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...., Nesting Data Collection and Analysis: We recorded nest parameters, whenever possible, including clutch size, nest depth, and emergence success. Females were tagged during nesting with Inconel tags (Style 681, National Band and Tag Company) in both front flippers and their curved carapace length (CCL) was measured. To analyse changes in length between nesting seasons, we used a Kruskal-Wallis test. For the CCL analyses, we considered only the first recorded data from each female per season to avoid potential bias introduced by repeat records of high-frequency nesters, ensuring that each turtle contributed only once to the data set within a nesting season. For other reproductive parameters such as clutch size, nest depth, emergence success, and incubation period, we conducted a descriptive statistical analysis using all available data from each female throughout the season. This involved calculating the mean, minimum, maximum, and standard deviation for each parameter to provide a compreh..., , # Green and hawksbill sea turtle nesting in the Gulf of Guinea: A 9-year survey

The dataset is structured with the following variables:

* RecCode: This is a unique automated code generated to link related datasets across multiple databases for tracking and analysis purposes.
* Season: Indicates the nesting season, spanning from July of one year to May of the following year, to accommodate the annual nesting cycle of the species.
* NewDate: Indicates the date of the nesting or false crawl event.
* Area: Indicates the area where the event occurred. Not the specific nesting beach but the area.
* Specie: Specifies the species of the turtle. CM stands for Chelonia mydas (Green Turtle) and EI stands for Eretmochelys imbricata (Hawksbill Turtle).
* LeftTag and RighhTag: Each turtle has one or two tags, in the left or right flippers.
* NewRecap: Designates whether the turtle is a new individual to the study (1 for New Turtle) or a recaptured individual that has been previously t...