Hatcheries efficiency for hawksbill sea turtle (Eretmochelys imbricata) conservation in the Persian Gulf: Over a decade monitoring of emergence success and incubation period

Abstract

Conservation of the critically endangered hawksbill sea turtles (Eretmochelys imbricata) is an important global concern that requires attention. There is currently a lot of debate surrounding the use of hatcheries as a technique for ex-situ conservation. Over the past decade, hatchery sites were established with the aim of reducing the embryonic mortality and increasing the number of hatchlings on Kish Island. Out of a total of 415 hawksbill turtle nests, 216 nests were monitored in their original location (in-situ) whereas the remaining nests were relocated to a hatchery site (ex-situ) due to several threats, including feral predators, coastal development, ecotourism pressure, and waves of monsoon storms. The aim of this study is to investigate the effectiveness of a hatchery site in the emergence success and incubation period compared to natural nests by analyzing the data from thirteen nesting seasons (2010–2022). In most years, the emergence success rate in ex-situ conditions has been significantly higher than in-situ (P < 0.05). Furthermore, a notable variation in the incubation period was noticed among various ex-situ years (P < 0.05), whereas it was not observed in in-situ. The incubation period in the ex-situ condition (57.38 ± 7.39 days) was 3.68 days shorter than the in-situ nests (61.25 ± 8.46 days). Delays in transferring eggs to the hatchery site from distant shores were found to be linked with a decrease in emergence success, 47.02% vs. 58.18% (P < 0.05). As a result, nest relocation in a minimum time, could significantly enhance turtle hatchlings’ emergence success and survival. On the other hand, reducing the incubation period due to ex-situ method maybe an important challenge in the future. Further research should be done to investigate the influence of nest relocation on morphological, physiological, immunological, and biometric offspring features, as well as on sex ratio.