Tasas de crecimiento somático de tortuga carey, Eretmochelys imbricata, en el Parque Nacional Natural Gorgona, Colombia, entre 2004 y 2018

Abstract

The Hawksbill Turtle, Eretmochelys imbricata, is globally assessed as Critically Endangered, and information in the Eastern Pacific Ocean is limited. For this reason, this investigation evaluated the somatic growth rates in an immature hawksbill sea turtle aggregation using capture-mark-recapture on the coral reefs at Playa Blanca and La Azufrada in the Gorgona Natural National Park, Colombia.Between 2004 and 2018, we made 89 captures of 49 hawksbill individuals. The mean curved carapace length (CCL) obtained was 41.6 cm (range 32-58 cm), and the mean straight-line carapace length (SCL) was 39.1 cm (range 30.0-54.1 cm), showing these reefs to be critical foraging grounds for immature individuals. The mean body condition index was 1.3 (range 1.0-1.5), suggesting that environmental conditions maintain the health of this aggregation in good conditions. Using the von Bertalanffy growth model and establishing a maximum length (L∞)of 63 cm of CCL (where the lowest coefficient of variation is obtained), we estimated a k of 0.081 and an average annual growth rate of 1.5 ± 1.8 cm/year. This indicated that individuals in this aggregation reach a CCL of 63 cm at 33-34 years of age, close to the sexual maturity for the tropical eastern Pacific region (approximately 66 cm CCL). This indicates the vulnerability of this species due to its late maturity and slow growth. Because of this, conservation efforts for this species must be long-term to ensure its recovery, since species with these characteristicstend to express very low population growth rates.