Climate change increases the production of female hatchlings at a northern sea turtle rookery

Abstract

Abstract. The most recent climate change projections show a global increase in temperatures, along with major adjustments to precipitation, throughout the 21st century. Species exhibiting temperature-dependent sex determination are highly susceptible to such changes since the incubation environment influences critical offspring characteristics such as survival and sex ratio. Here we show that the mean incubation duration of loggerhead sea turtle (Caretta caretta) nests from a high-density nesting beach on Bald Head Island, North Carolina, USA has decreased significantly over the past 25 yr. This decrease in incubation duration is significantly positively correlated with mean air temperature and negatively correlated with mean precipitation during the nesting season. Additionally, although no change in hatching success was detected during this same period, a potentially detrimental consequence of shorter incubation durations is that they lead to the production of primarily female offspring. Given that global temperatures are predicted to increase by as much as 4°C over the next century, the mass feminization of sea turtle hatchlings is a high-priority concern. While presently limited in number, studies using long-term data sets to examine the temporal correlation between offspring characteristics and climatic trends are essential for understanding the scope and direction of climate change effects on species persistence.

Feminization of hawksbill turtle hatchlings in the twenty-first century at an important regional nesting aggregation

“…Results from this study predict a significant increase in the proportion of female hatchlings pro-duced in Qatar in the 21 st century, an important nesting ground in the Gulf (Tayab & Quiton 2003, Pilcher et al 2014a, Chatting et al 2018. These results support other predictive studies forecasting significant feminization of primary sex ratios in marine turtle species around the world (Fuentes et al 2009, Laloë et al 2016, Reneker & Kamel 2016, Monsinjon et al 2019b, Patrício et al 2019). An almost 'complete feminization' of green turtles Chelonia mydas in the northern Great Barrier Reef has been predicted (Jensen et al 2018, p. 154).…”

Climate change resilience of a globally important sea turtle nesting population

“…Relatively few studies have inferred the sex ratio of marine turtle populations; however, the majority of these report female‐biased primary sex ratios which are expected to skew further with climate warming (Fuentes et al., ; Hawkes et al., ; Katselidis, Schofield, Stamou, Dimopoulos, & Pantis, ; Patino‐Martinez, Marco, Quiñones, & Hawkes, ; Reneker & Kamel, ), and incubation temperatures above a certain threshold are expected to reduce clutch survival (Hays et al., ; Santidrián Tomillo et al., ), and hatchling locomotor ability (Booth & Evans, ; Fuentes, Hamann, & Limpus, ). Significant losses of 8%–65% of nesting habitat are predicted for several sea turtle rookeries, under climate change scenarios of median severity (Baker, Littnan, & Johnston, ; Fish et al., , ; Fuentes, Limpus, Hamann, & Dawson, ; Katselidis, Schofield, Stamou, Dimopoulos, & Pantis, ).…”

The thermal impacts of beach nourishment across a regionally important loggerhead sea turtle (Caretta caretta) rookery

“…Whether these long‐lived species have the potential to adapt to global climate change via shifts in nesting phenology or nest‐site selection behaviors is still unknown (Hawkes et al 2007, Schwanz and Janzen 2008, Refsnider et al 2013, Reneker and Kamel 2016 b ). However, we have shown that beach nourishment can cause significant changes to the thermal profile of loggerhead nesting beaches and we support a directed effort to incorporate these impacts into species assessments.…”