Global warming and sea turtles

 Article Link: https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.221002

In an approach to climate change effects on habitats and animals, researchers Jacques-Olivier Laloe and Graeme C. Hays (2023) found a way to combat the issues surrounding global warming by altering the timing of nesting and hatching for sea turtles (Chelonioidea). 

Laloe and Hays target the phenology (seasonal times of life history events for an organism which can include egg laying, incubation times, migrations) of seven sea turtle species in their life histories. The thermal conditions for sea turtle nesting/incubation and hatching are successful indicators of how turtle populations will be impacted following the risk of climate warming. Laloe and Hays use a model that would include shifting the timing of nesting for these species so that thermal conditions can be maintained. 

In their methodology, Laloe and Hays gathered information on the temperature conditions at sea turtle nesting and hatching locations throughout the world in order to create their thermal response models. Based on a total of 297 nesting sites and 44 hatching sites, they created models of the link between temperature and the time of nesting and hatching events using this data in Figure 1. In order to predict how the thermal conditions at these locations are expected to vary under various climatic scenarios, the scientists employed these models. Based on two separate climate models, two possible climatic scenarios were considered. The first model predicted a moderate level of warming with a 1.5°C increase in average global temperature by 2100. The second model anticipated a worldwide temperature increase of 3.7°C by 2100. In Figure 2, the patterns of rising SST temperature and nesting are shown for each species observed in how warming is “mitigated” (Laloe and Hays, 2023).

The ability for sea turtles to change their nesting and hatching phenology to preserve favorable temperature conditions was also modeled by using a variety of data including geographical and temperature-based estimations of shifting nesting times, as pictured in Figure 4. Figure 4’s data demonstrates that phenological changes at higher temperatures have a great impact on regulating heat and not affecting sea turtle nesting. Estimates of the genetic variation in the timing of nesting and hatching events among various sea turtle populations like hawksbill and kemp's ridley sea turtles were used alongside five other Chelonioidea species. Environmental factors that may have an impact on sea turtle phenology, such as the presence of predators and the availability of suitable nesting sites.

The article offers a different perspective on climate change in observing how shifting nesting times for sea turtle species may be relevant in their conservation efforts, particularly in mitigating warming temperatures.