Green and hawksbill sea turtle nesting in the Gulf of Guinea: A 9-year survey

Sea turtles are critical components of marine ecosystems, and their conservation is important for Ocean Governance and Global Planet Health. However, there is limited knowledge of their ecology in the Gulf of Guinea. To fill this knowledge gap, this study presents the first integrative assessment of green and hawksbill turtles in the region, combining nesting area surveys over 9 years, and telemetry data, to offer insights into these population dynamics, and behaviours including nesting preferences, morphological and reproductive parameters, diving patterns and inter-nesting core-use areas. Green turtles are likely making a recovery in São Tomé, potentially driven by sustained conservation efforts. In contrast, the status of the hawksbill turtle remains less clear. There are preliminary indications of recovery, but we interpret this cautiously. Coupled with satellite tracking, this study estimated that 482 to 736 green turtles, and 135 to 217 hawksbills, nest on the beaches of São Tomé. Their movements overlap significantly with a proposed Marine Protected Area (MPA), which suggests they may be well placed for conservation if managed appropriately. However, the presence of artisanal fisheries and emerging threats, such as sand mining and unregulated tourism, highlight the urgent need for robust management strategies that align global conservation objectives with local socioeconomic realities. This study significantly enhances our understanding of the ecology and conservation needs of the green and hawksbill turtles in the Gulf of Guinea. The insights gleaned here can contribute to the development of tailored conservation strategies that benefit these populations and the ecosystem services upon which they depend.