect the green sea turtles that breed in Guinea-Bissau’s Bjiagós islands.
  • The Bijagós are the most important sea turtle breeding grounds in Africa — 5% of the global green turtle population breeds on the island of Poilâo alone.
  • Turtles are threatened by accidental capture in fishing nets, hunting, and overharvesting of their eggs, but traditional restriction of access to sacred islands in the Bijagós has protected these breeding grounds.
  • Barbosa’s work monitoring turtles and their breeding grounds respects and complements these traditional protections.

POILÃO ISLAND, Guinea-Bissau — Castro Barbosa’s eyes still light up when he recalls the first time he saw a sea turtle, in 1993. He was on a visit to Guinea-Bissau’s Bijagós archipelago; the turtles made such a strong impression on him that he has devoted his career since then to their protection.

“They were so calm, so nice. I saw they needed protection,” the biologist says as he walks along the beach on Poilão Island, one of many sea turtle nesting grounds off the coast of Guinea-Bissau.

Now in his 60s, Castro is the head of sea turtle monitoring at the National Institute of Biodiversity and Protected Areas (IBAP). He oversees important nesting grounds for green turtles in João Vieira-Poilão Marine National Park, which encompasses Poilão and three other islands. Scientists recognize Poilão as one of the world’s top five nesting sites for green sea turtles (Chelonia mydas) and the most important one in Africa. Around 5% of the global population nests on this 43-hectare (106-acre) island.

The green turtles that breed in the Bijagós spend the rest of their lives in the open ocean. Some stay close to the islands of João Vieira-Poilão and nearby Orango National Park, while others migrate as far as 1,000 kilometers (600 miles) up the West African coast to the seagrass meadows of the Banc d’Arguin, off the coast of Mauritania.

But all the sea turtles that hatch here will eventually return to these beaches to breed. Although green turtle populations globally are falling — mostly due to hunting, overharvesting of their eggs, or being accidentally caught in fishing nets — the Poilão population seems to be holding steady.

Castro Barbosa with a green sea turtle hatchling. Image by Ricci Shryock for Mongabay.

Barbosa grew up inland, in Guinea-Bissau’s Cacheu region, working on his father’s farm. He was always a keen student of nature, and when he trained as a biologist, he thought he would specialize in land-based mammals. “I knew very little about the turtles, because there are few on the mainland.”

While working as a biologist for IBAP in the 1990s, Barbosa visited the islands and fell in love with its sea turtles. He took part in lengthy negotiations to establish access for conservationists and park officials to islands such as Poilão, which is held as sacred by local people and considered off-limits to outsiders. “The negotiations were very difficult for people, because it was difficult to convince the people that our intention was to protect the turtles, and that this was also in the interest of the community.”

Preparations to create a formal conservation program here began in 1998. Barbosa says patience was essential when speaking with the community’s leaders, who would often ask the park officials to wait for hours after arriving to the meeting place before coming out to speak with them. Waiting and listening was essential to showing a mutual respect to community leaders, he adds.

Around the same time, locals told researchers conducting a census of green turtles that far fewer turtles were visiting many of the Bijagós beaches where they had once been common. Poilão, regarded as sacred and off-limits save for traditional ceremonies, was the only site still hosting turtles in large numbers. Yet even here, the researchers found evidence of temporary camps set up by migrant fishers, along with green turtle remains.

The park was officially established in 2000. Since then, Barbosa has overseen development of the park’s conservation program, including the monitoring, tagging and protection of the thousands of turtles that hatch in the park each year.

This is contributing to a more detailed understanding of green turtle movements during the rest of their life cycle, allowing conservationists to strengthen environmental protections — including restricting access — to these areas.

Locals told researchers that far fewer green turtles were visiting many of the Bijagós beaches where they had once been common. Image by Ricci Shryock for Mongabay.

Barbosa could have retired by now, but he says he doesn’t really want to do anything else besides be with the sea turtles. More than one co-worker jokes that after years of working with the animals, Barbosa — with his quiet, calm demeanor and gentle smile — has himself started to resemble a green sea turtle.

On a late September night on Poilão, more than 200 adult green sea turtles lumber ashore to lay their eggs. While the sea turtle mothers who climb up the beach to nest are large and less susceptible to predators, it’s the thousands of hatchlings that Barbosa feels drawn to protect. In the early hours of the morning, with a gray sky threatening rain, he wakes up from his tent and scans the beach. It’s the very beginning of the hatching season; amid the fresh tracks, the first of the eggs laid months earlier have begun to hatch, and a few small baby turtles are attempting to make it from their sandy cradle to their ocean home. Just a couple of inches long, they are easy prey for the birds circling above.

Barbosa spots one small newborn with an injured flipper. He bends over and gingerly picks it up.

“I am still always impressed every single time I see a turtle,” Barbosa says with a smile. “I feel like I am obligated to protect them.” He pauses. “I don’t know how to explain it. Something touches my heart. It makes me always want to protect them, so that nothing hurts them before they get to the sea.”

He sets the tiny turtle into a bucket of sand; he hopes the flipper will heal in a day or two, after which he will release it back to the beach to make its way to the water. Then he heads back to the beach to see if any other sea turtles need him.

Technology and tradition team up to watch over a sacred island’s sea turtles


Banner image: Rescued sea turtle hatchlings. Image by Ricci Shryock for Mongabay.


Catry, P., Barbosa, C., Indjai, B., Almeida, A., Godley, B. J., & Vié, J. (2002). First census of the green turtle at Poilão, Bijagós Archipelago, Guinea-Bissau: The most important nesting colony on the Atlantic coast of Africa. Oryx, 36(04), 400-403. doi:10.1017/s0030605302000765

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