Samenvatting

Climate change is a major threat for the Hawksbill turtle (Eretmochelys imbricata). A lot of research has been done on the possible effects, but a clear overview is still lacking. This literature review aims to provide an overview of the effects of climate change on the nesting success, sex ratio and diet of the Hawksbill turtle.Results showed that Hawksbill turtles have individual preferences for the location of their nests, considering vegetation coverage. It also shows that the expected sea level rise can flood nests located to close to the sea. Sea level rise also threatens the surface area of possible nesting beaches around the world. Heavy rainfall and vegetation can influence the temperature within the nest, both having cooling effects. The temperature within the nest determines the sex ratio of the offspring. Warmer temperatures produce more females, while colder temperatures produce more males. The pivotal temperature is around 29 degrees Celsius. The expected increase in temperature will thus lead to a potential increase in female hawksbill turtles. These skewed sex ratios will not immediately lead to the same skewed ratios in adults, because males reproduce more compared to females. It is also possible that a point will be reached, where almost no males are produced. This could cause the population to collapse.The diet of hawksbill turtles mostly consists of sponges, algae, and coral. Increasing temperature can potentially lead to mass sponge mortalities. As temperature influences the growth rate of algae, an increased temperature could also lead to a decrease in growth rate. Climate stressors can influence the herbivore-plant relationship between Hawksbill turtles and the algae. An increase in temperature will also cause more coral bleaching. A shift towards a sponge dominated reef is also possible. This could have positive effects on the species.To conclude, climate change will thus lead to a change in nesting beaches and nesting places. Higher temperatures will lead to a higher production of female offspring, which does not immediately equal a skewed sex ratio in the adult populations. Changes in diet of foraging grounds can also be expected. Recommendations are to shade nests, relocate nests to close to the sea. Creation of marine protected areas is also recommended. Further research is necessary regarding the diet and possible effects of this on the Hawksbill turtle.