Growth rate and projected age at sexual maturity for immature hawksbill turtles and green turtles foraging in the remote marine protected area of Aldabra Atoll, Seychelles

Abstract Changes in marine ecosystems from human stressors, and concerns over how species will respond to these changes have emphasized the importance of understanding monitoring crucial demographic parameters for population models. Long-lived, migratory, vertebrates such as sea turtles are particularly vulnerable changes. Life-history like growth-in-body size can be largely influenced by environmental processes which impact growth. We analyzed a 40-year (1981–2021) capture-mark-recapture dataset protected UNESCO World Heritage Site, Aldabra Atoll, Seychelles, estimate key parameters, including body growth, immature green ( Chelonia mydas ) hawksbill Eretmochelys imbricata ). Curved carapace length (CCL) range was 34.3–110.9 cm (mean ± SD: 51.0 11.4 cm, n = 1191) 28.7–89.4 (47.7 14.4 538) turtles. Recapture events, with an 11-month minimum period, revealed mean annual growth rate 3.2 1.5 year −1 (n 75) 2.8 1.4 110). Hawksbill exhibited non-monotonic while no significant growth-size relationship detected Green turtle per 10-cm class highest larger classes (50‒69.9 cm). cm) then declined largest (70‒79.9 may spend > 8 18 years, respectively, using Aldabra, foraging ground.