Implications of nest relocation for morphology and locomotor performance of green turtle (Chelonia mydas) hatchlings

Investigating the effectiveness of a well‐managed hatchery as a tool for hawksbill sea turtle (Eretmochelys imbricata) conservation

“…Management interventions must be considered within the context of the rookery, the species conservation and population status, threats faced as well as the overall management objectives (e.g., maximize the production of an endangered species), with continual evaluation of its use (Bevan et al, 2014;Caillouet, 2021;Caillouet et al, 2016). While nest relocation to hatcheries is often considered manipulative, it is widely argued to be a necessary intervention to place an endangered species (such as the hawksbill sea turtle) on a course to recovery, should alternative, less invasive management techniques prove inefficacious of alleviating external threats (Bevan et al, 2014;Caillouet et al, 2016;Eckert & Eckert, 1990;Martins et al, 2021;Tanabe et al, 2021). In the case of Cousine Island, observations of increased crab predation rates over the years, with predation levels reaching up to 90%-100% in safe nesting locations, in conjunction with up to 50% of nests at risk of being lost due to erosion, called for increased management intervention across years, each with varying degrees of success (Gane et al, 2020a(Gane et al, , 2020b(Gane et al, , 2021Hitchins et al, 2004).…”

“…While reports of negative consequences of nest relocation, such as increased embryo and hatchling mortality, increased exposure to predators, increased fungal, and disease prevalence as well as reduced hatchling mobility (Eckert & Eckert, 1990; Herrera‐Vargas et al, 2017; Tanabe et al, 2021; Wood et al, 2014), must be considered; several of these outcomes are argued to be driven by inefficient handling and poor hatchery management (Abella et al, 2007; Eckert & Eckert, 1990; McElroy et al, 2015; Wyneken et al, 1988). While potential consequences on hatchling health and mobility were not considered within this study, it is reasoned that the careful hatchery management as well as timely and efficient relocation of nests employed acts to minimize such risks (Abella et al, 2007; Eckert & Eckert, 1990; Martins et al, 2021).…”

“…Despite this, the use of nest relocation as a conservation tool remains controversial with a lack of consensus regarding its overall effectiveness (Marcovaldi & Laurent, 1996; Martins et al, 2021; McElroy et al, 2015). Several caveats such as reduced hatching success (Herrera‐Vargas et al, 2017; Marcovaldi & Laurent, 1996), reduced hatchling fitness (Herrera‐Vargas et al, 2017; Sönmez et al, 2011), and morphological/anatomical changes (Herrera‐Vargas et al, 2017; Sönmez et al, 2011; Tanabe et al, 2021) have been reported for relocated nests. Furthermore, with sea turtles exhibiting temperature‐dependant sex determination (TDS), altering the incubation temperatures of relocated versus in situ clutches may indirectly bias sex ratios of hatchlings (Jourdan & Fuentes, 2013; Martins et al, 2021).…”

How deep is deep enough? Analysis of sea turtle eggs nest relocation procedure at Chagar Hutang Turtle Sanctuary

“…These findings show that the artificial nest at Chagar Hutang successfully resemble the natural nest. We would like to point out various debates on the differences between natural and artificial incubation for sea turtles ( Stewart et al, 2020 , Tanabe et al, 2021 ). It can be summarised that each nesting beach is unique on its own; there are confounding factors that might affect one specific place compared to another, such as the sand grain size ( Stewart et al, 2020 ), the use of shades at the conservation centres ( Reboul et al, 2021 ).…”

“…The ex-situ conservation could do more harm than good if the management does not consider the relocation area, nest depth, nest shape, temperature, and precipitation during the translocation process ( Hewavisenthi, 2001 ). More recently, Tanabe et al (2021) suggested that relocation should only be implemented on clutches with a high potential to be disrupted or with a low chance of survival if left in situ.…”