Hatching Failure In Ex-Situ Nests Of Hawksbill Turtle (Eretmochelys Imbricata) In Melaka, Malaysia

See, Khai Wei (2022) Hatching Failure In Ex-Situ Nests Of Hawksbill Turtle (Eretmochelys Imbricata) In Melaka, Malaysia. Masters thesis, Universiti Sains Malaysia.

Download (418kB) | Preview


Hawksbill turtle (Eretmochelys imbricata, Linnaeus 1766) nesting in Melaka, Malaysia faces enormous pressures from various human activities along its coastline. The hatchery of the Department of Fisheries at Padang Kemunting, Melaka provides an important ex-situ conservation and management tool as threats such as egg poaching, inundation, and natural predation are prevalent at nesting beaches. Ex-situ conservation has been implicated in causing low hatching success to sea turtle nests. This study aims to identify the factors that contribute to hatching failure in ex-situ nests of hawksbill turtle using several approaches during three nesting seasons from 2018 to 2020, from 13 nesting beaches in Melaka. To analyse hatching success and egg mortality, post-emergence nest excavation was conducted on 241 clutches to determine the number of successfully hatched eggs and the stages of the unhatched eggs. The mean hatching success was 58.2 ± 28.2% (n = 241). Among the unhatched eggs (n = 9,872), 70.8% were undeveloped, 11.2% were in early embryonic stage, 1.1% were in mid embryonic stage, 6.3% were in late embryonic stage, 5.3% were depredated, and another 5.3% were decayed. Analysing eight potential determinants, only two variables were found to affect hatching success or egg mortality in this study, which were the incubation period and clutch size of the nests. The large number of undeveloped eggs led to the concern that the eggs were unfertilised. Egg fertility was determined using the white spot method conducted at the beginning of egg incubation on 50 clutches. The mean egg fertility was 85.9 ± 16.5% (n = 50), but the mean hatching success was significantly lower at 57.6 ± 24.3% (n = 50).

Item Type: Thesis (Masters)
Subjects: Q Science > QH Natural history > QH1 Natural history (General - Including nature conservation, geographical distribution)
Divisions: Pusat Pengajian Sains Kajihayat (School of Biological Sciences) > Thesis
Depositing User: Mr Mohammad Harish Sabri
Date Deposited: 08 May 2024 07:30
Last Modified: 08 May 2024 07:30
URI: http://eprints.usm.my/id/eprint/60594

Actions (login required)

View Item View Item