The potential future influence of sea level rise on leatherback turtle nests

- Climate change impacts are expected at leatherback turtle nesting beaches.
- Higher sand water content was correlated with reduced hatching success.
- Higher sand water content caused earlier embryonic death up to 12% water content.
- Hatchlings from wetter sands were smaller but did not appear to have less vigour.
- Projected future climate change may affect Caribbean leatherback turtle breeding.

Climate change models predict sea level rise and increased intensity of storms and hurricanes in tropical sea turtle nesting areas. These factors could significantly increase beach inundation and erosion, thus affecting water content of sea turtle nesting beaches. Here, we conducted a field and laboratory study of how sand water content is related to embryonic development and hatching success of leatherback turtle nests. Moreover, we have experimentally incubated eggs of this species in beach sand under standardized conditions, but at different realistic levels of sand water content, varying from 1% to 12%. On the beaches, females nested from the intertidal zone to the lower part of the sand vegetation dunes, where nests were exposed to a wide range of sand water contents that ranged from 0.8% to 22%. However, both field and experimental studies revealed a strong negative correlation between sand water content and emergence success (field study: r = − 0.73, P < 0.0001; experiment: r = − 0.84, P < 0.0001). In the field, mean emergence success varied from 0% for the wettest nests to 64% for the driest ones. Nests in wet sand suffered higher mortality, primarily in the earlier developmental stages. Eggs incubated in the driest sand lost mass, but there were no significant effects on hatchling mass or run speed compared to eggs that gained water during incubation. However, hatchling straight carapace length (SCL) was greater in eggs from the driest treatment. The results of the present study inform management of change under future climate change sea level rise scenarios, suggesting that leatherback turtle nesting success should be expected to decrease.