Effects of rising temperature on the viability of an important sea turtle rookery

Population viability at extreme sex-ratio skews produced by temperature-dependent sex determination

“…At rookeries around the world, current hatchling sex ratios have persisted for the past century [11,30,31], i.e. current hatchling sex ratios are not simply the consequence of recent climate warming and we need to search for an alternative explanation, aside from climate warming, to explain these sex-ratio skews.…”

“…In some cases, theoretical models explaining how sex-ratio biases may be adaptive have been supported by empirical observations [5,6], while in other cases sex-ratio biases seem maladaptive. For example, in groups with temperaturedependent sex determination (TSD, which is one form of ESD), such as reptiles, extreme sex-ratio biases caused by high incubation temperatures are thought to be an important extinction driver [7,8], and there is concern that this escalating extinction risk is associated with climate warming [9][10][11]. Yet surprisingly, while often inferred, the implications of variations in offspring sex ratios for adult breeding in species exhibiting TSD have only rarely been considered [8].…”

“…There has been long-standing concern that, all else being equal, rising air temperatures occurring as part of global climate change may lead to the feminization of populations and hence population extinction [13,14]. Given these concerns, there has been considerable work to describe current hatchling sex ratios as well as efforts to understand how these might have changed in the past and may change in the future [9][10][11]. For some populations, even in the face of climate warming, the production of male offspring may continue and hence these populations may remain viable [9][10][11].…”

“…Given these concerns, there has been considerable work to describe current hatchling sex ratios as well as efforts to understand how these might have changed in the past and may change in the future [9][10][11]. For some populations, even in the face of climate warming, the production of male offspring may continue and hence these populations may remain viable [9][10][11]. Furthermore, male turtles may fertilize multiple clutches.…”

Factors influencing variations of oxygen content in nests of green sea turtles during egg incubation with a comparison of two nesting environments

“…Development is faster at higher incubation temperature and result in higher gas exchange rate (e.g., Chen et al, 2010). Sea turtles also have TSD and so incubation temperature drives hatchling sex resulting in important climate change impacts on sex ratios (e.g., Laloê et al, 2014). Sand characters such as grain size, mineral type and sorting coefficient can influence gas and water circulation in the clutch (Ackerman, 1977(Ackerman, , 1980Foley et al, 2006;Garnett et al, 2010), heat conductivity (Speakman et al, 1998) and clutch viability (Mortimer, 1990).…”